CELLULAR IMMUNOLOGY 126, I- 15 ( 1990) Early Production of a Chemotactic Factor to T Lymphocytes by Peritoneal Macrophages RICARDOGOMEZ-FLORES,'CRISTINARODRIGUEZ-PADILLA, AND REYES TAMEZ-GUERRA* Lahoratorio de Inrnunologia y Virologia “Dr. Sergio Estruda Parra, ” Facultad de Ciencias Biol6gicas Universidad Aut&wna de Nuevo Lecin, San Nicolds de 10sGarza. Nuevo Lecin, M&ico Received March 27, 1989; accepted October 25, 1989 Supernatant fluids (SNF) were obtained from peritoneal exudate adherent cells stimulated in vitro with sheep red blood cells (SRBC) or BCG, and SNF collected at 6 and 24 hr were able to induce the migratory responses of rat leukocytes from the spleen and peripheral blood. The production of these SNF was dependent on protein active synthesis upon in vitro antigenic stimulation. The chemotactic activity from 6-hr SNF was inhibited by using several proteolytic enzymes and temperatures. We found the macrophages to be the producer cell of this activity, while the T cells were the target cells. The chemotactic activity from 6-hr SNF was found not to be due to IL-l. Six-hour chemotactic activity has not been reported previously. 0 1990 Academic Press, Inc. INTRODUCTION Mononuclear phagocytes in culture secrete a number of molecules with important biologic functions. These molecules include a number of well-defined proteases capa- ble of affecting extracellular proteins (such as collagenase, elastase, and plasminogen activator) (l-3) molecules involved in inflammation and in defense processes (the complement proteins C2 or C4, interferon, and lysozyme) (4-6), and a number of molecules defined mainly by their capacity to influence the behavior of other cells. Included in the latter group are a number of lymphostimulatory molecules which could conceivably be important in modulating some stages of the immune re- sponse (7-10). Macrophage-lymphocyte interaction is a central event in the starting and regulat- ing of the immune response to soluble and particulate antigens (11). The contact between macrophage and lymphocyte can be facilitated by the production of a che- motactic factor from T lymphocytes which attracts macrophages (12). On the other hand, it also has been demonstrated that interleukin-1 (IL-l) production by macro- phages has chemotactic effects on neutrophils, monocytes, and T and B lymphocytes (9, 10, 13, 14). Although, Oppenheim has recently shown that highly pure samples of IL- 1 do not have chemotactic action in vitro. Instead, a protein factor that has been ’ CONACYT fellow. * To whom correspondence should be addressed at Apartado Postal No. 46, Sucursal “F”, Ciudad Uni- versitaria, San Nicolis de 10sGarza, Nuevo Leon, CP. 66450, Mexico. ooog-8749190 $3.00 Copyright 0 1990 by Academic Press, Inc. All rights of reproduction in any form reserved.