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Background: Insufficient data on the rate and distribution of SARS-CoV-2 infection in Canada has presented a substantial challenge to the public health response to the COVID-19 pandemic. Our objective was to assess SARS-CoV-2 seroprevalence in a representative sample of pregnant people throughout Canada, across multiple time points over 2 years of the pandemic, to describe the seroprevalence and show the ability of this process to provide prevalence estimates., Methods: This Canadian retrospective serological surveillance study used existing serological prenatal samples across 10 provinces over multiple time periods: Feb. 3-21, 2020; Aug. 24-Sept. 11, 2020; Nov. 16-Dec. 4, 2020; Nov. 15-Dec. 3, 2021; and results from the province of British Columbia during a period in which the SARS-CoV-2 B.1.1.529 (Omicron) variant was predominant, from Nov. 15, 2021, to June 11, 2022. Age and postal code administrative data allowed for comparison with concurrent polymerase chain reactivity (PCR)-positive results collected by Statistics Canada and the Canadian Surveillance of COVID-19 in Pregnancy (CANCOVID-Preg) project., Results: Seropositivity in antenatal serum as early as February 2020 indicates SARS-CoV-2 transmission before the World Health Organization's declaration of the pandemic. Seroprevalence in our sample of pregnant people was 1.84 to 8.90 times higher than the recorded concurrent PCR-positive prevalence recorded among females aged 20-49 years in November-December 2020. Overall seropositivity in our sample of pregnant people was low at the end of 2020, increasing to 15% in 1 province by the end of 2021. Seroprevalence among pregnant people in BC during the Omicron period increased from 5.8% to 43% from November 2021 to June 2022., Interpretation: These results indicate widespread vulnerability to SARS-CoV-2 infection before vaccine availability in Canada. During the time periods sampled, public health tracking systems were under-reporting infections, and seroprevalence results during the Omicron period indicate extensive community spread of SARS-CoV-2 infection., Competing Interests: Competing interests: Lori Beach reports receiving funding from the Public Health Agency of Canada (PHAC) and from the Canadian Diagnostic Executive Forum, Toronto, for support for travel to speak at a meeting. Dr. Beach is also division head of Public Outreach and Communications for the Canadian Society of Clinical Chemists. Shelly Bolotin reports receiving support for the present manuscript from COVID-19 Immunity Task Force and Public Health Ontario. Dr. Bolotin is co-investigator on several COVID-19 grants funded by the Canadian Institutes of Health Research (CIHR), the Canadian Immunity Taskforce, the Canadian Immunization Research Network and PHAC. Dr. Bolotin is associate professor at the University of Toronto and, as part of that role, is director of the centre for Vaccine Preventable Diseases at the university. The centre is supported by the Dalla Lana School of Public Health (DLSPH), which receives funding from government, philanthropic, not-for-profit and private-sector organizations. Private-sector funding sources include vaccine manufacturers, specifically Merck, Sanofi and Pfizer. A set of governance processes are in place at the DLSPH to ensure independent operation of the centre. Isabelle Boucoiran reports receiving grants or contracts from Altona, the National Institutes of Health, CIHR and the Québec Ministère de la Santé et des Services Sociaux, and consulting fees from Pfizer. Dr. Boucoiran has also received equipment, materials, drugs, medical writing, gifts or other services from Altona. Mel Krajden reports receiving reagent support from Siemens to assess SARS-CoV-2 serology and had a contract with Hologic to support respiratory virus testing. Vanessa Poliquin reports receiving grants or contracts from GSK as the site principal investigator for a respiratory syncytial virus vaccine study. Dr. Poloquin has received an honorarium from Sanofi Pasteur for teaching at a continuing medical education event and payment for expert testimony from the Department of Justice Canada. George Zahariadis reports receiving support for the current manuscript from the Public Health Agency of Canada, as well as grants or contracts from Genome Atlantic and CIHR. Dr. Zahariadis also reports receiving unrestricted educational funding from Roche and Abbott to the Eastern Health Regional Health Authority to attend virtual meetings and in specific restricted circumstances, travel to educational, technical and research meetings. Dr. Zahariadis is the past president of the National Molecular Users Group. Jason Robinson reports receiving a Roche Ideas Grant including in-kind reagents for previous work on salivary antibody detection. Vanessa Tran reports receiving grants from CIHR, the COVID-19 Immunity Task Force, Canadian Immunization Research Network and PHAC, outside the submitted work. Dr. Tran is also a member of Canadian Immunization Research Network Management Committee and the COVID-19 Immunity Task Force Leadership Group. Deborah Money reports receiving support for the present manuscript from PHAC, paid to the institution on behalf of the COVID-19 Immunity Task Force. Dr. Money has also received past funding for unrelated work from Merck, GSK, Sanofi and Novartis, paid to the institution. No other competing interests were declared., (© 2023 CMA Impact Inc. or its licensors.)

