Demonstration of delayed hypersensitivity to soluble antigens of chemically induced tumors by inhibition of macrophage migration.
Sensitization to soluble antigens of chemically induced tumors is demonstrable in syngeneic strain 13 (inbred) guinea pigs by specific inhibition of macrophage migration. According to their capacity to (a) inhibit the migration of peritoneal cells from sensitized strain 13 donors or (b) release migration-inhibitory factor from their lymph node cells, the soluble antigens of three different chemically induced tumors did not cross react. This is in keeping with the absence of cross-reactivity among the same three tumors in previous tests of transplantation resistance or delayed hypersensitivity in vivo. Thus, inhibition of macrophage migration may provide a feasible assay in vitro for use in defining these soluble antigens further by physicochemical methods.