Packageable antiviral therapeutics against human immunodeficiency virus type 1: virion-targeted virus inactivation by incorporation of a single-chain antibody against viral integrase into progeny virions.
To determine their activities as an antiviral agent packageable within virions and suitable for continued expression in cells, we tested a single-chain antibody (scAb) against human immunodeficiency virus type 1 (HIV-1) integrase and its three fusion proteins: fused to viral protein R (scab-Vpr), a double-cassette of the WXXF motif binding to Vpr (scAb-WXXF), and viral major capsid protein (scAb-CA), respectively. Cotransfection of human 293T cells with expression plasmid for scAb-Vpr or -WXXF along with HIV-1 clone pLAI resulted in the production of a normal amount of progeny virions with infectivity decreased by more than 10(3)-fold. Immunoblot analyses showed that scAb-Vpr or -WXXF was associated with virions, whereas scAb or scAb-CA was not, suggesting that scAb-Vpr or -WXXF was incorporated into virions. The incorporation of scAb-WXXF appeared to be Vpr dependent, because the fusion protein was associated with the wild-type but not with Vpr-truncated HIV-1 virions. Since G418-selected HeLa clones carrying expression plasmid for scAb-WXXF were obtained much more frequently than those for scAb-Vpr, scAb-WXXF was inferred to be less toxic to cells than scAb-Vpr. These results suggest that scAb-WXXF may serve as a novel class of antiviral therapeutic that inactivates progeny HIV virions from within.
Okui
N
N
Division of Molecular Genetics, National Institute of Infectious Diseases, Tokyo, Japan.
Sakuma
R
R
Kobayashi
N
N
Yoshikura
H
H
Kitamura
T
T
Chiba
J
J
Kitamura
Y
Y
D000906:Antibodies / Q000235:genetics / Q000276:immunology*; D001483:Base Sequence; D001666:Binding Sites, Antibody; D002460:Cell Line; D017931:DNA Primers; D016336:Gene Products, vpr / Q000276:immunology; D019427:HIV Integrase / Q000276:immunology*; D015497:HIV-1 / Q000201:enzymology*; D006801:Humans; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D014771:Virion / Q000276:immunology*; D054325:vpr Gene Products, Human Immunodeficiency Virus
D000906:Antibodies; D017931:DNA Primers; D016336:Gene Products, vpr; D011993:Recombinant Fusion Proteins; D054325:vpr Gene Products, Human Immunodeficiency Virus; D019427:HIV Integrase