Background: The respiratory pathogen Streptococcus pneumoniae (the pneumococcus) is a genetically diverse bacterium associated with over 101 immunologically distinct polysaccharide capsules (serotypes). Polysaccharide conjugate vaccines (PCVs) have successfully eliminated multiple targeted serotypes, yet the mucoid serotype 3 has persisted despite its inclusion in PCV13. This capsule type is predominantly associated with a single globally disseminated strain, GPSC12 (clonal complex 180)., Methods: A genomic epidemiology study combined previous surveillance datasets of serotype 3 pneumococci to analyse the population structure, dynamics, and differences in rates of diversification within GPSC12 during the period of PCV introductions. Transcriptomic analyses, whole genome sequencing, mutagenesis, and electron microscopy were used to characterise the phenotypic impact of loci hypothesised to affect this strain's evolution., Results: GPSC12 was split into clades by a genomic analysis. Clade I, the most common, rarely underwent transformation, but was typically infected with the prophage ϕOXC141. Prior to the introduction of PCV13, this clade's composition shifted towards a ϕOXC141-negative subpopulation in a systematically sampled UK collection. In the post-PCV13 era, more rapidly recombining non-Clade I isolates, also ϕOXC141-negative, have risen in prevalence. The low in vitro transformation efficiency of a Clade I isolate could not be fully explained by the ~100-fold reduction attributable to the serotype 3 capsule. Accordingly, prophage ϕOXC141 was found to modify csRNA3, a non-coding RNA that inhibits the induction of transformation. This alteration was identified in ~30% of all pneumococci and was particularly common in the unusually clonal serotype 1 GPSC2 strain. RNA-seq and quantitative reverse transcriptase PCR experiments using a genetically tractable pneumococcus demonstrated the altered csRNA3 was more effective at inhibiting production of the competence-stimulating peptide pheromone. This resulted in a reduction in the induction of competence for transformation., Conclusion: This interference with the quorum sensing needed to induce competence reduces the risk of the prophage being deleted by homologous recombination. Hence the selfish prophage-driven alteration of a regulatory RNA limits cell-cell communication and horizontal gene transfer, complicating the interpretation of post-vaccine population dynamics., (© 2022. The Author(s).)

Objectives: The objectives of this study were to investigate recent trends in non-invasive prenatal testing (NIPT) utilisation, including factors associated with geographical variation, and to determine whether maternal or regional characteristics are associated with uptake the of NIPT., Methods: This retrospective cohort study included pregnant individuals in Ontario with an expected date of delivery from August 1st, 2016 to March 31st, 2020. Modified Poisson regression was used to estimate rate ratios for NIPT use adjusted for maternal and healthcare covariates., Results: We found substantial variation in NIPT uptake between regions within the province. The highest uptake was found in urban areas, highest quintile of neighbourhood income and education, for those who were ≥40 years of age and had a history of previous aneuploidy, for those with a prenatal care visit in the first trimester, multiple pregnancy, multigravidity and body mass index within the normal range (18.5-24.9 kg/m 2 )., Conclusion: Our study demonstrated significant regional and maternal differences in NIPT uptake across Ontario. Given the large sample size and diverse population, our study may have implications for other jurisdictions with large, socio-demographically and geographically diverse populations., (© 2022 John Wiley & Sons Ltd.)

Background: Gastroschisis is a congenital anomaly of the abdomen in which the intestines are found outside of the body at birth. While no clear causative factors have been identified, it is strongly associated with young maternal age. Other reported associations include low maternal socioeconomic status, low maternal body mass index (BMI), and smoking., Methods: This is a retrospective review of epidemiologic data relating to cases of gastroschisis in Ontario from 2012-2018 in the Better Outcomes Registry & Network (BORN) Ontario database, which is the province's prescribed maternal-newborn registry. We describe the epidemiology of gastroschisis in Ontario with respect to birth prevalence, maternal age, health, exposures, and geography., Results: The birth prevalence of gastroschisis is 2.31 cases/10,000 births. There was no apparent change in birth prevalence over the study period and there was no difference between male and female infants. Gastroschisis was associated with younger maternal ages and was inversely correlated with maternal BMI. Gastroschisis was associated with first completed pregnancy. Maternal diabetes was associated with a lower birth prevalence of gastroschisis than average. Mothers of babies with gastroschsis were more likely to report use of tobacco, alcohol, and drugs during pregnancy than those without gastroschisis, with marijuana use showing the largest increase in birth prevalence of gastroschisis. Mothers living in rural areas were more likely to have a baby with gastroschisis than those in urban centers, even after controlling for maternal age., Conclusions: This Ontario registry study reveals that mothers with babies with gastroschisis are more likely to be young and thin, live in rural areas, and report prenatal smoking, alcohol use, and drug use than women whose pregnancies do not have gastroschsis., (© 2021 Wiley Periodicals LLC.)

