title: Inhibition of human immunodeficiency virus type 1 (HIV-1) replication by a two-amino-acid insertion in HIV-1 Vif from a nonprogressing mother and child.
abstract: We studied a 15-year-old girl, patient X, who has maintained consistently low plasma loads of human immunodeficiency virus type 1 (HIV-1) RNA, as well as normal and stable CD4(+) T-cell concentrations. She has presented no clinical manifestations of AIDS, despite having only received zidovudine monotherapy for a part of her life. Patient X's HIV-positive mother (patient Y) has also not progressed to AIDS and has never been treated with antiretroviral agents. HIV-1 isolated from patient X replicated poorly in human peripheral blood mononuclear cells (PBMC). In order to map the determinant of the poor growth of patient X's isolate, viral sequences from patient X were determined and examined for insertion or deletion mutations. These sequences contained a two-amino-acid insertion mutation in the Vif gene, which was also observed in uncultured PBMC acquired at different times. Furthermore, Vif sequences harbored by patient Y contained the identical mutation. These observations suggest that polymorphic HIV-1 was transmitted to patient X perinatally 15 years previously and has been maintained since that time. Recombinant HIV-1, engineered with Vif sequences from patient X, replicated in PBMC to levels approximately 20-fold lower than that of wild type. Removal of the insertion mutation from this recombinant restored replication efficiency to wild-type levels, while introduction of the insertion mutation into wild-type Vif sequences resulted in greatly decreased replication. Furthermore, Vif protein from patient X's HIV-1 was aberrantly cleaved, suggesting a mechanism for loss of Vif function. Since HIV-1 containing these sequences replicates poorly, the implication is that the two-amino-acid insertion mutation in Vif contributes significantly to the nonprogressor status of this mother and child. Further studies of these sequences might provide information regarding contributions of Vif structure and/or function to HIV-1 virulence.
authors.affiliation: Department of Epidemiology and Public Health, Yale University School of Medicine, 60 College Street, New Haven, CT 06520, USA. louis.alexander@yale.edu
authors.forename: Louis
authors.initials: L
authors.lastname: Alexander
authors.forename: Mary Janette
authors.initials: MJ
authors.lastname: Aquino-DeJesus
authors.forename: Michael
authors.initials: M
authors.lastname: Chan
authors.forename: Warren A
authors.initials: WA
authors.lastname: Andiman
mesh_terms: D000293:Adolescent; D000595:Amino Acid Sequence; D000596:Amino Acids; D005260:Female; D016346:Gene Products, vif / Q000235:genetics* / Q000502:physiology; D015658:HIV Infections / Q000821:virology*; D020276:HIV Long-Term Survivors; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic; D014779:Virus Replication / Q000235:genetics*; D054320:vif Gene Products, Human Immunodeficiency Virus
chemical_list: D000596:Amino Acids; D016346:Gene Products, vif; D054320:vif Gene Products, Human Immunodeficiency Virus