title: The origins of sexually transmitted HIV among men who have sex with men.
abstract: Although it is known that most HIV-1 infections worldwide result from exposure to virus in semen, it has not yet been established whether transmitted strains originate as RNA virions in seminal plasma or as integrated proviral DNA in infected seminal leukocytes. We present phylogenetic evidence that among six transmitting pairs of men who have sex with men, blood plasma virus in the recipient is consistently more closely related to the seminal plasma virus in the source. All sequences were subtype B, and the env C2V3 of transmitted variants tended to have higher mean isoelectric points, contain potential N-linked glycosylation sites, and favor CCR5 co-receptor usage. A statistically robust phylogenetically corrected analysis did not detect genetic signatures reliably associated with transmission, but further investigation of larger samples of transmitting pairs holds promise for determining which structural and genetic features of viral genomes are associated with transmission.
authors.affiliation: University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Butler
authors.forename: Wayne
authors.initials: W
authors.lastname: Delport
authors.forename: Sergei L
authors.initials: SL
authors.lastname: Kosakovsky Pond
authors.forename: Malcolm K
authors.initials: MK
authors.lastname: Lakdawala
authors.forename: Pok Man
authors.initials: PM
authors.lastname: Cheng
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Little
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Richman
authors.forename: Davey M
authors.initials: DM
authors.lastname: Smith
mesh_terms: D000208:Acute Disease; D000328:Adult; D002451:Cell Compartmentation; D002908:Chronic Disease; D015658:HIV Infections / Q000635:transmission* / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D012661:Semen / Q000166:cytology / Q000821:virology*; D055815:Young Adult
chemical_list: D012367:RNA, Viral