title: Construction and enhanced cytotoxicity of a [cyanovirin-N]-[Pseudomonas exotoxin] conjugate against human immunodeficiency virus-infected cells.
abstract: Cyanovirin-N (CV-N) is a novel 11-kDa anti-HIV(human immunodeficiency virus) protein that binds with high affinity to the viral envelope glycoprotein gp120. In contrast to soluble CD4 and most known neutralizing antibodies that bind gp120, CV-N exerts potent anti-viral activity against primary clinical HIV isolates as well as laboratory-adapted strains of HIV. Here we describe the recombinant production, purification, and characterization of a chimeric toxin molecule, FLAG-CV-N-PE38, that contains CV-N as a gp120-targeting moiety linked to the translocation and cytotoxic domains of Pseudomonas exotoxin A. FLAG-CV-N-PE38 showed enhanced cytotoxicity to HIV-infected, gp120-expressing H9 cells compared to uninfected H9 cells. Competition experiments with free CV-N provided further support that the enhanced FLAG-CV-N-PE38-induced cytotoxicity was due to interactions of the CV-N moiety with cell surface gp120. This study establishes the feasibility of use of CV-N as a gp120-targeting sequence for construction and experimental therapeutic investigations of unique new chimeric toxins designed to selectively destroy HIV-infected host cells.
authors.affiliation: Laboratory of Drug Discovery Research and Development, National Cancer Institute, Frederick, Maryland 21702-1201, USA.
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.forename: R H
authors.initials: RH
authors.lastname: Shoemaker
authors.forename: J B
authors.initials: JB
authors.lastname: McMahon
authors.forename: R J
authors.initials: RJ
authors.lastname: Gulakowski
authors.forename: K R
authors.initials: KR
authors.lastname: Gustafson
authors.forename: M R
authors.initials: MR
authors.lastname: Boyd
mesh_terms: D036002:ADP Ribose Transferases; D019380:Anti-HIV Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000633:toxicity; D004797:Enzyme-Linked Immunosorbent Assay; D005098:Exotoxins / Q000737:chemistry / Q000235:genetics* / Q000633:toxicity; D015699:HIV Envelope Protein gp120 / Q000096:biosynthesis; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D007938:Leukemia; D010957:Plasmids; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D014407:Tumor Cells, Cultured; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D019380:Anti-HIV Agents; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D002352:Carrier Proteins; D005098:Exotoxins; D015699:HIV Envelope Protein gp120; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C107733:cyanovirin N