Studies on Ly-1+B Cells in Autoimmune-prone Strain of MRL/lpr Mice

Abstract

Ly-1 antigen is a surface antigen of murine T cells and is also expressed on the membrane of certain B cell population, especially the B cells in the peritoneal cavity of mice. Ly-1 antigen is the same molecule of CD5 antigen expressed on human T cells and a certain population of human B cells. It is suggested that Ly-l^(+)B cells are possibly involved in the pathogenesis of autoimmune diseases. In the present work, we analysed the profiles of the distribution of Ly-1^(+)B cells in the autoimmune-prone strain of MRL/1pr mice with different ages and normal mice (BALB/c and C57BL/6), because most of the studies for exploring the role of Ly-1^(+)B cells in the pathogenesis of autoimmune diseases have been carried out by using autoimmune-prone NZB-related mice. Two-parameter FACS analysis was used to investigate the percentage of Ly-1^(+)B cell subpopulation in spleens and peritoneal cavities of normal mice and autoimmune-prone MRL/1pr mice with different ages. It is shown that Ly-1^(+)B cell subpopulations in spleens and peritoneal cavities are present in increased number in MRL/lpr mice, suggesting an important role of Ly-1^(+)B cells in autoimmunity. In addition, older MRL/lpr mice showed higher number of Ly-1^(+)B cells as compared with those of young MRL/1pr mice.