RESUMO
An attempt was made to induce production of antibodies against C-type endogenous rat retrovirus BP 6. Syngenic Lewis rats were immunized with viable tumor cells, induced with benzo(a)pyrene, continuously producing BP 6 virus. By use of immunoblotting technique, neither short- nor long-term immunization did cause formation of any detectable amounts of antibody against structural proteins of the virus. On the other hand, in immunoblotting, antibodies arised in rats immunized with purified mouse leukemia virus have been found to cross-react with endogenous rat retrovirus.
Assuntos
Anticorpos Antivirais/biossíntese , Retroviridae/imunologia , Animais , Imunização , Vírus da Leucemia Murina/imunologia , Masculino , Ratos , Ratos Endogâmicos LewRESUMO
Concentration of retroviruses from volumes of up to 6 liters of medium by low-speed centrifugation is described. In contrast to pelleting, no damage or aggregation of particles was observed. Surface glycoproteins were also fully preserved. This method enables simple handling of relatively large volumes of medium. Highly purified mouse mammary tumor virus (MMTV) was obtained and its transframe protein p30 in SDS-PAGE was recognized as a double band.
Assuntos
Vírus do Tumor Mamário do Camundongo/isolamento & purificação , Retroviridae/isolamento & purificação , Animais , Linhagem Celular , Centrifugação/métodos , Eletroforese em Gel de Poliacrilamida , Peso Molecular , RNA Viral/biossíntese , RNA Viral/isolamento & purificação , Proteínas Virais/isolamento & purificaçãoRESUMO
To study the possible involvement of a murine leukemia virus (MuLV) related agent in human cancer, an extensive immunoblotting analysis of human sera (cancer, autoimmune as well as control normal ones) for the presence of antibodies to MuLV structural proteins was performed. Out of 350 sera, 89 reacted with gag precursor Pr65, 72 reacted with major viral core protein p30 and five with the matrix protein p15. Antibody reactivity to the env-encoded glycoprotein gp70 was detected in 7 cases out of 16 sera tested. There were no significant differences between pathological and normal sera concerning the patterns and the frequency of the reactivity. Sera from patients with various malignancies (mainly with breast cancer) generally displayed more intensive signals to MuLV p30 than normal sera. Epitope mapping revealed that MuLV p30-reactive antibodies recognize an antigenic determinant(s) located at the carboxyterminus of the protein.