A new antigen identified by the monoclonal antibody UCHB 1 delivers a costimulatory signal to a subset of human B cells

Eur J Immunol. 1988 Jan;18(1):67-76. doi: 10.1002/eji.1830180111.


A novel anti-B cell monoclonal antibody UCHB1 is described which detects an antigen present on a selected subpopulation of both normal and leukemic B cells. Approximately 20% of normal tonsil and peripheral blood (PB) B cells are UCHB 1+ and the majority of B cells from all cases of prolymphocytic leukemia (PLL) tested, together with a low, variable percentage of PB B cells from non-Hodgkin's lymphoma patients with centroblastic centrocytic leukemia also express this antigen. Chronic lymphocytic leukemia and hairy cell leukemia B cells, pre-B acute lymphoblastic leukemia and Epstein-Barr virus transformed cell lines all lack UCHB 1 positivity as do all non-B lineage leukocytes and cell lines so far tested. In tonsil sections UCHB 1 staining is almost completely confined to surface IgM+ mantle zone lymphocytes and follicular dendritic cells, but not B cells, within the germinal centers. UCHB 1 can induce a rise in the level of intracellular free calcium ([Ca2+]i) in PLL B cells and low concentrations of monoclonal antibody can result in the entry of these cells into cell cycle in the absence of additional factors. The proliferative effect of UCHB 1 is greatly enhanced in the presence of Staphylococcus aureus Cowan and, to a lesser extent, phorbol ester. A similar costimulatory effect is exerted on a proportion of normal tonsil B cells although here, despite inducing a rise in [Ca2+]i, UCHB 1 alone does not cause cells to proliferate. UCHB 1 may well prove to be a useful antibody both to distinguish between different B cell leukemias and to study the phenotype and function of leukemic and normal B cell subpopulations.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / physiology*
  • Antigen-Antibody Reactions
  • Antigens, Differentiation, B-Lymphocyte / analysis*
  • Antigens, Differentiation, B-Lymphocyte / immunology
  • B-Lymphocytes / classification*
  • B-Lymphocytes / immunology
  • B-Lymphocytes / metabolism
  • Calcium / metabolism
  • Cell Cycle
  • Cell Line
  • Humans
  • Intracellular Fluid / metabolism
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred BALB C
  • Palatine Tonsil / cytology
  • Phenotype
  • Receptors, Antigen, B-Cell / analysis
  • Thymidine / metabolism
  • Tumor Cells, Cultured


  • Antibodies, Monoclonal
  • Antigens, Differentiation, B-Lymphocyte
  • Receptors, Antigen, B-Cell
  • Calcium
  • Thymidine