Genetic diagnosis provides important information for prenatal decision-making and management. Promising results from exome sequencing (ES) for genetic diagnosis in fetuses with structural anomalies are emerging. The objective of this scoping review was to identify what is known about the use of ES for genetic testing in prenatal cases with known or suspected genetic disease. A rapid scoping review was conducted over a six-week timeframe of English-language peer-reviewed studies. Search strategies for major databases (e.g., Medline) and gray literature were developed, and peer reviewed by information specialists. Identified studies were categorized and charted using tables and diagrams. Twenty-four publications were included from seven countries published between 2014 and 2019. Most commonly reported outcomes were diagnostic yields, which varied widely from 5% to 57%, and prenatal phenotype. Few studies reported clinical outcomes related to impact, decision-making, and clinical utility. Qualitative studies (n = 6) provided useful insights into patient and health-care provider experiences with ES. Findings suggest prenatal ES is beneficial, but more research is needed to better understand the clinical utility, circumstances for ideal use, feasibility, and costs of offering rapid ES as a routine option for prenatal genetic testing.

Background: Few adequately validated patient-reported outcome measures are available, which can assess recovery profiles following childbirth., Objective: We aimed to determine whether quantitative recovery (using the Obstetric Quality of Recovery-10 patient-reported outcome measure) was superior following vaginal delivery compared with cesarean delivery and evaluate validity, reliability, and responsiveness of this patient-reported outcome measure in the obstetrical setting in the United States., Study Design: Women recruited into this single-center observational cohort study completed the Obstetric Quality of Recovery-10 and EuroQol 5-dimension 3L patient-reported outcome measures within 72 hours of childbirth. We assessed the validity with hypothesis testing and structural validity. In hypothesis testing, the primary outcome was Obstetric Quality of Recovery-10 scores after vaginal vs cesarean delivery. Secondary outcomes were differences in Obstetric Quality of Recovery-10 scores for vaginal delivery following induction of labor vs spontaneous labor and scheduled vs unplanned cesarean delivery, correlation with clinical parameters (American Society of Anesthesiologists classification grade, body mass index, length of hospital stay, estimated blood loss, transfusion requirement, antiemetic use, and neonatal intensive care unit admission), and qualitative ranking of Obstetric Quality of Recovery-10 items for each delivery mode. Structural validity was assessed by determining the correlation of the Obstetric Quality of Recovery-10 scores with the EuroQol 5-dimension 3L and global health visual analog scale scores. Reliability was assessed using Cronbach alpha and inter-item correlation of Obstetric Quality of Recovery-10 items. Responsiveness was assessed by evaluating the change in Obstetric Quality of Recovery-10 scores over the 72-hour postpartum period., Results: Data from 215 women were analyzed. In hypothesis testing, the median (interquartile range) Obstetric Quality of Recovery-10 scores were higher following vaginal delivery than cesarean delivery (86 [77-94] vs 77 [64-86], respectively; P<.001). Multivariate model demonstrated that Obstetric Quality of Recovery-10 scores were significantly lower after cesarean delivery when adjusting for American Society of Anesthesiologists classification grade, age, body mass index, and ethnicity (R=-8.97; P<.001). Obstetric Quality of Recovery-10 scores were similar between induction of labor and spontaneous labor, and scheduled cesarean delivery and unplanned cesarean delivery. Obstetric Quality of Recovery-10 was correlated with length of hospital stay (R=-0.248; P<.001), estimated blood loss (R=-0.3429; P<.001), transfusion requirement (R=-0.140; P=.041), and antiemetic use (R=-0.280; P<.001). The highest ranked Obstetric Quality of Recovery-10 items were ability to hold baby, feeling in control, and ability to look after personal hygiene. The lowest ranked items were pain and shivering. In structural validity, correlation of Obstetric Quality of Recovery-10 score was moderate with the global health visual analog scale (r=0.511) and EuroQol 5-dimension 3L scores (r=-0.509). In reliability, Cronbach alpha was 0.72 and more than 80% of individual items correlated. In responsiveness, Obstetric Quality of Recovery-10 scores did not change significantly over the study period., Conclusion: Quantitative inpatient recovery following vaginal delivery is superior to cesarean delivery. The Obstetric Quality of Recovery-10 appears to be a valid and reliable patient-reported outcome measure following these delivery modes. Further studies are needed to determine how to improve recovery domains identified in this study, to evaluate Obstetric Quality of Recovery-10 in different languages and determine whether these domains impact outcomes beyond hospitalization., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: Ontario offers a publicly funded modified contingent model of prenatal screening for aneuploidy in which cell-free DNA (cfDNA) screening is covered for pregnancies at higher risk of fetal aneuploidy. The objective of this study was to review utilization of provincially funded cfDNA screening and adherence to the criteria laid out in Ontario prenatal screening guidelines., Methods: This was a descriptive cohort study using data collected by Ontario's prescribed maternal and child registry. The study population included all pregnant individuals who received cfDNA screening from January 2016 to December 2017., Results: The most common criteria for provincially funded cfDNA screening were advanced maternal age ≥40 years (37.7%), positive multiple marker screen (34.1%), modifying risk factors such as ultrasound soft markers (7.1%), and previous aneuploidy (5.5%). The audit demonstrated that 2.9% of funded cfDNA screens tests did not meet funding criteria, and that 11.4% of self-paid cfDNA screens could have been publicly funded., Conclusion: Reviewing and auditing the application of criteria for funded cfDNA screening using prescribed registry data allows an opportunity to identify areas where targeted education may improve adherence to standardized screening protocols, and provides a basis for reassessment of the funding model., (© 2019 John Wiley & Sons, Ltd.)

