These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cyclic AMP-independent effects of cholera toxin on B cell activation. II. Binding of ganglioside GM1 induces B cell activation.
    Author: Francis ML, Ryan J, Jobling MG, Holmes RK, Moss J, Mond JJ.
    Journal: J Immunol; 1992 Apr 01; 148(7):1999-2005. PubMed ID: 1312102.
    Abstract:
    Although the physiologic function of gangliosides is unknown, evidence suggests they play a role in the regulation of cell growth. The binding of ganglioside GM1 by recombinant B subunit of cholera toxin (rCT-B) inhibited mitogen-stimulated B cell proliferation without elevating intracellular cAMP. CT-B paradoxically enhanced the expression of MHC class II (Ia) molecules and minor lymphocyte-stimulating determinants without altering the expression of some other immunologically relevant B cell surface Ag. Increased expression of Ia was not detected until 4 h after stimulation, kinetics similar to those seen when B cells are stimulated with anti-Ig antibody or IL-4, suggesting that the enhancement was not the result of redistribution of existing cell surface markers but rather the result of a new metabolic event. Both the inhibitory and stimulatory effects of CT-B could be blocked by incubation of CT-B with ganglioside GM1. Furthermore, enhancement of the CT-B-mediated effect was seen when additional ganglioside GM1 was incorporated into the B cell membrane. rCT-B with a mutation that interfered with its binding to ganglioside GM1 did not enhance Ia expression. Taken together, these results indicate that the observed effects of CT-B were most likely mediated through the binding of cell surface ganglioside GM1. CT-B-mediated stimulation of Ia expression provides a potential explanation for the previously described ability of CT-B to act as an immunoadjuvant. These results suggest that the binding of ganglioside GM1 has multiple B cell growth-regulating effects.
    [Abstract] [Full Text] [Related] [New Search]