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Background Infancy is a crucial period for establishing the intestinal microbiome. This process may be influenced by vitamin A (VA) status because VA affects intestinal immunity and epithelial integrity, factors that can, in turn, modulate microbiome development. Objectives The aim of this study was to determine if neonatal VA supplementation (VAS) affected the abundance of Bifidobacterium, a beneficial commensal, or of Proteobacteria, a phylum containing enteric pathogens, in early (6-15 wk) or late (2 y) infancy. Secondary objectives were to determine if VAS affected the abundance of other bacterial taxa, and to determine if VA status assessed by measuring plasma retinol was associated with bacterial abundance. Methods Three hundred and six Bangladeshi infants were randomized by sex and birthweight status (above/below median) to receive 1 VA dose (50,000 IU) or placebo within 48 h of birth. Relative abundance at the genus level and above was assessed by 16S rRNA gene sequencing. A terminal restriction fragment-length polymorphism assay was used to identify Bifidobacterium species and subspecies at 6 wk. Results Linear regression showed that Bifidobacterium abundance in early infancy was lower in boys (median, 1st/3rd quartiles; 0.67, 0.52/0.78) than girls (0.73, 0.60/0.80; P = 0.003) but that boys receiving VAS (0.69, 0.55/0.78) had higher abundance than boys receiving placebo (0.65, 0.44/0.77; P = 0.039). However this difference was not seen in girls (VAS 0.71, 0.54/0.80; placebo 0.75, 0.63/0.81; P = 0.25). VAS did not affect Proteobacteria abundance. Sex-specific associations were also seen for VA status, including positive associations of plasma retinol with Actinobacteria (the phylum containing Bifidobacterium) and Akkermansia, another commensal with possible health benefits, for girls in late infancy. Conclusions Better VA status in infancy may influence health both in infancy and later in life by promoting the establishment of a healthy microbiota. This postulated effect of VA may differ between boys and girls. This trial was registered at clinicaltrials.gov as NCT02027610.

OBJECTIVES: A variety of modifiable and non-modifiable factors such as ethnicity, age, and diet have been shown to influence bone health. Previous studies are usually limited to analyses focused on the association of a few a priori variables or on a specific subset of the population. The objective of this study was to use dietary, physiological, and lifestyle data to identify directly modifiable and non-modifiable variables predictive of bone mineral content (BMC) and bone mineral density (BMD) in healthy US men and women using machine learning models. METHODS: Ridge, lasso, elastic net, and random forest models were used to predict whole-body, femoral neck, and spine BMC and BMD in healthy US adults (n = 313) using non-modifiable anthropometric, physiological, and demographic variables, directly modifiable lifestyle (physical activity, tobacco use) and dietary (nutrient or food groups intake via food frequency questionnaire) variables, and variables approximating directly modifiable behavior (circulating vitamin D and stool pH). Model feature importances were used to identify variables useful for predicting BMC and BMD. RESULTS: Machine learning models using non-modifiable variables explained more variation in BMC and BMD (highest R(2) = 0.750) compared to when using only directly modifiable variables (highest R(2) = 0.107). Machine learning models had better performance compared to multivariate linear regression, which had lower predictive value (highest R(2 )= 0.063) when using directly modifiable variables only. BMI, body fat %, height, and menstruation history were predictors of BMC and BMD. For the directly modifiable features, betaine, cholesterol, hydroxyproline, menaquinone-4, dihydrophylloquinone, eggs, cheese, cured meat, refined grains, fruit juice, and alcohol consumption were predictors of BMC and BMD. Low stool pH, a proxy for fermentable fiber intake, was also predictive of higher BMC and BMD. CONCLUSIONS: Machine learning models can be used to identify previously unforeseen variables that may contribute to bone health. Modifiable factors explained less variation in the data compared to other features. Low stool pH, which has been shown to be associated with fermentable fiber intake, short chain fatty acid production, and enhanced calcium absorption, was associated with higher BMC and BMD in a healthy US population. FUNDING SOURCES: USDA-ARS

The mammalian immune system has evolved an innate component to identify classes of pathogens (e.g., viruses, types of bacteria, parasites) and respond with specific effector mechanisms to clear such infections. When the innate immune system cannot clear infections, the adaptive immune system develops pathogen-specific immunity that employs similar effector mechanisms to specifically target a particular pathogen in order to clear the initial infection and prevent further infections. The immune system protects the host at a nutritional cost which can be substantial in the case of frequent or severe infections. This cost is due both to the effects of the pathogen on host tissues and to the inflammatory response to infection that cause decreased food intake, nutrient malabsorption, nutrient loss, increased nutrient metabolism, and altered nutrient transport and storage. Malnutrition can compromise host defenses and increase the frequency or severity of infections. Most nutrients are required for adequate immunity, and examples are provided for several specific nutrients.

Background Bifidobacterium longum subsp. infantis (B. infantis) is a commensal bacterium that colonizes the gastrointestinal tract of breast-fed infants. B. infantis can efficiently utilize the abundant supply of oligosaccharides found in human milk (HMO) to help establish residence. We hypothesized that metabolites from B. infantis grown on HMO produce a beneficial effect on the host. Results In a previous study, we demonstrated that B. infantis routinely dominated the fecal microbiota of a breast fed Bangladeshi infant cohort (1). Characterization of the fecal metabolome of binned samples representing high and low B. infantis populations from this cohort revealed higher amounts of the tryptophan metabolite indole-3-lactic acid (ILA) in feces with high levels of B. infantis. Further in vitro analysis confirmed that B. infantis produced significantly greater quantities of the ILA when grown on HMO versus lactose, suggesting a growth substrate relationship to ILA production. The direct effects of ILA were assessed in a macrophage cell line and intestinal epithelial cell lines. ILA (1-10 mM) significantly attenuated lipopolysaccharide (LPS)-induced activation of NF-kB in macrophages. ILA significantly attenuated TNF-α- and LPS-induced increase in the pro-inflammatory cytokine IL-8 in intestinal epithelial cells. ILA increased mRNA expression of the aryl hydrogen receptor (AhR)-target gene CYP1A1 and nuclear factor erythroid 2–related factor 2 (Nrf2)-targeted genes glutathione reductase 2 (GPX2), superoxide dismutase 2 (SOD2), and NAD(P) H dehydrogenase (NQO1). Pretreatment with either the AhR antagonist or Nrf-2 antagonist inhibited the response of ILA on downstream effectors. Conclusions These findings suggest that ILA, a predominant metabolite from B. infantis grown on HMO and elevated in infant stool high in B. infantis, and protects gut epithelial cells in culture via activation of the AhR and Nrf2 pathway.

OBJECTIVES: Lactase persistence (LP) is a heritable trait in which lactose can be digested into adulthood. Lactase non-persisters (LNP) who consume lactose may experience microbial adaptations in response to the undigested lactose. The objective of this study was to determine the interaction between lactose consumption, LP genotype and gut microbiota in an observational cross-sectional study of healthy U.S. adults. METHODS: ASA24 dietary data and stool samples were collected from healthy U.S. adults genotyped for the lactase persistence SNP ID: rs4988235 (n = 280). Lactose was estimated by matching ASA24-reported foods to foods in the Nutrition Coordinating Center Food and Nutrient Database. The 16S rRNA V4/V5 region, amplified from bacterial DNA extracted from each frozen stool sample, was sequenced using Illumina MiSeq (300bp PE) and analyzed using Qiime 2 (v 2019.10). Bacterial sequence counts present at greater than 0.1% of the total data set were analyzed using DESeq2 and LEfSe. Taxa that were differentially abundant by both analyses at the family or genus level are reported here. RESULTS: On average 246 ng/uL (3.9 – 646.5ng/uL) DNA was obtained from each sample, yielding 21,470 sequences (10,122 – 56,837). LP genotypes were unevenly distributed by ethnicity and Clostridium (family Lachnospiraceae) was significantly enriched in Asian ethnicities. Therefore, only Caucasian and Hispanic participants were grouped as LP (AA or AG genotype) or LNP (GG genotype) for further analysis. The abundance of Roseburia and family Lachnospriaceae was higher in the upper (>12.4g), relative to lower (< 5.78g), tertile of lactose consumption in LNP adults, but not in LP. CONCLUSIONS: Increased abundance of Roseburia, a microbe capable of utilizing lactose, in LNP individuals consuming >12.4 g lactose/day suggests that this genus may metabolize lactose in LNP adults. FUNDING SOURCES: The California Dairy Research Foundation and the United States Department of Agriculture, Agricultural Research Service.

