Design and intracellular activity of a human single-chain antibody to human immunodeficiency virus type 1 conserved gp41 epitope.
A human lymphoid cell line (F172-D8) excreting a human immunodeficiency virus type 1 (HIV-1) anti-gp41 monoclonal antibody was used to construct a plasmid containing the cDNA of the single-chain variable fragment (scFvD8) corresponding to this antibody. A stable human osteosarcoma cell line was obtained which expressed the scFvD8 protein in the cytoplasm. Whereas a cell line transfected with a control construct (pCI-neo) was readily and productively infected with laboratory (Ba-L) or primary HIV-1 isolates, the scFvD8 cell line did not support productive infection. Binding of the virus, internalization, and reverse transcription were not altered by scFvD8 expression, but gp160 expression was dramatically reduced. These data suggest that cytoplasmic expression of this artificial single-chain antibody can interfere with gp160 expression, thereby reducing the production of mature viral envelope proteins.
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Virus des Hépatites, Rétrovirus Humains et Pathologies Associées, INSERM U271, 69 424 Lyon Cedex 03, France.
Desgranges
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D002460:Cell Line; D017124:Conserved Sequence; D003593:Cytoplasm / Q000737:chemistry; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D015483:HIV Antibodies / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D019302:HIV Envelope Protein gp160 / Q000378:metabolism; D015700:HIV Envelope Protein gp41 / Q000276:immunology*; D015497:HIV-1 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000502:physiology; D006801:Humans; D007128:Immunoglobulin Fragments / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D009500:Neutralization Tests; D015202:Protein Engineering; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D014779:Virus Replication
D000939:Epitopes; D015483:HIV Antibodies; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41; D007128:Immunoglobulin Fragments; D007135:Immunoglobulin Variable Region; D012333:RNA, Messenger