Identification of a specific HLA DR2 Ia molecule as a restriction element for measles virus-specific HLA class II-restricted cytotoxic T cell clones

By using a panel of HLA-D-defined subtypes of HLA-DR2 HCL with known β chain structural variabilities, we have demonstrated that HLA-DR2, OKT4⁺ cytotoxic T lymphocyte (CTL) clones specific for measles virus are apparently restricted to a distinct DR β chain. The presence of this DR β molecule correlated precisely with the susceptibility of measles virus-infected HLA-DR2 HCL to lysis by these CTL clones. These studies demonstrate that delineation of HLA-DR2 into various subgroups can have a functional significance that parallels the structural differences within the HLA-D region. These results are discussed in the context of the possible association of HLA class II-restricted, measles virus-specific CTL and multiple sclerosis.