CD70⁺ antigen-presenting cells control the proliferation and differentiation of T cells in the intestinal mucosa

Nature Immunology 6, 698 - 706 (2005)

Speaker：吳得嘉                       Time：15:10~16:00, Sep. 14, 2005

Commentator：林以行老師               Place：Room 601

Abstract :

The immune system in the intestinal mucosa distinguish pathogenic microorganisms from commensal bacteria and food antigens. Thus, the immunity can respond appropriately for pathogen clearance, but not eliciting inflammation during taking up food antigens. Functionally, slpenic DCs which provide stimulatory environment differ from the Peyer’s patch DCs that provide inhibitory milieu. Although the presence of tolerogenic subsets in the gut mucosa has been reported in previous study, the issue of where and how the intestinal T cells activated has remained controversial. Because there were other studies which had mentioned CD70-CD27 interaction being able to promote the generation of effector T cells with cytolytic function and the capacity to secret IFN-γ, the authors hypothesized that a unique antigen-presenting cell population which could constitutive express CD70 in intestinal mucosa may control the proliferation and differentiation of T cells in situ. First of all, the authors identify a unique nonhematopoetic cell that constitutively express the costimulatory molecule CD70 in the gut lamina propria. The CD70-expressing cell population show antigen presenting and phagocytic function. After orally infection with Listeria monocytogenes, the main proliferation and differentiation of antigen-specific T cells occurs in the intestinal mucosa where the CD70⁺ APCs reside. Besides, treatment with anti-CD70 abrogates T cell proliferation in the lamina propria and intraepithelial lymphocyte compartment. These findings may help elucidate how a stimulatory immune response can be generated in the generally suppressive environment of the gut mucosa.

References :

1.      Amale Laouar, Viraga Haridas, Dorothy Vargas et al. CD70⁺ antigen-presenting cells control the proliferation and differentiation of T cells in the intestinal mucosa. Nat. Immunol. 6, 698−706 (2005).

2.   Cecilia Johansson & Brian L Kelsall  Affecting the effectors: a kick in the gut? Nature Immunology 6, 644 - 646 (2005)