Functional macrophage cell lines transformed by Abelson leukemia virus.

Three cloned cell lines have been established from murine tumors induced with Abelson leukemia virus which express properties of macrophages. Two of the three original tumors in addition yielded lymphocyte cell lines, one typical of the Abelson virus disease and the other a thymic lymphoma. Two of the macrophage lines are tumorigenic when placed in syngeneic mice. All of the macrophage lines pinocytose neutral red, phagocytose zymosan and latex beads, mediate antibody-dependent killing and phagocytosis of sheep erythrocyte targets, and secrete high levels of lysozyme. None of these properties was exhibited by the lymphocyte lines. Of the two macrophage cell lines tested, neither was capable of replacing the adherent cell population required for the induction of in vitro immune responses. An agent that activates normal macrophages, bacterial lipopolysaccharide, specifically inhibits the growth of the transformed macrophages in culture. Secretion of infectious Abelson leukemia virus by two of the macrophage lines, RAW 309Cr and WR 19M, provides conclusive evidence that the Abelson virus is capable of productively infecting the macrophage cell type. The other macrophage line, RAW 264, fails to secrete detectable virus particles and is negative in the XC plaque formation assay, as well as the fibroblast transformation assay for Abelson virus, but becomes positive for Abelson virus production after rescue by Moloney leukemia virus.