Department of Life Science, College of Natural Science, Hanyang University, Seoul, South Korea.
Research Institute for Natural Science, College of Natural Science, Hanyang University, Seoul, South Korea.
Front Immunol. 2020 Jan 31;11:63. doi: 10.3389/fimmu.2020.00063. eCollection 2020.
hemocytes, like those of mammals, are given rise from two distinctive phases during both the embryonic and larval hematopoiesis. Embryonically derived hemocytes, mostly composed of macrophage-like plasmatocytes, are largely identified by genetic markers. However, the cellular diversity and distinct functions of possible subpopulations within plasmatocytes have not been explored in larvae. Here, we show that larval plasmatocytes exhibit differential expressions of and during development. Moreover, removal of plasmatocytes by overexpressing pro-apoptotic genes, and in -positive plasmatocytes, feeding high sucrose diet, or wasp infestation results in increased circulating hemocytes that are -negative. Interestingly these -negative plasmatocytes retain expression, and animals expressing -negative and -positive subtype largely attenuate growth and abrogate metabolism. Furthermore, elevated levels of a cytokine, , are detected when -positive hemocytes are ablated, which in turn activates JAK/STAT activity in several tissues including the fat body. Finally, we observed that insulin signaling is inhibited in this background, which can be recovered by concurrent loss of . Overall, this study highlights heterogeneity in plasmatocytes and a functional plasticity of each subtype, which reaffirms extension of their role beyond immunity into metabolic regulation for cooperatively maintaining internal homeostatic balance.
血细胞，与哺乳动物的血细胞一样，在胚胎期和幼虫期造血过程中都经历两个不同的阶段。胚胎来源的血细胞，主要由类似于巨噬细胞的浆细胞组成，主要通过遗传标记来识别。然而，在幼虫中，尚未探索浆细胞内可能亚群的细胞多样性和独特功能。在这里，我们显示幼虫浆细胞在发育过程中表现出 和 的差异表达。此外，通过过表达促凋亡基因 、 和 在 -阳性浆细胞中去除浆细胞，或饲喂高蔗糖饮食或黄蜂侵袭，会导致循环血细胞增加，这些血细胞为 -阴性。有趣的是，这些 -阴性浆细胞保留 表达，并且表达 -阴性和 -阳性亚型的动物在很大程度上减弱了生长并消除了新陈代谢。此外，当 -阳性血细胞被剔除时，检测到细胞因子 的水平升高，这反过来又激活了包括脂肪体在内的几种组织中的 JAK/STAT 活性。最后，我们观察到在这种背景下胰岛素信号被抑制，而同时缺失 可以恢复这种抑制。总的来说，这项研究强调了 浆细胞的异质性和每个亚型的功能可塑性，这再次证实了它们的作用不仅限于免疫，还扩展到代谢调节，以共同维持内部的体内平衡。
