The HTLV-I orfI protein is recognized by serum antibodies from naturally infected humans and experimentally infected rabbits

Virology. 2000 Aug 15;274(1):86-93. doi: 10.1006/viro.2000.0406.


The mechanism of T-cell transformation by human T-cell lymphotropic virus type I (HTLV-I), though not completely understood, appears to involve the interactions of several viral and cellular proteins. One of these viral proteins, p12(I), encoded by HTLV-I orfI, is a weak oncogene that binds the 16-kDa subunit of the vacuolar ATPase and interacts with the immature beta and gamma(c) chains of the IL-2 receptor. We have expressed the singly spliced orfI cDNA in the baculovirus system and used the recombinant protein as a tool to assess the presence of antibodies in naturally or experimentally infected hosts. In addition, rabbit antisera were raised against various p12(I) synthetic peptides and used to identify three antigenic regions within p12(I), one between the two putative transmembrane regions of p12(I) and two at the carboxy-terminus of the protein. More importantly, sera from a naturally infected human (1 of 32) and experimentally infected rabbits (9 of 20) recognized the rp12(I), demonstrating orfI expression and immunogenicity in vivo. Taken together these data provide the first evidence of orfI expression during HTLV-I infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Deltaretrovirus Antibodies / blood
  • Deltaretrovirus Antibodies / immunology*
  • Deltaretrovirus Antigens / genetics
  • Deltaretrovirus Antigens / immunology*
  • Disease Models, Animal
  • HTLV-I Infections / blood
  • HTLV-I Infections / immunology
  • HeLa Cells
  • Human T-lymphotropic virus 1 / genetics
  • Human T-lymphotropic virus 1 / immunology*
  • Humans
  • Molecular Sequence Data
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / immunology*
  • Peptides / immunology
  • Precipitin Tests
  • Rabbits
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Spodoptera / cytology
  • Transcription Factors*
  • Vaccines, Synthetic / genetics
  • Vaccines, Synthetic / immunology
  • Viral Regulatory and Accessory Proteins


  • Deltaretrovirus Antibodies
  • Deltaretrovirus Antigens
  • Oncogene Proteins, Viral
  • Peptides
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Vaccines, Synthetic
  • Viral Regulatory and Accessory Proteins
  • p12I protein, Human T-lymphotropic virus 1