title: Mutations in the env gene of human immunodeficiency virus type 1 NDK isolates and the use of African green monkey CXCR4 as a co-receptor in COS-7 cells.
abstract: A previous report from this laboratory described the isolation of the first CD4-independent human immunodeficiency virus type 1 isolate, m7NDK. This independence of CD4 is due to seven mutations located in the C2, V3 and C3 regions of the gp120 protein. The present report describes the entry features of the m5NDK virus, which contains five of the seven m7NDK mutations, located in the V3 loop and C3 region. The entry of this virus is strictly CD4-dependent but it can fuse with African green monkey (agm) COS-7 cells bearing human CD4 (h-CD4). This fusion is directly due to the five mutations in the envgene. It has also been shown that entry of m7NDK is CD4-independent in COS-7 cells. Since the wild-type NDK and m7NDK viruses use the human CXCR4 protein as co-receptor, agm-CXCR4 was cloned and used in transfection and fusion inhibition experiments to show that this receptor can be used by the m5 and m7NDK viruses. The wild-type NDK virus, which does not enter COS-7 cells, can use agm-CXCR4, but only when the receptor is transfected into target cells. Although co-receptor nature and expression levels are still major determinants of virus entry, this is the first case where a few mutations in the env gene can overcome this restriction.
authors.affiliation: INSERM Unité 380 Laboratoire de Génétique et Pathologie Expérimentales, Institut Cochin de Génétique Moléculaire, 22 rue Méchain, 75014 Paris, France1.
authors.forename: Julie
authors.initials: J
authors.lastname: Dumonceaux
authors.affiliation: INSERM Unité 380 Laboratoire de Génétique et Pathologie Expérimentales, Institut Cochin de Génétique Moléculaire, 22 rue Méchain, 75014 Paris, France1.
authors.forename: Chantal
authors.initials: C
authors.lastname: Chanel
authors.affiliation: INSERM Unité 380 Laboratoire de Génétique et Pathologie Expérimentales, Institut Cochin de Génétique Moléculaire, 22 rue Méchain, 75014 Paris, France1.
authors.forename: Susana
authors.initials: S
authors.lastname: Valente
authors.affiliation: INSERM Unité 380 Laboratoire de Génétique et Pathologie Expérimentales, Institut Cochin de Génétique Moléculaire, 22 rue Méchain, 75014 Paris, France1.
authors.forename: Laurence
authors.initials: L
authors.lastname: Quivet
authors.affiliation: INSERM Unité 380 Laboratoire de Génétique et Pathologie Expérimentales, Institut Cochin de Génétique Moléculaire, 22 rue Méchain, 75014 Paris, France1.
authors.forename: Pascale
authors.initials: P
authors.lastname: Briand
authors.affiliation: Université Paris 7 Denis Diderot, UFR de Biochimie, 75251 Paris Cedex 05, France2.|INSERM Unité 380 Laboratoire de Génétique et Pathologie Expérimentales, Institut Cochin de Génétique Moléculaire, 22 rue Méchain, 75014 Paris, France1.
authors.forename: Uriel
authors.initials: U
authors.lastname: Hazan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002460:Cell Line; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000378:metabolism; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D015752:Genes, env; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D019718:Receptors, CXCR4