Blood feeding induces hemocyte proliferation and activation in the African malaria mosquito, Anopheles gambiae Giles
Blood feeding induces hemocyte proliferation and activation in the African malaria mosquito, Anopheles gambiae Giles
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DOI：
10.1242/jeb.094573
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发表时间：
2014-04-01
影响因子：
2.8
通讯作者：
Michel, Kristin
中科院分区：
文献类型：
--
作者：
Bryant, William B.;Michel, Kristin
疟疾是一个全球性的公共卫生问题，特别是在撒哈拉以南非洲，那里的冈比亚按蚊是原生动物恶性疟原虫的主要传播媒介。疟疾媒介能力的一个决定因素是蚊子的免疫系统。血细胞是一个关键组成部分，因为它们产生支持或预防疟疾寄生虫发展的可溶性免疫因子。然而，尽管它们在媒介能力方面很重要，但对它们基本生物学的了解才刚刚发展。应用新技术对蚊子血细胞进行研究，研究了血粉对蚊子血细胞种群动态、DNA复制和细胞周期进程的影响。与普遍发表的工作相反，这里提出的数据表明，成年蚊子的血细胞继续经历低基础水平的复制。此外，血液摄入在24小时内引起血细胞的显著变化。血细胞表现出细胞数量、大小、粒度和Ras-MAPK信号的增加以及细胞表面部分的改变。由于这些变化是哺乳动物和黑腹果蝇免疫细胞活化的众所周知的标志，我们进一步研究了血餐是否会改变血细胞来源的免疫因子的表达。事实上，吸血24小时后，蚊子的血细胞显示出更高水平的补体和黑色素化免疫反应的关键成分。综上所述，这项研究表明，血液进食的正常生理过程激活了蚊子的先天免疫反应。这一过程可能部分受到Ras-MAPK信号的调控，强调了血液摄食和免疫之间的一种新的机制联系。
Malaria is a global public health problem, especially in sub-Saharan Africa, where the mosquito Anopheles gambiae Giles serves as the major vector for the protozoan Plasmodium falciparum Welch. One determinant of malaria vector competence is the mosquito's immune system. Hemocytes are a critical component as they produce soluble immune factors that either support or prevent malaria parasite development. However, despite their importance in vector competence, understanding of their basic biology is just developing. Applying novel technologies to the study of mosquito hemocytes, we investigated the effect of blood meal on hemocyte population dynamics, DNA replication and cell cycle progression. In contrast to prevailing published work, the data presented here demonstrate that hemocytes in adult mosquitoes continue to undergo low basal levels of replication. In addition, blood ingestion caused significant changes in hemocytes within 24 h. Hemocytes displayed an increase in cell number, size, granularity and Ras-MAPK signaling as well as altered cell surface moieties. As these changes are well-known markers of immune cell activation in mammals and Drosophila melanogaster Meigen, we further investigated whether a blood meal changes the expression of hemocyte-derived immune factors. Indeed, hemocytes 24 h post-blood meal displayed higher levels of critical components of the complement and melanization immune reactions in mosquitoes. Taken together, this study demonstrates that the normal physiological process of a blood meal activates the innate immune response in mosquitoes. This process is likely in part regulated by Ras-MAPK signaling, highlighting a novel mechanistic link between blood feeding and immunity.