Natural species-restricted attachment of human and murine T lymphocytes to various cells.

Murine and human T lymphocytes bear on their surface a receptor that confers on them the ability to attach to a variety of target cells from the same species, derived in vivo and in vitro. Thymocytes and activated T cells attached readily to target cells, while blood T lymphocytes were able to do so only after the removal of sialic acid from either their cell membrane or that of the target cell. The natural attachment (NA) receptor and the corresponding site on the target cells are trypsin sensitive and the conjugation between them is temperature dependent. The phenomenon may be a manifestation of self recognition in a broader sense--recognizing the species--which is also reflected in the reactivity of mitogen-activated T cells and specific immune responses against allo- or other antigens expressed on target cell surfaces.