Effect of simulated gastro-duodenal digestion on the allergenic reactivity of beta-lactoglobulin.
Effect of simulated gastro-duodenal digestion on the allergenic reactivity of beta-lactoglobulin.
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DOI：
10.1186/2045-7022-1-6
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发表时间：
2011-08-09
影响因子：
4.4
通讯作者：
Papageorgiou, Photini
中科院分区：
文献类型：
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作者：
Bossios, Apostolos;Theodoropoulou, Maria;Papageorgiou, Photini
背景：大约2%的婴儿对牛奶（CM）过敏。膳食蛋白质（包括来自CM的蛋白质）的致敏性与它们的消化率有关，尽管这种联系的普遍性及其因果关系仍有待证实。在这项研究中，我们使用体外消化系统，研究胃肠道转运过程中β -乳球蛋白（blg）的消化率，并评估这一过程对CM过敏儿童blg过敏反应的影响。方法：采用体外消化方案制备Blg食糜，模拟单独胃消化或十二指肠消化，分别添加或不添加磷脂酰胆碱（PC）。采用SDS-PAGE法对blg食糜进行生化分析，采用夹心ELISA法测定其浓度。在体外通过EAST抑制、特异性嗜碱性粒细胞活化（basotest）和淋巴细胞增殖（pcna -流式细胞术）测定对blg过敏患者的血清和细胞，以及在体内通过皮肤点刺试验（SPT）评估其致敏反应性。结果：在胃-十二指肠消化后，Blg仅被分解为较小的肽，尽管仍保留了相当数量的完整蛋白质。消化没有改变blg的IgE结合能力，除了在没有PC的情况下进行的胃-十二指肠消化。这些结果与食糜中保留的完整blg的数量一致。总的来说，胃和胃十二指肠消化都增强了blg致敏的嗜碱性细胞的激活和致敏淋巴细胞的增殖。然而，消化后SPT的平均直径有减小的趋势，在第1期消化期间单独使用PC会导致平均直径显著增加。结论：消化并没有显著降低blg的致敏反应性，PC抑制了消化，从而保护了blg的致敏反应性。在体外试验中，与blg免疫反应性相比，SPT反应性降低。
BACKGROUND: Cow's milk (CM) allergy affects about 2% of infants. The allergenicity of dietary proteins, including those from CM, has been related to their digestibility although the generality of the link and its causality remains to be demonstrated. In this study we use an in vitro digestion system, to investigate the digestibility of beta-lactoglobulin (blg) during gastrointestinal transit and to assess the impact of this process on blg allergenic reactivity in CM allergic children.METHODS: Blg digesta were prepared using an in vitro digestion protocol simulating either gastric digestion alone or followed by duodenal digestion with or without phosphatidylcholine (PC). Biochemical analysis of blg digesta was performed by SDS-PAGE and their concentration was measured by a sandwich ELISA. Assessment of their allergenic reactivity was done in vitro by EAST inhibition, specific basophil activation (basotest) and lymphocyte proliferation (PCNA-flow cytometry) assays using sera and cells from patients allergic to blg and in vivo by skin prick testing (SPT) of these patients.RESULTS: Blg was only broken down to smaller peptides after gastro-duodenal digestion although a sizeable amount of intact protein still remained. Digestion did not modify the IgE binding capacity of blg except for gastro-duodenal digestion performed in the absence of PC. These results are consistent with the quantity of intact blg remaining in the digesta. Overall both gastric and gastroduodenal digestion enhanced activation of sensitized basophils and proliferation of sensitized lymphocytes by blg. However, there was a tendency towards reduction in mean diameter of SPT following digestion, the PC alone during phase 1 digestion causing a significant increase in mean diameter.CONCLUSIONS: Digestion did not reduce the allergenic reactivity of blg to a clinically insignificant extent, PC inhibiting digestion and thereby protecting blg allergenic reactivity. SPT reactivity was reduced compared to blg immunoreactivity in in vitro tests.