Impaired T-cell differentiation in the thymus at the early stages of acute pathogenic chimeric simian–human immunodeficiency virus (SHIV) infection in contrast to less pathogenic SHIV infection
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- 作者：Makiko Motohara ; Kentaro Ibuki ; Ariko Miyake ; Yoshinori Fukazawa ; Katsuhisa Inaba ; Hajime Suzuki ; Kyoko Masuda ; Nagahiro Minato ; Hiroshi Kawamoto ; Tadashi Nakasone et al.
- 关键词：AIDS ; Animal model ; Rhesus monkey ; SHIV ; Thymopoiesis
- 刊名：Microbes and Infection
- 出版年：2006
- 出版时间：May 2006
- 年：2006
- 卷：8
- 期：6
- 页码：1539-1549
- 全文大小：935 K
文摘
One of the mechanisms by which HIV infection induces the depletion of CD4+ T cells has been suggested to be impairment of T-cell development in the thymus, although there is no direct evidence that this occurs. To examine this possibility, we compared T-cell maturation in the intrathymic progenitors between macaques infected with an acute pathogenic chimeric simian–human immunodeficiency virus (SHIV), which causes profound and irreversible CD4+ T-cell depletion, and macaques infected with a less pathogenic SHIV, which causes only a transient CD4+ T-cell decline. Within 27 days post-inoculation (dpi), the two virus infections caused similar increases in plasma viral loads and similar decreases in CD4+ T-cell counts. However, in the thymus, the acute pathogenic SHIV resulted in increased thymic involution, atrophy and the depletion of immature T cells including CD4+CD8+ double-positive (DP) cells, whereas the less pathogenic SHIV did not have these effects. Ex vivo differentiation of CD3−CD4−CD8− triple-negative (TN) intrathymic progenitors to DP cells was assessed by a monkey–mouse xenogenic fetal thymus organ culture system. Differentiation was impaired in the TN intrathymic progenitors of the acute pathogenic SHIV-infected monkeys, while differentiation was not impaired in the TN intrathymic progenitors of the less pathogenic SHIV-infected monkeys. These differences suggest that dysfunction of thymic maturation makes an important contribution to the irreversible depletion of circulating CD4+ T cells in vivo.