Ex vivo observation of insect hemocyte behavior against beads and nematodes in the presence of insect plasma.
Ex vivo observation of insect hemocyte behavior against beads and nematodes in the presence of insect plasma.
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在昆虫血浆存在的情况下，对昆虫血细胞针对珠子和线虫的行为进行离体观察。
DOI：
10.1017/s0031182019001550
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
T.
中科院分区：
文献类型：
--
作者：
Ono;M. Arimatsu;C. and Yoshiga;T.
昆虫寄生线虫已经获得了逃避宿主免疫反应的机制，从而成功地寄生。尽管从寄主免疫的角度理解逃避机制的进化很重要，但昆虫对非寄生线虫的免疫反应还没有得到很好的研究。在我们之前的研究中，我们证明了一种非昆虫寄生线虫秀丽线虫在大蜡蛾Galleria mellonella幼虫体内没有被血细胞包裹。为了了解线虫是如何影响昆虫血细胞逃脱包膜的，我们研究了线虫对梅隆线虫幼虫血腔中血细胞的影响。注射线虫后，血细胞密度下降，但血细胞死亡率和扩散能力不受影响，造血器官无明显变化。在体外，血细胞与线虫共孵育导致血细胞密度下降，我们观察到线虫对血细胞的摄食。向昆虫体内注射线虫取食延迟突变体不会引起血细胞密度的下降。血细胞密度的降低是由于线虫对血细胞的摄取。此外，昆虫病原线虫和其他细菌食性线虫也表现出相似的取食行为。线虫以血细胞为食的能力可能在摄食细菌的线虫中寄生线虫的进化中发挥了重要作用。
Insect parasitic nematodes have acquired mechanisms to evade their host immune response for successful parasitism. Despite the importance of understanding of the evolution of evasion mechanisms from host immunity, insect immune response against non-parasitic nematodes has not been well studied. In our previous study, we demonstrated that a non-insect parasitic nematode Caenorhabditis elegans was not encapsulated by haemocytes in the larvae of the greater wax moth Galleria mellonella. To understand how nematodes influence insect haemocytes to escape encapsulation, we examined the effect of C. elegans on haemocytes in the haemocoel of G. mellonella larvae. Injection of nematodes resulted in the decrease of haemocyte density while mortality and spreading ability of haemocytes, the haematopoietic organs were not affected. In vitro co-incubation of haemocytes with nematodes resulted in a decrease of haemocyte density and we observed feeding on haemocytes by nematodes. Injection of C. elegans feeding-delay mutants into insects did not cause the decrease of haemocyte density. The decrease of haemocyte density was due to the nematode's ingestion of haemocytes. Furthermore, an entomopathogenic nematode and other bacterial feeding nematodes also showed similar feeding behaviour. The nematode's ability to feed on haemocytes may have played an important role in the evolution of nematode parasitism in bacterial-feeding nematodes.