Immunologic differences in murine glial cells and their association with susceptibility to experimental allergic encephalomyelitis

We tested the hypothesis that glial cells from mice resistant or susceptible to the autoimmune disease experimental allergic encephalomyelitis (EAE) may differ in their abilities either to express Ia antigens and/or stimulate anti-class II (Ia)-specific T-cells. Ia antigens were induced on glial cells from EAE-susceptible (SJL/J) and -resistant (B10.S and DBA/2) strains of mice by culture with lymphokines from activated T-cells (2 degrees SN). Ia antigen expression was quantified with an enzyme-linked immunosorbent assay (ELISA) in which glia were exposed to monoclonal anti-Ia antibodies and alkaline phosphatase-labeled anti-mouse Ig antibodies. The ability of glial cells to stimulate anti-Ia T-cells was quantified by culturing irradiated glial cells with anti-Ia-specific T-cell lines and measuring the amounts of [3H]thymidine incorporated by these lines. Glial cells from all strains of mice could be induced to express Ia antigens and upon exposure to high concentrations of lymphokines, amounts of expressed Ia antigen were equivalent. However, at limiting lymphokine concentrations, glia from the EAE-resistant strain B10.S expressed greater amounts of Ia antigen than did glia from SJL/J mice (p less than 0.05), suggesting that B10.S glia were more sensitive to the Ia-inducing effects of T cell lymphokines. In contrast to the above results, glia from EAE-susceptible SJL mice consistently demonstrated an increased ability to induce T-cell proliferation in lines specific for Ias antigen, compared to glia from EAE-resistant mice, even those of the same Ia haplotype (i.e. B10.S). Spleen cells from resistant strains had equivalent and frequently greater ability to induce anti-Ia-specific T-cell proliferation than did SJL spleen cells. These data suggest (a) that there are differences in the sensitivity of glia from different strains of mice to the Ia antigen-inducing effects of T-cell lymphokines, (b) that expression of Ia antigen does not necessarily correlate with the ability to stimulate Ia-specific T-cells, (c) that there are organ-specific differences in the ability to stimulate Ia antigen-specific T-cells, and (d) that an additional variable involved in determining resistance or susceptibility to an organ-specific autoimmune disease may be the ability of the target organ to stimulate anti-Ia-specific T-cells.