title: Viral load in tissues during the early and chronic phase of non-pathogenic SIVagm infection.
abstract: African green monkeys (AGMs) persistently infected with SIVagm do not develop AIDS, although their plasma viremia levels can reach those reported for pathogenic HIV-1 and SIVmac infections. In contrast, the viral burden in lymph nodes in SIVagm-infected AGMs is generally lower in comparison with HIV/SIVmac pathogenic infections, at least during the chronic phase of SIVagm infection. We searched for the primary targets of viral replication, which might account for the high viremias in SIVagm-infected AGMs. We evaluated for the first time during primary infection SIVagm dissemination in various lymphoid and non-lymphoid tissues. Sixteen distinct organs at a time point corresponding to maximal virus production were analyzed for viral RNA and DNA load. At days 8 and 9 p.i., viral RNA could be detected in a wide range of tissues, such as jejunum, spleen, mesenteric lymph nodes, thymus and lung. Quantification of viral DNA and RNA as well as of productively infected cells revealed that viral replication during this early phase takes place mainly in secondary lymphoid organs and in the gut (5 x 10(4)-5 x 10(8) RNA copies/10(6) cells). By 4 years p.i., RNA copy numbers were below detection level in thymus and lung. Secondary lymphoid organs displayed 6 x 10(2)-2 x 10(6) RNA copies/10(6) cells, while some tissue fragments of ileum and jejunum still showed high viral loads (up to 10(9) copies/10(6) cells). Altogether, these results indicate a rapid dissemination of SIVagm into lymphoid tissues, including the small intestine. The latter, despite showing marked regional variations, most likely contributes significantly to the high levels of viremia observed during SIVagm infection.
authors.affiliation: Unité de Biologie des Rétrovirus, Institut Pasteur, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Gueye
authors.forename: O M
authors.initials: OM
authors.lastname: Diop
authors.forename: M J Y
authors.initials: MJ
authors.lastname: Ploquin
authors.forename: C
authors.initials: C
authors.lastname: Kornfeld
authors.forename: A
authors.initials: A
authors.lastname: Faye
authors.forename: M-C
authors.initials: MC
authors.lastname: Cumont
authors.forename: B
authors.initials: B
authors.lastname: Hurtrel
authors.forename: F
authors.initials: F
authors.lastname: Barré-Sinoussi
authors.forename: M C
authors.initials: MC
authors.lastname: Müller-Trutwin
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D017931:DNA Primers; D004279:DNA, Viral / Q000032:analysis; D017403:In Situ Hybridization; D008992:Monkey Diseases / Q000821:virology*; D016133:Polymerase Chain Reaction; D018809:Proliferating Cell Nuclear Antigen / Q000097:blood; D012367:RNA, Viral / Q000032:analysis; D019713:Receptors, CCR5 / Q000235:genetics; D012675:Senegal; D016097:Simian Acquired Immunodeficiency Syndrome / Q000821:virology*; D015302:Simian Immunodeficiency Virus; D019562:Viral Load / Q000662:veterinary*; D014766:Viremia / Q000662:veterinary
chemical_list: D017931:DNA Primers; D004279:DNA, Viral; D018809:Proliferating Cell Nuclear Antigen; D012367:RNA, Viral; D019713:Receptors, CCR5; C413374:p27 antigen