title: Cross-Reactivity Between Influenza Matrix- and HIV-1 P17-Specific CTL-A Large Cohort Study.
abstract: BACKGROUND
  It has been reported that HIV-1-specific cytotoxic T cells (CTL) recognizing the HLA-A2-restricted p17 epitope SLYNTVATL (SL9) can cross-react with the HLA-A2-restricted influenza matrix epitope GILGFVFTL (GL9). So far, the prevalence of GL9-cross-reacting HIV-1-specific CTL in larger cohorts of HIV-1-infected patients is unknown, and there are no data yet on whether SL9/GL9-cross-reactive CTL may influence the course of HIV-1 infection.
  
  
  METHODS
  We analyzed the presence of SL9/GL9-cross-reacting CTL in a cohort of 175 HLA-A2-positive HIV-1-infected patients. Peripheral blood mononuclear cells were stimulated in vitro with SL9 and GL9 peptides, and outgrowing cell lines regarding cross-reactivity and recognition of viral variants in γ-interferon enzyme-linked immunospot assays were analyzed.
  
  
  RESULTS
  SL9- and GL9-specific CTL could be generated in 52.6% and 53.7% of 175 patients, respectively. Both SL9- and GL9-specific CTL were more frequently observed in patients on antiretroviral therapy (ART). Of the 92 SL9-specific CTL and the 94 GL9-specific CTL, 65.2% and 66%, respectively, showed at least partial SL9/GL9 cross-reactivity. SL9/GL9-cross-reactive CTL could be detected in 42.9% of the 175 patients. Recognition of SL9 was associated with lower viral loads and higher CD4 cell counts in patients on ART. Patients with GL9/SL9 cross-reactivity displayed similar CD4 cell counts than patients without GL9/SL9-cross-reactive cells. GL9/SL9-cross-reactive cells were associated with higher viral loads in patients on ART.
  
  
  CONCLUSIONS
  Partially SL9/GL9-cross-reactive CTL are frequently observed in HIV-1-infected patients. So far, we could not detect a significant influence of the presence of SL9/GL9-cross-reacting CTL on the course of HIV-1 infection.
authors.affiliation: *Infectious Disease Unit, Department of Internal Medicine III, Institute of Clinical Immunology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany; †Department of Medicine 5, University Hospital Heidelberg, Heidelberg, Germany; and ‡German Competence Network on HIV/AIDS.
authors.forename: Angela G
authors.initials: AG
authors.lastname: Hückelhoven
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Etschel
authors.forename: Silke
authors.initials: S
authors.lastname: Bergmann
authors.forename: Kathrin
authors.initials: K
authors.lastname: Zitzelsberger
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Mueller-Schmucker
authors.forename: Ellen G
authors.initials: EG
authors.lastname: Harrer
authors.forename: Thomas
authors.initials: T
authors.lastname: Harrer
mesh_terms: D000914:Antibodies, Viral / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D015331:Cohort Studies; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology*; D015488:HIV Antigens / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D010446:Peptide Fragments / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology*; D014763:Viral Matrix Proteins / Q000276:immunology*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D015704:CD4 Antigens; D016827:CD8 Antigens; D000939:Epitopes; D015488:HIV Antigens; D010446:Peptide Fragments; D014763:Viral Matrix Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C448634:influenza matrix peptide (58-66); C054858:p17 protein, Human Immunodeficiency Virus Type 1