title: Construction and phenotypic characterization of HIV type 1 functional envelope clones of subtypes G and F.
abstract: Subtype G has been estimated to represent the fourth most prevalent clade in the HIV-1 pandemic and subtype F is widely circulating in parts of South America (frequently within BF recombinant forms) and in Romania. However, functional envelope clones of these subtypes are lacking, which are needed for studies on antibody-mediated neutralization, coreceptor usage, and efficiency of viral entry inhibitor drugs. Here we report the construction, neutralization properties, and coreceptor usage of HIV-1 functional envelope clones of subtypes G (n = 15) and F (n = 7). These clones were obtained through RT-PCR amplification of HIV-1 gp160 from plasma RNA, and were used for pseudovirus production. All 15 subtype G-enveloped pseudoviruses were resistant to neutralization by gp120-targeted broadly neutralizing monoclonal antibodies (MAbs) b12 and 2G12, while a majority were neutralized by gp41-targeted MAbs 2F5 and 4E10. With regard to the subtype F envelopes, all seven pseudoviruses were resistant to 2F5 and b12, six were resistant to G12, and six were neutralized by 4E10. Coreceptor usage testing revealed that 21 of 22 envelopes were CCR5-tropic, including all 15 subtype G envelopes, seven of which were from patients with CD4(+) T cell counts <200/ml. These results confirm the broadly neutralizing activity of 4E10 on envelope clones across all tested group M clades, including subtypes G and F, reveal the resistance of most subtype F-enveloped pseudoviruses to broadly neutralizing MAbs b12, 2G12, and 2F5, and suggest that, similarly to subtype C, CXCR4 tropism is uncommon in subtype G, even at advanced stages of infection.
authors.affiliation: Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Revilla
authors.forename: Elena
authors.initials: E
authors.lastname: Delgado
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Christian
authors.forename: Justin
authors.initials: J
authors.lastname: Dalrymple
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Vega
authors.forename: Cristina
authors.initials: C
authors.lastname: Carrera
authors.forename: María
authors.initials: M
authors.lastname: González-Galeano
authors.forename: Antonio
authors.initials: A
authors.lastname: Ocampo
authors.forename: Rafael Ojea
authors.initials: RO
authors.lastname: de Castro
authors.forename: María J
authors.initials: MJ
authors.lastname: Lezaún
authors.forename: Raúl
authors.initials: R
authors.lastname: Rodríguez
authors.forename: Ana
authors.initials: A
authors.lastname: Mariño
authors.forename: Patricia
authors.initials: P
authors.lastname: Ordóñez
authors.forename: Gustavo
authors.initials: G
authors.lastname: Cilla
authors.forename: Ramón
authors.initials: R
authors.lastname: Cisterna
authors.forename: Juan M
authors.initials: JM
authors.lastname: Santamaría
authors.forename: Santiago
authors.initials: S
authors.lastname: Prieto
authors.forename: Aza
authors.initials: A
authors.lastname: Rakhmanova
authors.forename: Anna
authors.initials: A
authors.lastname: Vinogradova
authors.forename: Maritza
authors.initials: M
authors.lastname: Ríos
authors.forename: Lucía
authors.initials: L
authors.lastname: Pérez-Álvarez
authors.forename: Rafael
authors.initials: R
authors.lastname: Nájera
authors.forename: David C
authors.initials: DC
authors.lastname: Montefiori
authors.forename: Michael S
authors.initials: MS
authors.lastname: Seaman
authors.forename: Michael M
authors.initials: MM
authors.lastname: Thomson
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D057134:Antibodies, Neutralizing / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D015704:CD4 Antigens / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D015483:HIV Antibodies / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D019302:HIV Envelope Protein gp160 / Q000737:chemistry / Q000145:classification / Q000276:immunology / Q000378:metabolism*; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D015658:HIV Infections / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D058889:Molecular Typing; D009500:Neutralization Tests; D010802:Phylogeny; D010957:Plasmids; D011485:Protein Binding; D015202:Protein Engineering / Q000379:methods*; D017434:Protein Structure, Tertiary; D014162:Transfection
chemical_list: D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D015704:CD4 Antigens; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41; C514787:gp41 protein, Human immunodeficiency virus 1