title: Development of HIV-1 Nef vaccine components: immunogenicity study of Nef mutants lacking myristoylation and dileucine motif in mice.
abstract: In an effort to develop a safe Nef component for use in Cytotoxic T-lymphocyte (CTL)-based HIV-1 vaccines, several versions of Nef constructs lacking myristoylation and dileucine motif were engineered and their abilities to elicit T cell responses were evaluated in mice. Nef-specific murine T cell epitopes were first mapped in three strains of mice (Balb/c, C3H/HeN and C57BL/6), and a pair of dominant Nef-specific CD4(+) and CD8(+) T cell epitopes were identified in C57BL/6 mice. C57BL/6 mice were subsequently immunized with engineered Nef DNA constructs, and Nef-specific CD4(+) and CD8(+) T cell responses were determined. A Nef mutant with simple alanine substitutions at the myristoylation and dileucine sites was impaired in its ability to elicit Nef-specific CD4(+) and CD8(+) T cell responses. Addition of human tissue plasminogen activator (TPA) leader sequence to the N terminus of Nef, which concomitantly inactivates the myristoylation site, significantly enhanced the Nef-specific T cell responses. These findings may have practical implications for developing HIV-1 Nef vaccine component.
authors.affiliation: Merck Research Laboratories, Department of Virus & Cell Biology, Merck and Co. Inc., Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA. xiaoping_liang@merck.com
authors.forename: Xaioping
authors.initials: X
authors.lastname: Liang
authors.forename: Tong-Ming
authors.initials: TM
authors.lastname: Fu
authors.forename: Hong
authors.initials: H
authors.lastname: Xie
authors.forename: Emilio A
authors.initials: EA
authors.lastname: Emini
authors.forename: John W
authors.initials: JW
authors.lastname: Shiver
mesh_terms: D016915:AIDS Vaccines / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D004279:DNA, Viral / Q000235:genetics; D004151:Dipeptides / Q000737:chemistry; D000939:Epitopes / Q000737:chemistry / Q000235:genetics; D005260:Female; D015693:Gene Products, nef / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D015754:Genes, nef; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009227:Myristic Acids / Q000737:chemistry; D015202:Protein Engineering; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014614:Vaccines, Synthetic / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D016915:AIDS Vaccines; D004279:DNA, Viral; D004151:Dipeptides; D000939:Epitopes; D015693:Gene Products, nef; D009227:Myristic Acids; D014614:Vaccines, Synthetic; D054311:nef Gene Products, Human Immunodeficiency Virus; C038361:leucylleucine