Malaria Parasite Development, Drug Resistance, Pathogenesis, and Genomics

在2012-2013年期间，我们专注于三个主要研究领域：1）筛选和表征用于联合治疗和传播阻断的药物; 2）使用约氏疟原虫/小鼠模型研究疟疾发病机制的分子机制; 3）卵囊发育缺陷的分子基础。 我们已经完成并发表了表征一组可以阻断疟疾寄生虫传播的化合物的工作（Eastman等人，2013，AAC 57，425）。我们与NCATS的科学家合作，正在进行大规模的药物组合筛选。已经确定了有希望的药物组合。我们还评估了Ca++和Na+通道阻断剂对寄生虫对青蒿素反应的影响。 本研究以约氏疟原虫为研究对象，在以下几个方面取得了较好的进展：1）在与宿主细胞因子/趋化因子反应相关的基因位点上，继续筛选候选基因。候选基因之一已被证明在等位基因替换后影响寄生虫生长。2)我们发现，I型干扰素（IFN-I）在控制啮齿类疟原虫约氏疟原虫尼日利亚N67的寄生虫血症中发挥了重要作用。我们还证明了RNA聚合酶III和MDA 5介导的信号传导有助于提高IFN-I应答。这部作品的手稿已经提交。3)我们开发并测试了用于约氏疟原虫基因组分型的微阵列平台。我们表明，芯片是高度可靠和准确的调用寄生虫基因型。这部作品的手稿已经提交。4)我们已经将卵囊发育缺陷与约氏疟原虫6号染色体上的一个位点联系起来，并正在检测该位点上的候选基因。5)我们已经进行了全基因组的连锁分析，从遗传杂交的后代感染宿主的反应，并确定了数百个寄生虫的遗传位点与许多宿主基因的反应。6)我们进行了几次额外的P.y.杂交。negeriensis N67C和P.y. yoelii YM，获得了52个后代。这些后代的基因型和表型的特点。7)我们还将伯氏疟原虫安娜和伯氏疟原虫NK 165杂交，获得了几个后代，以鉴定与脑型疟疾相关的基因。最后，我们也在研究约氏疟原虫感染后细胞凋亡和坏死性凋亡的分子机制。了解宿主-寄生虫相互作用的分子机制将有助于制定控制寄生虫发育及其引起的疾病的有效措施。

In the year between 2012-2013, we focused on three major research area: 1) screening and characterizing drugs for combination therapy and transmission blocking; 2) studying molecular mechanisms of malaria pathogenesis using Plasmodium yoelii/mouse model; 3) molecular basis of an oocyst development defect. We have completed and published the work characterizing a group of compounds that can block malaria parasite transmission (Eastman et al 2013, AAC 57, 425). In collaboration with scientists in NCATS, we are performing large-scale screening of drug combinations. Promising drug combinations have been identified. We are also evaluating the effect of Ca++ and Na+ channel blockers on parasite response to artemisinin. Using rodent malaria parasite P. yoelii, we have made good progresses in studying parasite-host interaction in several directions: 1) We continue to evaluate candidate genes in the loci linked to host cytokine/chemokine response. One of the candidate genes has been shown to affect parasite growth after allelic replacement. 2) We showed that type I interferon (IFN-I) played an important role in controlling parasitemia of rodent malaria parasite Plasmodium yoelii nigeriensis N67. We also demonstrated that the RNA polymerase III and MDA5 mediated signaling contributed to the elevated IFN-I response. A manuscript from this work has been submitted. 3) We developed and tested a microarray platform for genotyping P. yoelii genome. We showed that the array was highly reliable and accurate in calling parasite genotype. A manuscript from this work has been submitted. 4) We have linked an oocyst development defect to a locus on chromosome 6 of P. yoelii and are testing candidate genes in the locus. 5) We have performed a genome-wide linkage analysis on host response to infection of progeny from a genetic cross and identified hundreds of parasite genetic loci linked to responses of many host genes. 6) We performed several additional crosses of P. y. negeriensis N67C and P. y. yoelii YM and have obtained 52 progeny. The genotypes and phenotypes of these progeny are being characterized. 7) We have also crossed P. berghei ANNA and P. berghei NK165 and obtained several progeny to identify genes linked to cerebral malaria. Finally, we are also studying the molecular mechanism of apoptosis and necroptosis after P. yoelii infection. Understanding the molecular mechanism of host-parasite interaction will allow development of effective measures for controlling parasite development and the disease it causes.