Interleukin-1 is a chemotactic factor for human T-lymphocytes.

Macrophages and T-lymphocytes physically interact in the lung in disorders such as sarcoidosis to initiate and/or maintain cellular immune responses. In these studies, we demonstrated that natural interleukin-1 (IL-1), as well as recombinant IL-1 beta, a polypeptide released from stimulated macrophages, is a potent chemotactic factor that is relatively specific for helper T-cells. This chemotactic activity is blocked by a species-specific anti-IL-1. Compared with its capacity to augment proliferation of phytohemagglutinin-stimulated murine thymocytes, IL-1 is more active as a chemotactic factor for mature T-cells. These studies suggest that stimulated lung macrophages, as well as other macrophages, may enhance their interaction with circulating T-lymphocytes via IL-1, which acts as both a chemoattractant and an initiator of T-lymphocyte activation.