title: Efficient incorporation of HLA class II onto human immunodeficiency virus type 1 requires envelope glycoprotein packaging.
abstract: HLA class II DR is one of the most abundant cell surface proteins incorporated onto human immunodeficiency virus type 1 (HIV-1) during budding. The mechanism for HLA class II protein incorporation is not known and may involve a viral protein. To determine whether Env affects HLA class II protein incorporation, HIV-1 virions, either with or without Env on their surface, were produced from HLA class II-expressing cells and analyzed by whole-virus immunoprecipitation with antisera against HLA class II proteins. HLA class II proteins were detected on virions only when wild-type Env was incorporated, while similar experiments showed that HLA class I proteins were incorporated independent of Env packaging. Therefore, the packaging of HIV-1 Env protein is required for the efficient incorporation of HLA class II but not class I proteins into the virion. Analysis of two Env mutants revealed that the presence of a 43-amino-acid sequence between amino acids 708 and 750 in the gp41(TM) cytoplasmic tail was required for efficient incorporation of HLA class II proteins. These data show that HIV-1 actively incorporates HLA class II proteins in a process that, either directly or indirectly, requires Env.
authors.affiliation: AIDS Vaccine Program, SAIC Frederick, National Cancer Institute, Frederick Cancer Research and Development Center, Frederick, Maryland 21702-1201, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Poon
authors.forename: L V
authors.initials: LV
authors.lastname: Coren
authors.forename: D E
authors.initials: DE
authors.lastname: Ott
mesh_terms: D004705:Endocytosis; D015686:Gene Products, env / Q000235:genetics / Q000378:metabolism*; D015700:HIV Envelope Protein gp41 / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D011233:Precipitin Tests; D014443:Tyrosine / Q000737:chemistry; D014771:Virion / Q000276:immunology / Q000378:metabolism
chemical_list: D015686:Gene Products, env; D015700:HIV Envelope Protein gp41; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D014443:Tyrosine