The discovery of a Salmonella-targeting phage from the waterways of the United Kingdom provided an opportunity to address the mechanism by which Chi-like bacteriophage (phage) engages with bacterial flagellae. The long tail fibre seen on Chi-like phages has been proposed to assist the phage particle in docking to a host cell flagellum, but the identity of the protein that generates this fibre was unknown. We present the results from genome sequencing of this phage, YSD1, confirming its close relationship to the original Chi phage and suggesting candidate proteins to form the tail structure. Immunogold labelling in electron micrographs revealed that YSD1&#95;22 forms the main shaft of the tail tube, while YSD1&#95;25 forms the distal part contributing to the tail spike complex. The long curling tail fibre is formed by the protein YSD1&#95;29, and treatment of phage with the antibodies that bind YSD1&#95;29 inhibits phage infection of Salmonella. The host range for YSD1 across Salmonella serovars is broad, but not comprehensive, being limited by antigenic features of the flagellin subunits that make up the Salmonella flagellum, with which YSD1&#95;29 engages to initiate infection., (© 2019 John Wiley & Sons Ltd.)

Objective: The objectives of this study were as follows: (1) to investigate the accuracy of IVF identification on the prenatal screening record from prenatal screening laboratories; (2) to compare the screening markers in IVF and non-IVF pregnancies in the population of Ontario; and (3) to propose more appropriate IVF adjustment factors for the Ontario population., Methods: Two years of IVF treatment, data from all fertility clinics in Ontario were merged with the corresponding prenatal screening data from all five prenatal screening labs. New adjustment factors for IVF were developed for each maternal serum screening marker and nuchal translucency measurement. Means and SDs and linear regression models were reported for all prenatal screening records, as well as for records that had IVF identified through the prenatal screening requisition and records that were identified through the Canadian Assisted Reproductive Technologies Register (CARTR) Plus database., Results: Significant differences between IVF and non-IVF groups on the basis of the prenatal screening requisition information and CARTR Plus information were found among the ethnicity-adjusted mean multiple of the medians for alpha fetoprotein, first trimester pregnancy-associated plasma protein A, second trimester unconjugated estradiol, first trimester human chorionic gonadotropin, total human chorionic gonadotropin, and dimeric inhibin A., Conclusion: This study proposed alternate IVF adjustment factors that will produce more accurate screening results within the population of Ontario., (Copyright © 2018 Society of Obstetricians and Gynaecologists of Canada. Published by Elsevier Inc. All rights reserved.)

