title: Isolation and characterization of covalently closed circular proviral DNA molecules of several type D retroviruses isolated from human cell lines.
abstract: Infection of a human lymphoblastoid B cell line (Raji cells) with type D retroviruses, originally isolated either from subhuman primates (MPMV, LV) or from permanent human cell lines (PMFV, HeLaV, HEp-2V) led to the production of type D retrovirus particles. Subsequent cocultivation of uninfected and virus-producing Raji cells was employed for the generation of sufficient amounts of covalently closed circular DNA molecules (cccDNA). Highest amounts of cccDNA were obtained after cocultivation of virus-producing Raji cells and homologous uninfected cells at a ratio of 1 to 3 for 72 hr. The cccDNAs of type D retroviruses migrated at about 4.3 kbp compared to lambda DNA/HindIII markers. Digestion of cccDNAs with restriction endonucleases which have one recognition site generated molecules of approximately 8 kbp. The restriction endonuclease site analysis of the cccDNA of type D retroviruses revealed a genomic heterogeneity among the different isolates.
mesh_terms: D002460:Cell Line; D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D004270:DNA, Circular / Q000235:genetics / Q000302:isolation & purification*; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D012190:Retroviridae / Q000235:genetics / Q000302:isolation & purification*; D014779:Virus Replication
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral; D004262:DNA Restriction Enzymes