Na Xiong, PhD

Research:

Our research interests concern development and function of γδ T cells, a class of immune cells with various roles in microbial immunity, regulation of inflammation, tumor surveillance and others. Unlike conventional αβ T cells, γδ T cells preferentially reside in epithelial tissues covering the surface of a body, where they function in the first line of defense. Using transgenic and knockout mouse models as experimental approaches, we try to uncover molecular mechanisms underlying development of tissue specific γδ T cells and define their functional mechanism in infection and inflammation.

Molecular mechanism of skin γδ T cell development
Murine skin γδ T cells are the most representative of tissue specific γδ T cells. They reside in epidermal layer of the skin and are involved in preventing cutaneous tumorigenesis, controlling skin inflammation, wound healing and others. All the skin γδ T cells express identical γδ T cell receptors (TCR) composed of canonical Vγ3+ TCRγ and Vδ1+ TCRδ chain and originate from the fetal thymus. Recently, we discovered that positive selection of the Vγ3+/Vδ1+ γδ T cells in the fetal thymus results in a coordinate switch in expression of a set of chemokine and cytokine receptors, which in turn direct migration and expansion of the positively selected γδ T cells in the skin (Figure 1). This finding establishes that central thymic selection of γδ T cells play an important role in their peripheral tissue distribution, a novel advance in understanding development of tissue-specific T cells. The future research will focus on molecular events involved in the TCR-mediated positive selection, regulation of the chemokine receptor expression and its roles in skin γδ T cell development.