Abstract
Lymphokines produced by antigenic or mitogenic stimulation of human, guinea pig and mouse lymphocytes were tested for their effects on monocytes or macrophages of the same and heterologous species, to determine whether there is any species restriction in their reactivity. Supernatants from lymphocyte cultures were tested for migration inhibitory activity in an indirect agarose microdroplet assay and for their ability to augment cytolytic activity of macrophages or monocytes in a [^3^H] thymidine‐release assay. Supernatants of human peripheral blood mononuclear cells, stimulated with phytohemagglutinin or purified protein derivative of tuberculin (PPD) were able to strongly inhibit the migration of human monocytes and guinea pig peritoneal exudate cells (PEC), but had no detectable effect on mouse PEC. The human Supernatants could also significantly augment the cytolytic activity of human monocytes, but had no effect on cytotoxicity by mouse peritoneal macrophages. Conversely, Supernatants of PPD‐stimulated spleen cells from mice immune to bacillus Calmette‐Guérin (BCG) strongly inhibited the migration of, and significantly augmented cytolysis by, mouse PEC, but had no detectable effects on human monocytes. Moreover, Supernatants of concanavalin A‐stimulated lymph node cells from guinea pigs inhibited the migration of guinea pig PEC and human monocytes, but had no effects on mouse PEC. The migration inhibitory effects of the human and mouse Supernatants did not appear to be mediated by interferon (IF), since partially purified type‐1 IF had no detectable effect. In addition, Supernatants of human lymphocytes stimulated by Corynebacterium parvum strain 5888, that induced little or no IF, were able to inhibit the migration of, and augmented cytolysis by, human monocytes. These C. parvum super‐natants also showed migration inhibitory activity on mouse PEC but did not induce cytolytic activity in these cells'.