title: HIV-infected cells are killed by rCD4-ricin A chain.
abstract: The gp120 envelope glycoprotein of the human immunodeficiency virus (HIV), which is expressed on the surface of many HIV-infected cells, binds to the cell surface molecule CD4. Soluble derivatives of recombinant CD4 (rCD4) that bind gp120 with high affinity are attractive vehicles for targeting a cytotoxic reagent to HIV-infected cells. Soluble rCD4 was conjugated to the active subunit of the toxin ricin. This conjugate killed HIV-infected H9 cells but was 1/1000 as toxic to uninfected H9 cells (which do not express gp120) and was not toxic to Daudi cells (which express major histocompatibility class II antigens, the putative natural ligand for cell surface CD4). Specific killing of infected cells can be blocked by rgp120, rCD4, or a monoclonal antibody to the gp120 binding site on CD4.
authors.affiliation: Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.
authors.forename: M A
authors.initials: MA
authors.lastname: Till
authors.forename: V
authors.initials: V
authors.lastname: Ghetie
authors.forename: T
authors.initials: T
authors.lastname: Gregory
authors.forename: E J
authors.initials: EJ
authors.lastname: Patzer
authors.forename: J P
authors.initials: JP
authors.lastname: Porter
authors.forename: J W
authors.initials: JW
authors.lastname: Uhr
authors.forename: D J
authors.initials: DJ
authors.lastname: Capon
authors.forename: E S
authors.initials: ES
authors.lastname: Vitetta
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000008:administration & dosage* / Q000276:immunology; D001665:Binding Sites; D002460:Cell Line; D002470:Cell Survival; D004591:Electrophoresis, Polyacrylamide Gel; D006678:HIV / Q000276:immunology*; D015699:HIV Envelope Protein gp120; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology; D012191:Retroviridae Proteins / Q000276:immunology* / Q000378:metabolism; D012276:Ricin / Q000378:metabolism / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000276:immunology / Q000382:microbiology / Q000502:physiology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D015699:HIV Envelope Protein gp120; D000949:Histocompatibility Antigens Class II; D011994:Recombinant Proteins; D012191:Retroviridae Proteins; D012276:Ricin