title: Recombinant rabbit single-chain antibodies bind to the catalytic and C-terminal domains of HIV-1 integrase protein and strongly inhibit HIV-1 replication.
abstract: The human immunodeficiency virus type 1 (HIV-1) integrase (IN) protein plays an important role during the early stages of the retroviral life cycle and therefore is an attractive target for therapeutic intervention. We immunized rabbits with HIV-1 IN protein and developed a combinatorial single-chain variable fragment (scFv) library against IN. Five different scFv antibodies with high binding activity and specificity for IN were identified. These scFvs recognize the catalytic and C-terminal domains of IN and block the strand-transfer process. Cells expressing anti-IN-scFvs were highly resistant to HIV-1 replication due to an inhibition of the integration process itself. These results provide proof-of-concept that rabbit anti-IN-scFv intrabodies can be designed to block the early stages of HIV-1 replication without causing cellular toxicity. Therefore, these anti-IN-scFvs may be useful agents for "intracellular immunization"-based gene therapy strategies. Furthermore, because of their epitope binding characteristics, these scFvs can be used also as new tools to study the structure and function of HIV-1 IN protein.
authors.affiliation: URIA-Centro de Patogénese Molecular, Faculdade de Farmácia, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Frederico Aires
authors.initials: FA
authors.lastname: da Silva
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rato
authors.forename: Sara
authors.initials: S
authors.lastname: Maia
authors.forename: Rui
authors.initials: R
authors.lastname: Malhó
authors.forename: Kylie
authors.initials: K
authors.lastname: Warren
authors.forename: David
authors.initials: D
authors.lastname: Harrich
authors.forename: Robert
authors.initials: R
authors.lastname: Craigie
authors.forename: Carlos
authors.initials: C
authors.lastname: Barbas
authors.forename: Joao
authors.initials: J
authors.lastname: Goncalves
mesh_terms: D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D020134:Catalytic Domain; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D018604:Epitope Mapping; D019427:HIV Integrase / Q000737:chemistry* / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology*; D057127:Single-Chain Antibodies / Q000737:chemistry / Q000276:immunology*; D016662:Virus Integration / Q000276:immunology; D014779:Virus Replication / Q000276:immunology*
chemical_list: D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; D019427:HIV Integrase