Targeting the midgut secreted PpChit1 reduces Leishmania major development in its natural vector, the sand fly Phlebotomus papatasi.
Targeting the midgut secreted PpChit1 reduces Leishmania major development in its natural vector, the sand fly Phlebotomus papatasi.
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DOI：
10.1371/journal.pntd.0000901
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发表时间：
2010-11-30
影响因子：
3.8
通讯作者：
Ramalho-Ortigao M
中科院分区：
文献类型：
--
作者：
Coutinho-Abreu IV;Sharma NK;Robles-Murguia M;Ramalho-Ortigao M
在沙蝇载体内的发育周期中，利什曼原虫必须在早期蛋白水解攻击中存活下来，逃离周围营养基质，然后附着在中肠上皮上，以防止残存的血粉排出体外。这三个步骤对于在病媒内建立感染至关重要，并与控制特定物种病媒能力的相互作用有关。PpChit1是木瓜白血鱼中肠特异性几丁质酶，可能参与了周围营养基质的成熟和降解。沙蝇中肠几丁质酶，如PpChit1，无论是单独作用还是与利什曼原虫分泌的几丁质酶协同作用，都可能在利什曼原虫从内营养空间逃逸中起作用。因此，我们预测沉默沙蝇几丁质酶将导致沙蝇载体肠道内利什曼原虫的减少或消除。我们通过注射dsRNA诱导PpChit1转录本（dsPpChit1）的敲低，并评估了对血餐后蛋白水平（PBM）和木瓜假体利什曼原虫主要发展的影响。注射dsPpChit1导致PpChit1转录本从24小时显著减少到96小时PBM。更重要的是，dsPpChit1导致蛋白水平和Le数量的显著降低。主要存在于受感染的木瓜假单胞菌的中肠。我们的数据支持靶向PpChit1作为潜在的利什曼病传播阻断疫苗候选物。为了在沙蝇媒介的中肠内成功发展，利什曼原虫必须克服媒介施加的几个障碍。克服这些障碍的能力与物种特异性有关，干扰沙蝇媒介-寄生虫平衡可以改变媒介感染的结果。最近，我们小组对沙蝇中肠白蛉（Phlebotomus papatasi）进行了转录组评估，发现了许多可能与利什曼原虫发育障碍有关的转录本。为了验证这些基因的作用，我们开发了一个专用的RNA干扰（RNAi）平台来评估靶向这些基因的RNAi是否可以减少利什曼原虫的主要发展。PpChit1是一种中肠特异性几丁质酶，可能参与了沙蝇在血食后肠道中营养基质的成熟/降解。我们的研究结果表明，通过RNAi敲除PpChit1导致Le显著降低。这支持了PpChit1作为阻断沙蝇传播利什曼病传播策略靶点的潜在用途。
During its developmental cycle within the sand fly vector, Leishmania must survive an early proteolytic attack, escape the peritrophic matrix, and then adhere to the midgut epithelia in order to prevent excretion with remnants of the blood meal. These three steps are critical for the establishment of an infection within the vector and are linked to interactions controlling species-specific vector competence. PpChit1 is a midgut-specific chitinase from Phlebotomus papatasi presumably involved in maturation and degradation of the peritrophic matrix. Sand fly midgut chitinases, such as PpChit1, whether acting independently or in a synergistic manner with Leishmania-secreted chitinase, possibly play a role in the Leishmania escape from the endoperitrophic space. Thus, we predicted that silencing of sand fly chitinase will lead to reduction or elimination of Leishmania within the gut of the sand fly vector. We used injection of dsRNA to induce knock down of PpChit1 transcripts (dsPpChit1) and assessed the effect on protein levels post blood meal (PBM) and on Leishmania major development within P. papatasi. Injection of dsPpChit1 led to a significant reduction of PpChit1 transcripts from 24 hours to 96 hours PBM. More importantly, dsPpChit1 led to a significant reduction in protein levels and in the number of Le. major present in the midgut of infected P. papatasi following a infective blood meal. Our data supports targeting PpChit1 as a potential transmission blocking vaccine candidate against leishmaniasis. For a successful development within the midgut of the sand fly vector, Leishmania must overcome several barriers which are imposed by the vector. The ability to overcome these barriers has been associated with species specificity, and interference with the sand fly vector-parasite balance can change the outcome of the infection in the vector. Recently, our group has carried out a transcriptome assessment of the sand fly Phlebotomus papatasi midgut, uncovering many transcripts possibly associated with the barrier to Leishmania development. In order to validate the role of such genes, we have developed a dedicated RNA interference (RNAi) platform to assess whether RNAi targeting such genes can reduce Leishmania major development. PpChit1 is a midgut-specific chitinase presumably involved in the maturation/degradation of the peritrophic matrix in the gut of the sand fly after a blood meal. Our results show that knockdown of PpChit1 via RNAi led to a significant reduction of Le. major within the gut, supporting the potential use of PpChit1 as a target for transmission blocking strategies against sand fly-transmitted leishmaniasis.
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DOI：
10.1590/s0074-02762010000100001
发表时间：
2010-02-01
期刊：
Memórias do Instituto Oswaldo Cruz
影响因子：
--
作者：
Coutinho-Abreu, Iliano V;Ramalho-Ortigao, Marcelo
通讯作者：
Ramalho-Ortigao, Marcelo
影响因子：
3.8
作者：
Ramalho-Ortigao, JM;Traub-Csekö, YM
通讯作者：
Traub-Csekö, YM
影响因子：
2.4
作者：
Pimenta, PFP;Modi, GB;Sacks, DL
通讯作者：
Sacks, DL
影响因子：
3.8
作者：
Ramalho-Ortigao, JM;Kamhawi, S;Valenzuela, JG
通讯作者：
Valenzuela, JG
影响因子：
2.4
作者：
SACKS, DL;SARAIVA, EM;PIMENTA, PF
通讯作者：
PIMENTA, PF