Molecules on the surface of t-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (antigens, cd3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (receptors, antigen, t-cell, alpha-beta) or gamma-delta (receptors, antigen, t-cell, gamma-delta) chains.