Accession Number:

ADA230045

Title:

Activation of Human B Lymphocytes by Nanogram Concentrations of Anti- IgM-Dextran Conjugates

Descriptive Note:

Journal article

Corporate Author:

NAVAL MEDICAL RESEARCH INST BETHESDA MD

Report Date:

1990-01-01

Pagination or Media Count:

7.0

Abstract:

Surface immunoglobulin sIg cross-linking on B lymphocytes by high concentrations of anti-Ig antibody has been used to mimic antigen-stimulated B cell activation. In order to develop a system to study sIg-medicated T cell- independent B cell activation using low concentrations of antigen that are achieved under in vivo conditions, we conjugated monoclonal anti-human IgM antibody anti-mu to dextran molecular weight 2 x 10 to the sixth power thereby increasing its valency. This dextran conjugate anti-mu-Dex simulated comparable levels of thymidine incorporation and B cell size increases as were seen with unconjugated anti-mu but at 100- to 1000-fold lower concentrations. Anti-mu-dex also simulated increases in intracellular ionized calcium Ca to the second power i in a higher percentage of cells, of greater magnitude and of longer duration than that stimulated by unconjugated anti-mu. Interestingly, there was no direct correlation between the increases in Ca to the second poweri that were simulated by anti-mu-Dex and its ability to simulate B cell proliferation. The concentrations of anti-mu-Dex 10ugml that led to the highest increase in Ca to the second power i resulted in thymidine incorporation that was no greater than that of medium control, whereas 0.01 to 0.1 mugml stimulated significant thymidine incorporation with 50 lower levels of stimulation of Ca to hte second power i. These data demonstrate that anti-mu-Dex is a potent activator of human B lymphocytes.

Subject Categories:

  • Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE