Partial "repair" of defective NEF genes in a long-term nonprogressor with human immunodeficiency virus type 1 infection.
A 36-bp deletion close to the 5' end of NEF that impaired Nef function was found in a long-term nonprogressor with human immunodeficiency virus type 1 (HIV-1) infection. Forms containing an adjacent duplication of 33 bp were also frequently observed. The duplication showed no homology to the deleted region but restored the overall length of the first variable loop of Nef. NEF alleles carrying the duplication were active in class I major histocompatibility complex (MHC-I) down-modulation and enhancement of virus infectivity. However, they showed little activity in CD4 down-regulation and were unable to stimulate viral replication in human peripheral blood mononuclear cells. Our study indicates that the enhancement of virion infectivity and the stimulation of HIV-1 replication in lymphocytes are distinct functions of Nef. Our findings also illustrate the capacity for repair of attenuating deletions in HIV-1 infection and suggest that a selective pressure for Nef-mediated MHC-I down-modulation and/or enhancement of virion infectivity exists.
Carl
S
S
Institute for Clinical Virology, University of Erlangen-Nürnberg, Erlangen, Germany.
Daniels
R
R
Iafrate
A J
AJ
Easterbrook
P
P
Greenough
T C
TC
Skowronski
J
J
Kirchhoff
F
F
D000328:Adult; D000483:Alleles; D000595:Amino Acid Sequence; D016022:Case-Control Studies; D004260:DNA Repair; D020440:Gene Duplication; D015693:Gene Products, nef / Q000235:genetics; D015754:Genes, nef; D015658:HIV Infections / Q000453:epidemiology / Q000235:genetics*; D020276:HIV Long-Term Survivors; D015497:HIV-1 / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis; D006716:Homosexuality; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D054311:nef Gene Products, Human Immunodeficiency Virus
D015693:Gene Products, nef; D015395:Histocompatibility Antigens Class I; D054311:nef Gene Products, Human Immunodeficiency Virus