Williams David L, Asahi Hiroko, Oke Tolulope T, Lopes da Rosa Jessica, Stadecker Miguel J
Department of Biological Sciences, Illinois State University, Normal, IL 61790, USA.
Int J Parasitol. 2005 Jul;35(8):875-82. doi: 10.1016/j.ijpara.2005.03.012.
Pathology in schistosomiasis consists of granuloma formation around parasite eggs. There is considerable variation in the severity of disease in individuals with schistosomiasis, which may result from differential responses to egg antigens. The egg-induced immunopathology is mediated by CD4+ T helper cells sensitised to egg antigens. In this study, cellular responses to a 25-kDa fraction of egg proteins identified a novel T-cell antigen, SmEP25. The native SmEP25 elicited significant proliferative responses as well as gamma interferon (IFN-gamma), IL-2, IL-4, and IL-5 secretion in CD4+ cells from 8.5-week infected CBA and C57BL/6 mice. In C57BL/6 mice, proliferative responses to SmEP25 were relatively stronger than those directed against the major egg antigen Sm-p40, whereas in CBA mice the reverse was found. SmEP25 elicited stronger Th2 type response than Sm-p40 in both mouse strains. By comparison, recombinant SmEP25 elicited a smaller, Th1-polarised response, with significant IFN-gamma, low levels of IL-5 and essentially no IL-4. B-cell responses to SmEP25 coincided with the start of parasite egg production and SmEP25 protein was restricted to parasite eggs. The systematic identification of T-cell-sensitising egg components will lead to a better understanding of the processes involved in granuloma formation.
血吸虫病的病理学表现为围绕寄生虫卵形成肉芽肿。血吸虫病患者的疾病严重程度存在很大差异，这可能是由于对卵抗原的不同反应所致。卵诱导的免疫病理学由对卵抗原致敏的CD4 + T辅助细胞介导。在本研究中，对25 kDa卵蛋白组分的细胞反应鉴定出一种新的T细胞抗原SmEP25。天然SmEP25在感染8.5周的CBA和C57BL / 6小鼠的CD4 +细胞中引发了显著的增殖反应以及γ干扰素（IFN-γ）、IL-2、IL-4和IL-5分泌。在C57BL / 6小鼠中，对SmEP25的增殖反应比对主要卵抗原Sm-p40的反应相对更强，而在CBA小鼠中则相反。在两种小鼠品系中，SmEP25引发的Th2型反应比Sm-p40更强。相比之下，重组SmEP25引发的反应较小，呈Th1极化，IFN-γ显著，IL-5水平低且基本没有IL-4。B细胞对SmEP25的反应与寄生虫卵产生的开始相一致，并且SmEP25蛋白仅限于寄生虫卵。对T细胞致敏的卵成分进行系统鉴定将有助于更好地理解肉芽肿形成所涉及的过程。
