S. Deas1, M. Melendez-Ferro1, V. Yeramilli4, C. Culbreath2, R. Lorenz5, C. Martin1,3 1University Of Alabama at Birmingham,Surgery,Birmingham, Alabama, USA 2Inova Fairfax Hospital,Surgery,Falls Church, VA, USA 3Children’s Of Alabama,Surgery,Birmingham, ALABAMA, USA 4University Of Alabama at Birmingham,Microbiology,Birmingham, Alabama, USA 5University Of Alabama at Birmingham,Pathology,Birmingham, Alabama, USA
Introduction: Psychological and environmental stress have been linked to several health conditions. During pregnancy, stress can negatively affect both the mother and child. Potential psychological stressors include a challenging home environment or life event, substance abuse, or chronic health problems. The impact of maternal psychological stress on the neonatal immune system remains unknown. A key element of immune development in neonates is the transfer of protective antibodies from the mother to the newborn. Specifically, the presence of immunoglobulin A (IgA) and early bacterial colonization are key processes in the development of passive immunity in neonates. IgA protects the mucosal surface of the gut by binding to pathogenic bacteria and preventing colonization; in the early stages of development, it is passed from mother to child in breast milk. The gut microbiome further protects mucosa, and it is primarily transmitted from the vaginal microbiome during passage through the birth canal and feeding. We hypothesize that prenatal psychological stress depresses immune function in the mother, thereby impairing transmission of passive immunity to neonates.
Methods: 8-week-old C57BL/6 littermates underwent timed breeding. The females of three mating pairs were subjected to daily psychological stress by using a well-established restraint model during days 7-14 of the gestational period. The control group experienced no stress. Maternal vaginal microbiome was sampled two days prior to delivery via vaginal lavage; samples were then cultured on Schaedler agar in aerobic conditions for 24 hours at 37°C. Enzyme-linked immunosorbent assay (ELISA) was used to measure fecal IgA levels in in 2-week-old pups.
Results: Two-week-old mice from the stressed group had significantly less fecal IgA compared with the control group; stress group mean = 51658.51 ng/mL, standard error = 11982.92; control group mean = 200320.22 ng/mL, standard error = 57674.83 (P value = 0.0033). Microbial culture of vaginal microbiome from the mother revealed 98 colony forming units (CFUs) for the stressed group, compared to 187 CFUs for the control group (see figure).
Conclusion: Maternal gestational stress results in significantly less fecal IgA in offspring compared to controls. Additionally, stressed dams had lower vaginal bacterial colonization compared to controls, which could explain this finding. Future experiments will further elucidate this mechanism by analyzing serum IgA levels in the pups and stress hormones in dams and pups.
