MEASLES VIRUS-DIRECTED RESPONSES OF CD4-LYMPHOCYTES IN MS PATIENTS AND HEALTHY-INDIVIDUALS( T)

Article abstract-To analyze the antigen specificities of measles virus (MV)-reactive CD4+ T cells in multiple sclerosis (MS) patients as com pared with those of healthy donors, we established 492 MV-reactive sho rt-term T-cell lines (TCL) from blood of 12 MS patients (n = 243 TCL) and 12 healthy subjects (n = 249 TCL). We determined antigen specifici ties of these TCL by proliferative responses to optimal concentrations of recombinant MV structural proteins (MV-SP) and human myelin basic protein (MBP). In both donor groups, there was a dominant reactivity a gainst the MV fusion protein and the MV nucleocapsid protein. However, there was a substantial heterogeneity of T-cellular polypeptide speci ficities among MS patients as well as among healthy individuals, which was true even in subjects sharing identical HLA-DR and HLA-DQ haploty pes. By comparing the T-cell antigen specificity patterns obtained in both donor populations, we found decreased percentages of TCL reactive with the MV fusion protein, the hemagglutinin, and the phosphoprotein in MS patients, but these differences failed to reach statistical sig nificance. None of the 492 MV-specific TCL, nor an additional 276 TCL, showed any reactivity to MBP. Therefore, we did not detect any MS-spe cific pattern of T-cell responses to MV-SP. Furthermore, our study sug gests that mechanisms other than molecular mimic between MV-SP and MBP may cause myelin-directed autoimmunity.