OBJECTIVES: Lactase persistence (LP), a heritable trait in which lactose can be digested throughout adulthood, is often used to predict dairy intake. However, it is currently unknown how LP relates to daily lactose consumption in healthy US adults. The objective of the study was to estimate lactose from foods reported in the Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24) and to compare lactose and total dairy consumption in relation to LP genotypes. METHODS: ASA24 dietary data were collected from healthy Caucasians and Hispanics (n = 215) genotyped for the lactase persistence SNP ID: rs4988235. ASA24 outputs servings of dairy but not the nutrient lactose. Lactose was estimated by matching ASA24-reported foods to foods in the Nutrition Coordinating Center Food and Nutrient Database, which outputs lactose. Analysis of covariance was used to identify whether genotype influenced lactose and total dairy consumption with total energy intake and weight as covariates. Pairwise testing was conducted on the adjusted means using the Tukey adjustment to correct for multiple testing. RESULTS: Median lactose consumption for subjects with the AA genotype (homozygous LP) was 12.08 g (min: 0.91 g, max: 81.85 g), 10.05 g (min: 0.46 g, max: 45.82) for subjects with the AG genotype (heterozygous LP), and 8.97 g (min: 0.47, max: 38.96 g) for subjects with the GG genotype (homozygous lactase non-persistent). AA subjects consumed more lactose than GG subjects (P = 0.024). When stratifying by sex, there were no significant differences among genotypes in women, although GG women consumed the least amount of lactose compared to AA and AG women. AA men consumed more lactose than AG (P = 0.028) and GG men (P = 0.032). Subjects with the AA genotype consumed the most, and GG subjects the least amount of dairy. However, there were no significant differences in total dairy consumption among genotypes. CONCLUSIONS: The median amount of lactose consumed daily by healthy adults is 9–12 g/day, with higher consumption by those with an LP genotype. Total dairy intake was not significantly influenced by genotype, highlighting the value in specifically estimating lactose consumption. Maximal lactose intake by lactase non-persisters exceeding 15 g/day suggests alternate routes of lactose catabolism. FUNDING SOURCES: The California Dairy Research Foundation and the USDA-ARS.

OBJECTIVES: Lack of microbiota accessible carbohydrates (MAC) can drive gut commensal extinctions. Infant formula lacks the MAC found in breastmilk, human milk oligosaccharides (HMOs). As a result, a switch from breastmilk feeding (high MAC) to formula (low MAC) may drive extinctions of infant gut commensals. METHODS: The prevalence of Bifidobacterium longum subsp. infantis, a bacterium that efficiently consumes HMOs, was compared in cohorts from Austria, Bangladesh, Finland, Gambia, Germany, Switzerland, and United States. Scientific literature reports that both Bangladesh and Gambia have long duration breastfeeding without a history of prevalent formula use; Bangladesh has a mean duration of breastfeeding of 31.9 months and Gambia has a median duration of breastfeeding >18 months. This contrasts with European countries and the US, who all have median duration of breastfeeding 50% relative abundance Bifidobacterium) despite the low frequency of colonization with B. infantis. The R0 of B. infantis transmission varied by country. CONCLUSIONS: The prevalence of infant colonization with B. infantis may be sensitive to breastfeeding duration in populations. Our data supports the concept that lack of MAC drives commensal extinctions, and suggests that deliberate intervention may be needed to restore B. infantis, a bacteria that benefits infant health. More studies are needed, particularly to determine whether species of Bifidobacterium other than B. infantis are sensitive to breastfeeding duration, and to understand the impact of different types of Bifidobacterium on infant health. FUNDING SOURCES: NIH awards F32HD093185 (DHT), AT007079 (DAM), and AT008759 (DAM).

BACKGROUND: The intestinal microbiome in early infancy affects immunologic development and thus may affect vaccine memory, though few prospective studies have examined such associations. We examined the association of Bifidobacterium levels in early infancy with memory responses to early vaccination measured at 2 years of age. METHODS: In this prospective observational study, we examined the association of Bifidobacterium abundance in the stool of healthy infants at 6 to 15 weeks of age, near the time of vaccination, with T-cell and antibody responses measured at 6 weeks, 15 weeks, and 2 years of age. Infants were vaccinated with Bacillus Calmette-Guérin (BCG) (at birth), oral polio virus (at birth and at 6, 10, and 14 weeks), tetanus toxoid (TT) (at 6, 10, and 14 weeks), and hepatitis B virus (at 6, 10, and 14 weeks). Fecal Bifidobacterium was measured at 6, 11, and 15 weeks. Bifidobacterium species and subspecies were measured at 6 weeks. RESULTS: Mean Bifidobacterium abundance in early infancy was positively associated with the CD4 T-cell responses to BCG, TT, and hepatitis B virus at 15 weeks, with CD4 responses to BCG and TT at 2 years, and with plasma TT-specific immunoglobulin G and stool polio-specific immunoglobulin A at 2 years. Similar associations were seen for the predominant subspecies, Bifidobacterium longum subspecies infantis. CONCLUSIONS: Bifidobacterium abundance in early infancy may increase protective efficacy of vaccines by enhancing immunologic memory. This hypothesis could be tested in clinical trials of interventions to optimize Bifidobacterium abundance in appropriate populations.

OBJECTIVES: We examined associations between reported dairy intake and markers of gastrointestinal (GI) inflammation in a healthy human adult population. We hypothesized there would be a negative association of yogurt intake with GI inflammation, suggesting a protective effect, and no associations of total dairy, fluid milk, and cheese intake with GI inflammation. METHODS: Participants completed up to 3 unannounced 24-hour dietary recalls using ASA24 and a Block 2014 Food Frequency Questionnaire (FFQ) to assess recent and habitual intake, respectively. Those who also provided a stool sample were included in this analysis (n = 342). Stool samples were stored on ice immediately after collection and homogenized within 24 hours. Inflammatory markers from stool, including calprotectin, neopterin, and myeloperoxidase were measured by ELISA along with LPS-binding protein (LBP) from plasma. Regression models tested associations between dairy intake variables and inflammatory markers with and without covariates: sex, age, and body mass index (BMI). As yogurt is episodically consumed, t-tests were used to examine differences in inflammatory marker levels between consumers (>1 cup per month reported in FFQ) and non-consumers. Each dairy variable was also expressed as a percentage of mean energy intake from 24-hour recalls and regressed with inflammatory markers. RESULTS: Without covariates, we found no associations between total dairy, fluid milk, and yogurt from both dietary assessments with any inflammatory markers. Cheese intake reported in the FFQ was positively associated with plasma LBP (P = 0.02). However, this association was not significant after covariate adjustment. There were no significant differences in GI inflammatory marker levels between yogurt consumers and non-consumers (P > 0.05). When expressed as a percentage of mean energy intake, cheese from ASA24 was associated with increased LBP (P = 0.03), but this was not significant after adjustment for covariates. There were no other associations of dairy variables as a percentage of energy intake with GI inflammatory markers. CONCLUSIONS: We found no clinically relevant associations between dairy intake and markers of GI inflammation in a healthy human adult cohort. FUNDING SOURCES: California Dairy Research Foundation, USDA ARS 2032–51,530-026–00D.

Infants are vulnerable to an array of infectious diseases, and as the gut microbiome may serve as a reservoir of AMR for pathogens, reducing the levels of AMR in infants is important to infant health. This study demonstrates that high levels of Bifidobacterium are associated with reduced levels of AMR in early life and suggests that probiotic interventions to increase infant Bifidobacterium levels have the potential to reduce AMR in infants. However, this effect is not sustained at year 2 of age in Bangladeshi infants, underscoring the need for more detailed studies of the biogeography and timing of infant AMR acquisition., Bifidobacterium species are important commensals capable of dominating the infant gut microbiome, in part by producing acids that suppress growth of other taxa. Bifidobacterium species are less prone to possessing antimicrobial resistance (AMR) genes (ARGs) than other taxa that may colonize infants. Given that AMR is a growing public health crisis and ARGs are present in the gut microbiome of humans from early life, this study examines the correlation between a Bifidobacterium-dominated infant gut microbiome and AMR levels, measured by a culture-independent metagenomic approach both in early life and as infants become toddlers. In general, Bifidobacterium dominance is associated with a significant reduction in AMR in a Bangladeshi cohort, both in the number of acquired AMR genes present and in the abundance of AMR genes. However, by year 2, Bangladeshi infants had no significant differences in AMR related to their early-life Bifidobacterium levels. A generalized linear model including all infants in a previously published Swedish cohort found a significant negative association between log-transformed total AMR and Bifidobacterium levels, thus confirming the relationship between Bifidobacterium levels and AMR. In both cohorts, there was no change between early-life and later-life AMR abundance in high-Bifidobacterium infants but a significant reduction in AMR abundance in low-Bifidobacterium infants. These results support the hypothesis that early Bifidobacterium dominance of the infant gut microbiome may help reduce colonization by taxa containing ARGs. IMPORTANCE Infants are vulnerable to an array of infectious diseases, and as the gut microbiome may serve as a reservoir of AMR for pathogens, reducing the levels of AMR in infants is important to infant health. This study demonstrates that high levels of Bifidobacterium are associated with reduced levels of AMR in early life and suggests that probiotic interventions to increase infant Bifidobacterium levels have the potential to reduce AMR in infants. However, this effect is not sustained at year 2 of age in Bangladeshi infants, underscoring the need for more detailed studies of the biogeography and timing of infant AMR acquisition.

