Cross-presentation of viral and self antigens by skin-derived CD103⁺ dendritic cells

Nature Immunology 10: 488-95 (2009)

Speaker: Wen-Ling Yeh (葉玟伶)                             Time: 13:00~14:00 Nov. 4, 2009

Commentator: Dr. Ai-Li Shiau (蕭璦莉 老師)     Place: Room 601

Abstract:

Dentritic cell (DC), mainly distributing in spleen, lymph nodes, and skin, is the bridge between innate and adaptive immunity serving an antigen-presenting function to prime T cell immune responses ^[1]. In skin-draining lymph nodes, the DCs population consists of epidermis-derived Langerhans cells (CD205^hiCD8α^-) and dermis-derived DCs (CD205^intCD8α^-). Some studies identified a third skin-associated DC population, unlike Langerhans cells, expresses integrin CD103 ^[2]. The specific functions of these different DCs in immune responses are not well understood. In this study, the authors initially found that HSV-specific CD8⁺ T cells were not only activated in the lymph nodes surrounding the primary infection site (the first phase), but also in the lymph nodes of the secondary skin lesion in response to viral recrudescence (the secondary phase). Further experiments showed that CD8α⁺ DCs mainly induced T cell proliferation during the first phase, but the CD8α^-CD103⁺ DCs which were the subpopulation of CD8α^- dermal DC (dDC) induced T cell proliferation during the secondary phase. They further proved that all DCs including CD103⁺ DCs could activate HSV-specific CD4⁺ T cells and that only CD103⁺ DCs were able to activate HSV-specific CD8⁺ T cells. Moreover, the CD103⁺ DCs from the mice of OVA expressing in epidermal keratinocytes could also activate OVA-specific CD8⁺ T cells. In conclusion, the study indicates that CD103⁺ DCs are the mainly DCs involved in cross-presentation of self and viral antigens, and activation through CD103⁺ DCs may (?) provide a new strategy for vaccine development.

References:

1.      Steinman, R.M, et al. Dendritic cells: versatile controllers of the immune system. Nature Medicine 13: 1155-59 (2007)

2.      Allan, R.S, et al. Epidermal viral immunity induced by CD8α⁺ dendritic cells but not by Langerhans cells. Science 301: 1925-28 (2003)