Preincubation of peritoneal macrophages and their subsequent culture with recombinant soluble T cell receptor (sTCR) results in significant increase of: TNF-alpha, IL-1beta, IL-6, IL-10, IL-12 production and nitric oxide (NO) synthesis and this phenomenon was dose dependent. Moreover, treatment of macrophages with sTCR showed two to three fold increase of luminol dependent chemiluminescence (LCL) when compared to untreated macrophages (Mf). In contrast, in our study we did not find any influence of sTCR on co-stimulatory (B7.1 and B7.2), adhesion molecule (ICAM-1) or FcRII/III expression by macrophages. However, macrophages treated with control supernatants received after phosphatidylinositol-specific phospholipase C (PI-PLC) treatment of BW1100 cells or thymocytes termed s-BW or s-Th did not influence their biological activity.