title: Maternal neutralizing antibodies against a CRF01_AE primary isolate are associated with a low rate of intrapartum HIV-1 transmission.
abstract: Mother-to-child transmission (MTCT) of HIV-1 provides a model for studying the role of passively acquired antibodies in preventing HIV infection. We determined the titers of neutralizing antibodies (NAbs) against six primary isolates of clades B and CRF01_AE in sera from 45 transmitting and 45 nontransmitting mothers matched for the main independent factors associated with MTCT in Thailand. A lower risk of MTCT, particularly for intrapartum transmission, was associated only with higher NAb titers against the CRF01_AE strain, MBA. The envelope glycoprotein of this strain showed an unusually long V2 domain of 63 amino acids, encoding six potential N-linked glycosylation sites. We provided experimental data indicating that the extended V2 domain contributed to the higher level of resistance to neutralization by mothers' sera in this strain. Taken together the data suggest that some primary isolates with specific properties may be useful indicators for identifying protective antibodies.
authors.affiliation: Université François-Rabelais, Inserm U, Tours, France.
authors.forename: Tanawan
authors.initials: T
authors.lastname: Samleerat
authors.forename: Suzie
authors.initials: S
authors.lastname: Thenin
authors.forename: Gonzague
authors.initials: G
authors.lastname: Jourdain
authors.forename: Nicole
authors.initials: N
authors.lastname: Ngo-Giang-Huong
authors.forename: Alain
authors.initials: A
authors.lastname: Moreau
authors.forename: Pranee
authors.initials: P
authors.lastname: Leechanachai
authors.forename: Jirapan
authors.initials: J
authors.lastname: Ithisuknanth
authors.forename: Karin
authors.initials: K
authors.lastname: Pagdi
authors.forename: Pornpun
authors.initials: P
authors.lastname: Wannarit
authors.forename: Suraphan
authors.initials: S
authors.lastname: Sangsawang
authors.forename: Marc
authors.initials: M
authors.lastname: Lallemant
authors.forename: Francis
authors.initials: F
authors.lastname: Barin
authors.forename: Martine
authors.initials: M
authors.lastname: Braibant
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D005260:Female; D015483:HIV Antibodies / Q000097:blood* / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000276:immunology; D015658:HIV Infections / Q000097:blood* / Q000635:transmission*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood* / Q000821:virology; D017434:Protein Structure, Tertiary / Q000235:genetics; D016415:Sequence Alignment; D013785:Thailand
chemical_list: D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C514793:gp120 protein, Human immunodeficiency virus 1