title: The differential ability of HLA B*5701+ long-term nonprogressors and progressors to restrict human immunodeficiency virus replication is not caused by loss of recognition of autologous viral gag sequences.
abstract: Although the HLA B(*)5701 class I allele is highly overrepresented among human immunodeficiency virus (HIV)-infected long-term nonprogressors (LTNPs), it is also present at the expected frequency (11%) in patients with progressive HIV infection. Whether B57(+) progressors lack restriction of viral replication because of escape from recognition of highly immunodominant B57-restricted gag epitopes by CD8(+) T cells remains unknown. In this report, we investigate the association between restriction of virus replication and recognition of autologous virus sequences in 27 B(*)57(+) patients (10 LTNPs and 17 progressors). Amplification and direct sequencing of single molecules of viral cDNA or proviral DNA revealed low frequencies of genetic variations in these regions of gag. Furthermore, CD8(+) T-cell recognition of autologous viral variants was preserved in most cases. In two patients, responses to autologous viral variants were not demonstrable at one epitope. By using a novel technique to isolate primary CD4(+) T cells expressing autologous viral gene products, it was found that 1 to 13% of CD8(+) T cells were able to respond to these cells by gamma interferon production. In conclusion, escape-conferring mutations occur infrequently within immunodominant B57-restricted gag epitopes and are not the primary mechanism of virus evasion from immune control in B(*)5701(+) HIV-infected patients. Qualitative features of the virus-specific CD8(+) T-cell response not measured by current assays remain the most likely determinants of the differential abilities of HLA B(*)5701(+) LTNPs and progressors to restrict virus replication.
authors.affiliation: Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Migueles
authors.forename: Alisha C
authors.initials: AC
authors.lastname: Laborico
authors.forename: Hiromi
authors.initials: H
authors.lastname: Imamichi
authors.forename: W Lesley
authors.initials: WL
authors.lastname: Shupert
authors.forename: Cassandra
authors.initials: C
authors.lastname: Royce
authors.forename: Mary
authors.initials: M
authors.lastname: McLaughlin
authors.forename: Linda
authors.initials: L
authors.lastname: Ehler
authors.forename: Julia
authors.initials: J
authors.lastname: Metcalf
authors.forename: Shuying
authors.initials: S
authors.lastname: Liu
authors.forename: Claire W
authors.initials: CW
authors.lastname: Hallahan
authors.forename: Mark
authors.initials: M
authors.lastname: Connors
mesh_terms: D000595:Amino Acid Sequence; D017951:Antigen Presentation; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005434:Flow Cytometry; D015683:Gene Products, gag / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D015658:HIV Infections / Q000276:immunology* / Q000821:virology; D020276:HIV Long-Term Survivors; D015497:HIV-1 / Q000235:genetics / Q000276:immunology; D015235:HLA-B Antigens / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology; D014779:Virus Replication
chemical_list: D018984:Epitopes, T-Lymphocyte; D015683:Gene Products, gag; D015235:HLA-B Antigens; D016056:Immunodominant Epitopes; D014764:Viral Proteins