Differential effect of Listeria monocytogenes infection on cytokine production and cytotoxicity of CD8 T cells.
Bacterial infection induces a shift to type 1 CD4 T cell subset in an infected host and this shift is important for protection of the host from disease development. Many researchers think that the shift is antigen-dependent, but we previously demonstrated an initial induction step for CD4 T cell subsets during Listeria monocytogenes (Lm) infection is antigen-independent. Although Listeria is a TLR2 ligand, the immune system of the Lm-infected host responded to the pathogen to induce expression of CD69 but not CD25 on CD4 T cells, CD8 T cells and B cells even in the absence of TLR2 or MyD88. The antigen-independent activation of type 1 CD4 T cells accelerate the clearance of pathogens by activating innate immune cells with type 1 cytokines. Type 1 CD4 T cells and CD8 T cells also collaborate to protect the host from intracellular Lm infection. Since CD8 T cells function mainly as cytotoxic T cells and CD69-positive CD8 T cells increase during Lm-infection, cytotoxic activity of CD8 T cells was evaluated during Lm-infection. Although CD8 T cells were activated to produce IFN-gamma, the cytotoxic function of CD8 T cells in Lymphocytic choriomeningitis virus (LCMV) p14 TCR-transgenic mouse was not augmented by Lm-infection. Therefore, Lm-infection differentially influences on cytokine production and cytotoxicity of CD8 T cells.
Maruyama
Saho
S
Department of Immunology and Host Defenses, Ehime University Graduate School of Medicine, Toon, Ehime, Japan.
Shen
Hua
H
Kanoh
Makoto
M
Matsumoto
Akira
A
Asano
Yoshihiro
Y
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D003602:Cytotoxicity, Immunologic; D007371:Interferon-gamma / Q000378:metabolism; D037181:Lectins, C-Type; D008089:Listeria monocytogenes; D008088:Listeriosis / Q000276:immunology*; D008213:Lymphocyte Activation; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D051379:Mice; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism*; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D016207:Cytokines; D007371:Interferon-gamma; D037181:Lectins, C-Type; D011948:Receptors, Antigen, T-Cell; D000099192:CD69 Antigens