LIPIDS ALTER THE LEVEL AND DISTRIBUTION OF MOUSE MAMMARY-TUMOR VIRUS GP52 IN-VITRO

Linoleic acid, cholesterol, dexamethasone and progesterone were tested by immunocytochemistry and immunoprecipitation for their single and c ombined effects in vitro on mouse mammary tumor virus (MMTV) gp52 dist ribution among three compartments: cell-associated antigen, extracellu lar virus particles and extracellular shed antigen unassociated with v irus particles. Results indicated that all additives significantly inc reased total MMTV gp52 levels and altered the distribution. Linoleic a cid and dexamethasone induced the greatest relative proportion of extr acellular gp52, whereas cholesterol and progesterone induced the great est proportion of cell-associated gp52. The implications of these find ings for the immune response to mammary tumors is discussed.