Human cytotoxic T-cells against measles virus-infected and myelin basic protein-coated targets are cross-reactive.

Cytotoxic T lymphocytes (CTL) which recognized measles virus antigens were generated by in vitro sensitization of peripheral blood lymphocytes from normal volunteers against autologous measles virus-infected lymphocytes. Cytotoxicity of measles virus-infected targets by these effectors was considerably enhanced when the effector-target cell mixtures were incubated in presence of 10 or 100 ng myelin basic protein (MBP) for the 3-hour duration of the 51Cr release assay. In most experiments, specific release of radioisotope was doubled or tripled. Bovine serum albumin caused only slight increases in cytotoxicity. The killing of allogeneic target cells by alloimmune CTL was not affected by either of these reagents. Measles-specific CTL were also able to kill target cells that were cultured overnight in presence of MBP but washed prior to the assay. Conversely, CTL generated by culturing lymphocytes in presence of MBP for 6 days were able to kill MBP-coated and measles virus-infected target cells. The implications of these findings in the pathogenesis of multiple sclerosis are discussed.