Simultaneous assessment of CD4 and MHC-I downregulation by Nef primary isolates in the context of infection.
The HIV-1 Nef protein plays a key role in pathogenesis, as demonstrated by strong selective pressure to maintain its open reading frame, and disease attenuation when it is deleted. Among myriad cellular effects attributed to Nef, downregulation of cell surface CD4 and major histocompatibility complex class I (MHC-I) proteins are the best documented. However, few data regarding primary isolate Nef functions are available, and most studies have been performed using transient transfections to express Nef driven by a non-physiologic promoter. A novel assay system to measure simultaneously the downregulation of CD4 and MHC-I by primary HIV-1 nef in a more physiologic viral genomic context is presented. Examination of plasma nef mixtures allowed comprehensive profiling of these Nef functions within the quasispecies in vivo. Subsets within the circulating nef population were observed that are either fully functional or non-functional. These data demonstrated that this assay system allows rapid characterization of bulk and clonal Nef functional profiles that can be used in pathogenesis studies to define further its important role in pathogenesis.
Ali
Ayub
A
Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
Realegeno
Susan
S
Yang
Otto O
OO
Lewis
Martha J
MJ
D015704:CD4 Antigens / Q000096:biosynthesis*; D002460:Cell Line; D015536:Down-Regulation; D015658:HIV Infections / Q000378:metabolism / Q000821:virology*; D016325:HIV Long Terminal Repeat / Q000235:genetics; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D054884:Host-Pathogen Interactions; D054298:Human Immunodeficiency Virus Proteins / Q000172:deficiency; D006801:Humans; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins; D054334:Viral Regulatory and Accessory Proteins / Q000172:deficiency; D014773:Virology / Q000379:methods; D014774:Virulence; D054299:env Gene Products, Human Immunodeficiency Virus / Q000172:deficiency; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism*; D000086082:Viroporin Proteins
D015704:CD4 Antigens; D015395:Histocompatibility Antigens Class I; D054298:Human Immunodeficiency Virus Proteins; D011993:Recombinant Fusion Proteins; D054334:Viral Regulatory and Accessory Proteins; D054299:env Gene Products, Human Immunodeficiency Virus; D054311:nef Gene Products, Human Immunodeficiency Virus; C514837:nef protein, Human immunodeficiency virus 1; C514859:vpu protein, Human immunodeficiency virus 1; D000086082:Viroporin Proteins