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l-Arginine is an important nutrient in the infant diet that significantly regulates the maturation of the immune system in neonates, including the maturation of CD4+ T cells. The biological activities of CD4+ T cells differ substantially between neonates and adults, and these differences may be governed by epigenetic processes. Investigating these differences and the causative processes may help understand neonatal and developmental immunity. In this study, we compared the functional DNA methylation profiles in CD4+ T cells of neonates and adults, focusing on the role of l-arginine supplementation. Umbilical cord blood and adult CD4+ T cells were cultured with/without l-arginine treatment. By comparing DNA methylation in samples without l-arginine treatment, we found that CD4+ T cells of neonatal cord blood generally showed higher DNA methylation than those of adults (average CpG methylation percentage 0.6305 for neonate and 0.6254 for adult, t-test p-value < 0.0001), suggesting gene silencing in neonates. By examining DNA methylation patterns of CpG dinucleotides induced by l-arginine treatment, we found that more CpG dinucleotides were hypomethylated and more genes appeared to be activated in neonatal T-cells as compared with adult. Genes activated by l-arginine stimulation of cord blood samples were more enriched regarding immune-related pathways. CpG dinucleotides at IL-13 promoter regions were hypomethylated after l-arginine stimulation. Hypomethylated CpG dinucleotides corresponded to higher IL-13 gene expression and cytokine production. Thus, DNA methylation partially accounts for the mechanism underlying differential immune function in neonates. Modulatory effects of l-arginine on DNA methylation are gene-specific. Nutritional intervention is a potential strategy to modulate immune function of neonates.

Kawasaki disease (KD) is the leading cause of acquired heart disease during childhood in the developed countries. Coronary artery lesions (CAL) are the major complications of KD. A unique proteomic profiling with increased or decreased fibrinogen, alpha-1-antitrypsin, clusterin, and immunoglobulin free light chains were noted in KD in our previous study. The purpose of this study was to evaluate relations between these biomarkers and CAL in KD and to establish within the markers the appropriate cut-off value with which to predict the occurrence of CAL. A total of 47 KD patients were enrolled, including 14 with CAL and 33 without CAL. Plasma samples from patients with KD before intravenous immunoglobulin administration were indicated for measurement of these biomarkers. A potential relation among CAL, clinical characteristics, and these biomarkers was investigated, and a receiver operating characteristic curve was used to identify a cut-off value of the significant marker that best predicated the occurrence of CAL. Among these biomarkers, only plasma clusterin level was associated with the occurrence of CAL. Using a cut-off value of clusterin <12.0 mg/l, the relative risk for CAL was 4.53-fold (95% confidence interval [CI] 1.060-19.347%, P = 0.014). Results from this study suggest that plasma clusterin level <12.0 mg/l in KD is significantly associated with the occurrence of CAL. Results from this study provide a potential biomarker of KD that may help predict the occurrence of CAL. [ABSTRACT FROM AUTHOR]

We propose that a C-type lectin receptor, SIGNR-1 (also called Cd209b), helps to condition dendritic cells (DCs) in the gastrointestinal lamina propria (LPDCs) for the induction of oral tolerance in a model of food-induced anaphylaxis. Oral delivery of BSA bearing 51 molecules of mannoside (Man51-BSA) substantially reduced the BSA-induced anaphylactic response. Man51-BSA selectively targeted LPDCs that expressed SIGNR1 and induced the expression of interleukin-10 (IL-10), but not IL-6 or IL-12 p70. We found the same effects in IL-10-GFP knock-in (tiger) mice treated with Man51-BSA. The Man51-BSA-SIGNR1 axis in LPDCs, both in vitro and in vivo, promoted the generation of CD4+ type 1 regulatory T (Tr1)-like cells that expressed IL-10 and interferon-γ (IFN-γ), in a SIGNR-1- and IL-10-dependent manner, but not of CD4+CD25+Foxp3+ regulatory T cells. The Tr1-like cells could transfer tolerance. These results suggest that sugar-modified antigens might be used to induce oral tolerance by targeting SIGNR1 and LPDCs. [ABSTRACT FROM AUTHOR]