Suppression of host Th1-type granulomatous inflammation by Taenia solium metacestodes is related to down-regulation of osteopontin gene expression

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• 作者：I-Chuang Wang ; Ping-Chin Fan ; Sen-Chi Lu ; Chia-Kwung Fan ; Kua-Eyre Su
• 关键词：Taenia solium ; OPN ; Cysticercosis ; Th1-type responses ; IL-12 ; IFN-γ ; Granulomatous inflammation
• 刊名：International Journal for Parasitology
• 出版年：2008
• 出版时间：February 2008
• 年：2008
• 卷：38
• 期：2
• 页码：239-248
• 全文大小：1203 K

文摘

Inflammation and granuloma formation in human neurocysticercosis has been attributed to Th1-type immune responses of the host. In the present murine model, over 94 % of Taenia solium metacestodes were viable and elicited no granulomatous inflammation, whereas parasites killed by praziquantel treatment elicited rapid granuloma formation that calcified within 2 weeks. Osteopontin (OPN) is a Th1-related cytokine that is up-stream of IL-12 and which may play an essential role in granuloma formation and calcification. OPN mRNA expression was down-regulated in tissues surrounding viable cysticerci, but was up-regulated in inflammatory tissues surrounding degenerating cysticerci. Moreover, co-culture with a viable cysticercus or ES products from these metacestodes led to a decrease in OPN, IFN-γ and IL-12 expression, whereas co-culture with somatic proteins enhanced OPN expression by leukocytes. Addition of recombinant mouse OPN (rmOPN) counteracted the down-regulation of IL-12 and IFN-γ mRNA expression, but not OPN mRNA expression, in leukocyte cultures. Furthermore, injection of rmOPN into the tissues surrounding implanted cysticerci enhanced inflammatory responses while a similar injection of an anti-rmOPN antibody reduced inflammation. These findings suggest that the suppression of host Th1-type granulomatous inflammation by ES products from T. solium metacestodes is related to down-regulation of OPN gene expression.