Abstract
Expression of CD45RB on CD4+ or CD8+ cells in combination with TCRVβ usages (Vβ6, Vβ8.1, Vβ8.2, Vβ11 and Vβ7a) in normal mouse strains (BALB/c and C57BL/6) was compared with autoimmune-prone strains ((NZW × BXSB) F1 and MRL/1pr) at young and old ages. The frequencies, and also the numbers of CD45RB cells in CD4+ T cells with various TcR repertoires was significantly less in the autoimmune-prone strains at old ages, while, in normal control strains, they remained unchanged. Furthermore, CD4+/CD45RB- cells are CD4high and CD62L (L-selectin).low These findings suggest that most T cells, especially CD4+ T cells, in old W/BF1 and old MRL/1pr mice, were activated and this may reflect the elevation of autoantibodies and the progress of autoimmune status in aged autoimmune-prone mice. This will be discussed in relation to the progress of the autoimmune diseases.
Key Words: