title: Octapeptide but not nonapeptide from HIV-1 p24gag protein upregulates cell surface HLA-C expression.
abstract: OBJECTIVE
  The HLA-Cw3 molecule has been reported to present peptides derived from HIV-1 p24gag protein to a cytotoxic T lymphocyte clone. We have shown previously that the synthetic octapeptide 145-152 derived from the p24gag sequence upregulated cell surface HLA-C expression on HLA-Cw*0303+ cells. Here, we examined the question of whether the nonapeptide 144-152 also exerts a similar effect.
  
  
  METHODS
  The HLA-Cw*0303+ B-LCL PAJ and control HLA-Cw3-negative cells B-LCL HAJ and T-LCL 500/C9 were used. HLA expression on peptide-pulsed and non-pulsed cells was evaluated using specific antibodies and flow cytofluorimetry. Binding of dansylated peptides onto different cell lines was measured spectrofluorimetrically.
  
  
  RESULTS
  The HIV-1 p24gag octapeptide upregulated cell surface HLA-C on PAJ (Cw*0303+) cells, whereas the nonapeptide did not. HLA-A2 expression was not affected by these peptides. Specificity of the effect of octapeptide was confirmed by the lack of HLA-C upregulation on HLA-Cw3- cells and by lower binding of dansylated peptide to the HLA-Cw3- cells HAJ and 500/C9.
  
  
  CONCLUSIONS
  The above results indicate that HLA-Cw*0303 preferentially binds the octapeptide rather than the nonapeptide derived from HIV-1 p24gag protein.
authors.affiliation: Laboratory of Immunogenetics and Laboratory of Signalling Proteins, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Kozłowska
authors.forename: W
authors.initials: W
authors.lastname: Gorczyca
authors.forename: Z
authors.initials: Z
authors.lastname: Maćkiewicz
authors.forename: I
authors.initials: I
authors.lastname: Wojciechowska
authors.forename: P
authors.initials: P
authors.lastname: Kuśnierczyk
mesh_terms: D000911:Antibodies, Monoclonal / Q000235:genetics; D002460:Cell Line; D005434:Flow Cytometry; D015967:Gene Expression Regulation, Viral; D016655:HIV Core Protein p24 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015236:HLA-C Antigens / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D009842:Oligopeptides / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D000911:Antibodies, Monoclonal; D016655:HIV Core Protein p24; D015236:HLA-C Antigens; D009842:Oligopeptides