A novel role for the peritrophic matrix in protecting Leishmania from the hydrolytic activities of the sand fly midgut
A novel role for the peritrophic matrix in protecting Leishmania from the hydrolytic activities of the sand fly midgut
复制标题
围食基质在保护利什曼原虫免受白蛉中肠水解活性方面的新作用
作者：
P. Pimenta;G. Modi;S. T. Pereira;M. Shahabuddin;D. Sacks
围食基质（PM）的作用，在发展中的利什曼原虫感染的天然载体，Phlebotomus papatasi，通过添加外源性几丁质酶的血粉，这完全阻止PM的形成进行了研究。令人惊讶的是，PM的缺失与中肠感染的丧失有关。几丁质酶对寄生虫没有直接毒性，也没有由于过早排出血粉而失去中肠感染。大多数寄生虫被杀死几丁质酶处理的苍蝇在第一个4小时内喂养后。在对照果蝇中也观察到大量的早期杀伤，这表明PM的缺乏加剧了通常存在于血液喂养的中肠中的致死条件。大豆胰蛋白酶抑制剂可逆转早期寄生虫死亡率。几丁质酶的特异性抑制剂Allosamadin导致PM增厚，并且还防止了在感染的苍蝇中观察到的早期寄生虫死亡。肠道蛋白酶的敏感性是非常高的过渡阶段的寄生虫，而无鞭毛体和完全转化的前鞭毛体相对耐药。PM在促进寄生虫生存的一个新的作用的建议，其中PM创建了一个障碍，消化酶的快速扩散，并限制寄生虫暴露于这些酶的时间，当他们特别容易受到蛋白水解损伤。
The role of the peritrophic matrix (PM) in the development of Leishmania major infections in a natural vector, Phlebotomus papatasi, was investigated by addition of exogenous chitinase to the bloodmeal, which completely blocked PM formation. Surprisingly, the absence of the PM was associated with the loss of midgut infections. The chitinase was not directly toxic to the parasite, nor were midgut infections lost due to premature expulsion of the bloodmeal. Most parasites were killed in chitinase-treated flies within the first 4 h after feeding. Substantial early killing was also observed in control flies, suggesting that the lack of PM exacerbates lethal conditions which normally exist in the blood-fed midgut. Early parasite mortality was reversed by soybean trypsin inhibitor. Allosamadin, a specific inhibitor of chitinase, led to a thickening of the PM, and also prevented the early parasite mortality seen in infected flies. Susceptibility to gut proteases was extremely high in transitional-stage parasites, while amastigotes and fully transformed promastigotes were relatively resistant. A novel role for the PM in promoting parasite survival is suggested, in which the PM creates a barrier to the rapid diffusion of digestive enzymes, and limits the exposure of parasites to these enzymes during the time when they are especially vulnerable to proteolytic damage.
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影响因子：
2.1
作者：
L. L. Walters-L.;K. P. Irons;H. Guzmán;R. Tesh
通讯作者：
L. L. Walters-L.;K. P. Irons;H. Guzmán;R. Tesh
吸血昆虫消化红细胞的模式：对媒介能力的限制。
影响因子：
2.1
作者：
Vaughan,JA;Azad,AF
通讯作者：
Azad,AF
白蛉白蛉（双翅目：Psychodidae）对巴拿马利什曼原虫感染具有抵抗力。
DOI：
10.4269/ajtmh.1992.46.211
发表时间：
1992
期刊：
The American journal of tropical medicine and hygiene
影响因子：
--
作者：
Walters,LL;Irons,KP;Modi,GB;Tesh,RB
通讯作者：
Tesh,RB
DOI：
10.1073/pnas.90.9.4266
发表时间：
1993-05-01
影响因子：
11.1
作者：
SHAHABUDDIN, M;TOYOSHIMA, T;KASLOW, DC
通讯作者：
KASLOW, DC