title: Envelope-dependent restriction of human immunodeficiency virus type 1 spreading in CD4(+) T lymphocytes: R5 but not X4 viruses replicate in the absence of T-cell receptor restimulation.
abstract: The human immunodeficiency virus (HIV) replicates in activated CD4(+) T lymphocytes. However, only CD4(+) Th2 and Th0, but not Th1, CD4(+) T-cell clones have been reported to efficiently support HIV-1 replication. This dichotomous pattern was further investigated in the present study in Th1, Th2, or Th0 cell lines derived from umbilical human cord blood and in T-cell clones obtained from the peripheral blood mononuclear cells (PBMC) of healthy adults. Both primary and laboratory-adapted HIV-1 strains with CCR5 as the exclusive entry coreceptor (R5 viruses) efficiently replicated in Th1, Th2, and Th0 cells. In sharp contrast, CXCR4-dependent (X4) viruses poorly replicated in both polarized and unpolarized CD4(+) T cells, including adults' PBMC infected several days after mitogenic stimulation. Unlike the X4 HIV-1(NL4-3), a chimera in which the env gene had been replaced with that of the R5 HIV-1(NL(AD8)), efficiently replicated in both Th1 and Th2 cells. This X4-dependent restriction of HIV replication was not explained by either the absence of functional CXCR4 on the cell surface or by the inefficient viral entry and reverse transcription. T-cell receptor stimulation by anti-CD3 monoclonal antibodies fully rescued X4 HIV-1 replication in both Th1 and Th2 cells, whereas it did not alter the extent and kinetics of R5 HIV-1 spreading. Thus, R5 HIVs show a replicative advantage in comparison to X4 viruses in their ability to efficiently propagate among suboptimally activated T lymphocytes, regardless of their polarized or unpolarized functional profiles. This observation may help to explain the absolute predominance of R5 HIVs over X4 viruses observed after viral transmission and during early-stage disease.
authors.affiliation: AIDS Immunopathogenesis Unit, DIBIT, San Raffaele Scientific Institute, 20132 Milan, Italy. vicenzi.elisa@hsr.it
authors.forename: E
authors.initials: E
authors.lastname: Vicenzi
authors.forename: P P
authors.initials: PP
authors.lastname: Bordignon
authors.forename: P
authors.initials: P
authors.lastname: Biswas
authors.forename: A
authors.initials: A
authors.lastname: Brambilla
authors.forename: C
authors.initials: C
authors.lastname: Bovolenta
authors.forename: M
authors.initials: M
authors.lastname: Cota
authors.forename: F
authors.initials: F
authors.lastname: Sinigaglia
authors.forename: G
authors.initials: G
authors.lastname: Poli
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000378:metabolism; D017252:CD3 Complex / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000502:physiology / Q000821:virology; D002478:Cells, Cultured; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000378:metabolism; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism / Q000821:virology; D006801:Humans; D019713:Receptors, CCR5 / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000378:metabolism*; D018417:Th1 Cells / Q000166:cytology / Q000378:metabolism / Q000821:virology*; D018418:Th2 Cells / Q000166:cytology / Q000378:metabolism / Q000821:virology*; D013997:Time Factors; D014158:Transcription, Genetic; D014779:Virus Replication
chemical_list: D000911:Antibodies, Monoclonal; D017252:CD3 Complex; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D015699:HIV Envelope Protein gp120; D019713:Receptors, CCR5; D019718:Receptors, CXCR4