Yu X-Q, Ling E, Tracy M E, Zhu Y
Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, 64110, USA.
Insect Mol Biol. 2006 Apr;15(2):119-28. doi: 10.1111/j.1365-2583.2006.00618.x.
Insect C-type lectins function as pattern recognition receptors in innate immunity. In the tobacco hornworm Manduca sexta, we have previously isolated three C-type lectins named immulectins, which are involved in innate immune responses. Here, we report a new member of the immulectin family, immulectin-4 (IML-4). IML-4 mRNA was detected in the fat body of control larvae and was induced in the fat body when larvae were injected with bacteria. Recombinant IML-4 bound to bacterial lipopolysaccharide (LPS) and lipoteichoic acid (LTA), and the binding activity was not affected by addition of calcium or EGTA. IML-4 agglutinated bacteria and yeast, and agglutination of Escherichia coli by IML-4 was concentration- and calcium-dependent. IML-4 also enhanced haemocyte encapsulation and melanization.
昆虫C型凝集素在先天免疫中作为模式识别受体发挥作用。在烟草天蛾Manduca sexta中，我们之前已分离出三种名为免疫凝集素的C型凝集素，它们参与先天免疫反应。在此，我们报告了免疫凝集素家族的一个新成员，免疫凝集素-4（IML-4）。在对照幼虫的脂肪体中检测到IML-4 mRNA，当幼虫注射细菌时，其在脂肪体中被诱导表达。重组IML-4与细菌脂多糖（LPS）和脂磷壁酸（LTA）结合，且结合活性不受添加钙或乙二醇双四乙酸（EGTA）的影响。IML-4能凝集细菌和酵母，IML-4对大肠杆菌的凝集作用具有浓度依赖性和钙依赖性。IML-4还能增强血细胞包囊化和黑化作用。