Background: In 2014, Ontario augmented its publicly funded multiple-marker screening program for prenatal aneuploidy by incorporating cell-free fetal DNA (cffDNA) analysis for high-risk pregnancies. We assessed trends in the use of multiple-marker screening, cffDNA screening and prenatal diagnostic testing before and after implementation of public funding., Methods: We conducted a descriptive study based on data from the Better Outcomes Registry & Network (BORN) Ontario. The study population included all pregnant women in Ontario with a singleton pregnancy and an expected date of delivery between July 1, 2012, and Mar. 31, 2016, with pregnancy data captured in BORN. Pregnancy losses and terminations before 20 weeks' gestation not captured in BORN were excluded. We generated descriptive statistics to show trends and regional variations in use., Results: The study sample included 534 210 singleton pregnancies. After cffDNA screening was funded for specific indications, uptake of multiple-marker screening increased slightly, from 66.5% to 68.1% ( p < 0.001). Uptake of cffDNA screening among women with a positive multiple-marker screening result increased substantially, from 3.2% to 48.8% ( p < 0.001). In contrast, the rate of prenatal diagnostic testing in this group decreased from 54.8% to 30.8% ( p < 0.001). Although women aged 40 years or older are eligible for primary cffDNA screening, only a small decrease in the use of multiple-marker screening was observed in this group. The greatest use of cffDNA screening and greatest decline in prenatal diagnostic testing were seen in women with a level of risk for trisomy 21 of 1:101-1:200 based on multiple-marker screening., Interpretation: After public funding of cffDNA screening was implemented in Ontario, there was a significant increase in cffDNA screening and a significant decrease in prenatal diagnostic testing among women with a positive multiple-marker screening result. These changing patterns show the significant impact of public policy and funding decisions on women's choices regarding prenatal testing., Competing Interests: Competing interests: None declared., (Copyright 2018, Joule Inc. or its licensors.)

MAX giant associated protein (MGA) is a dual transcriptional factor containing both T-box and bHLHzip DNA binding domains. In vitro studies have shown that MGA functions as a transcriptional repressor or activator to regulate transcription of promotors containing either E-box or T-box binding sites. BS69 (ZMYND11), a multidomain-containing (i.e., PHD, BROMO, PWWP, and MYND) protein, has been shown to selectively recognizes histone variant H3.3 lysine 36 trimethylation (H3.3K36me3), modulates RNA Polymerase II elongation, and functions as RNA splicing regulator. Mutations in MGA or BS69 have been linked to multiple cancers or neural developmental disorders. Here, by TALEN and CRISPR/Cas9-mediated loss of gene function assays, we show that zebrafish Mga and Bs69 are required to maintain proper Bmp signaling during early embryogenesis. We found that Mga protein localized in the cytoplasm modulates Bmpr1a activity by physical association with Zmynd11/Bs69. The Mynd domain of Bs69 specifically binds the kinase domain of Bmpr1a and interferes with its phosphorylation and activation of Smad1/5/8. Mga acts to antagonize Bs69 and facilitate the Bmp signaling pathway by disrupting the Bs69-Bmpr1a association. Functionally, Bmp signaling under control of Mga and Bs69 is required for properly specifying the ventral tailfin cell fate.

Objective: Prenatal screening for trisomy 21 is a standard of care. Emerging cell-free fetal DNA (cffDNA) technologies can improve screening performance, but they are expensive. This study was conducted to propose a contingent screening model that would incorporate cffDNA technology, would remain affordable, and could be applied equitably in a publically funded system., Methods: Using performance and cost parameters from published literature, four prenatal screening strategies were compared. Scenario 1 modelled integrated prenatal screening (first trimester nuchal translucency and biochemical markers from both the first and second trimesters) with no cffDNA. Scenarios 2 and 3 modelled first trimester combined screening (FTS) and "enhanced FTS" (adding serum placental growth factor and alpha fetoprotein to FTS), respectively, with contingent cffDNA following a positive result. Scenario 4 modelled cffDNA as the primary screening test., Results: Scenario 1 provides a known detection rate (DR) of 88%, with a false positive rate (FPR) of 3.3%. Scenarios 2 and 3 result in a DR of 94% and overall FPR of 0.59% and 0.33%, respectively, comparable to the DR of 96% and FPR of 0.1% with primary cffDNA (assuming the published test failure rate of 3%). The total cost, cost per woman screened, and cost per case of trisomy 21 detected were lower with scenario 3 (enhanced FTS with contingent cffDNA) compared with primary cffDNA or scenario 2 (FTS with contingent cffDNA)., Conclusion: Enhanced FTS with contingent cffDNA following a positive result provides a similar performance to that of primary cffDNA at a substantially lower cost., (Copyright © 2017 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.)

