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

Abstract

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.

• Authors: R J Armitage, D J Rowe, P C Beverly
• Journal: European journal of immunology (Eur J Immunol) Vol. 18 Issue 1 Pg. 67-76 (Jan 1988) ISSN: 0014-2980 [Print] Germany
• PMID: 3257923 (Publication Type: Journal Article)

Chemical References

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

Topics

• Animals
• Antibodies, Monoclonal (physiology)
• Antigen-Antibody Reactions
• Antigens, Differentiation, B-Lymphocyte (analysis, immunology)
• B-Lymphocytes (classification, immunology, 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