Early-life stress reduces viral lung infection severity in adult male rats, but not females 2286

Description Impact of stress on immunity is increasingly recognized, especially in adults. Acute stress increases the innate inflammatory response, more in women than men, whereas chronic stress is linked to immunosuppression. Our group showed that early-life stress has long-term, sex-specific impacts on brain functions. However, few studies examine the long-term effects of early-life stress on adult immune response. The objective of this study was therefore to assess sex-specific impacts of neonatal stress on adult antiviral response using a neonatal maternal separation (NMS) rat model. Sprague Dawley pups were separated from their mother for 3h daily from postnatal days 3 to 12. At 8 weeks, rats were infected intranasally with Sendai virus. Viral load and acute inflammatory antiviral response was analyzed by flow cytometry at 4 days post-infection (DPI). Data from NMS rats were compared to controls. At 4 DPI, male NMS rats had lower viral loads, and recruitment of neutrophils and inflammatory macrophages than male CTRL rats and female NMS rats. Both male and female NMS rats showed lower proportions of interstitial macrophages compared to their non-stressed counterparts. Additionally, proportions of CD8+ and CD4+ T lymphocytes were higher in male CTRL rats than in female CTRL rats, and reduced in male SMN rats. Thus, early-life stress has a sex-specific impact on antiviral response later in life, while further research is needed to determine the underlying molecular mechanisms involved. Funding Sources Supported by Canadian Institutes of Health Research Topic Categories Viral Immunology (VIR)