Dantu血型的紅細胞張力可預防嚴重瘧疾
作者:
小柯機器人發布時間:2020/9/18 13:54:16
英國劍橋大學Julian C. Rayner、Pietro Cicuta以及英國倫敦帝國理工學院Thomas N. Williams研究組合作在研究中取得進展。他們發現紅細胞張力可預防Dantu血型中的嚴重瘧疾。 相關論文於2020年9月16日發表於國際頂尖學術期刊《自然》。
他們證明了Dantu對瘧疾寄生蟲惡性瘧原蟲裂殖子形式入侵紅細胞(RBCs)能力的影響。他們發現Dantu與RBC表面蛋白種類的廣泛變化有關,但是,出乎意料的是,抑制入侵與特定RBC-寄生蟲受體-配體的相互作用無關。通過使用視頻顯微鏡觀察入侵,他們發現RBC張力與裂殖子入侵之間有很強的聯繫,並確定了一個張力閾值,即使在非Dantu RBC中也很少發生入侵。Dantu RBC的平均張力高於非Dantu RBC,這意味著更大的入侵抵抗力。
這些發現既為Dantu的保護作用提供了解釋,又為在個體內部和個體之間發現的異種紅細胞群體中惡性瘧原蟲入侵的效率不同提供了新的見解。
研究人員表示,瘧疾已對人類基因組產生重大影響,在瘧疾流行地區,已將許多保護性多態性(例如鐮刀狀細胞性狀)選擇為高頻率。血型變異體Dantu對純合個體的所有形式的嚴重瘧疾提供74%的保護,這與鐮狀細胞性狀所提供的保護程度相似,並且遠比最好的瘧疾疫苗所提供的保護程度高。但是,到目前為止,保護機制還不清楚。
附:英文原文
Title: Red blood cell tension protects against severe malaria in the Dantu blood group
Author: Silvia N. Kariuki, Alejandro Marin-Menendez, Viola Introini, Benjamin J. Ravenhill, Yen-Chun Lin, Alex Macharia, Johnstone Makale, Metrine Tendwa, Wilfred Nyamu, Jurij Kotar, Manuela Carrasquilla, J. Alexandra Rowe, Kirk Rockett, Dominic Kwiatkowski, Michael P. Weekes, Pietro Cicuta, Thomas N. Williams, Julian C. Rayner
Issue&Volume: 2020-09-16
Abstract: Malaria has had a major effect on the human genome, with many protective polymorphisms—such as the sickle-cell trait—having been selected to high frequencies in malaria-endemic regions1,2. The blood group variant Dantu provides 74% protection against all forms of severe malaria in homozygous individuals3,4,5, a similar degree of protection to that afforded by the sickle-cell trait and considerably greater than that offered by the best malaria vaccine. Until now, however, the protective mechanism has been unknown. Here we demonstrate the effect of Dantu on the ability of the merozoite form of the malaria parasite Plasmodium falciparum to invade red blood cells (RBCs). We find that Dantu is associated with extensive changes to the repertoire of proteins found on the RBC surface, but, unexpectedly, inhibition of invasion does not correlate with specific RBC–parasite receptor–ligand interactions. By following invasion using video microscopy, we find a strong link between RBC tension and merozoite invasion, and identify a tension threshold above which invasion rarely occurs, even in non-Dantu RBCs. Dantu RBCs have higher average tension than non-Dantu RBCs, meaning that a greater proportion resist invasion. These findings provide both an explanation for the protective effect of Dantu, and fresh insight into why the efficiency of P. falciparum invasion might vary across the heterogenous populations of RBCs found both within and between individuals.
DOI: 10.1038/s41586-020-2726-6
Source: https://www.nature.com/articles/s41586-020-2726-6