The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
PLoS One. 2012;7(7):e40615. doi: 10.1371/journal.pone.0040615. Epub 2012 Jul 9.
Integrins are a family of adhesion receptors which regulate cell proliferation, differentiation, leukocyte migration, and complement receptor-dependent phagocytosis. In invertebrates, as a cell adhesion receptor, β integrins play an important role for the balanced activation of immune defense responses especially during the encounter of infections. The present study attempts to characterize the immune functions of shrimp integrin (LvIntegrin) to have better understanding on the immune system and its regulation mechanisms in shrimps.
A shrimp integrin was identified from the Pacific white shrimp Litopenaeus vannamei (designated as LvIntegrin). Its full-length cDNA was of 2621 bp with an open reading frame (ORF) of 2439 bp encoding a polypeptide of 812 amino acids. The mRNA expression of LvIntegrin was significantly up-regulated at 3, 6 and 12 h after Listonella anguillarum challenge. The cDNA fragment encoding β integrin domains (βA and hybrid domain) of LvIntegrin was recombined and expressed in Escherichia coli BL21(DE3)-pLysS. The recombinant protein (rLvIntegrin) could significantly agglutinate the tested microbe including E. coli JM109, L. anguillarum, Micrococcus luteus and Candida dattiladattila in the presence of divalent cations. Moreover, when NIH3T3 cells were cultured with rLvIntegrin, the proliferation rate increased significantly in a dose-dependent manner.
LvIntegrin, a shrimp β integrin was identified from L. vannamei, shared several highly conserved features. LvIntegrin exhibited broad-spectrum agglutination activity towards both bacteria and fungi and could improve the proliferation of NIH3T3 cells, indicating that LvIntegrin is involved in the immune response against microbe challenge and regulation of cell proliferation as a cell adhesion receptor in shrimp.
整合素是一类细胞黏附受体家族，其调节细胞增殖、分化、白细胞迁移和补体受体依赖性吞噬作用。在无脊椎动物中，作为一种细胞黏附受体，β整合素在免疫防御反应的平衡激活中发挥重要作用，特别是在遇到感染时。本研究试图描述虾整合素（LvIntegrin）的免疫功能，以便更好地了解虾类的免疫系统及其调节机制。
从斑节对虾（Litopenaeus vannamei）中鉴定出一种虾整合素（命名为 LvIntegrin）。其全长 cDNA 为 2621bp，开放阅读框（ORF）为 2439bp，编码 812 个氨基酸的多肽。LvIntegrin 的 mRNA 表达在鳗弧菌攻毒后 3、6 和 12 小时显著上调。LvIntegrin 的β整合素结构域（βA 和杂交结构域）的 cDNA 片段在大肠杆菌 BL21(DE3)-pLysS 中重组表达。重组蛋白（rLvIntegrin）在二价阳离子存在的情况下，可显著凝集测试的微生物，包括大肠杆菌 JM109、鳗弧菌、藤黄微球菌和地霉。此外，当 NIH3T3 细胞与 rLvIntegrin 共培养时，增殖率呈剂量依赖性显著增加。
从斑节对虾中鉴定出的虾类β整合素 LvIntegrin 具有几个高度保守的特征。LvIntegrin 对细菌和真菌均具有广谱的凝集活性，并能提高 NIH3T3 细胞的增殖率，表明 LvIntegrin 作为细胞黏附受体参与了虾类对微生物挑战的免疫反应和细胞增殖的调节。
