CHARACTERIZATION OF 2 DISTINCT ANTIGENS EXPRESSED ON EITHER RESTING OR ACTIVATED HUMAN B-CELLS AS DEFINED BY MONOCLONAL-ANTIBODIES

  • 1 May 1986
    • journal article
    • research article
    • Vol. 64  (2) , 382-391
Abstract
Two antigen systems (L29 and L30) expressed on two distinct human B cell subpopulations were identified by using BL1-4D6 and TB3-7D5 monoclonal antibodies, respectively. L29 was expressed on approximately one-third of B cells in human lymphoid tissues. These B cells associated with L29 were large activated B cells located in the germinal centres of lymphoid follicles. L30, 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, L30 was shared on mature granulocytes. With the use of polyclonal activators such as pokeweek mitogen (PWM) and protein A-bearing staphylococci (SAC), L29 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, L30 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 L29 and L30 was expressed on normal, non-activated human thymus and peripheral T cells, L29 but not L30 was expressed on concanavalian A-activated T cells. Immunochemical studies showed that L30 consist of a single polypeptide with mol, wt of 40,000. L29 antigen is presently under study.