T-Lymphocyte Proliferation Stimulated by αβTCR/CD2 Bispecific Antibody is Dependent on LFA- 1/ICAM-1 Recognition of Accessory Cells

Abstract

Resting lymphocytes preferentially recirculate via the blood and lymphatics, migrating to the lymph nodes and spleen for efficient antigen encounter. Following activation, lymphocytes display altered migration pathways in that they preferentially return (“home”) to their site of activation. Activated lymphocytes also migrate to non-lymphoid organs and sites of inflammation, ensuring efficient antigen elimination. The receptor mechanisms that regulate migration are, as yet, unclear but appear to be altered upon lymphocyte activation and by the action of cytokines on endothelial cells. In order to study the role of activated T lymphocytes in lymphocyte recirculation and migration into inflammatory sites, a reproducible means of generating large numbers of lymphoblasts is required. We have investigated the use of a bispecific antibody (BsAb) constructed by Tutt et al.,¹ consisting of chemically crosslinked mouse Fab’ fragments from R73 (anti-rat αß T cell receptor) and MRC-OX54 (anti-rat CD2) to stimulate the proliferation of rat T cells.