The association between inflammation and vitamin A (VA) metabolism and status assessment has been documented in multiple studies with animals and humans. The relation between inflammation and carotenoid status is less clear. Nonetheless, it is well known that carotenoids are associated with certain health benefits. Understanding these relations is key to improving health outcomes and mortality risk in infants and young children. Hyporetinolemia, i.e., low serum retinol concentrations, occurs during inflammation, and this can lead to the misdiagnosis of VA deficiency. On the other hand, inflammation causes impaired VA absorption and urinary losses that can precipitate VA deficiency in at-risk groups of children. Many epidemiologic studies have suggested that high dietary carotenoid intake and elevated plasma concentrations are correlated with a decreased risk of several chronic diseases; however, large-scale carotenoid supplementation trials have been unable to confirm the health benefits and in some cases resulted in controversial results. However, it has been documented that dietary carotenoids and retinoids play important roles in innate and acquired immunity and in the body's response to inflammation. Although animal models have been useful in investigating retinoid effects on developmental immunity, it is more challenging to tease out the effects of carotenoids because of differences in the absorption, kinetics, and metabolism between humans and animal models. The current understanding of the relations between inflammation and retinoid and carotenoid metabolism and status are the topics of this review.

Background Metabolic imbalance is a key determinant of risk of chronic diseases. Metabolic health cannot be assessed solely by body mass calculations or by static, fasted state biochemical readouts. Although previous studies have described temporal responses to dietary challenges, these studies fail to assess the environmental factors associated with certain metabolic phenotypes and therefore, provide little scientific rationale for potentially effective intervention strategies. Methods/design In this phenotyping study of healthy US adults, we are evaluating lifestyle, biological and environmental factors in addition to metabolic parameters to determine the factors associated with variations in metabolic health. A series of practical fitness, dietary, and emotional challenges are introduced and temporal responses in various areas of specialization, including immunology, metabolomics, and endocrinology, are monitored. We expect that this study will identify key factors related to healthy or unhealthy metabolic phenotypes (metabotypes) that may be modifiable targets for the prevention of chronic diseases in an individual. Discussion This study will provide novel insights into metabolic variability among healthy adults in balanced strata defined by sex, age and body mass index. Usual dietary intake and physical activity will be evaluated across these strata to determine how diet is associated with health status defined using many indicators including immune function, metabolism, body composition, physiology, response to exercise andmeal challenges and neuroendocrine assessment. A principal study goal is to identify dietary and other personal factors that will differentiate different levels of "health" among study participants. Trial registration ClinicalTrials.gov NCT02367287 .

Lactase persistence (LP) is a trait in which lactose can be digested throughout adulthood, while lactase non-persistence (LNP) can cause lactose intolerance and influence dairy consumption. One single nucleotide polymorphism (SNP ID: rs4988235) is often used as a predictor for dairy intake, since it is responsible for LP in people in European descent, and can occur in other ethnic groups. The objective of this study was to determine whether rs4988235 genotypes and ethnicity influence reported dairy consumption in the United States (U.S.). A food frequency questionnaire (FFQ) and multiple Automated Self-Administered 24-h recalls (ASA24&reg, ) were used to measure habitual and recent intake, respectively, of total dairy, cheese, cow&rsquo, s milk, plant-based alternative milk, and yogurt in a multi-ethnic U.S. cohort genotyped for rs4988235. Within Caucasian subjects, LP individuals reported consuming more recent total dairy and habitual total cow&rsquo, s milk intake. For subjects of all ethnicities, LP individuals consumed more cheese (FFQ p = 0.043, ASA24 p = 0.012) and recent total dairy (ASA24 p = 0.005). For both dietary assessments, Caucasians consumed more cheese than all non-Caucasians (FFQ p = 0.036, ASA24 p = 0.002) independent of genotype, as well as more recent intake of yogurt (ASA24 p = 0.042). LP subjects consumed more total cow&rsquo, s milk than LNP, but only when accounting for whether subjects were Caucasian or not (FFQ p = 0.015). Fluid milk and alternative plant-based milk consumption were not associated with genotypes or ethnicity. Our results show that both LP genotype and ethnicity influence the intake of some dairy products in a multi-ethnic U.S. cohort, but the ability of rs4988235 genotypes to predict intake may depend on ethnic background, the specific dairy product, and whether intake is reported on a habitual or recent basis. Therefore, ethnicity and the dietary assessment method should also be considered when determining the suitability of rs4988235 as a proxy for dairy intake.

Routine methods for enumerating antigen-specific T-helper cells may not identify low-frequency phenotypes such as Th2 cells. We compared methods of evaluating such responses to identify tetanus toxoid- (TT) specific Th1, Th2, Th17 and IL10(+) cells. Eight healthy subjects were given a TT booster vaccination. Blood was drawn before, 3, 7, 14, and 28days after vaccination and peripheral blood mononuclear cells (PBMC) were cultured for 7days with TT, negative control (diluent), and a positive control (Staphylococcus enterotoxin B [SEB]). Activation markers (CD25 and CD69) were measured after 44h (n=8), cytokines in supernatant after 3 and 7days, and intracellular cytokine staining (ICS) of proliferated cells (identified by dye dilution) after 7days (n=6). Vaccination increased TT-specific expression of CD25 and CD69 on CD3(+)CD4(+) lymphocytes, and TT-specific proliferation at 7, 14 and 28days post vaccination. Vaccination induced TT-specific Th1 (IFN-γ, TNF-α, and IL-2) Th2 (IL-13, IL-5, and IL-4), Th17 (IL-17A) and IL-10(+) cells as measured by ICS. TT-specific Th1 cells were the most abundant (12-15% of all TT-specific CD4(+) T-cells) while IL10(+) (1.8%) Th17 (1.1%) and Th2 cells (0.2-0.6%) were less abundant. TT-specific cytokine concentrations in PBMC supernatants followed the same pattern where a TT-specific IL-9 response was also seen. In conclusion, TT booster vaccination induced a broad T-helper cell response. This method of evaluating cytokine phenotypes may be useful in examining the impact of nutrition and environmental conditions on the plasticity of T-helper cell memory responses.

The goal of this study was to explore the effects of trans-placental tetanus toxoid (TT) and pertussis (PT) antibodies on an infant's response to vaccination in the context of antenatal immunization with tetanus but not with pertussis. 38 mothers received a single dose of TT vaccine during pregnancy. Infants received tetanus and pertussis vaccines at 6, 10 and 14wk of age. TT and PT anti-IgG secretion by infant lymphocytes was measured at 15wk. Plasma antibodies were measured at 6wk (pre-vaccination), 15wk and 1 y of age. Prior to vaccination, TT and PT antibody were detected in 94.6% and 15.2% of infants. At 15wk anti-TT-IgG and anti-PT-IgG in plasma was increased by 7-9 fold over pre-vaccination levels, while at 1 y plasma anti-TT-IgG was decreased by approximately 5-fold from the peak and had returned to near the pre-vaccination level. At 1 y plasma anti-PT-IgG was decreased by 2-fold 1 yfrom the 15wk level. However, 89.5% and 82.3% of infants at 1 y had protective levels of anti-TT and anti-PT IgG, respectively. Pre-vaccination plasma IgG levels were associated with lower vaccine-specific IgG secretion by infant lymphocytes at 15wk (p < 0.10). This apparent inhibition was seen for anti-TT-IgG at both 15wk (p < 0.05) and t 1 y (p < 0.10) of age. In summary, we report an apparent inhibitory effect of passively derived maternal antibody on an infants' own antibody response to the same vaccine. However, since the cut-off values for protective titers are low, infants had protective antibody levels throughout infancy.

