Recipient of a grant from the Ministère de la Recherche et de la Technologie.
CD77: an antigen of germinal center B cells entering apoptosis
Article first published online: 22 NOV 2005
Copyright © 1991 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
European Journal of Immunology
Volume 21, Issue 5, pages 1131–1140, May 1991
How to Cite
Mangeney, M., Richard, Y., Coulaud, D., Tursz, T. and Wiels, J. (1991), CD77: an antigen of germinal center B cells entering apoptosis. Eur. J. Immunol., 21: 1131–1140. doi: 10.1002/eji.1830210507
- Issue published online: 22 NOV 2005
- Article first published online: 22 NOV 2005
- Manuscript Received: 14 DEC 1990
- Ligue Nationale Francaise contre le Cancer
- Association pour la Recherche sur le Cancer. Grant Number: (ARC 6015)
We have previously reported that a neutral glycolipid (globotriaosylceramide; Gb3) was specifically expressed on Burkitt's lymphoma cells and on a subset of germinal center tonsillar B lymphocytes. Recently the Gb3 molecule was recognized as a new B cell differentiation antigen and now defines the CD77 cluster. Here we report an extensive phenotypic and functional characterization of the tonsillar CD77+ B lymphocytes. These cells have a low buoyant density and are thus purified using a Percoll gradient. They express various B cell antigens such as CD19, CD20, CD21, CD22 and CD40, as well as the adhesion molecules LFA-1, LFA-3 and CD44. They are positive for surface IgM and negative for surface IgD. Although these results suggest a phenotype of activated B cells, the CD77+ cells are negative for the classical activation antigens: CD23 (the low-affinity Fc receptor for IgE), CD25 [the interleukin (IL) 2 receptor α chain] and CD71 (the transferrin receptor). Proliferation and protein synthesis of CD77+ cells was measured after stimulation with a range of mitogens and IL. None of the agents tested are able to induce proliferation and protein synthesis with the exception of a combination of recombinant IL 4 plus anti-CD40 antibody. When examined by electron microscopy, CD77+ B lymphocytes present a morphology similar to that of cells undergoing programmed cell death, also called apoptosis (i.e. chromatin condensation, nuclear fragmentation, membrane blebbing). As shown by direct examination of DNA, these CD77+ cells are indeed in the process of apoptosis. Treatment of the CD77+ cells by recombinant IL 4 and anti-CD40 antibody prevents apoptosis. All these results suggest that the CD77 molecule defines a B lymphocyte maturation pathway, specific for germinal center, where the cells undergo programmed cell death.