AUTHOR=Harker James A. , Greene Trever T. , Barnett Burton E. , Bao Phuc , Dolgoter Aleksandr , Zuniga Elina I. TITLE=IL-6 and IL-27 play both distinct and redundant roles in regulating CD4 T-cell responses during chronic viral infection JOURNAL=Frontiers in Immunology VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2023.1221562 DOI=10.3389/fimmu.2023.1221562 ISSN=1664-3224 ABSTRACT=

The IL-6 cytokine family signals through the common signal transduction molecule gp130 combined with a cytokine-specific receptor. Gp130 signaling on CD4 T cells is vital in controlling chronic infection of mice with lymphocytic choriomeningitis virus clone 13 (LCMV Cl13), but the precise role of individual members of the IL-6 cytokine family is not fully understood. Transcriptional analysis highlighted the importance of gp130 signaling in promoting key processes in CD4 T cells after LCMV Cl13 infection, particularly genes associated with T follicular helper (Tfh) cell differentiation and IL-21 production. Further, Il27r−/−Il6ra−/− mice failed to generate antibody or CD8 T-cell immunity and to control LCMV Cl13. Transcriptomics and phenotypic analyses of Il27r−/−Il6ra−/− Tfh cells revealed that IL-6R and IL-27R signaling was required to activate key pathways within CD4 T cells. IL-6 and IL-27 signaling has distinct and overlapping roles, with IL-6 regulating Tfh differentiation, IL-27 regulating CD4 T cell survival, and both redundantly promoting IL-21.