Migration and function of Th17 cells and PD-1+ T cells

Chuanwu Wang, Purdue University

Abstract

My study has been focused mainly on IL-17-producing T helper (Th17) cells and PD-1+ T cells. Th17 cells regulate anti-pathogenic and inflammatory responses, whereas PD1+ T cells regulate B cell response. In part one, I examined the migration behavior and trafficking receptors of Th17 cells to mucosal tissues. We found that Th17 cells preferentially migrate to the intestine and associated-lymphoid tissues, and CCR6 regulates Th17 cell migration to the gut and effector T cell balance/distribution in inflamed intestine. In part two, I studied the roles of vitamin A and retinoic acid in generation of inflammatory Th17 cells with distinct tissue tropisms within the intestine. We found that Th17 cells with distinct tissue tropisms and pathogenic activities are generated depending on the available concentration of retinoic acid (RA). In part three, I investigated the function of PD-1-expressing T cells in regulation of human follicular T helper cells. We found that there are three different PD-1-expressing memory T cell subsets (i.e. PD-1 low (+), PD-1medium (++), and PD-1high (+++) cells) in human tonsil. We found that these three PD-1-expressing T cell subsets are differentially localized in tonsils and have different functions. Moreover, we found that PD-1 restrains the B cell-helping function of germinal center-localized T cells to prevent excessive antibody response. Taken together, the research results indicate that T cells are highly heterogeneous in effector function and they have distinct migration capacities that determine the tissue sites of their effector functions.

Degree

Ph.D.

Advisors

Kim, Purdue University.

Subject Area

Cellular biology|Immunology

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