Expression of a hypoglycosylated form of CD86 (B7-2) on human T cells with altered binding properties to CD28 and CTLA-4

Item Type:	Article
Title:	Expression of a hypoglycosylated form of CD86 (B7-2) on human T cells with altered binding properties to CD28 and CTLA-4
Creators Name:	Hoellsberg, P. and Scholz, C. and Anderson, D.E. and Greenfield, E.A. and Kuchroo, V.K. and Freeman, G.J. and Hafler, D.A.
Abstract:	CD80 (B7-1) and CD86 (B7-2) on APC provide a major costimulatory signal through interactions with CD28 on T cells. Absent from resting human T cells, CD86 is up-regulated early upon T cell activation, whereas CD80 expression appears later. Whereas T cell expression of CD80 has been implicated in costimulation, the functional significance of CD86 expression on T cells is unclear. We now demonstrate that CD86 expressed on human CD4+ T cell clones does not provide a costimulatory signal for other CD4+ T cell clones. Binding studies using CD28-Ig and CTLA-4-Ig fusion proteins demonstrate that CD86 expressed on T cells has significantly reduced binding affinity for CTLA-4 and no detectable binding to CD28. Biochemical analysis demonstrates that post-translational modifications of CD86 in human T cells are different from those of CD86-transfected Chinese hamster ovary cells or EBV-transformed B cells, in that T cells express a hypoglycosylated form of CD86 on the surface membrane. Thus, our results suggest that while CD86 is expressed on a number of different cell types, its costimulatory function and affinity for its ligands may be regulated by cell type-specific post-translational modifications.
Keywords:	CD Antigens, CD4-Positive T-Lymphocytes, CHO Cells, Clone Cells, Differentiation Antigens, Glycosylation, Immunoconjugates, Lymphocyte Activation, Membrane Glycoproteins, Monoclonal Antibodies, Protein Binding, T-Lymphocyte Subsets, Transformed Cell Line, Animals, Cricetinae
Source:	Journal of Immunology
ISSN:	0022-1767
Publisher:	American Association of Immunologists
Volume:	159
Number:	10
Page Range:	4799-4805
Date:	15 November 1997
Official Publication:	http://www.jimmunol.org/cgi/content/abstract/159/10/4799
PubMed:	View item in PubMed

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