Abraham D, Grieve R B, Mika-Grieve M
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706.
Exp Parasitol. 1988 Apr;65(2):157-67. doi: 10.1016/0014-4894(88)90119-1.
The objective of this study was to analyze surface properties of larval Dirofilaria immitis with potential relevance to protective immunity. Comparisons were made between third (L3)- and fourth-stage larvae (L4) based on their net surface charge, surface carbohydrate and antigen composition, ability to nonspecifically absorb host proteins, complement activation, and nonspecific cellular adherence. It was determined that L3 had a net negative surface charge, whereas L4 had either a neutral or weakly positive surface charge. The lectin Con A, but not any of the other lectins tested, bound only to the surface of L4, and not to that of L3. Monoclonal antibodies were prepared which reacted with the surface of L3 or with the surface of L4, but never both. L4 were found to nonspecifically adsorb host protein to their surfaces, whereas L3 did not. Both L3 and L4 were found to activate complement through the alternate pathway. Finally, nonspecific cellular adherence was found on L3 both in vitro and in vivo but not on L4. The surfaces of L3 and L4 were thus shown to be significantly different and, potentially, in ways which would have great impact in the generation and effectiveness of a protective immune response.
本研究的目的是分析犬恶丝虫幼虫的表面特性，这些特性可能与保护性免疫相关。基于第三期（L3）和第四期幼虫（L4）的净表面电荷、表面碳水化合物和抗原组成、非特异性吸附宿主蛋白的能力、补体激活以及非特异性细胞黏附，对两者进行了比较。结果表明，L3具有净负表面电荷，而L4具有中性或弱阳性表面电荷。凝集素Con A仅与L4的表面结合，而不与L3的表面结合，其他测试的凝集素均无此现象。制备了与L3表面或L4表面反应，但从不与两者都反应的单克隆抗体。发现L4能将宿主蛋白非特异性吸附到其表面，而L3则不能。发现L3和L4均通过替代途径激活补体。最后，在体外和体内均发现L3存在非特异性细胞黏附，而L4则没有。因此，L3和L4的表面显示出显著差异，并且可能以对保护性免疫反应的产生和有效性有重大影响的方式存在差异。
