Laboratory of Aquacultural Biology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori Amamiya-machi, Aoba-ku, Sendai, Miyagi 981-8555, Japan.
Laboratory of Aquacultural Biology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori Amamiya-machi, Aoba-ku, Sendai, Miyagi 981-8555, Japan; Laboratory of Molecular Marine Biology, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8564, Japan.
Dev Comp Immunol. 2014 Mar;43(1):30-4. doi: 10.1016/j.dci.2013.10.011. Epub 2013 Nov 4.
Peptidoglycan recognition protein (PGRP) recognizes invading bacteria through their peptidoglycans (PGN), a component of the bacterial cell wall. Insect PGRPs contribute to effective immune systems as inducers of other host defense responses, while this function has not been reported from PGRP of bivalves. In this study, recombinant CgPGRP-S1S (rCgPGRP-S1S), produced in the mantle and the gill, was synthesized and used to elucidate the immunological function of CgPGRP-S1S. rCgPGRP-S1S bound specifically to DAP-type PGN and to Escherichia coli cells, but not to other DAP-type PGN-containing bacterial species, Vibrio anguillarum, or Bacillus subtilis. Antibacterial activity was not detected, but E. coli cells were agglutinated. Moreover, in addition to these direct interactions with bacterial cells, rCgPGRP-S1S induced secretion of granular contents by hemocyte degranulation. Taken together, these results suggest for the first time that a PGRP of bivalves is, just as in insects, involved in host defense, not only by direct interaction with bacteria, but also by triggering other defense pathways.
肽聚糖识别蛋白 (PGRP) 通过其肽聚糖 (PGN) 识别入侵的细菌，PGN 是细菌细胞壁的组成部分。昆虫 PGRPs 作为其他宿主防御反应的诱导剂，有助于有效的免疫系统，而这种功能尚未从双壳类动物的 PGRP 中报道过。在这项研究中，在套膜和鳃中合成了重组 CgPGRP-S1S(rCgPGRP-S1S)，并用于阐明 CgPGRP-S1S 的免疫学功能。rCgPGRP-S1S 特异性结合 DAP 型 PGN 和大肠杆菌细胞，但不结合其他 DAP 型含有 PGN 的细菌物种，鳗弧菌或枯草芽孢杆菌。未检测到抗菌活性，但大肠杆菌细胞被凝集。此外，除了与细菌细胞的这些直接相互作用外，rCgPGRP-S1S 还通过血细胞脱颗粒诱导颗粒内容物的分泌。综上所述，这些结果首次表明，双壳类动物的 PGRP 与昆虫一样，不仅通过与细菌的直接相互作用，而且通过触发其他防御途径参与宿主防御。
