CD5(-) B1-LIKE LYMPHOCYTES IN HEALTHY GUINEA-PIG() AND CD5()

Spleen, lymph node, and peripheral blood lymphocytes from healthy guin ea pigs (gp) were examined for their ability to produce polyreactive a utoantibodies to a battery of self-antigens and to cryptic determinant s (phosphatidylcholine) on bromelain-treated mouse red blood cells (Br -MRBC). The mouse monoclonal antibody (Mab) 8BE6 anti-gp pan-T (CD5) m arker was used for identification of CD5(+) B1 cells by the plaque-for ming assay (PFC), immunofluorescence, complement-mediated cytotoxicity , and immunocytochemistry. The detection of CD5(+) cells by the 8BE6 M ab depended on the method used. They were better demonstrated by cytol ysis and immunocytochemistry than by FAGS analysis. By the latter meth od, the level of the CD5(+) B cell subpopulation was associated neithe r with the age of the gp nor with the organ examined. Similarly wide r anges of PFC were detected in untreated or LPS-treated animals regardl ess of age and organ. The vast majority of the LPS-stimulated IgM anti body-secreting B lymphocytes reacting with the Br-MRBC, and those prod ucing natural autoantibodies, did not bind the 8BE6 Mab. (C) 1997 Acad emic Press.