EFFECTS OF INTERLEUKIN-1 AND INTERLEUKIN-1 RECEPTOR ANTAGONIST IN AIDS-KAPOSIS SARCOMA

Kaposi's sarcoma (KS) is the most common tumor seen in patients with H IV-1 infection. HIV-1 may induce KS directly through viral protein(s) or indirectly through regulation of cytokines such as IL-1 and IL-6. W e have shown that AIDS-KS spindle cells express IL-1 beta and that IL- 1ra inhibits KS-spindle cell growth. IL-1ra had little effect on human umbilical vein endothelial cells (HUVEC), human aortic smooth muscle cells (HASM), and human foreskin fibroblast (NN41). These findings sup port an autocrine activity for IL-1. Furthermore, exogenous IL-1 can e nhance AIDS-KS cell growth, and this effect is completely blocked by I L-1ra. As expected, IL-1ra also blocks IL-1 mediated upregulation of I L-6 and bFGF, both of which are autocrine growth factors for KS, IL-1r a is thus a potential candidate for the treatment of AIDS-associated K S.