Anti-IL-10 Antibody Enhances the Proliferation of CD8+ T Cell Clones: Autoregulatory Role of Murine IL-10 in CD8+ T Cells

All CD8+ T cell clones used in this study secreted IL-10, and their proliferation was inhibited by exogenous IL-10. This study addresses the question of whether IL-10 produced by responding T cell clones would inhibit proliferation of the secreting T cells themselves. Anti-IL-10 antibodies enhanced the proliferative response of the CD8+ T cell clones, the enhancing effect appearing in the late period of proliferation. However, the proliferation of both CD4+ Th1 and Th2 clones was not affected by anti-IL-10 throughout the culture. In addition to that of the cloned T cells, the proliferative response of a primary culture of CD8+ T cells was enhanced by the anti-IL-10 antibody. This is the first report on a lymphokine which has an autoregulatory role in inhibiting T cell proliferation.