Comparative histopathological studies in the early stages of acute pathogenic and nonpathogenic SHIV-infected lymphoid organs.
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.
Shimada
Toshihide
T
Department of Pathology, Kyoto City Hospital, 604-8845, Kyoto, Japan.
Suzuki
Hajime
H
Motohara
Makiko
M
Kuwata
Takeo
T
Ibuki
Kentaro
K
Ui
Masahiro
M
Iida
Tohko
T
Fukumoto
Manabu
M
Miura
Tomoyuki
T
Hayami
Masanori
M
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
D004279:DNA, Viral