Characterization of two distinct antigens expressed on either resting or activated XXXX B cells as defined by monoclonal antibodies.

@entity1 @entity48659 @entity48660
Two antigen systems ( @entity48660 _ @entity48659 ) expressed on two distinct @entity1 B cell subpopulations were identified by using BL1-4D6 and TB3-7D5 monoclonal antibodies, respectively. @entity48660 was expressed on approximately one-third of B cells in @entity1 lymphoid tissues. These B cells associated with @entity48660 were large activated B cells located in the germinal centres of lymphoid follicles. @entity48659 , on the other hand, existed on approximately two-thirds of B cells mainly located in the mantle zone of lymphoid follicles, most of which also expressed IgM and IgD on their cell membrane. In addition, @entity48659 was shared on mature granulocytes. With the use of polyclonal activators such as pokeweek mitogen (PWM) and protein A-bearing staphylococci (SAC), @entity48660 antigen was inducible on PWM- or SAC-stimulated B cells in correspondence with the emergence of Tac and T10 antigens of these B cells. In contrast, @entity48659 antigen on the B cells stimulated by the polyclonal activators was decreased in its expression and was finally lost from these B cells. Although none of @entity48660 and @entity48659 was expressed on normal, non-activated @entity1 thymus and peripheral T cells, @entity48660 but not @entity48659 was expressed on concanavalin A-activated T cells. Immunochemical studies showed that @entity48659 consist of a single polypeptide with mol. wt of 40,000. @entity48660 antigen is presently under study.
