The biological activity and immunotherapeutic properties of AS-101, a synthetic organotellurium compound.

AS-101 (ammonium trichloro[dioxoethylene-O,O'-]tellurate) is a newly developed synthetic compound with immunomodulating properties and minimal toxicity. We evaluated the effects of AS-101 on various parameters of the activation and function of immunocompetent cells. AS-101 induced IL-2 receptor expression, IL-2 production and proliferation by human and mouse lymphocytes in vitro and enhanced the production colony-stimulating factor (CSF) by mouse spleen cells. In vivo treatment of Balb/c mice with AS-101 caused a significantly increased production of IL-2 and CSF in vitro in the presence of mitogen. When administered systemically to mice, AS-101 mediated antitumor effects in vivo. These results suggest that AS-101 is an active biological response modifier, which might have potential use in the treatment of conditions such as malignancy, AIDS and some types of immune deficiency.