title: Herpesvirus saimiri-immortalized human lymphocytes: novel hosts for analyzing HIV type 1 in vitro neutralization.
abstract: Herpesvirus saimiri-immortalized CD4(+) T lymphocytes (HVS T cells) are activated memory cells that support efficient replication of primary R5 strains of HIV-1, which predominate in virus transmission. Being continuous, they are phenotypically more stable and technically less demanding than peripheral blood mononuclear cells (PBMCs). Here we present the first report using HVS T cells to assay HIV-1 neutralization in vitro. Neutralization sensitivities of paired viruses isolated from individuals in both HVS T cells (CN-2 cells) and PBMCs were similar, with homologous and heterologous plasma/sera in both CN-2- and PBMC-based assays. Analysis of V3 loop and CD4-binding site (CD4-BS) sequences showed that changes present in CN-2 isolates were neither more numerous nor more significant than those selected in their PBMC counterparts. Neutralization profiles of CN-2/PBMC virus pairs were similar again when V3- and CD4-binding site (BS)-specific monoclonal antibodies, whose mapped epitopes were conserved or of similar sequence in the virus pairs, were tested. Unlike other T cell line isolates, CN-2 isolates were not more sensitive to neutralization than their PBMC counterparts. We also show that HVS T cells do not appear to exert significant biological selection pressures on primary isolates. Paired viruses have a similar phenotype with respect to syncytium formation, cell tropism, and coreceptor usage. Thus CN-2 cells are suitable hosts for assaying neutralization and could be useful in standardizing neutralization assays performed in different laboratories.
authors.affiliation: School of Biological and Applied Sciences, University of North London, London N7 8DB, UK. c.vella@unl.ac.uk
authors.forename: Cherelyn
authors.initials: C
authors.lastname: Vella
authors.forename: Natalie N
authors.initials: NN
authors.lastname: Zheng
authors.forename: Philippa
authors.initials: P
authors.lastname: Easterbrook
authors.forename: Rod S
authors.initials: RS
authors.lastname: Daniels
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001665:Binding Sites; D015704:CD4 Antigens / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D015483:HIV Antibodies / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology; D015658:HIV Infections / Q000276:immunology; D020276:HIV Long-Term Survivors; D015497:HIV-1 / Q000276:immunology*; D006567:Herpesvirus 2, Saimiriine / Q000502:physiology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments