EVIDENCE FOR CONSERVATION OF PERIPHERAL LYMPHOCYTE HOMING RECEPTORS BETWEEN THE BOVINE, MURINE AND HUMAN SPECIES

In rodents and humans, lymphocytes circulate throughout the body and return preferentially to their tissues of origin via a process termed homing. The specificity of homing is controlled by the binding of tissue-specific receptors on lymphocytes to ligands on specialized high-walled endothelial venules (HEV) found in lymphoid tissue. The murine and human peripheral lymphocyte homing receptors (PLHR) have been characterized and shown to be similar to each other. We present evidence for a similar receptor in the bovine. Bovine peripheral blood lymphocytes (PBL) bind to the HEV of murine peripheral lymph node tissue in vitro. The same sugars that have been shown to decrease the binding of murine or human lymphocytes to murine HEV also decrease the binding of bovine PBL to murine HEV. Neuraminidase treatment affects lymphocyte binding in a similar manner in the bovine. murine and human species. Phorbol myristate acetate (PMA) stimulation, which has been shown to reduce the expression of murine and human PLHR, also reduces the binding of bovine PBL to murine HEV. These data suggest conservation of PLHR between these species.