| Abstract: | Soluble membrane fractions derived from polyoma tumor cells trigger lymphocytes, derived from polyoma-immunized animals, but not from nonimmunized controls, to release the lymphokine, macrophage migration-inhibitory factor. The reaction can be blocked by sera from polyoma-bearing animals. Absorption of these sera with polyoma cells, but not with nonpolyoma cell lines, abrogates this activity. These findings suggest that there is a polyoma virus-induced membrane component that can induce polyoma-specific macrophage migration inhibition. |
