Data from: Specificity of oral immune priming in the red flour beetle Tribolium castaneum

Immune specificity is the degree to which a host’s immune system discriminates among various pathogens or antigenic variants. Vertebrate immune memory is highly specific due to antibody responses. On the other hand, some invertebrates show immune priming, i.e. improved survival after secondary exposure to a previously encountered pathogen. Until now, specificity of priming has only been demonstrated via the septic infection route or when live pathogens were used for priming. Therefore, we tested for specificity in the oral priming route in the red flour beetle, Tribolium castaneum. For priming, we used pathogen-free supernatants derived from three different strains of the entomopathogen, Bacillus thuringiensis, which express different Cry toxin variants known for their toxicity against this beetle. Subsequent exposure to the infective spores showed that oral priming was specific for two naturally occurring strains, while a third engineered strain did not induce any priming effect. Our data demonstrate that oral immune priming with a non-infectious bacterial agent can be specific, but the priming effect is not universal across all bacterial strains.

免疫特异性（immune specificity）指宿主免疫系统区分不同病原体或抗原变异株的程度。脊椎动物的免疫记忆因抗体应答（antibody responses）而具备高度特异性。与之相对，部分无脊椎动物（invertebrates）可表现出免疫致敏（immune priming），即再次接触此前暴露过的病原体后存活率显著提升。截至目前，免疫致敏的特异性仅通过败血症感染途径（septic infection route）致敏实验，或使用活病原体（live pathogens）进行致敏的实验得到证实。为此，我们以赤拟谷盗（Tribolium castaneum）为研究对象，验证其口服致敏途径（oral priming route）下的免疫特异性。本次致敏实验所用制剂，为3株昆虫病原细菌苏云金芽孢杆菌（Bacillus thuringiensis）的无病原体上清液（pathogen-free supernatants），各菌株分别表达对该甲虫具有已知毒性的不同Cry毒素变异体（Cry toxin variants）。后续对感染性孢子（infective spores）的暴露实验结果显示，口服致敏对两株天然菌株具有特异性，而第三株工程菌株未诱导任何致敏效应。本研究数据表明，使用非感染性细菌制剂（non-infectious bacterial agent）进行口服免疫致敏可具备特异性，但该致敏效应并非在所有细菌菌株中均通用。