This work was supported by AI-72631, AI-72656, and CA-16042
Article first published online: 8 MAR 2005
Copyright © 1993 Wiley-Liss, Inc.
Volume 14, Issue 2, pages 196–204, 1993
How to Cite
Hultin, L. E., Hausner, M. A., Hultin, P. M. and Giorgi, J. V. (1993), Cd20 (pan-B cell) antigen is expressed at a low level on a subpopulation of human T lymphocytes. Cytometry, 14: 196–204. doi: 10.1002/cyto.990140212
This manuscript uses the style proposed in Nature 325:660, 1987. Thus, CDX refers to the cell surface differentiation antigen, e.g., the CD20 molecule, that is defined by a cluster of monoclonal antibodies (mAb). CD20 mAb refers to the cluster of mAb used to define the molecule specified, e.g., CD20 mAb refers to the cluster that includes Leu16, B1. and 1F5.
- Issue published online: 21 JUN 2005
- Article first published online: 8 MAR 2005
- Manuscript Accepted: 31 AUG 1992
- Manuscript Received: 10 JUN 1992
- Ca2+ flux;
- flow cytometry;
- cell surface antigen
Despite the previous description of the leukocyte differentiation antigen CD20 as B cell restricted, the findings reported here indicate that a small subset of human T cells expresses low levels of CD20 or a cross-reacting antigen. Three different CD20 monoclonal antibodies (mAb), Leu16, B1, and 1F5, reacted with the T cell subset. B cells that expressed CD20 were CD20bright and constituted an average of 9.2 ± 3.3% of adult PBL. Meanwhile, T cells that expressed CD20 were CD20dim and represented 2.4 ± 1.5% of the PBL. This population may have been overlooked in previous studies due to the low level of CD20 expression per T cell and the small size of the subset in most individuals. Blocking studies indicated that CD20 mAb binding to CD3+ cells was due to the antigen-reactive regions of the CD20 antibodies and was not a result of Fc receptor binding, or non-specific fluorochrome or protein binding. The T cell nature of the CD20dim CD3+ cells was confirmed by the rapid rise in the intracellular calcium concentration ([Ca2+]i) of CD20dim cells observed following treatment with CD3 mAb but not following treatment with anti-human immunoglobulin (Ig). Extensive three-color immunophenotypic analyses indicated that CD20dim T cells were phenotypically heterogeneous and displayed a leukocyte differentiation profile that was slightly different than that of CD20− T cells. Thus, the CD20dim T cells were more likely than CD20− T cells to be γ/δ T cell antigen receptor positive (14% vs. 3.4%), CD8+ (57% vs. 33%), and CD45RO+ (82% vs. 51%); fewer were CD38+ (5% vs. 24%) or CD4+ (35% vs. 61%). Given that most differentiation antigens expressed on leukocytes participate in the functions of the cells that express them, it is possible that CD20 plays a role on the T cells on which it is expressed, although the function(s) of the CD20 molecule on T and B cells remains unknown. © 1993 Wiley-Liss, Inc.