Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; Danone Nutricia Research, Utrecht, The Netherlands.
TNO, Utrecht, The Netherlands.
Toxicol Lett. 2020 Oct 15;333:312-321. doi: 10.1016/j.toxlet.2020.05.020. Epub 2020 May 27.
This 4-center study is part of a project to validate a food allergy murine model for safety testing of hydrolyzed infant formulas.
The aim of the current multi-center experiment was to evaluate the residual allergenicity of three partial hydrolyzed whey proteins (pWH) in a multiple-parameter cow's milk allergy murine model and to compare to the classically used guinea pig model. Previous work showed differences in the magnitude of the allergic response to whey between centers. To get a first insight in the effect of housing on the robustness of the mouse model, microbiota composition of non-sensitized mice was analyzed and compared between centers.
Mice were sensitized intragastrically (i.g.) with whey, pWH or eWH using cholera toxin as an adjuvant. In mice, whey-IgE/IgG1, acute allergic symptoms were determined upon whey challenge. Guinea pigs were orally sensitized ad libitum via the drinking water (day 0-37) and challenged intravenously with whey on day 49. The microbial composition in fecal samples was determined in non-sensitized mice in all 4 research centers before and after conduct of the study.
Elevated levels of whey-IgG1 were detected in whey-sensitized mice in all centers. Except for pWH-A in center 4, we observed elevated levels of whey-IgE in whey-sensitized mice and mice sensitized with pWH-A, -B, -C. Center 2 was excluded from further analysis because of non-significant IgE levels in the positive control. In contrast to whey-mice, pWH-A treated mice showed no acute skin response, mMCP-1 release or change in body temperature upon whey challenge in all centers, which corresponds with the absence of anaphylactic shock symptoms in both the mouse and guinea pig model. pWH-B and -C induced anaphylactic shock symptoms in the guinea-pig and mice whereas results on the remaining allergic outcomes in mice were inconclusive. No differences in microbiota composition were measured in response to the challenge and Microbiota composition depended on the location of the centers.
Both animal models showed comparable results on the residual allergenicity of partial hydrolyzed whey proteins, but none of the centers was able to differentiate between the residual sensitizing capacities of the pWH-B and -C based on a single elicitation parameter in the murine model. Differences in microbiota composition might contribute to the robustness of the food allergy murine model. For a well-balanced prediction on the potential allergenicity of hydrolyzed infant formulas a multiple murine parameter model is suggested to decrease the risk of false positive or false negative results. A future challenge is to develop an overall scoring system for proper risk assessment, taking all parameters into account.
本四项中心研究是验证水解婴儿配方食品安全性测试用食物过敏鼠模型的项目的一部分。
本多中心实验的目的是评估三种部分水解乳清蛋白（pWH）在牛乳过敏鼠模型中的残留致敏性，并与经典的豚鼠模型进行比较。先前的工作表明，各中心对乳清的过敏反应程度存在差异。为了初步了解饲养对鼠模型稳健性的影响，分析了非致敏小鼠的微生物组成，并在各中心之间进行了比较。
用霍乱毒素作为佐剂，通过胃内（i.g.）给予乳清、pWH 或 eWH 使小鼠致敏。在小鼠中，在乳清攻毒时测定乳清-IgE/IgG1、急性过敏症状。豚鼠通过自由饮水（第 0-37 天）经口致敏，并在第 49 天静脉内用乳清攻毒。在所有 4 个研究中心进行研究之前和之后，均在非致敏小鼠的粪便样本中测定微生物组成。
除中心 4 的 pWH-A 外，我们观察到所有中心的乳清致敏小鼠和用 pWH-A、-B、-C 致敏的小鼠中均检测到乳清-IgE 水平升高。由于阳性对照中 IgE 水平无统计学意义，中心 2 被排除在进一步分析之外。与乳清处理的小鼠不同，pWH-A 处理的小鼠在所有中心的乳清攻毒时均未出现急性皮肤反应、mMCP-1 释放或体温变化，这与在鼠和豚鼠模型中均未出现过敏性休克症状相对应。pWH-B 和 -C 在豚鼠和小鼠中引起过敏性休克症状，而在小鼠中其余过敏结果的结果尚无定论。在微生物组组成方面，没有因攻毒而发生变化，微生物组组成取决于中心的位置。
两种动物模型在部分水解乳清蛋白的残留致敏性方面均显示出可比的结果，但没有一个中心能够根据鼠模型中的单一激发参数区分 pWH-B 和 -C 的残留致敏能力。微生物组组成的差异可能有助于食物过敏鼠模型的稳健性。为了对水解婴儿配方食品的潜在致敏性进行良好的平衡预测，建议使用多参数鼠模型，以降低假阳性或假阴性结果的风险。未来的挑战是开发一种整体评分系统，以适当考虑所有参数进行正确的风险评估。
