title: Humoral and cellular immune responses to HIV-1 nef in mice DNA-immunised with non-replicating or self-replicating expression vectors.
abstract: OBJECTIVE
  HIV accessory protein Nef is expressed early in the infectious cycle of the virus and has been shown to be an effective immunogen in humoral and cellular immune responses. We have used two different self-replicating pBN vectors and one non-replicating pCGal2 derived (pCG) vector expressing HIV-1 Nef in DNA immunisation of mice in order to determine their efficiency in raising humoral and cellular immune responses.
  
  
  METHODS
  The expression of Nef by the three plasmids was tested by transfections into COS-1 cells. Balb/c mice were immunised with the pBN-NEF and pCGE2-NEF constructs using gold particle bombardment. Immunoblotting and immunocytochemistry were used to detect in vitro expression of Nef. 51Cr release assay, ELISA and immunoblotting were used to detect cellular and humoral immune responses in immunised mice.
  
  
  RESULTS
  Efficient in vitro expression of Nef was detected in pBN and pCGE2-NEF transfected cells, in pBN-NEF transfected cells the expression lasting up to three weeks. Anti-Nef antibodies in sera of 13 of 16 pBN-NEF immunised mice were detected within four weeks after the last immunisation, whereas only 2 of 12 pCGE2-NEF immunised mice had very weak anti-Nef antibodies. Twelve of the pBN-NEF immunised mice (75%) and 6 the pCGE2-NEF immunised mice (50%) showed Nef-specific cytotoxic T lymphocyte (CTL) responses within four weeks.
  
  
  CONCLUSIONS
  We conclude that the three eukaryotic expression vectors tested are capable of inducing a cell mediated immune response towards HIV-1 Nef and should be considered as part of a genetic HIV vaccine.
authors.affiliation: Institute of Medical Technology, University of Tampere, Tampere, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Collings
authors.forename: J
authors.initials: J
authors.lastname: Pitkänen
authors.forename: M
authors.initials: M
authors.lastname: Strengell
authors.forename: M
authors.initials: M
authors.lastname: Tähtinen
authors.forename: A
authors.initials: A
authors.lastname: Lagerstedt
authors.forename: K
authors.initials: K
authors.lastname: Hakkarainen
authors.forename: V
authors.initials: V
authors.lastname: Ovod
authors.forename: G
authors.initials: G
authors.lastname: Sutter
authors.forename: M
authors.initials: M
authors.lastname: Ustav
authors.forename: E
authors.initials: E
authors.lastname: Ustav
authors.forename: A
authors.initials: A
authors.lastname: Männik
authors.forename: A
authors.initials: A
authors.lastname: Ranki
authors.forename: P
authors.initials: P
authors.lastname: Peterson
authors.forename: K
authors.initials: K
authors.lastname: Krohn
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D019556:COS Cells; D005260:Female; D015693:Gene Products, nef / Q000276:immunology*; D005822:Genetic Vectors; D015483:HIV Antibodies / Q000097:blood; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D016915:AIDS Vaccines; D015693:Gene Products, nef; D015483:HIV Antibodies; D019444:Vaccines, DNA