Development and cytolytic function of intestinal intraepithelial T lymphocytes in antigen-minimized mice.
Intraepithelial T lymphocytes in the small intestine (IEL) consist of alpha beta T-cell receptor (TCR)-bearing T cells (alpha beta-IEL) and gamma delta TCR-bearing T cells (gamma delta-IEL). Development and cytolytic activation of alpha beta-IEL sharply attenuate in germ-free (GF) mice fed a natural diet (Nat-GF), but the number and cytotoxicity of gamma delta-IEL are comparable between conventional (CV) and Nat-GF mice. In this report, we compared the properties of IEL in Nat-GF mice and GF mice fed antigen-minimized diet (AgM-GF mice) of C57BL/6 strain to evaluate an influence of gut antigenic load on IEL development. Numbers of alpha beta-IEL and gamma delta-IEL in AgM-GF mice were less by 1.9- and 1.4-fold than those in Nat-GF mice, respectively. Significant decreases in the proportions of CD4+8-, CD4-8 alpha beta +, and CD4+8+ subsets and a resultant increase in the ratio of CD4-8 alpha alpha + subset were evident in alpha beta-IEL of Nat-GF mice compared with CV mice, but the subset constitution of alpha beta-IEL was similar between Nat-GF and AgM-GF mice. In contrast, relative composition of gamma delta-IEL was not different between CV, Nat-GF, and AgM-GF mice. alpha beta-IEL displayed low cytolytic activity in Nat-GF mice and were almost deprived of their cytotoxicity under the antigen-minimized condition. While gamma delta-IEL were strongly cytolytic in Nat-GF mice their cytolytic activity was remarkably reduced in AgM-GF mice. These results indicate that gamma delta-IEL are activated independently of microbial colonization in the gastrointestinal tract but their activation occurs in response to the exogenous antigenic substances other than live micro-organisms.
Kawaguchi-Miyashita
M
M
Yakult Central Institute for Microbiological Research, Tokyo, Japan.
Shimizu
K
K
Nanno
M
M
Shimada
S
S
Watanabe
T
T
Koga
Y
Y
Matsuoka
Y
Y
Ishikawa
H
H
Hashimoto
K
K
Ohwaki
M
M
D000818:Animals; D000941:Antigens / Q000008:administration & dosage* / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D004032:Diet; D004848:Epithelium / Q000276:immunology; D005260:Female; D005856:Germ-Free Life; D007413:Intestinal Mucosa / Q000276:immunology*; D007421:Intestine, Small / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000941:Antigens; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta