title: Replicative fitness of CCR5-using and CXCR4-using human immunodeficiency virus type 1 biological clones.
abstract: CCR5-tropic viruses cause the vast majority of new HIV-1 infections while about half of the individuals infected with HIV-1 manifest a co-receptor switch (CCR5 (R5) to CXCR4 (X4)) prior to accelerated disease progression. The underlying biological mechanisms of X4 outgrowth in AIDS patients are still poorly understood. Although X4 viruses have been associated with increased "virulence" in vivo, in vitro replication and cytopathicity studies of X4 and R5 viruses have led to conflicting conclusions. We studied the replicative fitness of HIV-1 biological clones with different co-receptor tropism, isolated from four AIDS patients. On average, R5 and X4 clones replicated equally well in mitogen-activated T cells. In contrast, X4 variants were transferred more efficiently from dendritic cells to autologous CD4+ T cells. These observations suggest that interaction between X4 viruses, DC and T cells might contribute to the preferential outgrowth of X4 viruses in AIDS patients.
authors.affiliation: HIV and Retrovirology Research Unit, Department of Microbiology, Institute for Tropical Medicine, Nationalestraat 155, B-2000 Antwerpen, Belgium. karien@itg.be
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Ariën
authors.forename: Youssef
authors.initials: Y
authors.lastname: Gali
authors.forename: Abdelkarim
authors.initials: A
authors.lastname: El-Abdellati
authors.forename: Leo
authors.initials: L
authors.lastname: Heyndrickx
authors.forename: Wouter
authors.initials: W
authors.lastname: Janssens
authors.forename: Guido
authors.initials: G
authors.lastname: Vanham
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000821:virology; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics; D015752:Genes, env; D015699:HIV Envelope Protein gp120 / Q000235:genetics; D015497:HIV-1 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007963:Leukocytes, Mononuclear / Q000821:virology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D019713:Receptors, CCR5 / Q000502:physiology*; D019718:Receptors, CXCR4 / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: D004279:DNA, Viral; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D019713:Receptors, CCR5; D019718:Receptors, CXCR4