accessory molecules

ac·ces·so·ry mol·e·cules

surface receptors on immune cells, which participate in cell-cell interactions and modulate the immunologic outcome. For example, in T-cell recognition of B-cell presented-antigen, the primary interaction occurs through CD3-CD4 binding to MHC and antigen, but this interaction is amplified if concomitant accessory molecule binding also occurs, for example, CD28 to B7.

ac·ces·so·ry mol·e·cules

(ak-ses'ŏr-ē mol'ĕ-kyūlz) Cell surface adhesion molecules on T cells that are involved in binding of one cell to another cell or in signal transduction.