Joshi Deepak, Pan Xiaoling, McFadden Michael J, Bevins David, Liang Xiao, Lu Peng, Thiem Suzanne, Xi Zhiyong
Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA.
Comparative Medicine and Integrative Biology Program, Michigan State University East Lansing, MI, USA.
Front Microbiol. 2017 Mar 8;8:366. doi: 10.3389/fmicb.2017.00366. eCollection 2017.
The endosymbiont AlbB induces refractoriness to in , the primary mosquito vector of human malaria in the Middle East and South Asia. However, it remains unknown whether such refractoriness can be extended to other malaria species. In particular, it was reported that under very specific conditions, AlbB can enhance infection in some hosts. Here, we measured the impact of AlbB on the rodent malaria parasite in by comparing the load of oocysts and sporozoites in midguts and salivary glands, respectively, between AlbB-infected and -uninfected mosquitoes. To investigate whether AlbB modulated mosquito immune defense against parasites, we compared the expression of the immune genes, which were previously reported to involve in antimalarial response, in both midguts and the remaining carcass tissues of mosquitoes. The stable association of AlbB with resulted in reduction of parasites by more than half at the oocyst stage, and up to 91.8% at the sporzoite stage. The anti- immune genes, including , , Toll pathway gene and the effector , were induced by AlbB in different mosquito body tissues. These findings suggest that immune priming is a potential cause of AlbB-mediated antimalarial response in . More importantly, no evidence was found for any enhancement of infection in stably infected with AlbB. We discuss these findings with possible implementations of for malaria control in disease endemic areas.
内共生菌AlbB可使中东和南亚地区人类疟疾的主要蚊媒——按蚊对疟原虫产生抗性。然而，这种抗性是否能扩展到其他疟原虫物种仍不清楚。特别是，有报道称在非常特殊的条件下，AlbB可增强某些宿主对疟原虫的感染。在此，我们通过比较感染AlbB和未感染AlbB的按蚊中肠和唾液腺中卵囊和子孢子的负荷，来测定AlbB对啮齿动物疟原虫伯氏疟原虫在按蚊体内的影响。为了研究AlbB是否调节蚊子对寄生虫的免疫防御，我们比较了先前报道参与抗疟反应的免疫基因在蚊子中肠和其余胴体组织中的表达。AlbB与伯氏疟原虫的稳定关联导致卵囊阶段寄生虫减少一半以上，子孢子阶段减少高达91.8%。包括CecA1、Defensin、Toll途径基因Toll9和效应分子SP1在内的抗疟免疫基因在不同蚊子身体组织中被AlbB诱导。这些发现表明免疫启动是AlbB介导的按蚊抗疟反应的潜在原因。更重要的是，在稳定感染AlbB的按蚊中未发现其对疟原虫感染有任何增强作用的证据。我们将这些发现与在疾病流行地区利用按蚊进行疟疾控制的可能实施方案进行了讨论。
