title: Detection of HIV-1 neutralizing antibodies in a human CD4⁺/CXCR4⁺/CCR5⁺ T-lymphoblastoid cell assay system.
abstract: Sensitive assays are needed to meaningfully assess low levels of neutralizing antibodies (NAbs) that may be important for protection against the acquisition of HIV-1 infection in vaccine recipients. The current assay of choice uses a non-lymphoid cell line (TZM-bl) that may lack sensitivity owing to over expression of CD4 and CCR5. We used transfection of a human CD4+/CXCR4+/α4β7+ T-lymphoblastoid cell line (A3.01) with a CMV IE promoter-driven CCR5neo vector to stably express CCR5. The resulting line, designated A3R5, is permissive to a wide range of CCR5-tropic circulating strains of HIV-1, including HIV-1 molecular clones containing a Tat-inducible Renilla luciferase reporter gene and expressing multiple Env subtypes. Flow cytometric analysis found CCR5 surface expression on A3R5 cells to be markedly less than TZM-bl but similar to CD3.8 stimulated PBMC. More importantly, neutralization mediated by a diverse panel of monoclonal antibodies, HIV-1 positive polyclonal sera and sCD4 was consistently greater in A3R5 compared to TZM-bl cells. The A3R5 cell line provides a novel approach to guide the development and qualification of promising new HIV-1 vaccine immunogens.
authors: Military HIV-1 Research Program, WRAIR, Silver Spring, Maryland, United States of America.
authors: Robert J
authors: RJ
authors: McLinden
authors: Celia C
authors: CC
authors: Labranche
authors: Agnès-Laurence
authors: AL
authors: Chenine
authors: Victoria R
authors: VR
authors: Polonis
authors: Michael A
authors: MA
authors: Eller
authors: Lindsay
authors: L
authors: Wieczorek
authors: Christina
authors: C
authors: Ochsenbauer
authors: John C
authors: JC
authors: Kappes
authors: Stephen
authors: S
authors: Perfetto
authors: David C
authors: DC
authors: Montefiori
authors: Nelson L
authors: NL
authors: Michael
authors: Jerome H
authors: JH
authors: Kim
mesh_terms: D057134:Antibodies, Neutralizing / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000821:virology*; D002460:Cell Line; D015870:Gene Expression; D015483:HIV Antibodies / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D009500:Neutralization Tests; D010641:Phenotype; D019713:Receptors, CCR5 / Q000235:genetics / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism
chemical_list: D057134:Antibodies, Neutralizing; D015483:HIV Antibodies; D019713:Receptors, CCR5; D019718:Receptors, CXCR4