APPLICATION OF 2-COLOR IMMUNOFLUORESCENCE STAINING TO DEMONSTRATION OF T-CELLS AND HLA-DR-BEARING CELLS IN RHEUMATOID SYNOVITIS

We studied the localization of T-cells and HLA-DR antigen-bearing (DR+) cells in rheumatoid synovitis by employing an improved two-color immunofluorescent staining (TCIF) technique. With this technique we have successfully identified DR+ activated T-cells in the inflammatory synovium. T-cells expressed HLA-DR antigen when they were in contact with DR+ antigen-presenting cells (APC). In addition, activated T-cells showed characteristic distribution within the synovium: they were found around high endothelial venules, within lymphoid follicles, and in hyperplastic synovial lining, suggesting their involvement in the development of rheumatoid synovial lesions via interaction with synovial DR+ APC lineage cells. These findings may contribute to better understanding of the role of activated T-cells in the histogenesis of rheumatoid synovitis, a typical chronic inflammatory lesion.