Few foods contain ergocalciferol or cholecalciferol. Treatment of mushrooms with UV light increases ergocalciferol content and could provide a dietary source of vitamin D. We evaluated the impact of consuming UV-treated white button mushrooms (Agaricus bisporus) on the vitamin D status of healthy adults. Thirty-eight volunteers were randomized to 4 treatments consumed with a standard meal for 6 wk: the control (C) group received untreated mushrooms providing 0.85 mg/d ergocalciferol (n = 10); groups M1 and M2 received UV-treated mushrooms providing 8.8 (n = 10) and 17.1 mg/d (n =9 ), respectively; and the supplement (S) group received purified ergocalciferol plus untreated mushrooms, providing a total of 28.2 mg/d (n = 9). Serum total 25-hydroxyvitamin D [25(OH)D] and 25-hydroxyergocalciferol [25(OH)D2] were 83 6 38 and 2.4 6 2.0 nmol/L, respectively, at baseline (mean 6 SD). At wk 6, 25(OH)D2 had increased and was higher in all treatment groups than in the C group, whereas 25-hydroxycholecalciferol [25(OH)D3] had decreased and was lower in the M2 and S groups than in the C group. Increases in 25(OH)D2 for groups C, M1, M2, and S were 1.2 6 5.2, 13.8 6 7.3, 12.7 6 3.7, and 32.8 6 3.3 nmol/L and decreases in 25(OH)D3 were 23.9 6 16.3, 210.4 6 6.4, 220.6 6 14.6, and 229.5 6 15.9 nmol/L, respectively. Concentrations did not change in group C. In summary, ergocalciferol was absorbed and metabolized to 25(OH) D2 but did not affect vitamin D status, because 25(OH)D3 decreased proportionally. J. Nutr. 142: 1246‐1252, 2012.

We evaluated the genetic contribution of the leukotriene (LT) pathway to risk of coronary artery disease (CAD) in 4,512 Caucasian and African American subjects ascertained through elective cardiac evaluation. Of the three previously associated variants, the shorter “3” and “4” alleles of a promoter repeat polymorphism in ALOX5 increased risk of CAD in African Americans (OR = 1.4, 95% CI 1.0–1.9; p = 0.04), whereas a haplotype of LTA4H (HapK) was associated with CAD in Caucasians (OR = 1.2, 95% CI 1.01–1.4; p = 0.03). In Caucasians, first-stage analysis of 254 haplotype-tagging SNPs in 15 LT pathway genes with follow-up of 19 variants in stage 2 revealed an LTA4H SNP (rs2540477) that increased risk of CAD (OR = 1.2, 95% CI 1.1–1.5; p = 0.003) and a PLA2G4A SNP (rs12746200) that decreased risk of CAD (OR = 0.7, 95% CI 0.6–0.9; p = 0.0007). The PLA2G4A rs12746200 variant also decreased risk of experiencing a major adverse cardiac event (MACE = myocardial infarction, stroke, or death) over 3 years of follow-up (HR = 0.7, 95% CI 0.5–0.9; p = 0.01), consistent with its cardioprotective effect. Functional experiments demonstrated that stimulated monocytes from carriers of LTA4H variants HapK or rs2540477 had 50% (p = 0.002) and 33% (p = 0.03) higher LTB4 production, respectively, compared to non-carriers. These ex vivo results are consistent with LTB4 being the direct product of the reaction catalyzed by LTA4H and its role in promoting monocyte chemotaxis to sites of inflammation, including the artery wall of atherosclerotic lesions. Taken together, this study provides additional evidence that functional genetic variation of the LT pathway can mediate atherogenic processes and the risk of CAD in humans. Electronic supplementary material The online version of this article (doi:10.1007/s00439-011-0963-3) contains supplementary material, which is available to authorized users.

Recommendations for vitamin A intake are based on maintaining liver stores of ≥ 0·070 μmol/g, which is sufficient to maintain normal vision. We propose that higher levels may be required to maintain normal immune function. To test this hypothesis, we conducted an 8-week residential study among thirty-six healthy Bangladeshi men with low vitamin A stores. Subjects were randomised to receive vitamin A (240 mg in four doses) or placebo during study weeks 2 and 3. Vitamin A stores were estimated by isotopic dilution at week 8. Total T-cells, the naive T-cells:memory T-cells ratio and mitogen-induced lymphocyte proliferation were positively and significantly correlated with vitamin A stores (P P P

Extrathymic induction of regulatory T (T reg) cells is essential to the regulation of effector T cell responses in the periphery. In addition to Foxp3, T reg cell expression of suppressive cytokines, such as IL-10, is essential for peripheral tolerance, particularly in the intestines. TGF-β has been shown to induce expression of Foxp3 as well as IL10 and the vitamin A metabolite; all-trans retinoic acid (RA [at-RA]) has been found to enhance the former. We report that in contrast to its enhancement of TGF-β–mediated Foxp3 induction, at-RA potently inhibits the TGF-β–mediated induction of Il10 in naive CD4 T cells. Thus, mucosal DC subsets that are active producers of at-RA inhibit induction of Il10 in naive CD4 T cells while promoting induction of Foxp3. Accordingly, mice with vitamin A deficiency have increased numbers of IL-10–competent T reg cells. Activation of DCs by certain Toll-like receptors (TLRs), particularly TLR9, suppresses T cell induction of Foxp3 and enables induction of Il10. Collectively, our data indicate that at-RA has reciprocal effects on the induction of Foxp3 and Il10 in developing CD4+ T reg cells and suggest that TLR9-dependent inhibition of at-RA production by antigen-presenting cells might represent one mechanism to promote the development of IL-10–expressing T cells.

The Th1/Th2 paradigm has become an important issue in the pathogenesis of asthma, characterized by normal Th1 and elevated Th2 cytokine expression. Vitamin A deficiency (VAD) can produce a Th1 bias, whereas high-level dietary vitamin A can promote a Th2 bias. We used the OVA exposure mouse model to determine the contributions of vitamin A-deficient, control (4IU/g), and high-level vitamin A (250-IU/g) diets to the development of allergic airway inflammation and hyperresponsiveness. VAD reduced serum IgE and IgG1 responses, pulmonary eosinophilia, and the levels of IL-4 and IL-5 in bronchoalveolar lavage specimens, whereas the 250-IU/g diet increased serum IgE. Also, VAD blocked pulmonary hyperresponsiveness following methacholine challenge while the 250-IU/g diet exacerbated pulmonary hyperresponsiveness. In conclusion, VAD diminished and high-level dietary vitamin A enhanced the development of experimental asthma in this model system. These data suggest that excessive intake of vitamin A may increase the risk or severity of asthma in industrialized countries whereas vitamin A deficiency continues to increase mortality from infectious diseases in developing countries.

Retinoid X receptor (RXR) agonists, including the vitamin A metabolite 9-cis retinoic acid, decrease T-lymphocyte apoptosis and promote T helper type 2 (Th2) development ex vivo. To examine the in vivo role of RXR-alpha in T-lymphocyte development and function, we disrupted the Rxra gene in thymocytes and T lymphocytes using cyclization recombinase (Cre)-loxP-mediated excision of Rxra exon 4. Expression of Cre was targeted to these cells using the Lck promoter. Successful disruption of exon 4 was seen in thymus and T lymphocytes. Mice were healthy and the thymus, spleen and lymph nodes appeared normal. However, knockout mice had a lower percentage of double-positive (CD4(+) CD8(+)) and a higher percentage of double-negative thymocytes than wild-type mice. The percentage of splenic B lymphocytes was lower in unimmunized and ovalbumin-immunized knockout mice and the percentage of T lymphocytes was lower in immunized knockout mice. Ex vivo proliferation was decreased and apoptosis was increased in T lymphocytes from knockout mice. Memory CD4(+) T lymphocytes from knockout mice produced more interferon-gamma and interleukin-2 (IL-2) and less IL-5 and IL-10 than memory cells from wild-type mice, indicating a Th1 bias in vivo. However, Rxra disruption did not similarly bias ex vivo differentiation of naive CD4(+) T lymphocytes, nor did Rxra disruption alter the serum immunoglobulin G1/immunoglobulin G2a response to immunization. In summary, disruption of Rxra altered the percentages of T and B lymphocytes, produced a Th1 bias in vivo, and altered T-lymphocyte proliferation and apoptosis ex vivo. These differences were modest in magnitude and their impact on disease resistance is yet to be examined.

