Hemomucin, an O-Glycosylated Protein on Embryos of the Wasp <b><i>Macrocentrus cingulum</i></b> That Protects It against Encapsulation by Hemocytes of the Host <b><i>Ostrinia furnacalis</i></b>
作者：Hu Jian, Qiuyun Xu, Shengfeng Hu, Xiao‐Qiang Yu, Zhikun Liang, Wenqing Zhang · 发表于：Journal of Innate Immunity · 年份：2014 · DOI：10.1159/000360819 · 被引用次数：30 · 研究领域：Insect Resistance and Genetics、Trypanosoma species research and implications、Invertebrate Immune Response Mechanisms
It is unclear how endoparasites passively evade their host's immune reactions in most parasite-host systems. Hemomucin from the parasitoid wasp <i>Macrocentrus cingulum</i> (<i>Mc</i>HEM) is a 97-kDa transmembrane protein containing 51 potential O-glycosylation sites that can be specifically recognized by <i>Arachis hypogaea</i> lectin. <i>Mc</i>hem mRNA is highly expressed in <i>M. cingulum</i> eggs, morulae and secondary embryos, and <i>Mc</i>HEM protein is mainly located on the extraembryonic membrane of embryos. When secondary embryos of <i>M. cingulum</i> were transplanted into naïve larvae of their host, <i>Ostrinia furnacalis</i>, the embryos proliferated to generate dozens of embryos. However, more than 90% of these embryos were encapsulated by host hemocytes after blocking with anti-<i>Mc</i>HEM serum. Similarly, following knockdown of <i>Mc</i>hem expression using double-stranded RNA encoding<i> Mc</i>hem (<i>ds</i>hem), many more embryos were encapsulated by host hemocytes after transplantation compared to controls (p < 0.01). Furthermore, approximately 70% of the embryos were encapsulated by host hemocytes following digestion with O-glycosidase, which specifically digests β-gal (1&#x2192;3) linkages between GalNAc and Ser/Thr of proteins. Western blotting results showed that O-glycosidase digested <i>Mc</i&...