title: Isolation and characterization of human cells resistant to retrovirus infection.
abstract: BACKGROUND
  Identification of host cell proteins required for HIV-1 infection will add to our knowledge of the life cycle of HIV-1 and in the development of therapeutics to combat viral infection. We and other investigators have mutagenized rodent cells and isolated mutant cell lines resistant to retrovirus infection. Since there are differences in the efficiency of single round infection with VSVG pseudotyped HIV-1 on cells of different species, we conducted a genetic screen to isolate human cells resistant to HIV-1 infection. We chemically mutagenized human HeLa cells and validated our ability to isolate mutants at test diploid loci. We then executed a screen to isolate HeLa cell mutants resistant to infection by an HIV-1 vector coding for a toxic gene product.
  
  
  RESULTS
  We isolated two mutant cell lines that exhibit up to 10-fold resistance to infection by HIV-1 vectors. We have verified that the cells are resistant to infection and not defective in gene expression. We have confirmed that the resistance phenotype is not due to an entry defect. Fusion experiments between mutant and wild-type cells have established that the mutations conferring resistance in the two clones are recessive. We have also determined the nature of the block in the two mutants. One clone exhibits a block at or before reverse transcription of viral RNA and the second clone has a retarded kinetic of viral DNA synthesis and a block at nuclear import of the preintegration complex.
  
  
  CONCLUSIONS
  Human cell mutants can be isolated that are resistant to infection by HIV-1. The mutants are genetically recessive and identify two points where host cell factors can be targeted to block HIV-1 infection.
authors.affiliation: Molecular, Cellular, Developmental Biology and Genetics Graduate Program, University of Minnesota, Minneapolis, Minnesota, USA. lechx001@umn.edu
authors.forename: Patrycja
authors.initials: P
authors.lastname: Lech
authors.forename: Nikunj V
authors.initials: NV
authors.lastname: Somia
mesh_terms: D004279:DNA, Viral / Q000096:biosynthesis; D005808:Genes, Recessive; D015497:HIV-1 / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D007113:Immunity, Innate; D009052:Leukemia Virus, Murine / Q000502:physiology; D016296:Mutagenesis; D010641:Phenotype; D014764:Viral Proteins / Q000378:metabolism; D053586:Virus Internalization; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins