title: Enhancement of immunogenicity of an HIV Env DNA vaccine by mutation of the Tyr-based endocytosis motif in the cytoplasmic domain.
abstract: We investigated the effect of the conserved tyrosine-based endocytosis motif (YXXPhi) in the cytoplasmic domain of the human immunodeficiency viruses (HIV) envelope protein (Env) on its immunogenicity. Genes with codons optimized for mammalian expression were synthesized for the HIV 89.6 Env with a truncated cytoplasmic domain and a mutant Env in which the tyrosine residue in the YXXPhi motif was changed into a serine. Mutation of the Tyr residue enhanced surface expression of the Env protein. Analysis of immune responses induced by DNA immunization of mice showed that the DNA construct for the Tyr mutant Env induced moderately higher levels of T cell responses. More interestingly, the DNA construct for the mutant Env induced significantly higher levels of antibody responses against the Env protein in comparison to the construct for the wild type Env. Our results suggest that the YXXPhi motif in the HIV Env cytoplasmic domain may play a role in virus evasion of host immune responses through affecting its immunogenicity.
authors.affiliation: National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, CAAS, 427 Maduan Street, Harbin 150001, P.R. China.
authors.forename: Zhigao
authors.initials: Z
authors.lastname: Bu
authors.forename: Ling
authors.initials: L
authors.lastname: Ye
authors.forename: Andrei
authors.initials: A
authors.lastname: Vzorov
authors.forename: Dahnide
authors.initials: D
authors.lastname: Taylor
authors.forename: Richard W
authors.initials: RW
authors.lastname: Compans
authors.forename: Chinglai
authors.initials: C
authors.lastname: Yang
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D020816:Amino Acid Motifs / Q000276:immunology; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D002452:Cell Count; D002478:Cells, Cultured; D003593:Cytoplasm; D004705:Endocytosis; D005260:Female; D006678:HIV / Q000235:genetics / Q000276:immunology*; D015483:HIV Antibodies / Q000097:blood; D015700:HIV Envelope Protein gp41 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015658:HIV Infections / Q000097:blood / Q000276:immunology*; D007114:Immunization; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D012694:Serine / Q000378:metabolism; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology; D014443:Tyrosine / Q000378:metabolism; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: D016915:AIDS Vaccines; D015483:HIV Antibodies; D015700:HIV Envelope Protein gp41; D019444:Vaccines, DNA; D014443:Tyrosine; D012694:Serine