Transformed and normal cell surface glycoproteins that induce interferon production by nonsensitized lymphocytes

Nonsensitized human and mouse lymphocytes produce interferon (IFN)-alpha and IFN-alpha/beta, respectively, in response to most transformed cells, as well as normal xenogeneic cells. The treatment of transformed human (WISH) and mouse (L) or normal mouse embryo (ME) cells with trypsin, pepsin, or neuraminidase resulted in a loss of the cell's ability to induce IFN-alpha or alpha/beta. These findings suggested that a cell surface glycoprotein is responsible for the induction of IFN-alpha and alpha/beta. The sonication of WISH, L, and ME cells released glycoproteins which retained IFN-inducing activity in the soluble form. The inducing molecules from WISH, L, and ME cells had molecular weights of 130,000, 90,000, and 68,000, respectively. Further purification, plus a confirmation of the glycoprotein nature of the inducer molecule, was shown by specifically binding and eluting L cell inducer bioactivity from a concanavalin A-Sepharose affinity column.