title: TAP-independent human histocompatibility complex-Cw1 antigen processing of an HIV envelope protein conserved peptide.
abstract: Individuals with nonfunctional transporters associated with antigen processing (TAP) complexes are not particularly susceptible to viral infections or neoplasms. Therefore, their immune system must be reasonably efficient, and the present, though reduced, cytolytic CD8 αβ T subpopulation specific for TAP-independent antigens may be sufficient to establish an immune defense protecting against viral infections in these individuals. The objective of the present study was to identify TAP-independent ligands from HIV gp160 protein. An analysis and comparison of complex human histocompatibility complex (HLA)-bound peptide pools isolated from large quantities of healthy or HIV gp160-expressing human cells was performed using mass spectrometry and bioinformatics tools. A conserved TAP-independent HLA peptide ligand endogenously processed and presented in infected human cells was identified. This ligand originates from the envelope protein bound to the HLA-Cw1 class I molecule with high affinity. It was concluded that HLA class I peptides derived from a large fraction of the N-terminal HIV envelope protein could be presented even in the absence of the TAP complex.
authors.affiliation: Unidad de Procesamiento Antigénico, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Lorente
authors.forename: Susana
authors.initials: S
authors.lastname: Infantes
authors.forename: Eilon
authors.initials: E
authors.lastname: Barnea
authors.forename: Ilan
authors.initials: I
authors.lastname: Beer
authors.forename: Ruth
authors.initials: R
authors.lastname: García
authors.forename: Fátima
authors.initials: F
authors.lastname: Lasala
authors.forename: Mercedes
authors.initials: M
authors.lastname: Jiménez
authors.forename: Arie
authors.initials: A
authors.lastname: Admon
authors.forename: Daniel
authors.initials: D
authors.lastname: López
mesh_terms: D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000276:immunology*; D015236:HLA-C Antigens / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D008285:Major Histocompatibility Complex; D011485:Protein Binding; D014764:Viral Proteins / Q000276:immunology*
chemical_list: D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D015236:HLA-C Antigens; C047431:HLA-Cw1 antigen; D014764:Viral Proteins; C071692:TAP2 protein, human