CD40L Expression Allows CD8 + T Cells to Promote Their Own Expansion and Differentiation through Dendritic Cells

• Published in: Frontiers in immunology 2017-11, Vol.8, p.1484-1484
• Main Authors: Tay, Neil Q, Lee, Debbie C P, Chua, Yen Leong, Prabhu, Nayana, Gascoigne, Nicholas R J, Kemeny, David M
• Format: Article
• Language: English
• Subjects: CD40; CD40L; CD8+ T cells; cell differentiation; cell proliferation; dendritic cells; Immunology
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2017.01484

CD8 T cells play an important role in providing protective immunity against a wide range of pathogens, and a number of different factors control their activation. Although CD40L-mediated CD40 licensing of dendritic cells (DCs) by CD4 T cells is known to be necessary for the generation of a robust CD8 T cell response, the contribution of CD8 T cell-expressed CD40L on DC licensing is less clear. We have previously shown that CD8 T cells are able to induce the production of IL-12 p70 by DCs in a CD40L-dependent manner, providing some evidence that CD8 T cell-mediated activation of DCs is possible. To better understand the role of CD40L on CD8 T cell responses, we generated and characterized CD40L-expressing CD8 T cells both and . We found that CD40L was expressed on 30-50% of effector CD8 T cells when stimulated and that this expression was transient. The expression of CD40L on CD8 T cells promoted the proliferation and differentiation of both the CD40L-expressing CD8 T cells and the bystander effector CD8 T cells. This process occurred a cell-extrinsic manner and was mediated by DCs. These data demonstrate the existence of a mechanism where CD8 T cells and DCs cooperate to maximize CD8 T cell responses.