The Journal of Immunology, Vol 147, Issue 12 4103-4108, Copyright © 1991 by American Association of Immunologists

ARTICLES

Rapid signaling to B cells by antigen-specific T cells requires CD18/CD54 interaction

PJ Lane, FM McConnell, EA Clark and E Mellins
Department of Microbiology, University of Washington, Seattle 98195.

This study reports early B and T cell signaling events during cognate interactions between a human B cell line pulsed with peptide and an Ag- specific T cell clone. As has been previously reported, peptide in the context of the appropriate class II molecule stimulated a rise in intracellular calcium [Ca2+]i in the Ag-specific T cell clone. The activation of the T cell clone was associated with a reciprocal rise in [Ca2+]i in the B cells. Engagement of receptors on the B cell surface by the T cell also was associated with inositol phospholipid turnover comparable to that elicited by stimulation through sIg. Early signaling events in B cells can therefore be stimulated in cognate interactions with Ag-specific T cells, without the direct engagement of Ig receptors. A class II deficient B lymphoblastoid mutant, 6.1.6, which was incapable of presenting peptide to the T cell clone, could be stimulated to produce a rise in [Ca2+]i if the T cell clone was activated by monoclonal antibodies to CD3. Therefore, the interaction of class II molecules on the B cell with the TCR and/or the CD4 accessory molecule was not essential for T-dependent B cell activation. However, T-dependent signalling of B cells was profoundly inhibited by mAb to CD18 (beta-chain of LFA-1) on the T cell or CD54 (ICAM-1) on the B cell, demonstrating the importance of this pair of adhesion molecules in early T-B cell interactions.

This article has been cited by other articles:

				S. G. Tangye, D. T. Avery, E. K. Deenick, and P. D. Hodgkin Intrinsic Differences in the Proliferation of Naive and Memory Human B Cells as a Mechanism for Enhanced Secondary Immune Responses J. Immunol., January 15, 2003; 170(2): 686 - 694. [Abstract] [Full Text] [PDF]