Development of genetic vaccines for pathogenic genes: construction of attenuated vif DNA immunization cassettes.
OBJECTIVE
To develop a putative immunization cassette using HIV-1 vif accessory gene derived from HIV-1 clinical specimens as a component of a DNA vaccine for HIV-1.


METHODS
vif genes were cloned from HIV-1-infected patients and the sequence variation present within the patients was analyzed. Prototypic genetic variants were selected and the ability of these clones to induce humoral and cellular immune responses was studied in animals. The selected protective genetic variants were biologically characterized through transcomplementation assays using primary cells infected with a vif-defective HIV-1 proviral clone.


RESULTS
Analysis of vif variants from different patients revealed that vif is highly conserved with the open reading frame remaining intact in vivo. It was shown that attenuated vif clones from HIV-1-infected subjects can effectively induce both humoral and cellular responses against Vif protein in mice. Evaluation of the cellular responses in vitro using human cellular targets infected with a clinical HIV-1 isolate showed that vif clones could induce cellular responses capable of destroying the virus.


CONCLUSIONS
The vif variants developed in this study exhibited non-productive phenotypes, yet were capable of inducing specific immune responses against HIV-1. These constructs could be used as part of a DNA vaccine strategy for HIV-1. This vaccine adaptation strategy could be used for the development of immunogens for any pathogen resulting in cross-reactive immunity and attenuated gene pathogenesis.
Ayyavoo
V
V
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia 19104, USA.
Nagashunmugam
T
T
Boyer
J
J
Mahalingam
S
S
Fernandes
L S
LS
Le
P
P
Lin
J
J
Nguyen
C
C
Chattargoon
M
M
Goedert
J J
JJ
Friedman
H
H
Weiner
D B
DB
D016915:AIDS Vaccines / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000276:immunology; D015870:Gene Expression; D016346:Gene Products, vif / Q000235:genetics* / Q000276:immunology; D015483:HIV Antibodies / Q000032:analysis; D015658:HIV Infections / Q000517:prevention & control; D015497:HIV-1; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010957:Plasmids / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014407:Tumor Cells, Cultured; D014613:Vaccines, Attenuated / Q000235:genetics; D019444:Vaccines, DNA / Q000235:genetics; D054320:vif Gene Products, Human Immunodeficiency Virus
D016915:AIDS Vaccines; D004279:DNA, Viral; D016346:Gene Products, vif; D015483:HIV Antibodies; D014613:Vaccines, Attenuated; D019444:Vaccines, DNA; D054320:vif Gene Products, Human Immunodeficiency Virus