Foreign epitope-specific regulatory T cells respond robustly to vaccination and limit Th1 differentiation by conventional T cells specific for the same epitope

• Published in: The Journal of immunology (1950) Vol. 204; no. 1_Supplement; pp. 230 - 230.21
• Main Authors: Krueger, Peter D, Jenkins, Marc K
• Format: Journal Article
• Language: English
• Published: 01.05.2020
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.204.Supp.230.21

Abstract CD4+ naïve T cell populations specific for MHCII-bound foreign peptides contain FOXP3− conventional (Tconv) cells and less abundant FOXP3+ regulatory (Treg) cells. Little is known about how naïve Treg cells respond to foreign peptides and for what purpose given that their activation might impede immunity. We addressed this issue by tracking naïve T cells after vaccination with a foreign peptide in an oil-based adjuvant. The Tconv and Treg naïve cells specific for the peptide proliferated extensively during the first week after vaccination. The Tconv population generated only Tconv progeny, mainly of the T helper 1 (Th1) and follicular helper (Tfh) varieties. Most of the naïve Treg cells formed Th1- or T helper 17 (Th17)-like Treg progeny while a minority lost FOXP3 and adopted a Tfh phenotype. The Treg progeny limited the formation of conventional Th1 cells in peptide-specific manner. Thus, foreign peptide-specific naïve Treg cells undergo a robust primary response that generates progeny resembling Th1 and Th17 cells that limit differentiation of their conventional Th1 counterparts.