In a cross-sectional study involving subjects from the Reaching for Excellence in Adolescent Health cohort, we examined the associations between HIV status, disease severity, immune activation, and oxidative damage. Subjects (265 HIV-positive and 127 HIV-negative) were young (range: 14-23 years of age) and primarily female (75%) and black (67%). Many subjects, particularly female subjects, were overweight or obese. Relatively few HIV-positive subjects had advanced HIV disease (13%), and 54% were taking antiretroviral therapy (ART). The 2 markers of oxidative damage used in this study (plasma malondialdehyde and protein carbonyl concentrations) did not correlate with each other, and neither was higher in HIV-positive subjects than in HIV-negative controls. Increased oxidative damage was seen in association with male gender, cigarette smoking, marijuana use, immune activation (as indicated by activated CD8 T-cell counts and plasma C-reactive protein concentration), and use of ART, however. Plasma ceruloplasmin was associated with decreased oxidative damage in HIV-positive subjects, although this association was not seen in those taking ART.

Vitamin A deficiency impairs both T helper type 1 (Th1)- and type 2 (Th2)-mediated immune responses, although Th2 responses seem to be principally affected. Multiple mechanisms are involved in this immune suppression, but the hypothesis that deficiency affects development of Th1/Th2 memory cell phenotype has not been tested directly in vivo. To do so, lymphocytes from DO11.10 T cell receptor (TCR)-transgenic mice were transferred to vitamin A-deficient or control BALB/c recipients. Recipients were then immunized with the cognate peptide antigen for the TCR-transgenic DO11.10 T cells (OVA(323-339)). After 2-5 wk, the transferred OVA(323-339)-specific T cells were identified from draining lymph nodes with the TCR-clonotypic antibody KJ1-26, and their Th1/Th2 phenotype was characterized by intracellular cytokine staining after in vitro stimulation with phorbol myristate acetate and ionomycin. The percentage of CD4(+)KJ1-26(+) cells positive for IL-10 was 100% greater in vitamin A-deficient mice (3.49 +/- 0.41%; mean +/- SE) than in control mice (1.74 +/- 0.37%). IL-4 did not differ between groups. In addition, the percentages of CD4(+)KJ1-26(+) cells from vitamin A-deficient mice that were positive for interferon (IFN)-gamma (8.8 +/- 0.73%) and interleukin (IL)-2 (39.5 +/- 3.1%) were both lower than the percentages in control mice (11.4 +/- 0.67 and 47.0 +/- 2.8%, respectively). Thus vitamin A deficiency, at the time of initial antigen exposure, enhances the development of IL-10-producing Th2 or T regulatory cells and diminishes the development of Th1 memory cells.

Tissue glucose transporter (GLUT1-3) and cationic amino acid transporter (CAT1-3) mRNA expression was determined in growing broiler chicks posthatch. In two experiments, tissues were either collected on days 1, 3 and 7 or days 1 and 14 posthatch. Heart and liver were the only tissues expressing a GLUT isoform on day 1. All tissues expressed a GLUT isoform on day 7 except for the thymus. Most tissues expressing a CAT isoform on day 1 decreased mRNA levels through day 7 (P

Background: The relative-dose-response (RDR) test is used to identify subjects with marginal liver vitamin A stores, but its use has not been evaluated during episodes of infection. Objective: The objective was to assess, with the RDR test, the vitamin A status of children recovering from pneumonia. Design: As part of a double-blind, placebo-controlled clinical trial of high-dose vitamin A supplements among children hospitalized with pneumonia in Lima, Peru, we examined the association of treatment group, nutritional status, severity of disease, and induction of the acute phase response [on the basis of serum C-reactive protein (CRP)] on serum retinol and the RDR test. Results: Serum retinol was low at admission and increased significantly in both the vitamin A and placebo groups during recovery. Serum CRP had a significant, inverse association with retinol at both admission and discharge. Serum retinol and CRP concentrations never differed significantly between the treatment groups. Among subjects with CRP ≥ 10 mg/L, 21% in the vitamin A group and 20% in the placebo groups (P = 0.83) had a positive RDR test result. Among subjects with CRP < 10 mg/L, 56% in the placebo group but only 6% in the vitamin A group had positive RDR test results (P = 0.002). Conclusion: The RDR test was useful in assessing the vitamin A status of children recovering from pneumonia when CRP concentrations were < 10 mg/L but not when CRP concentrations were higher. Am J Clin Nutr 2002;76:1351‐7.

Vitamin A deficiency diminishes Th2-mediated Ab responses, and high-level dietary vitamin A or treatment with the vitamin A metabolite retinoic acid (RA) enhances such responses. To identify a potential mechanism(s) underlying this in vivo activity of vitamin A, we examined the effects of all-trans and 9-cis RA on development of Th1 and Th2 cell populations using in vitro stimulation of Ag-naive Th0 cells from the DO11.10 TCR-transgenic mouse. Treatment with 9-cis, but not with all-trans RA, at primary stimulation strongly enhanced Th2 development. IL-4-neutralizing Ab blocked this activity, but IL-12- and IFN-γ-neutralizing Ab did not. Because 9-cis RA regulates gene transcription via either RA receptors or retinoid X receptors (RXRs), we tested the Th2-enhancing activities of the RXR- and RA receptor-selective agonists AGN194204 and 4-((E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl)benzoic acid (TTNPB). AGN194204 strongly enhanced Th2 development, whereas TTNPB did not. This RXR agonist also enhanced Th2 development when purified, naive Th0 cells (L-selectinhigh/CD4+) were stimulated with CD3 and CD28 Abs in the absence of APCs. During primary antigenic stimulation of naive Th0 cells from DO11.10 mice, AGN194204 increased IL-4 and IL-5 production, decreased IFN-γ production, increased mRNA in responding T cells for genes involved in Th2 development (IL-4, GATA-3, and c-maf), and decreased mRNA for genes involved in Th1 development (IFN-γ, T-bet, and IL-12R). These data show that stimulation of the RXR pathway enhances Th2 development, perhaps by affecting the relative expression of pertinent transcription factors, cytokines, and cytokine receptors.

OBJECTIVE: Oral vaccine efficacy is low in less-developed countries, perhaps due to intestinal dysbiosis. This study determined if stool microbiota composition predicted infant oral and parenteral vaccine responses. METHODS: The stool microbiota of 48 Bangladeshi infants was characterized at 6, 11, and 15 weeks of age by amplification and sequencing of the 16S ribosomal RNA gene V4 region and by Bifidobacterium-specific, quantitative polymerase chain reaction. Responses to oral polio virus (OPV), bacille Calmette-Guérin (BCG), tetanus toxoid (TT), and hepatitis B virus vaccines were measured at 15 weeks by using vaccine-specific T-cell proliferation for all vaccines, the delayed-type hypersensitivity skin-test response for BCG, and immunoglobulin G responses using the antibody in lymphocyte supernatant method for OPV, TT, and hepatitis B virus. Thymic index (TI) was measured by ultrasound. RESULTS: Actinobacteria (predominantly Bifidobacterium longum subspecies infantis) dominated the stool microbiota, with Proteobacteria and Bacteroidetes increasing by 15 weeks. Actinobacteria abundance was positively associated with T-cell responses to BCG, OPV, and TT; with the delayed-type hypersensitivity response; with immunoglobulin G responses; and with TI. B longum subspecies infantis correlated positively with TI and several vaccine responses. Bacterial diversity and abundance of Enterobacteriales, Pseudomonadales, and Clostridiales were associated with neutrophilia and lower vaccine responses. CONCLUSIONS: Bifidobacterium predominance may enhance thymic development and responses to both oral and parenteral vaccines early in infancy, whereas deviation from this pattern, resulting in greater bacterial diversity, may cause systemic inflammation (neutrophilia) and lower vaccine responses. Vaccine responsiveness may be improved by promoting intestinal bifidobacteria and minimizing dysbiosis early in infancy.

