CTLA4 is a cell surface molecule that shares 30% homology with CD28 and binds B7 family
members with high affinity. Analysis of surface expression on murine T cells revealed up …

T cell costimulation by molecules on the antigen presenting cell (APC) is required for optimal
T cell proliferation. The B7 molecule on APC binds the T lymphocyte receptor CD28 …

CTLA-4 is an adhesion receptor expressed on activated T cells. The amino acid sequence of
CTLA-4 is related to CD28, and although the function of CTLA-4 remains unknown, it shares …

Engagement of the TCR/CD3 complex together with ligation of CD28 by its counterstructures
B7-1 (CD80) and B7-2 (CD86) on APC are required for mitogenic T cell activation. After …

While interactions between CD28 and members of the B7 family costimulate and enhance T
cell responses, recent evidence indicates that the CD28 homologue CTLA-4 plays a …

CTLA-4 is expressed on T cells after activation and shares homology with the CD28
costimulatory receptor. In contrast to CD28, CTLA-4 is thought to be a negative regulator of T …

CTLA-4 is a CD28 homologue believed to be a negative regulator of T cell function.
However, the mechanism of this downregulatory activity is not well understood. The present …

T cell activation requires at least two distinct signals, including signaling via the Ag-specific
TCR and a costimulatory pathway. The best characterized costimulatory pathway involves …

Occupancy of CTLA‐4 (cytotoxic T‐lymphocyte antigen‐4 or CD152) negatively regulates
the activation of mouse T lymphocytes, as indicated by the fate of CTLA‐4‐deficient mice, by …

CTLA-4 is an immunoregulatory receptor expressed on the surface of activated T and B
lymphocytes. The counterreceptors for CTLA-4 are the B7 family molecules. We describe …