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研究揭示恶性疟原虫跨季传播原因
作者:小柯机器人 发布时间:2020/10/27 16:33:20

德国海德堡大学医院Silvia Portugal团队的一项最新研究显示,恶性疟原虫的循环时间增加是干旱季节持续无症状感染的基础。该项研究成果发表在2020年10月26日出版的《自然-医学》杂志上。

他们显示低水平的恶性疟原虫寄生虫在5至6个月的干旱季节持续存在于无症状马里人的血液中,几乎不引起症状,并且对宿主免疫反应的影响最小。在干燥季节分离出的寄生虫在转录上与在传播季节患有高热疟疾的个体在转录上截然不同,这与寄生虫性红细胞的每个复制周期内更长的循环时间一致,而没有粘附在血管内皮上。

干旱季节的寄生虫水平低并不是由于复制受损,而是由于循环较长的受感染红细胞脾脏清除增加,这可能使寄生虫病保持在临床和免疫学雷达之下。他们建议对季节性疟疾传播地区的恶性疟原虫毒力进行调节,以使寄生虫降低其内皮结合能力,从而增加脾脏清除率,并使亚临床寄生虫持久存在数月。

研究人员表示,在许多疟疾流行地区,旱季是恶性疟原虫寄生虫的主要挑战,在该地区,水的可利用性仅将蚊媒传播到一年的一部分。恶性疟原虫如何跨过两个传播季节,却没有被人类宿主清除或损害宿主生存,对此知之甚少。

附:英文原文

Title: Increased circulation time of Plasmodium falciparum underlies persistent asymptomatic infection in the dry season

Author: Carolina M. Andrade, Hannah Fleckenstein, Richard Thomson-Luque, Safiatou Doumbo, Nathalia F. Lima, Carrie Anderson, Julia Hibbert, Christine S. Hopp, Tuan M. Tran, Shanping Li, Moussa Niangaly, Hamidou Cisse, Didier Doumtabe, Jeff Skinner, Dan Sturdevant, Stacy Ricklefs, Kimmo Virtaneva, Muhammad Asghar, Manijeh Vafa Homann, Louise Turner, Joana Martins, Erik L. Allman, Marie-Esther NDri, Volker Winkler, Manuel Llins, Catherine Lavazec, Craig Martens, Anna Frnert, Kassoum Kayentao, Aissata Ongoiba, Thomas Lavstsen, Nuno S. Osrio, Thomas D. Otto, Mario Recker, Boubacar Traore, Peter D. Crompton, Silvia Portugal

Issue&Volume: 2020-10-26

Abstract: The dry season is a major challenge for Plasmodium falciparum parasites in many malaria endemic regions, where water availability limits mosquito vectors to only part of the year. How P. falciparum bridges two transmission seasons months apart, without being cleared by the human host or compromising host survival, is poorly understood. Here we show that low levels of P. falciparum parasites persist in the blood of asymptomatic Malian individuals during the 5- to 6-month dry season, rarely causing symptoms and minimally affecting the host immune response. Parasites isolated during the dry season are transcriptionally distinct from those of individuals with febrile malaria in the transmission season, coinciding with longer circulation within each replicative cycle of parasitized erythrocytes without adhering to the vascular endothelium. Low parasite levels during the dry season are not due to impaired replication but rather to increased splenic clearance of longer-circulating infected erythrocytes, which likely maintain parasitemias below clinical and immunological radar. We propose that P. falciparum virulence in areas of seasonal malaria transmission is regulated so that the parasite decreases its endothelial binding capacity, allowing increased splenic clearance and enabling several months of subclinical parasite persistence. Malaria cases are predominant during the rainy seasons in many endemic regions owing to the life cycle of the mosquito vector. How Plasmodium falciparum adapts in humans during the intervening dry season, without causing malaria symptoms or killing the host, offers new insights into its persistence in humans.

DOI: 10.1038/s41591-020-1084-0

Source: https://www.nature.com/articles/s41591-020-1084-0

期刊信息

Nature Medicine:《自然—医学》,创刊于1995年。隶属于施普林格·自然出版集团,最新IF:30.641
官方网址:https://www.nature.com/nm/
投稿链接:https://mts-nmed.nature.com/cgi-bin/main.plex