Although the effects of fish oil supplements on airway inflammation in asthma have been studied with varying results, the independent effects of the fish oil components, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), administered separately, are untested. Here, we investigated airway inflammation and hyperresponsiveness using a mouse ovalbumin exposure model of asthma assessing the effects of consuming EPA (1.5% wt/wt), DHA (1.5% wt/wt), EPA plus DHA (0.75% each), or a control diet with no added omega-3 polyunsaturated fatty acids. Consuming these diets for 6 weeks resulted in erythrocyte membrane EPA contents (molar %) of 9.0 (± 0.6), 3.2 (± 0.2), 6.8 (± 0.5), and 0.01 (± 0.0)%; DHA contents were 6.8 (± 0.1), 15.6 (± 0.5), 12.3 (± 0.3), and 3.8 (± 0.2)%, respectively. The DHA group had the highest bronchoalveolar lavage (BAL) fluid eosinophil and IL-6 levels (P < 0.05). Similar trends were seen for macrophages, IL-4, and IL-13, whereas TNF-α was lower in omega-3 polyunsaturated fatty acid groups than the control (P < 0.05). The DHA group also had the highest airway resistance, which differed significantly from the EPA plus DHA group (P < 0.05), which had the lowest. Oxylipins were measured in plasma and BAL fluid, with DHA and EPA suppressing arachidonic acid-derived oxylipin production. DHA-derived oxylipins from the cytochrome P450 and 15-lipoxygenase pathways correlated significantly with BAL eosinophil levels. The proinflammatory effects of DHA suggest that the adverse effects of individual fatty acid formulations should be thoroughly considered before any use as therapeutic agents in asthma.

Background: Serum retinol decreases transiently during the acute phase response and can thus result in misclassification of vitamin A status. Objective: Our objective was to determine the prevalence of acute phase response activation in a representative sample of the US population, identify the factors associated with this activation, and determine whether persons with an active acute phase response have lower serum retinol concentrations. Design: Data from the third National Health and Nutrition Examination Survey (NHANES III) were analyzed. A serum C-reactive protein (CRP) concentration ≥ 10 mg/L indicated an active acute phase response. Results: Mean serum retinol was lowest in subjects aged < 10 y and increased with age. Concentrations were higher in males than in females aged 20‐59 y. The prevalence of a CRP concentration ≥ 10 mg/L was lowest in subjects aged < 20 y (≤ 4%) and increased with age to a maximum of nearly 15%. An elevated CRP concentration was 2.4-fold greater in females than in males aged 20‐59 y. Serum retinol was lower in subjects with elevated CRP concentrations. Conclusions: Serum retinol increases with age and males have higher mean values than do females aged 20‐59 y. The prevalence of a CRP concentration ≥ 10 mg/L also increases with age, is 2-fold greater in females than in males aged 20‐69 y, and is associated with common inflammatory conditions. Thus, inflammation appeared to contribute to the misclassification of vitamin A status in the NHANES III population, and serum CRP is useful in identifying subjects who may be misclassified. Am J Clin Nutr 2000;72:1170‐8.

Vitamin A supplementation during acute pneumonia has not improved recovery in most human clinical trials. We hypothesize that high vitamin A intake may decrease the production of T-helper type-1 (Th1) cytokines and thereby inhibit antiviral responses. Such decreases might impair recovery from viral respiratory infections. We thus examined the effect of three interventions on viral pneumonia: 1) a high level vitamin A [250,000 IU/kg diet or 75,000 retinol equivalents (RE)/kg], or 2) control diet (4000 IU/kg diet or 1200 RE/kg) given before and during infection, and 3) initiating the high level diet upon infection to simulate the adjuvant therapy used in clinical trials. No difference was seen among the interventions in severity of disease (weight loss, lung virus titers and survival). However, both the high level diet group and the group in which vitamin A was increased at the time of infection had greater salivary immunoglobulin (Ig)A responses (geometric means, 166 and 105 microg/L, respectively) than did the control group (59 microg/L) (P = 0.0019). In contrast, the serum IgG response was higher in the control group (324+/-158 mg/L) than in the high level group (225+/-95 mg/L) (P = 0.028), although it did not differ from the group in which the diet was changed upon infection (230+/-163 mg/L) (P = 0.084). The production of interferon-gamma (IFN-gamma), a Th1 cytokine, was lower in the high level diet group (median, 0.153 microg/L) compared with the control group (median, 0.839 microg/L) (P = 0.014), whereas the production of interleukin-10 (IL-10), a Th2 cytokine, was higher with the high level diet (median, 0.304 microg/L) than with the control (median, 0.126 microg/L) (P = 0.022). This change in the Th1/Th2 pattern was not sufficient to affect recovery from viral pneumonia but may account for the increased IgA and decreased IgG responses seen with high level dietary vitamin A in this study. These data reinforce the lack of utility of vitamin A in treating acute pneumonia in children and suggest that high dose vitamin A supplements may enhance Th2-mediated immune responses, which are particularly beneficial in the case of extracellular bacterial and parasitic infections and IgA-mediated responses to mucosal infections.

Viruses in the genus Coronavirus are currently placed in three groups based on antigenic cross-reactivity and sequence analysis of structural protein genes. Consensus polymerase chain reaction (PCR) primers were used to obtain cDNA, then cloned and sequenced a highly conserved 922 nucleotide region in open reading frame (ORF) 1b of the polymerase (pol) gene from eight coronaviruses. These sequences were compared with published sequences for three additional coronaviruses. In this comparison, it was found that nucleotide substitution frequencies (per 100 nucleotides) varied from 46.40 to 50.13 when viruses were compared among the traditional coronavirus groups and, with one exception (the human coronavirus (HCV) 229E), varied from 2.54 to 15.89 when compared within these groups. (The substitution frequency for 229E, as compared to other members of the same group, varied from 35.37 to 35.72.) Phylogenetic analysis of these pol gene sequences resulted in groupings which correspond closely with the previously described groupings, including recent data which places the two avian coronaviruses--infectious bronchitis virus (IBV) of chickens and turkey coronavirus (TCV)--in the same group [Guy, J.S., Barnes, H.J., Smith L.G., Breslin, J., 1997. Avian Dis. 41:583-590]. A single pair of degenerate primers was identified which amplify a 251 bp region from coronaviruses of all three groups using the same reaction conditions. This consensus PCR assay for the genus Coronavirus may be useful in identifying as yet unknown coronaviruses.

Acute infections including diarrhea are associated with an increased risk of vitamin A deficiency. Urinary retinol excretion during such infections may contribute to this risk. The mechanism accounting for urinary retinol loss has not been clearly defined. This study attempted to determine whether urinary retinol loss in children with acute infection is associated with impaired kidney function particularly impaired tubular protein reabsorption. Urinary retinol excretion and kidney function were examined in 66 hospitalized children 5 mo to 5 y of age with acute Shigella dysentery. Urinary retinol loss occurred in 59% of children and was substantial (> 0.1 µmol/d) in 8% of them. Children with more severe disease excreted higher concentrations of urinary retinol; those with a body temperature = 40°C excreted a mean of 0.10 ± 0.18 µmol/d compared with 0.005 ± 0.008 µmol/d for other children (P 0.10 µmol/d (15% of the daily metabolic requirement). Impaired tubular reabsorption of low-molecular-weight proteins such as RBP transporting retinol appeared to be the cause of this urinary retinol loss. (authors)

Lymphocytic choriomeningitis virus (LCMV), which is one of several arenaviruses that are pathogenic for humans, causes encephalitis and meningitis in man. In this study, single-stage and nested reverse transcription-polymerase chain reaction (RT-PCR) assays were developed that targeted the GPC and N genes of LCMV. Both assays detected

Although substantial variation exists in individual responses to omega-3 (ω-3) (n-3) fatty acid supplementation, the causes for differences in response are largely unknown. Here we investigated the associations between the efficacy of ω-3 fatty acid supplementation and a broad range of nutritional and clinical factors collected during a double-blind, placebo-controlled trial in participants of African ancestry, randomly assigned to receive either 2 g eicosapentaenoic acid (EPA) + 1 g docosahexaenoic acid (n = 41) or corn/soybean oil placebo (n = 42) supplements for 6 wk. Food-frequency questionnaires were administered, and changes in erythrocyte lipids, lipoproteins, and monocyte 5-lipoxygenase-dependent metabolism were measured before and after supplementation. Mixed-mode linear regression modeling identified high (n = 28) and low (n = 13) ω-3 fatty acid response groups on the basis of changes in erythrocyte EPA abundance (P < 0.001). Compliance was equivalent (∼88%), whereas decreases in plasma triglycerides and VLDL particle sizes and reductions in stimulated monocyte leukotriene B4 production were larger in the high-response group. Although total diet quality scores were similar, the low-response group showed lower estimated 2005 Healthy Eating Index subscores for dark-green and orange vegetables and legumes (P = 0.01) and a lower intake of vegetables (P = 0.02), particularly dark-green vegetables (P = 0.002). Because the findings reported here are associative in nature, prospective studies are needed to determine if dietary dark-green vegetables or nutrients contained in these foods can enhance the efficacy of ω-3 fatty acid supplements. This trial was registered at clinicaltrials.gov as NCT00536185.

