Loss of antigenic epitopes as the result of env gene recombination in retrovirus-induced leukemia in immunocompetent mice

Virology. 1993 Feb;192(2):587-95. doi: 10.1006/viro.1993.1075.


The murine leukemia virus, E-55+ virus, induces a thymic lymphoma/leukemia in 100% of BALB.K mice infected as adults after a latent period of 4 months or more (Pozsgay et al., Virology 173, 330-334, 1989). Two molecular clones of virus designated E-55+ and E-55- based on their ability to encode the E-55 epitope detected by the monoclonal antibody 55 (mAb 55) were isolated from a leukemic BALB.K mouse inoculated with a biologically cloned E-55+ virus (Chesebro et al., Virology 112, 131-144, 1981). Env gene sequence analysis of E-55+ and E-55- clones showed that the E-55- virus was generated from the E-55+ virus as the result of a recombination between E-55+ virus and the endogenous ecotropic virus, emv-1, carried in the genome of the BALB.K mouse strain. The recombinant E-55- virus is replication competent. This recombination event and the consequential expression of E-55- virus consistently occur in immunocompetent BALB.K mice inoculated with the E-55+ virus and appear to play a role in the loss of epitopes recognized by virus neutralizing antibodies. The loss of these epitopes apparently allows the virus to evade the host immune response.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Viral / genetics*
  • Antigens, Viral / immunology*
  • Base Sequence
  • Cell Line
  • Cloning, Molecular
  • DNA Probes
  • DNA, Viral / genetics
  • DNA, Viral / isolation & purification
  • Epitopes / genetics*
  • Genes, env*
  • Genes, gag
  • Genes, pol
  • Genome, Viral*
  • Leukemia Virus, Murine / genetics*
  • Leukemia Virus, Murine / isolation & purification
  • Leukemia Virus, Murine / pathogenicity
  • Leukemia, Experimental / genetics*
  • Leukemia, Experimental / microbiology*
  • Lymph Nodes / microbiology
  • Lymphoma / genetics
  • Lymphoma / microbiology
  • Mice
  • Mice, Inbred BALB C / microbiology
  • Mice, Inbred C3H
  • Molecular Sequence Data
  • Oligodeoxyribonucleotides
  • Polymerase Chain Reaction / methods
  • Recombination, Genetic*
  • Repetitive Sequences, Nucleic Acid
  • Sequence Homology, Nucleic Acid
  • Spleen / microbiology
  • Thymus Gland / microbiology
  • Thymus Neoplasms / genetics
  • Thymus Neoplasms / microbiology
  • Virus Integration


  • Antigens, Viral
  • DNA Probes
  • DNA, Viral
  • Epitopes
  • Oligodeoxyribonucleotides