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Demonstration of strong enterobacterial reactivity of CD4 + CD25 – T cells from conventional and germ‐free mice which is counter‐regulated by CD4 + CD25 + T cells
Author(s) -
Gad Monika,
Pedersen Anders Elm,
Kristensen Nanna N.,
Claesson Mogens H.
Publication year - 2004
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.200324394
Subject(s) - il 2 receptor , biology , antigen , microbiology and biotechnology , interleukin 21 , t lymphocyte , t cell , immune system , immunology , cd8
Abstract Unfractionated CD4 + T cells from the gut‐associated lymphoid tissue (GALT) and peripheral lymph nodes are unresponsive when exposed to enterobacterial antigens in vitro . Under similar conditions, CD4 + T cells depleted in vivo or in vitro of CD4 + CD25 + T cells proliferate extensively. The CD4 + CD25 – T cell reactivity depends on MHC class II presentation, specific TCR stimulation, CD4 ligation, and antigen processing by antigen‐presenting cells. The CD4 + CD25 – T cells respond to autologousand heterologous enterobacterial antigens, but not to antigens from the feces of germ‐free mice. Surprisingly, CD4 + CD25 – T cells obtained from the GALT of germ‐free mice also proliferate when exposed to enterobacterial antigens, and adding back the conventional or germ‐free CD4 + CD25 + T cells to the enteroantigen‐stimulated CD4 + CD25 – T cells abolishes proliferation. As judged from carboxyfluorescein diacetate succinimidyl ester‐labeling experiments, 4–5% of the CD4 + CD25 – T cells respond to enteroantigen. The data show for the first time that CD4 + CD25 – T cells with reactivity towards the enterobacterial flora and regulatory CD4 + CD25 + T cells are present in both conventional and germ‐free mice. The data suggest that a significant proportion of the peripheral pool of CD4 + CD25 – T cells express anti‐enterobacterial reactivity, which, due to the presence of regulatory CD4 + CD25 + T cells, is kept in a quiescent state.