Abstract: This invention provides processes and compositions for enhancing the immunogenicity of tumor or infected cells by increasing expression of major histocompatibility complex (MHC) class I surface molecules. Tumor cells often circumvent immune recognition by reducing or eliminating MHC expression. The lack of MHC on their surface allows tumor cells to evade immune detection and enables uncontrolled growth. Similarly, certain viral or microbial infections result in MHC class I downregulation and the resulting immune evasion. With a unique reporter assay, we have determined that some cannabinoid compounds and structural analogs can increase MHC class I expression on tumor cells grown in cell culture. The increase of tumor and infected cell MHC class I expression will enable detection and destruction by cytotoxic T-lymphocyte cells. The process and compositions increase the immunogenicity of the target cells, e.g. tumor or infected cells, to enhance their destruction by cytotoxic lymphocytes.

Abstract: A DNA molecule is provided which encodes a polypeptide which is capable of binding human TNF.alpha. and which has the first three cysteine-rich subdomains, but not the fourth cysteine-rich subdomain, of the extracellular binding domain of a receptor selected from the 55 kD and 75 kD receptors for human TNF.alpha.. The ability of the polypeptide to bind to TNF.alpha. means that it can be used for treating diseases mediated by TNF.alpha. activity, such as rheumatoid arthritis.