Early immune and host cell responses to Cryptosporidium infection.
Early immune and host cell responses to Cryptosporidium infection.
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DOI：
10.3389/fpara.2023.1113950
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发表时间：
2023-01-01
期刊：
影响因子：
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通讯作者：
Mead, Jan R
中科院分区：
文献类型：
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作者：
Mead, Jan R
隐孢子虫属类是机会原生动物寄生虫，感染小肠上皮细胞并导致免疫功能正常和免疫缺陷个体腹泻。这些感染在免疫功能低下的个体和幼儿中可能更严重，特别是在发展中国家的2岁以下儿童中。该寄生虫具有全球分布，是儿童腹泻的重要原因，可能导致认知障碍和生长缺陷。目前的治疗方法是有限的与硝唑尼特是唯一的FDA批准的药物。然而，它对免疫功能低下的患者无效。此外，没有隐孢子虫病的疫苗可用。虽然需要获得性免疫来完全清除隐孢子虫寄生虫，但先天免疫和对感染的早期反应在控制感染方面很重要，以便有时间发展适应性反应。感染局限于肠道的上皮细胞。因此，宿主细胞防御在对感染的早期反应中是重要的，并且可以通过诱导许多信号通路、干扰素、细胞因子和其他免疫介质的toll受体或炎性体来触发。趋化因子和趋化因子受体被上调，其将免疫细胞如嗜中性粒细胞、NK细胞和巨噬细胞募集到感染部位以帮助宿主细胞防御以及树突细胞，树突细胞是先天性和适应性反应之间的重要桥梁。本文将重点介绍在感染早期阶段重要的宿主细胞反应和免疫反应。
Cryptosporidium spp. are opportunistic protozoan parasites that infect epithelial cells of the small intestine and cause diarrheal illness in both immunocompetent and immunodeficient individuals. These infections may be more severe in immunocompromised individuals and young children, especially in children under 2 in developing countries. The parasite has a global distribution and is an important cause of childhood diarrhea where it may result in cognitive impairment and growth deficits. Current therapies are limited with nitazoxanide being the only FDA-approved drug. However, it is not efficacious in immunocompromised patients. Additionally, there are no vaccines for cryptosporidiosis available. While acquired immunity is needed to clear Cryptosporidium parasites completely, innate immunity and early responses to infection are important in keeping the infection in check so that adaptive responses have time to develop. Infection is localized to the epithelial cells of the gut. Therefore, host cell defenses are important in the early response to infection and may be triggered through toll receptors or inflammasomes which induce a number of signal pathways, interferons, cytokines, and other immune mediators. Chemokines and chemokine receptors are upregulated which recruit immune cells such neutrophils, NK cells, and macrophages to the infection site to help in host cell defense as well as dendritic cells that are an important bridge between innate and adaptive responses. This review will focus on the host cell responses and the immune responses that are important in the early stages of infection.