RESUMO
The three type C retroviruses, gibbon ape leukemia virus (GALV), simian sarcoma-associated virus (SSAV), and feline leukemia virus subgroup B (FeLV-B), infect human cells by interacting with the same cell surface receptor, GLVR1. Using LacZ retroviral pseudotypes and murine cells transfected with mutant GLVR1 expression vectors, we show that the same 9-amino-acid region of human GLVR1 is critical for infection by the three viruses. Rat cells were not susceptible to infection by LacZ (FeLV-B) pseudotypes because of a block at the receptor level. We found multiple amino acid differences from human GLVR1 in the 9-amino-acid critical region of rat GLVR1. Expression of a human-rat chimeric GLVR1 in murine cells demonstrated that rat GLVR1 could function as a receptor for GALV and SSAV but not for FeLV-B. Substitution of human GLVR1 amino acids in the critical region of rat GLVR1 identified three amino acids as responsible for resistance to FeLV-B infection; two of these affect SSAV infection, but none affects GALV infection.
Assuntos
Vírus da Leucemia Felina/crescimento & desenvolvimento , Vírus da Leucemia do Macaco Gibão/crescimento & desenvolvimento , Receptores Virais/genética , Vírus do Sarcoma do Macaco-Barrigudo/crescimento & desenvolvimento , Sequência de Aminoácidos , Animais , Análise Mutacional de DNA , Humanos , Camundongos , Dados de Sequência Molecular , Mutação , Ratos , Receptores Virais/química , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Relação Estrutura-AtividadeAssuntos
Substâncias de Crescimento/fisiologia , Oncogenes , Sequência de Aminoácidos , Plaquetas/metabolismo , Transformação Celular Neoplásica , Humanos , Oncogenes/classificação , Fator de Crescimento Derivado de Plaquetas/fisiologia , Proteínas Quinases/metabolismo , Proteínas Tirosina Quinases , Vírus do Sarcoma do Macaco-Barrigudo/crescimento & desenvolvimento , Relação Estrutura-Atividade , Temperatura , Transcrição Gênica , Proteínas Virais/genética , Proteínas Virais/fisiologiaRESUMO
Simian sarcoma-associated virus (SSaV) was repeatedly passaged on three human cell lines. The proteins of the progeny virus were analysed for the presence of variant polypeptides. Occasionally, a few variant polypeptides were observed. One-dimensional peptide maps of the major virus protein p30 revealed no modifications after 25 cycles of infection on the three cell lines studied. The peptide map of Pr65gag of virus grown through 25 passages on a human chondrosarcoma cell line was slightly different from that of the virus stock before passaging. The relative amount of the virus protein p30 as compared to p18 and p16 (possibly the SSaV equivalents of p15E and p12E) was variable depending on the host cell. Virus grown on Daudi cells was relatively deficient in p18 and p16. These virus particles were morphologically altered and had a low infectivity.
Assuntos
Retroviridae/análise , Vírus do Sarcoma do Macaco-Barrigudo/análise , Proteínas Virais/análise , Animais , Linfoma de Burkitt , Linhagem Celular , Condrossarcoma , Cães , Eletroforese em Gel de Poliacrilamida , Humanos , Peptídeos/análise , Rabdomiossarcoma , Vírus do Sarcoma do Macaco-Barrigudo/crescimento & desenvolvimento , Vírus do Sarcoma do Macaco-Barrigudo/ultraestrutura , TimoAssuntos
Transformação Celular Viral , Genes Virais , Retroviridae/genética , Vírus do Sarcoma do Macaco-Barrigudo/genética , Proteínas Virais/biossíntese , Animais , Callitrichinae , Linhagem Celular , Eletroforese em Gel de Poliacrilamida , Hibridização de Ácido Nucleico , Peptídeos , Vírus do Sarcoma do Macaco-Barrigudo/crescimento & desenvolvimento , Infecções Tumorais por VírusRESUMO
Mason-Pfizer monkey virus (MPMV), baboon endogenous virus (BaEV) and simian sarcoma virus associated virus (SSAV) induced fusion in cultured human cells derived from tumors or transformed in vitro. Not only virus-transformed cells, but also cells transformed spontaneously by 4-nitroquinoline 1-oxide (4-NQO) treatment or by 60Co-gamma ray irradiation were fused by these simian retroviruses. Non-transformed cells derived from normal human embryos were not fused by any of these viruses. Of these tumor or transformed cells, cells carrying Rous sarcoma virus (RSV) genome were most extensively fused by these simian retroviruses. Anti-MPMV, anti-BaEV and anti-SSAV sera blocked the cell fusion mediated by MPMV, BaEV and SSAV, respectively, and not that by other viruses, indicating that the cell fusion was virus-specific.
Assuntos
Fusão Celular , Transformação Celular Neoplásica/patologia , Retroviridae/crescimento & desenvolvimento , Vírus do Sarcoma Aviário , Carcinoma/patologia , Linhagem Celular , Transformação Celular Viral , Glioma/patologia , Humanos , Vírus do Sarcoma do Macaco-Barrigudo/crescimento & desenvolvimentoRESUMO
Cell lines competent to infection by DNA from cultures chronically infected by type C viruses of the simian sarcoma virus and baboon endogenous virus groups were identified. Significant differences were observed in the relative susceptibility of some cell lines to infection by a given proviral DNA. Practical applications of transfection techniques for the separation of viruses from dually infected cultures and to free virus stocks from mycoplasmal contamination are described.
Assuntos
DNA Viral/genética , Retroviridae/genética , Vírus do Sarcoma do Macaco-Barrigudo/genética , Transfecção , Linhagem Celular , Retroviridae/crescimento & desenvolvimento , Vírus do Sarcoma do Macaco-Barrigudo/crescimento & desenvolvimentoRESUMO
MRC-5 human diploid cells infected with Simian Sarcoma Virus from woolly monkey (SSV-1) were not transformed but an efficient replication of non transforming SiLV was demonstrated. Increase of virus reverse transcriptase activity paralleled cell replication during successive passages. Preliminary results concerning the influence of viral infection on the life span and the karyotype of MRC-5 diploid cells will be reported and several implications of these findings discussed.
