Induced resistance of mice to a lymphoid strain of leukemia virus (moloney)

Abstract

Live Moloney virus derived from chronically infected cell lines or infected mouse plasma stimulates formation of neutralizing antibodies in a susceptible mouse strain (BALB/c) and resistant mouse strains (C‐57/BL and BDF1). Inactivated tissue‐culture Moloney virus produces detectable neutralizing antibodies in the resistant mouse but not the susceptible mouse strain. BALB/c mice immunized with live tissue‐culture attenuated Rauscher virus develop active immunity against challenge with tumor cells induced by Moloney virus.

A novel virulence-associated cell surface structure composed of 47-kd protein subunits in Yersinia enterocolitica.

“…To connect the surface projections with the 47-kd protein, we finally studied thin sections of cells treated with antiserum specific to this protein. We selected a method best compatible with preservation of the native structure (Lawn, 1967;Mayyasi et al, 1967;Lai et al, 1973;Emyanitoff, 1976). Thus, the bacteria were treated with antiserum before any fixation.…”

Protective cellular retroviral immunity requires both CD4+ and CD8+ immune T cells

“…Klarnet et al, however, found that CD4+ and CD8+ T cells from mice immunized with FV-induced leukemia were capable of recognizing distinct antigens encoded by FV (12). BALB/c mice immunized with live RLV attenuated by tissue culture passage developed active immunity against challenge with Moloney murine leukemia virus-induced leukemic cells (20). In a different retrovirus system, Leclerc and Cantor found both T-cell subsets to be necessary for preventing tumor formation with murine sarcoma virus-transformed cells as well as with Moloney murine leukemia virus-induced lymphoma (15).…”

“…Immunization with Formalin-inactivated FV led to 80% protection against FV-induced leukemia (9). Vaccination with formaldehyde-inactivated Moloney murine leukemia virus led to detectable levels of neutralizing antibodies in resistant mice but not in susceptible strains (20). Subunit vaccination with purified gp85 of FV was found to be successful (11); detection of serum antibodies against gp85 correlated with protection against FV viremia and disease.…”

Immunization with envelope proteins of the KoRV as a basis for a preventive vaccine

“…The approaches have included killed virus (Fink & Rauscher, 1964), subunit vaccines (Fischinger et al, 1976;Hunsmann et al, 1975;Hunsmann et al, 1981;Hunsmann, 1985), recombinant vaccinia viruses expressing viral gene products (Earl et al, 1986;Morrison et al 1987), peptide vaccines (Bayer & Hunsman, 1987), and live attenuated viruses. Attenuation was achieved by prolonged passage through tissue culture (Mayyasi & Moloney, 1967;Ruan & Lilly, 1992), or by the use of live pathogenic virus blocked by antiretroviral drugs such as azidothymidin (AZT) and interferon alpha from replicating (Ruprecht et al, 1990(Ruprecht et al, , 1996. When mice were immunized with the SU (gp70, molecular weight 70,000 Dalton) and TM (p15E, molecular weight 15,000 Dalton, E stands for envelope) antigens of the murine leukemia virus (MuLV) substrain Friend leukemia virus (FLV) neutralizing antibodies were induced and protection from disease was reported (Fischinger et al, 1976;Hunsmann et al, 1975;Hunsmann, 1985;Schäfer et al, 1977;Thiel et al, 1987).…”