title: Comparative histopathological studies in the early stages of acute pathogenic and nonpathogenic SHIV-infected lymphoid organs.
abstract: To clarify the early pathological events in simian and human immunodeficiency chimeric virus (SHIV)-infected lymphoid organs, we examined rhesus macaques infected with an acute pathogenic SHIV (SHIV89.6P) or a nonpathogenic SHIV (NM-3rN) by sequential biopsies and serial necropsies. In the SHIV89.6P-infected monkeys, acute thymic involution as shown by increased cortical tingible-body macrophages and by neutrophilic infiltrates without follicular aggregation in the medulla began within 14 days postinoculation (dpi). Cells that were strongly positive for the virus were identified in the thymic medulla. SHIV89.6P-infected lymph nodes showed severe paracortical lymphadenitis with scattered virus-positive cells at 14 dpi and they developed paracortical depletion without the obvious follicular involution. In contrast, NM-3rN-infected monkeys showed no signs of thymic dysinvolution and the lymph nodes exhibited only follicular hyperplasia. NM-3rN-infected monkeys showed much fewer virus-positive cells in these lymphoid tissues than did SHIV89.6P-infected monkeys during the same period. These differences clearly reflect the difference in the virulence of these SHIVs.
authors.affiliation: Department of Pathology, Kyoto City Hospital, 604-8845, Kyoto, Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Shimada
authors.forename: Hajime
authors.initials: H
authors.lastname: Suzuki
authors.forename: Makiko
authors.initials: M
authors.lastname: Motohara
authors.forename: Takeo
authors.initials: T
authors.lastname: Kuwata
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ibuki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ui
authors.forename: Tohko
authors.initials: T
authors.lastname: Iida
authors.forename: Manabu
authors.initials: M
authors.lastname: Fukumoto
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miura
authors.forename: Masanori
authors.initials: M
authors.lastname: Hayami
mesh_terms: D000818:Animals; D001483:Base Sequence; D018791:CD4 Lymphocyte Count; D002678:Chimera; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D004195:Disease Models, Animal; D006678:HIV / Q000235:genetics / Q000472:pathogenicity; D015658:HIV Infections / Q000209:etiology / Q000473:pathology* / Q000821:virology; D008221:Lymphoid Tissue / Q000473:pathology; D008253:Macaca mulatta; D008854:Microscopy, Electron; D011533:Proviruses / Q000235:genetics / Q000302:isolation & purification; D016097:Simian Acquired Immunodeficiency Syndrome / Q000209:etiology / Q000473:pathology* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000472:pathogenicity; D014766:Viremia / Q000821:virology; D014774:Virulence
chemical_list: D004279:DNA, Viral