Genetic control of immune responses to Moloney leukemia virus in rats.

When BN and LEW rats were immunized with untreated or with inactivated Moloney murine leukemia virus (M-MuLV), BN rats produced high antibody responses to the p15, p30, and gp70 antigens of the virus, whereas LEW rats were low responders to these antigens. BN rats also exhibited a high response and LEW rats a low response when the two strains were immunized with purified p30. Studies of (LEW X BN)F1 and backcross rats suggested that factors associated with AgB exerted major influences on responses to antigens of M-MuLV and that other factors were also important. When other rat strains representing 5 AgB alleles were tested, some were high and some were low responders to M-MuLV, and responses to p15, p30, and gp70 were not always parallel. Since M-MuLV replication was greater in cells of BN rats than in cells of LEW rats, replication of M-MuLV may have influenced the levels of responses to some viral antigens. Control of virus replication appeared to be due to cell mechanisms rather than to the environment of the host.