Department of Entomology, Washington State University, Pullman, WA, United States.
Hy-Line International, Dallas Center, IA, United States.
Front Immunol. 2024 Aug 7;15:1448320. doi: 10.3389/fimmu.2024.1448320. eCollection 2024.
Natural antibodies are used to compare immune systems across taxa, to study wildlife disease ecology, and as selection markers in livestock breeding. These immunoglobulins are present prior to immune stimulation. They are described as having low antigen specificity or polyreactive binding and are measured by binding to self-antigens or novel exogenous proteins. Most studies use only one or two antigens to measure natural antibodies and ignore potential effects of antigen specificity in analyses. It remains unclear how different antigen-specific natural antibodies are related or how diversity among natural antibodies may affect analyses of these immunoglobulins. Using genetically distinct lines of chickens as a model system, we tested the hypotheses that (1) antigen-specific natural antibodies are independent of each other and (2) antigen specificity affects the comparison of natural antibodies among animals. We used blood cell agglutination and enzyme-linked immunosorbent assays to measure levels of natural antibodies binding to four antigens: (i) rabbit erythrocytes, (ii) keyhole limpet hemocyanin, (iii) phytohemagglutinin, or (iv) ovalbumin. We observed that levels of antigen specific natural antibodies were not correlated. There were significant differences in levels of natural antibodies among lines of chickens, indicating genetic variation for natural antibody production. However, line distinctions were not consistent among antigen specific natural antibodies. These data show that natural antibodies are a pool of relatively distinct immunoglobulins, and that antigen specificity may affect interpretation of natural antibody function and comparative immunology.
天然抗体被用于比较不同分类单元的免疫系统，研究野生动物疾病生态学，并作为家畜育种中的选择标记。这些免疫球蛋白在免疫刺激之前就存在。它们被描述为具有低抗原特异性或多反应性结合，通过与自身抗原或新的外源性蛋白质结合来测量。大多数研究仅使用一种或两种抗原来测量天然抗体，而忽略了抗原特异性在分析中的潜在影响。不同的抗原特异性天然抗体如何相关，或者天然抗体的多样性如何影响这些免疫球蛋白的分析，目前仍不清楚。我们使用遗传上不同的鸡系作为模型系统，检验了以下假设：(1) 抗原特异性天然抗体彼此独立；(2) 抗原特异性会影响动物之间天然抗体的比较。我们使用血细胞凝集和酶联免疫吸附试验来测量与四种抗原结合的天然抗体水平：(i) 兔红细胞；(ii) 贻贝血蓝蛋白；(iii) 植物血球凝集素；或(iv) 卵清蛋白。我们观察到，抗原特异性天然抗体的水平没有相关性。不同鸡系之间的天然抗体水平存在显著差异，表明天然抗体产生存在遗传变异。然而，抗原特异性天然抗体之间的系别差异并不一致。这些数据表明，天然抗体是一组相对独特的免疫球蛋白，而抗原特异性可能会影响对天然抗体功能和比较免疫学的解释。
