title: HIV-1 biological phenotype in long-term infected individuals evaluated with an MT-2 cocultivation assay.
abstract: OBJECTIVE
  We have previously demonstrated that detection of syncytium-inducing (SI) HIV-1 in asymptomatic seropositive individuals is associated with rapid progression to AIDS. In the present study, we sought to develop and evaluate an HIV-1 phenotyping assay for the screening of large numbers of individuals.
  
  
  METHODS
  Efficiency of HIV-1 isolation from patient peripheral blood mononuclear cells (PBMC) was studied with donor PBMC or seven different CD4+ T-cell lines as target cells. The biological phenotype of sequential isolates from 20 long-term asymptomatic HIV-1-seropositive individuals was determined by two different assays.
  
  
  RESULTS
  Non-SI isolates, efficiently recovered by cocultivation with donor PBMC, were never isolated with T-cell lines as target cells. Direct cocultivation with MT-2 cells, but not with six other CD4+ T-cells, resulted in the efficient recovery of SI isolates. HIV-1 MT-2 tropism and SI capacity were shown to be coupled properties at the clonal level. SI isolates emerged in 10 out of 20 longitudinally-studied individuals. In these long-term infected individuals, appearance of SI isolates was associated with progression to AIDS.
  
  
  CONCLUSIONS
  Direct cocultivation of patient PBMC with the MT-2 cell line is a sensitive, specific and convenient method to detect SI isolates. The availability of an assay suitable for the screening of large groups allows further study of the value of HIV-1 biological phenotyping as a prognostic marker.
authors.affiliation: Department of Clinical Viro-Immunology, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam.
authors.forename: M
authors.initials: M
authors.lastname: Koot
authors.forename: A H
authors.initials: AH
authors.lastname: Vos
authors.forename: R P
authors.initials: RP
authors.lastname: Keet
authors.forename: R E
authors.initials: RE
authors.lastname: de Goede
authors.forename: M W
authors.initials: MW
authors.lastname: Dercksen
authors.forename: F G
authors.initials: FG
authors.lastname: Terpstra
authors.forename: R A
authors.initials: RA
authors.lastname: Coutinho
authors.forename: F
authors.initials: F
authors.lastname: Miedema
authors.forename: M
authors.initials: M
authors.lastname: Tersmette
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000382:microbiology* / Q000503:physiopathology; D002460:Cell Line; D002478:Cells, Cultured; D015726:Giant Cells / Q000166:cytology*; D015658:HIV Infections / Q000382:microbiology* / Q000503:physiopathology; D015497:HIV-1 / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D009000:Monocytes / Q000166:cytology / Q000382:microbiology; D010641:Phenotype; D013601:T-Lymphocytes / Q000166:cytology / Q000382:microbiology; D014779:Virus Replication