RESUMEN
A receptor that confers susceptibility to infection by subgroup A avian leukosis and sarcoma viruses (ALSV-A) has been described (P. Bates, J. A. T. Young, and H. E. Varmus, Cell 74:1043-1051, 1993). A soluble form of the receptor was generated to determine whether this protein interacts directly with virus particles in the absence of other cell surface factors. The soluble protein comprised the extracellular region of the ALSV-A receptor fused to an antibody epitope tag and six histidine residues. Preincubating this protein with virus led to an efficient block to infection of avian cells by ALSV-A but had no effect on infection by ALSV-B, ALSV-C, or ALSV-D. Furthermore, an antibody directed against the introduced epitope tag immunoprecipitated ALSV-A particles bound to the soluble receptor. In contrast, other ALSV subgroups were not immunoprecipitated by this procedure. These data demonstrate that the cloned receptor interacts directly with ALSV-A and discriminates between different ALSV subgroups at the level of virus binding.
Asunto(s)
Alpharetrovirus/efectos de los fármacos , Alpharetrovirus/metabolismo , Receptores Virales/biosíntesis , Alpharetrovirus/clasificación , Animales , Pollos , Pruebas de Precipitina , Codorniz , Receptores Virales/genética , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/farmacología , Solubilidad , Especificidad de la Especie , Replicación Viral/efectos de los fármacosAsunto(s)
Alpharetrovirus/efectos de los fármacos , Antineoplásicos/farmacología , Antivirales/farmacología , Oxazinas/farmacología , ADN Polimerasa Dirigida por ARN/efectos de los fármacos , Alpharetrovirus/enzimología , Alpharetrovirus/aislamiento & purificación , Animales , Virus de la Mieloblastosis Aviar/efectos de los fármacos , Virus de la Mieloblastosis Aviar/enzimología , Virus de la Mieloblastosis Aviar/aislamiento & purificación , Pollos , Relación Dosis-Respuesta a Droga , PavosAsunto(s)
Alpharetrovirus/efectos de los fármacos , Antivirales/farmacología , Infecciones por Retroviridae/tratamiento farmacológico , Timidina/análogos & derivados , Alpharetrovirus/enzimología , Alpharetrovirus/fisiología , Animales , Leucosis Aviar/tratamiento farmacológico , Embrión de Pollo , Pollos , Evaluación Preclínica de Medicamentos , Ratones , Inhibidores de la Transcriptasa Inversa , Timidina/farmacología , Replicación Viral/efectos de los fármacos , ZidovudinaRESUMEN
A method of activating endogenous cDNA synthesis in avian retroviruses that results in the formation of two species of full-length cDNA in high yield is described. Tests of biological activity show infectivity of at least the same order of magnitude as for full-length cDNA made by other procedures. Melittin, the major component of bee venom, is used as an alternative to nonionic detergents to make the viral envelope permeable and thus activate the endogenous RNA-dependent DNA polymerase. This compound is a toxic peptide known to interact with phospholipid membranes. It appears to be less disruptive to the viral structure than detergents, resulting in a more efficient transcription of the viral genome. Preliminary tests indicate that this method will also prove useful for studying enzymatic activities associated with other enveloped viruses.