Regulatory T cells restrict immunity and pathology in distal tissue sites following a localized infection

• Published in: Mucosal immunology Vol. 17; no. 5; pp. 923 - 938
• Main Authors: Graham, Jessica B., Swarts, Jessica L., Koehne, Amanda L., Watson, Christine E., Lund, Jennifer M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2024
• Subjects: Animals; CD8-Positive T-Lymphocytes - immunology; Central Nervous System - immunology; Central Nervous System - pathology; Cytokines - metabolism; Disease Models, Animal; Female; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; T-Lymphocytes, Regulatory - immunology; Vagina - immunology; Vagina - pathology; Vagina - virology; Zika Virus - immunology; Zika Virus Infection - immunology
• ISSN: 1933-0219; 1935-3456; 1935-3456
• DOI: 10.1016/j.mucimm.2024.06.007

[Display omitted] •Regulatory T cells (Tregs) are required to generate a robust antigen-specific response at mucosal infection sites.•Tregs restrict interleukin-15 and bystander activation of cluster of differentiation 8+ T cells at tissue sites.•Treg-mediated limitation of persistent bystander inflammation limits immunopathology. Regulatory T cells (Tregs) are well-known to mediate peripheral tolerance at homeostasis, and there is a growing appreciation for their role in modulating infectious disease immunity. Following acute and chronic infections, Tregs can restrict pathogen-specific T cell responses to limit immunopathology. However, it is unclear if Tregs mediate control of pathology and immunity in distal tissue sites during localized infections. We investigated the role of Tregs in immunity and disease in various tissue compartments in the context of “mild” vaginal Zika virus infection. We found that Tregs are critical to generating robust virus-specific CD8 T cell responses in the initial infection site. Further, Tregs limit inflammatory cytokines and immunopathology during localized infection; a dysregulated immune response in Treg-depleted mice leads to increased T cell infiltrates and immunopathology in both the vagina and the central nervous system (CNS). Importantly, these CNS infiltrates are not present at the same magnitude during infection of Treg-sufficient mice, in which there is no CNS immunopathology. Our data suggest that Tregs are necessary to generate a robust virus-specific response at the mucosal site of infection, while Treg-mediated restriction of bystander inflammation limits immunopathology both at the site of infection as well as distal tissue sites.