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Background: Cervicovaginal CD4+ T cells are preferential targets for human immunodeficiency virus (HIV) infection and have consequently been used as a proxy measure for HIV susceptibility. The ECHO randomized trial offered a unique opportunity to consider the association between contraceptives and Th17-like cells within a trial designed to evaluate HIV risk. In a mucosal substudy of the ECHO trial, we compared the impact of initiating intramuscular depot medroxyprogesterone acetate (DMPA-IM), copper-IUD, and the levonorgestrel (LNG) implant on cervical T cells., Methods: Cervical cytobrushes from 58 women enrolled in the ECHO trial were collected at baseline and 1 month after contraceptive initiation. We phenotyped cervical T cells using multiparameter flow cytometry, characterized the vaginal microbiome using 16s sequencing, and determined proteomic signatures associated with Th17-like cells using mass spectrometry., Results: Unlike the LNG implant or copper-IUD, DMPA-IM was associated with higher frequencies of cervical Th17-like cells within 1 month of initiation (P = .012), including a highly susceptible, activated population co-expressing CD38, CCR5, and α4β7 (P = .003). After 1 month, women using DMPA-IM also had more Th17-like cells than women using the Cu-IUD (P = .0002) or LNG implant (P = .04). Importantly, in women using DMPA-IM, proteomic signatures signifying enhanced mucosal barrier function were associated with the increased abundance of Th17-like cells. We also found that a non-Lactobacillus-dominant microbiome at baseline was associated with more Th17-like cells post-DMPA-IM (P = .03), although this did not influence barrier function., Conclusions: Our data suggest that DMPA-IM-driven accumulation of HIV-susceptible Th17-like cells might be counteracted by their role in maintaining mucosal barrier integrity., Clinical Trials Registration: NCT02550067., Competing Interests: Potential conflicts of interest. J.-A. S. P. reports the following grants or contracts all paid to the author’s institution and unrelated to this work: Bill and Melinda Gates Foundation (BMGF) Vaginal Microbiome Research Consortium (VMRC) Planning Grant (Principal Investigator [PI]: Dr Jo-Ann Passmore. Co-PI: Dr Leila Mansoor; Co-Investigators: Nigel Garrett, Cheryl Baxter, Sinaye Ngcapu, Lenine Liebenberg, Aida Sivro, Brian Kullin, Anna Happel. US $512 088 for 12 months); European and Developing Countries Clinical Trials Partnership (EDCTP) RIA2020I (3297) for project entitled “GIFT for HIV Prevention” (Passmore, Co-PI: Masson (Burnett Institute, Australia); Co-Investigators: Suzanna Francis and Katharina Kranzer (The London School of Hygiene & Tropical Medicine, UK), Janneke van der Wijgert (University Medical Center, Netherlands), Tania Crucitti (Institute Pasteur Madegascar, Madagascar), David Anderson (Burnet Institute, Australia), Ayako Honda (Sophia University, Japan), Chido Dziva-Chikwari (The Organization for Public Health Interventions and Development, Zimbabwe), Katherine Gill (Desmond Tutu Health Foundation, South Africa) (Euro 3 508 462 for 36 months); BMGF Calestous Juma Scientific Leadership Award for project entitled “VMRC4Africa” (PI: Passmore. US $1 million over 5 years); and Medical Research Council Strategic Health Innovation Partnerships (South Africa), Genital inflammation test for females (GIFT) (PIs: Dr Jo-Ann Passmore and Dr Lindi Masson, ZAR 5 million per year for 4 years). J.-A. S. P. also reports a patent granted in 2022 with no payment made (Method for diagnosing an inflammatory condition in the female genital tract; PCT/IB2014/065740; EP3063542B1); and unpaid participation on a Data Safety Monitoring Board (DSMB) or Advisory Board for a phase 2 placebo-controlled randomized trial of LACTIN-V (Lactobacillus crispatus CTV-05) among women at high risk of HIV acquisition in Durban, South Africa (Chair DSMB; Cohen et al National Institute of Child Health and Human Development [NICHD] grant 1R01HD098978). R. H. reports grants or contracts unrelated to this work and paid to the author’s institution from the NICHD. H. J. reports support for attending meetings and/or travel from World Vaccine Congress. S. E. B. reports grants or contracts unrelated to this work from the National Institutes of Health (NIH R01 HD089831): Effects of Hormonal Contraceptives on Genital Immunity and HIV Susceptibility. B. P. B. reports support for attending meetings and/or travel (NIH R01HD089831). J. M. H. reports grants to institution unrelated to this work from the NIH, USAID, and BMGF; and employment (with stocks and stock options) with Gilead Sciences. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

