{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T13:52:07Z","timestamp":1786715527494,"version":"build-2736575974"},"reference-count":0,"publisher":"Scientific Archives","issue":"2","license":[{"start":{"date-parts":[[2025,1,1]],"date-time":"2025-01-01T00:00:00Z","timestamp":1735689600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.scientificarchives.com\/about-us"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Cell Immunol"],"abstract":"<jats:p>Using four core genotypes (FCG) mice, we have previously shown a larger number of CD4+ and CD8+ T cells in the spleens of female mice, a sex difference that develops by postnatal day 7 and is retained through adulthood. This difference in splenic T cell number is a consequence of reduced thymic egress and reduced splenic seeding in male mice, caused in part by the male-specific perinatal surge of testosterone, and in part by Sry, which is overexpressed in this model. Here, we used the background strain for FCG mice (C57BL\/6J) to ask whether sex influenced actual immunity in the postnatal period. Pups were immunized on postpartum days 1 or 3 with Mycobacterium tuberculosis (Mtb), challenged on day 7 with Mtb purified protein derivative (PPD), and sacrificed on day 8. Subsequent ex vivo challenges of splenocytes showed PPD-stimulated CD8+ responses (increased CD8+, increased CD8+CD44hi, decreased CD8+CD44hiCD127-\/lo) but no differences between males and females. However, when CD8+ T cells were analyzed for IFN-\u03b3 and IL-2 production, although there was no sex difference in mono-functional IFN-\u03b3+ (100%) or IL-2+ (67%), only females (0% of males and 42% of females) produced bi-functional (IFN-\u03b3+IL-2+) cells. Ex vivo PPD-stimulated responses of other relevant cells from the spleen showed no sex differences in dendritic cells (CD11c+CD86+IL-6+) but females had more (3-fold) IL-6-producing macrophages (F4\/80+CD86+IL-6+) and reduced T regulatory cells (CD4+CD25+Foxp3+). We conclude that some sex differences in immunity are evident at one week of age in Mtb immunized mouse pups, with females exhibiting qualitatively superior Mtb-specific immune responses.<\/jats:p>","DOI":"10.33696\/immunology.7.225","type":"journal-article","created":{"date-parts":[[2025,7,3]],"date-time":"2025-07-03T05:18:08Z","timestamp":1751519888000},"page":"52-63","source":"Crossref","is-referenced-by-count":2,"title":["The Ability of Neonatal Mice to Develop Immunity to Mycobacterium tuberculosis Shows Sex Differences, with Females Displaying Evidence of an Enhanced Immune Response"],"prefix":"10.33696","volume":"7","author":[{"given":"Mrinal K.","family":"Ghosh","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ameae M.","family":"Walker","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"18993","published-online":{"date-parts":[[2025]]},"container-title":["Journal of Cellular Immunology"],"original-title":[],"language":"en","deposited":{"date-parts":[[2025,7,3]],"date-time":"2025-07-03T05:18:08Z","timestamp":1751519888000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.scientificarchives.com\/article\/the-ability-of-neonatal-mice-to-develop-immunity-to-mycobacterium-tuberculosis-shows-sex-differences-with-females-displaying-evidence-of-an-enhanced-immune-response"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025]]},"references-count":0,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025]]}},"URL":"https:\/\/doi.org\/10.33696\/immunology.7.225","relation":{},"ISSN":["2689-2812"],"issn-type":[{"value":"2689-2812","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025]]}}}