CYTOTOXIC AND INTERFERON-GAMMA-PRODUCING ACTIVITIES OF GAMMA-DELTA-T-CELLS IN THE MOUSE INTESTINAL EPITHELIUM ARE STRAIN-DEPENDENT

We have analyzed the cytolytic activity of freshly isolated intraepithetial T cells (i-IEL) from the intestines of several different mouse strains in an anti-T-cell receptor monoclonal antibody-mediated redirected lysis assay. The cytolytic activity of gammadelta i-IEL but not that of alphabeta i-IEL was strain dependent. Mouse strains could be divided into high (H), marginal (M), and null (N) strains. The anti-gammadelta T-cell receptor monoclonal antibody-induced interferon gamma production showed the same strain-dependent variability, but the protiferative responses to gammadelta T-cell receptor crosslinking did not show this variability. The N phenotype of gammadelta i-IEL was found to be dominant in (H x N)F1 mice. In radiadon bone-marrow chimeras the H/N phenotype was determined by the genotype of the reconstituting bone-marrow-derived cells but was not determined by the genotype of the radioresistant host cells. Analysis of (H x N)F1 backcross animals indicated that at least two genes are involved in determination of the H/N phenotype. One of these genes is major-histocompatibility-complex linked. No difference in the use of the variable region segment of the gamma-chain or delta-chain was seen between the gammadelta i-IEL from H and N strains. Various models that might explain the strain-dependent gammadelta i-IEL phenotypes are discussed.