Tenofovir disoproxil fumarate (TDF) causes bone, endocrine, and renal changes by an unknown mechanism(s). Data are limited on tenofovir pharmacokinetics and these effects. Using baseline data from a multicenter study of HIV-infected youth on stable treatment with regimens containing TDF ( n = 118) or lacking TDF ( n = 85), we measured cross-sectional associations of TDF use with markers of renal function, vitamin D-calcium-parathyroid hormone balance, phosphate metabolism (tubular reabsorption of phosphate and fibroblast growth factor 23 [FGF23]), and bone turnover. Pharmacokinetic-pharmacodynamic associations with plasma tenofovir and intracellular tenofovir diphosphate concentrations were explored among those receiving TDF. The mean age was 20.9 (standard deviation [SD], 2.0) years; 63% were male; and 52% were African American. Compared to the no-TDF group, the TDF group showed lower mean estimated glomerular filtration rates and tubular reabsorption of phosphate, as well as higher parathyroid hormone and 1,25-dihydroxy vitamin D [1,25-OH(2)D] levels. The highest quintile of plasma tenofovir concentrations was associated with higher vitamin D binding protein, lower free 1,25-OH(2)D, higher 25-OH vitamin D, and higher serum calcium. The highest quintile of intracellular tenofovir diphosphate concentration was associated with lower FGF23. Higher plasma tenofovir concentrations were associated with higher vitamin D binding protein and lower free 1,25-OH(2)D, suggesting a functional vitamin D deficiency explaining TDF-associated increased parathyroid hormone. The finding of lower FGF23 accompanying higher intracellular tenofovir diphosphate suggests that different mechanisms mediate TDF-associated changes in phosphate handling. Separate pharmacokinetic properties may be associated with distinct TDF toxicities: tenofovir with parathyroid hormone and altered calcium balance and tenofovir diphosphate with hypophosphatemia and FGF23 regulation. IMPORTANCE (The clinical trial registration number for this study is NCT00490412 and is available online at http://clinicaltrials.gov/ct2/show/NCT00490412 .)

Serum 25-hydroxyvitamin D [25(OH)D] is often deficient (

We examined the effect of vitamin A deficiency on the secretory immunoglobulin (Ig) A and serum IgG response to influenza A virus infections in BALB/c mice. Mice fed a vitamin A-deficient (VAD mice) or a control diet were inoculated with influenza virus at 7 or 9 wk of age when serum retinol concentration had dropped toor = 0.35 mumol/L in the VAD mice. The influenza-specific salivary IgA response to a mild infection (intranasal inoculation without anesthesia) was not significantly lower in the VAD group (5.3 +/- 2.1% of total IgA 4 wk after infection) than in the control group (10 +/- 11%, P0.05). In a separate experiment, this salivary IgA response was significantly lower in the VAD mice (0.3 +/- 0.4% of total IgA) following a more severe infection (intranasal infection while under anesthesia) than it was in control mice (4.2 +/- 4.6% of total IgA, P0.0001). In contrast, the concentration of total salivary IgA was uniformly greater in the VAD mice than in the control mice during both the mild infection (VAD, 17 +/- 6 mg/L vs. control, 8 +/- 11 mg/L at 3 wk, P0.0001) and the severe infection (VAD, 38 +/- 30 mg/L vs. control, 9 +/- 7 mg/L, P0.0001). Similarly, the influenza-specific serum IgG response was also greater in the VAD mice than in the control mice during both the mild infection (VAD, 194 +/- 91 mg/L vs. control, 79 +/- 95 mg/L at 5 wk, P = 0.0002) and the severe infection [VAD median, 202 mg/L (25th, 75th percentiles, 153, 409 mg/L) vs. control, 123 mg/L (42, 165 mg/L), P = 0.0023]. Thus VAD significantly impairs the secretory IgA response to influenza infection but modestly increases the serum IgG response to the same infection.

Callitrichid hepatitis is an infection of New World primates caused by an arenavirus, currently referred to as callitrichid hepatitis virus, that is closely related to lymphocytic choriomeningitis virus (LCMV). We have cloned and sequenced the GP-C gene of callitrichid hepatitis virus and found that the cDNA sequence is 84 to 86% identical to those of the GP-C genes of LCMV strains Armstrong and WE, while the deduced amino acid sequence is 95 to 96% identical to those of the GP-C gene products of the same strains. This high degree of similarity indicates that the etiologic agent of callitrichid hepatitis is in fact LCMV. The wide geographic distribution of callitrichid hepatitis outbreaks in the United States serves as a reminder that LCMV is also a human pathogen whose public health implications are not well understood.

Vitamin A was called the anti-infective vitamin early in the twentieth century when vitamin A deficiency was shown to increase the severity of infections of experimental animals.

Vitamin A has an important role to play in vision, bone growth, reproduction, cell division, and cell differentiation. With the focus on Vitamin A and Carotenoids, this book includes the latest research in these areas and starts with an overview putting the compounds in context with other vitamins, supplementation and discussing the importance of beta-carotene. Details of the chemistry, structure and biochemistry of the compounds begins with nomenclature followed by information on encapsulation, thermal degradation and occurrence. Developments in analytical and bioanalytical techniques concerning these compounds in plant, milk and human tissue systems are covered in detail. Finally, the book covers the extensive functions and effects of Vitamin A on eg developmental growth, immune function, cancer risk, the brain and lungs as well as vision. Delivering high quality information, this book will be of benefit to anyone researching this area of health and nutritional science. It will bridge scientific disciplines so that the information is more meaningful and applicable to health in general. Part of a series of books, it is specifically designed for chemists, analytical scientists, forensic scientists, food scientists, dieticians and health care workers, nutritionists, toxicologists and research academics. Due to its interdisciplinary nature it could also be suitable for lecturers and teachers in food and nutritional sciences and as a college or university library reference guide.

Arachidonate 5-lipoxygenase (ALOX5) gene variants that are common in people of African ancestry are associated with a differential cardiovascular disease (CVD) risk that may be ameliorated by intake of (n-3) PUFA, such as EPA or DHA. We conducted a double-masked, placebo (PL)-controlled trial of fish oil (FO) supplements to determine if changes in erythrocyte (n-3) PUFA composition, heart rate, blood pressure, and plasma lipid and lipoprotein concentrations are modified by genotype. Participants received 5 g/d FO (2 g EPA, 1 g DHA) or 5 g/d corn/soy oil (PL). A total of 116 healthy adults of African ancestry with selected genotypes (genotypes = “dd,” “d5,” and “55” with “d” representing the deletion of 1 or 2 Sp1 binding sites in the ALOX5 promoter and “5” indicating the common allele with 5 sites) were enrolled and 98 completed the study. FO caused significant increases (relative to PL) in erythrocyte EPA, DHA, and total (n-3) PUFA and a decrease in the (n-6) PUFA:(n-3) PUFA ratio in the low-CVD risk “d5” and “55” genotypes but not in the high-risk “dd” genotype. Similarly, HDL particle concentration decreased with FO relative to PL in the “d5” and “55” but not “dd” genotypes. The plasma TG concentration decreased significantly with FO relative to PL in the “d5” but not “dd” and “55” genotypes. No changes were seen in LDL particle or cholesterol concentrations, heart rate, or blood pressure. These findings indicate that the efficacy of FO supplements vary by ALOX5 genotype.

The biological activities of vitamin A in promoting growth and sustaining vision were described nearly a century ago (Wolf 2001)(Table 29.1). Within a few years vitamin A was additionally termed the “anti-infective vitamin” because deficient animals were found to develop symptomatic infections of mu...

BackgroundN-3 fatty acids are associated with favorable, and obesity with unfavorable, concentrations of chronic disease risk biomarkers.ObjectiveWe examined whether high eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid intakes, measured as percentages of total red blood cell (RBC) fatty acids, modify associations of obesity with chronic disease risk biomarkers.MethodsIn a cross-sectional study of 330 Yup'ik Eskimos, generalized additive models (GAM) and linear and quadratic regression models were used to examine associations of BMI with biomarkers across RBC EPA and DHA categories.ResultsMedian (5th-95th percentile) RBC EPA and DHA were 2.6% (0.5-5.9%) and 7.3% (3.3-8.9%), respectively. In regression models, associations of BMI with triglycerides, glucose, insulin, C-reactive protein (CRP) and leptin differed significantly by RBC EPA and DHA. The GAM confirmed regression results for triglycerides and CRP: at low RBC EPA and RBC DHA, the predicted increases in triglycerides and CRP concentrations associated with a BMI increase from 25 to 35 were 99.5±45.3 mg/dl (106%) and 137.8±71.0 mg/dl (156%), respectively, for triglycerides and 1.2±0.7 mg/l (61%) and 0.8±1.0 mg/l (35%), respectively, for CRP. At high RBC EPA and RBC DHA, these predicted increases were 13.9±8.1 mg/dl (23%) and 12.0±12.3 mg/dl (18%), respectively, for triglycerides and 0.5±0.5 mg/l (50%) and -0.5±0.6 mg/l (-34%), respectively, for CRP.ConclusionsIn this population, high RBC EPA and DHA were associated with attenuated dyslipidemia and low-grade systemic inflammation among overweight and obese persons. This may help inform recommendations for n-3 fatty acid intakes in the reduction of obesity-related disease risk.

The objective of this study was to determine whether 5-lipoxygenase (ALOX5) gene variants associated with cardiovascular disease affect eicosanoid production by monocytes. The study was a randomized, double-masked, parallel intervention trial with fish oil (5.0 g of fish oil daily, containing 2.0 g of eicosapentaenoic acid [EPA] and 1.0 g of docosahexaenoic acid [DHA]) or placebo oil (5.0 g of corn/soy mixture). A total of 116 subjects (68% female, 20–59 years old) of African American ancestry enrolled, and 98 subjects completed the study. Neither ALOX5 protein nor arachidonic acid-derived LTB4, LTD4, and LTE4 varied by genotype, but 5-hydroxyeicosatetraenoate (5-HETE), 6-trans-LTB4, 5-oxo-ETE, 15-HETE, and 5,15-diHETE levels were higher in subjects homozygous for the ALOX5 promoter allele containing five Sp1 element tandem repeats (“55” genotype) than in subjects with one deletion (d) (three or four repeats) and one common (“d5” genotype) allele or with two deletion (“dd”) alleles. The EPA-derived metabolites 5-HEPE and 15-HEPE and the DHA-derived metabolite 17-HDoHE had similar associations with genotype and increased with supplementation; 5-HEPE and 15-HEPE increased, and 5-oxo-ETE decreased to a greater degree in the 55 than in the other genotypes. This differential eicosanoid response is consistent with the previously observed interaction of these variants with dietary intake of omega-3 fatty acids in predicting cardiovascular disease risk.

An ELISA was developed for measuring serum antibodies against the arenavirus lymphocytic choriomeningitis virus (LCMV) and a closely related isolate termed callitrichid hepatitis virus (CHV). The ELISA was used to test sera from healthy adults and from hepatitis patients. In Birmingham, Alabama, the seropositivity rate for healthy black women was 5.1% (7/138), and the rate for patients with all types of hepatitis or cirrhosis was 4.3% (2/46). In San Antonio, Texas, the seropositivity rate among a clinical series of patients with non-A, non-B hepatitis was 0 (0/20), and the rate among persons rejected from blood donation because of high serum alanine aminotransferase levels was 2.4% (2/82). These results indicate that infection with LCMV or CHV is common in Birmingham but that infection is not associated with hepatitis.

A monoclonal antibody solution hybridization (MASH) assay was developed to detect fecal excretion of mouse hepatitis virus (MHV). The assay used a biotinylated cDNA probe to detect viral RNA target sequences by hybridization in solution, capture of hybrids on the solid phase with antibiotin antibody, and immunoassay with an enzyme-labelled monoclonal antibody specific for DNA-RNA hybrids. The MASH assay was used to monitor the time course of enterotropic MHV excretion after oronasal inoculation. Infectivity of the inoculated mice was simultaneously monitored with sentinel animals. The MASH assay detected MHV excretion in all inoculated mice, with the highest mean excretion levels occurring from day 3 through day 9 postinoculation. Mean excretion then decreased gradually to below detection limits by day 21 postinoculation. Sentinels became infected on exposure to inoculated mice up to but not after day 21 postinoculation. Infected sentinel mice showed a time course of virus excretion similar to that of inoculated mice. These results indicate that the MASH assay is useful for rapid, sensitive, and specific detection of MHV in clinical specimens from laboratory mice.

Variants of a hexanucleotide repeat polymorphism in the promoter of the 5-lipoxygenase (5-LO) gene have been associated with cardiovascular disease traits in humans, which may be due, at least in part, to differential expression of the at-risk alleles. To more fully characterize these variants, we carried out gene expression and DNA methylation studies in primary leukocytes from healthy individuals carrying various 5-LO promoter alleles. Regardless of genotype, 5-LO and 5-LO-activating protein (FLAP) gene expression was higher in granulocytes compared with monocytes and lymphocytes, whereas leukotriene A4 hydrolase (LTA4H) expression was higher in monocytes. In all three leukocyte populations, 5-LO mRNA levels were positively correlated with those of FLAP and LTA4H, with the highest correlation observed in granulocytes. In lymphocytes, individuals homozygous for the shorter 3 and 4 repeat alleles had between 20-35% higher 5-LO, FLAP and LTA4H expression compared with homozygous carriers of the wild-type 5 repeat allele (P = 0.03-0.0001). DNA methylation analysis of four CpG islands in a 1500 bp region encompassing the 5-LO promoter and the first approximately 100 bp of intron 1 revealed relatively low overall DNA methylation across all genotypes and leukocyte populations. However, analysis of the promoter repeats themselves demonstrated that, regardless of cell population, the 4 allele was methylated approximately twice as much as the 3 allele (P0.0001). Our results demonstrate that, in lymphocytes, the shorter repeat alleles of the 5-LO promoter lead to higher gene expression, which may be regulated through differential DNA methylation of the CpGs located within these repeats.

Callitrichid hepatitis (CH) is an acute, often fatal viral infection of New World primates from the family Callitrichidae. The etiologic agent of CH is unknown. We report here the isolation of an arenavirus from a common marmoset (Callithrix jacchus) with CH by using in vitro cultures of marmoset hepatocytes and Vero-E6 cells. Enveloped virions 67 to 133 nm in diameter with ribosomelike internal structures were seen in infected cultures. Immunofluorescence and Western immunoblot analysis using CH-specific antisera (principally from animals exposed to CH during zoo outbreaks) revealed three antigens in cells infected with this CH-associated virus (CHV). These antigens had the same electrophoretic mobilities on sodium dodecyl sulfate-polyacrylamide gels as did the nucleocapsid, GP2, and GPC proteins of lymphocytic choriomeningitis virus (LCMV). Monoclonal antibodies specific for these arenavirus proteins also reacted with the three CHV antigens. Conversely, the CH-specific antisera reacted with the nucleocapsid, GP2, and GPC proteins of LCMV. CHV thus appears to be a close antigenic relative of LCMV. The serologic association of CHV with several CH outbreaks implicate it as the etiologic agent of this disease.

Recommendations for vitamin A intake and liver stores are based on maintaining normal vision. We propose that higher levels may be required to maintain normal innate immune function. To test this hypothesis, we conducted an 8-wk residential study among 36 healthy Bangladeshi men with low vitamin A stores. Subjects were randomized to receive vitamin A (240 mg in 4 doses) or placebo during study wk 2 and 3. They received 2 vaccines during wk 5 and vitamin A stores were estimated by isotopic dilution at wk 8. The serum concentration of the chemokine interferon-gamma-induced protein 10, a component of T-helper 1 (Th1) response, increased significantly after supplementation and was positively and significantly associated with vitamin A stores. Blood concentrations of natural killer (NK) and NK T-cells, which have anticancer and antiviral activity, were positively associated with stores (P < 0.05), as was monocyte oxidative burst (P < 0.05), a marker of bacterial killing ability. However, serum interleukin (IL)-6 and IL-17, cytokines that regulate the antibacterial Th17 response, were significantly and negatively associated with stores, as was production of the regulatory cytokine IL-10 by whole-blood cultures stimulated with bacterial lipopolysaccharide. In summary, vitamin A stores were positively associated with several measures of innate immune activity across a broad range of stores, suggesting that vitamin A enhances protection against diverse pathogens even at concentrations above those needed to maintain normal vision. The negative association of stores with serum IL-6 and IL-17 suggests that not all protective responses are similarly enhanced by vitamin A.