Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
Immunogenetics. 2012 Feb;64(2):155-61. doi: 10.1007/s00251-011-0571-3. Epub 2011 Sep 27.
Drosophila larvae react against eggs from the endoparasitoid wasp Leptopilina boulardi by surrounding them in a multilayered cellular capsule. Once a wasp egg is recognized as foreign, circulating macrophage-like cells, known as plasmatocytes, adhere to the invader. After spreading around the wasp egg, plasmatocytes form cellular junctions between the cells, effectively separating the egg from the hemocoel. Next, a second sub-type of circulating immunosurveillance cell (hemocyte), known as lamellocytes, adhere to either the wasp egg or more likely the plasmatocytes surrounding the egg. From these events, it is obvious that adhesion and cell shape change are an essential part of Drosophila's cellular immune response against parasitoid wasp eggs. To date, very few genes have been described as being necessary for a proper anti-parasitization response in Drosophila. With this in mind, we performed a directed genetic miniscreen to discover new genes required for this response. Many of the genes with an encapsulation defect have mammalian homologues involved in cellular adhesion, wound healing, and thrombosis, including extracellular matrix proteins, cellular adhesion molecules, and small GTPases.
果蝇幼虫通过在多层细胞胶囊中包围它们来抵抗内寄生蜂 Leptopilina boulardi 的卵。一旦蜂卵被识别为外来物，循环的巨噬细胞样细胞（称为浆血细胞）就会附着在入侵者上。在蜂卵周围扩散后，浆血细胞在细胞之间形成细胞连接，有效地将卵与血腔隔开。接下来，第二种循环免疫监视细胞（血细胞），称为瓣细胞，附着在蜂卵上或更可能附着在围绕卵的浆血细胞上。从这些事件中可以明显看出，黏附和细胞形状的变化是果蝇细胞免疫反应针对寄生蜂卵所必需的。迄今为止，只有少数基因被描述为在果蝇中对抗寄生虫的适当反应是必需的。考虑到这一点，我们进行了定向遗传微筛，以发现这种反应所需的新基因。许多具有包封缺陷的基因在哺乳动物中具有参与细胞黏附、伤口愈合和血栓形成的同源物，包括细胞外基质蛋白、细胞黏附分子和小 GTP 酶。