According to the 2004 American Academy of Pediatrics guideline on the management of hyperbilirubinemia, every newborn should be assessed for the risk of developing severe hyperbilirubinemia with the help of predischarge total serum bilirubin or transcutaneous bilirubin measurements and/or assessments of clinical risk factors. The aim of this rapid review is 1) to review the evidence for 1) predicting and preventing severe hyperbilirubinemia and bilirubin encephalopathy, 2) determining the efficacy of home/community treatments (home phototherapy) in the prevention of severe hyperbilirubinemia, and 3) non-invasive/transcutaneous methods for estimating serum bilirubin level., Methods: In this rapid review, studies were identified through the Medline database. The main outcomes of interest were severe hyperbilirubinemia and encephalopathy. A subset of articles was double screened and all articles were critically appraised using the SIGN and AMSTAR checklists. This review investigated if systems approach is likely to reduce the occurrence of severe hyperbilirubinemia., Results: Fifty-two studies met the inclusion criteria. Included studies assessed the association between bilirubin measurement early in neonatal life and the subsequent development of severe hyperbilirubinemia and chronic bilirubin encephalopathy/kernicterus. It was observed that, highest priority should be given to (i) universal bilirubin screening programs; (ii) implementation of community and midwife practice; (iii) outreach to communities for education of prospective parents; and (iv) development of clinical pathways to monitor, evaluate and track infants with severe hyperbilirubinemia., Conclusions: We found substantial observational evidence that severe hyperbilirubinemia can be accurately predicted and prevented through universal bilirubin screening. So far, there is no evidence of any harm., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

The ability of phagocytes to clear pathogens is an essential attribute of the innate immune response. The role of signaling lipid molecules such as phosphoinositides is well established, but the role of membrane sphingolipids in phagocytosis is largely unknown. Using a genetic approach and small molecule inhibitors, we show that phagocytosis of Candida albicans requires an intact sphingolipid biosynthetic pathway. Blockade of serine-palmitoyltransferase (SPT) and ceramide synthase-enzymes involved in sphingolipid biosynthesis- by myriocin and fumonisin B1, respectively, impaired phagocytosis by phagocytes. We used CRISPR/Cas9-mediated genome editing to generate Sptlc2-deficient DC2.4 dendritic cells, which lack serine palmitoyl transferase activity. Sptlc2-/- DC2.4 cells exhibited a stark defect in phagocytosis, were unable to bind fungal particles and failed to form a normal phagocytic cup to engulf C. albicans. Supplementing the growth media with GM1, the major ganglioside present at the cell surface, restored phagocytic activity of Sptlc2-/- DC2.4 cells. While overall membrane trafficking and endocytic pathways remained functional, Sptlc2-/- DC2.4 cells express reduced levels of the pattern recognition receptors Dectin-1 and TLR2 at the cell surface. Consistent with the in vitro data, compromised sphingolipid biosynthesis in mice sensitizes the animal to C. albicans infection. Sphingolipid biosynthesis is therefore critical for phagocytosis and in vivo clearance of C. albicans.

Cross-presentation is the process by which professional APCs load peptides from an extracellularly derived protein onto class I MHC molecules to trigger a CD8(+) T cell response. The ability to enhance this process is therefore relevant for the development of antitumor and antiviral vaccines. We investigated a new TLR2-based adjuvant, Small Molecule Immune Potentiator (SMIP) 2.1, for its ability to stimulate cross-presentation. Using OVA as model antigen, we demonstrated that a SMIP2.1-adjuvanted vaccine formulation induced a greater CD8(+) T cell response, in terms of proliferation, cytokine production and cytolytic activity, than a non-adjuvanted vaccine. Moreover, using an OVA-expressing tumor model, we showed that the CTLs induced by the SMIP2.1 formulated vaccine inhibits tumor growth in vivo. Using a BCR transgenic mouse model we found that B cells could cross-present the OVA antigen when stimulated with SMIP2.1. We also used a flow cytometry assay to detect activation of human CD8(+) T cells isolated from human PBMCs of cytomegalovirus-seropositive donors. Stimulation with SMIP2.1 increased the capacity of human APCs, pulsed in vitro with the pp65 CMV protein, to activate CMV-specific CD8(+) T cells. Therefore, vaccination with an exogenous antigen formulated with SMIP2.1 is a successful strategy for the induction of a cytotoxic T cell response along with antibody production.