Recombinant human antibodies against the reverse transcriptase of human immunodeficiency virus type-1.
Inhibitory antibodies to the reverse transcriptase (RT) of human immunodeficiency virus type-1 (HIV-1) can be used to block the life cycle of the virus. We have isolated five different human single chain Fv (ScFv) antibodies specific for HIV-1 RT from an antibody phage display library. Three of these antibodies inhibited the RNA-dependent DNA polymerase (RDDP) activity of RT and one of the three (F-6) inhibited also its DNA-dependent DNA polymerase (DDDP) activity. Unexpectedly, F-6 binds to the carboxyl terminus of the large subunit of RT, which contains the ribonuclease H (RNase H) domain, and not the polymerase domain of the protein. Moreover, this binding did not inhibit the RNase H enzymatic activity. To further characterize F-6 antibody, two cyclic synthetic peptides based on the amino acids sequences of the CDR3 of F-6 were synthesized. Peptide F-6CDRH3, with the sequence of CDR3 of the heavy chain, inhibited the RDDP activity of RT while peptide F-6CDRL3, with the sequence of CDR3 of the light chain, had no effect on this activity of RT. These results indicate that some of the effects of F-6 are mediated by the CDR3 of the heavy chain. The antibodies identified here will be further tested as intrabodies for their capacity to protect human cells from HIV-1 infection.
Herschhorn
Alon
A
Department of Cell Biology and Histology, Sackler School of Medicine, Tel Aviv University, Israel.
Admon
Arie
A
Hizi
Amnon
A
D000595:Amino Acid Sequence; D000914:Antibodies, Viral / Q000235:genetics / Q000276:immunology*; D000918:Antibody Specificity / Q000235:genetics; D003001:Cloning, Molecular; D005803:Genes, Immunoglobulin; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007135:Immunoglobulin Variable Region; D008969:Molecular Sequence Data; D019151:Peptide Library; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology
D000914:Antibodies, Viral; D007135:Immunoglobulin Variable Region; D019151:Peptide Library; D011994:Recombinant Proteins; D054303:HIV Reverse Transcriptase