The role of Myeloid-Derived Suppressor Cells (MDSC) in infant immune ontogeny is unknown. Here, we evaluated MDSC frequency and relationship with infant vaccine responses throughout the first year of life in a prospective cohort study. Ninety-one South African infant-mother pairs were enrolled at delivery, and blood samples were collected at 0, 6, 10, and 14 weeks, 6 months, 9 months, and 1 year. MDSC frequencies were quantified, and immune responses to the childhood vaccines Bacillus Calmette-Guérin (BCG), hepatitis B (HepB), and combination diphtheria, tetanus, and pertussis (dTaP) were measured by Ag-specific CD4 + T cell proliferation and interferon gamma (IFN-γ) production. Vaccine-specific Ab responses to HepB, dTaP, and Haemophilus influenzae type b (Hib) were quantified via Enzyme-Linked Immunosorbent assay (ELISA). MDSC frequency in mother-infant pairs was strongly correlated; the frequency of MDSC decreased in both mothers and infants during the months after delivery/birth; and by 1 year, infant MDSC frequencies rebounded to birth levels. Higher MDSC frequency at vaccination was associated with a lack of subsequent IFN-γ release in response to vaccine Ags, with the exception of BCG. With the exception of a weak, positive correlation between MDSC frequency at 6 weeks (time of initial vaccination) and peak Hepatitis B surface antigen Ab titer, Polymorphonuclear Myeloid-Derived Suppressor Cells (PMN-MDSC) was not correlated with T cell proliferation or Ab responses in this study. The potential for MDSC-mediated suppression of vaccine Ag-specific IFN-γ responses should be explored further, and considered when evaluating candidate infant vaccines., (©2021 Society for Leukocyte Biology.)

Microbiota from various maternal sites, including the gut, vagina and breast milk, are known to influence colonization in infants. However, emerging evidence suggests that these sites may exert their influence prior to delivery, in turn influencing fetal immune development. The dogma of a sterile womb continues to be challenged. Regardless, there is convincing evidence that the composition of the maternal gut prior to delivery influences neonatal immunity. Therefore, while the presence and function of placental microbiome is not clear, there is consensus that the gut microbiota during pregnancy is a critical determinant of offspring health. Data supporting the notion of bacterial translocation from the maternal gut to extra-intestinal sites during pregnancy are emerging, and potentially explain the presence of bacteria in breast milk. Much evidence suggests that the maternal gut microbiota during pregnancy potentially determines the development of atopy and autoimmune phenotypes in offspring. Here, we highlight the role of the maternal microbiota prior to delivery on infant immunity and predisposition to diseases. Moreover, we discuss potential mechanisms that underlie this phenomenon., (© 2019 British Society for Immunology.)

Sixty-six children who were receiving antiretroviral treatment were assessed for treatment adherence and virological outcome to compare boosted protease inhibitor-based regimens with nonnucleoside reverse-transcriptase inhibitor-based regimens. Children who were receiving protease inhibitor-based regimens demonstrated higher rates of virological suppression, even with poor treatment adherence (<80%). In children, boosted protease inhibitors seem to be more forgiving of poor adherence than do nonnucleoside reverse-transcriptase inhibitors.