Central Product Safety, Miami Valley Innovation Center, The Procter & Gamble Company, Cincinnati, Ohio 45253, USA.
Toxicol Sci. 2011 Aug;122(2):422-36. doi: 10.1093/toxsci/kfr101. Epub 2011 May 9.
To establish further a practical quantitative in chemico reactivity assay for screening contact allergens, lysine peptide was incorporated into a liquid chromatography and tandem mass spectrometry-based assay for reactivity assessments of hapten and pre-/pro-hapten chemical sensitizers. Loss of peptide was determined following 24 h coincubation with test chemical using a concentration-response study design. A total of 70 chemicals were tested in discrete reactions with cysteine or lysine peptide, in the presence and absence of horseradish peroxidase-hydrogen peroxide oxidation system. An empirically derived prediction model for discriminating sensitizers from nonsensitizers resulted in an accuracy of 83% for 26 haptens, 19 pre-/pro-haptens, and 25 nonsensitizers. Four sensitizers were shown to selectively react with lysine including two strong/extreme and two weak sensitizers. In addition, seven sensitizers were identified as having higher reactivity toward lysine compared with cysteine. The majority of sensitizing chemicals (27/45) were reactive toward both cysteine and lysine peptides. An estimate of the relative reactivity potency was determined based on the concentration of test chemical that depletes peptide at or above a threshold positive value. Here, we report the use of EC15 as one example to illustrate the use of the model for screening the skin sensitization potential of novel chemicals. Results from this initial assessment highlight the utility of lysine for assessing a chemical's potential to elicit sensitization reactions or induce hypersensitivity. This approach has the potential to qualitatively and quantitatively evaluate an important mechanism in contact allergy for hazard and quantitative risk assessments without animal testing.
为了进一步建立一种实用的定量化学反应性分析方法，以筛选接触过敏原，将赖氨酸肽纳入基于液相色谱和串联质谱的分析方法中，用于评估半抗原和预/前半抗原化学敏化剂的反应性。采用浓度反应研究设计，在与测试化学物质共孵育 24 小时后，测定肽的损失。用胱氨酸或赖氨酸肽与 70 种化学物质进行了离散反应，分别在辣根过氧化物酶-过氧化氢氧化体系存在和不存在的情况下进行了测试。一个从经验中得出的预测模型，用于区分敏化剂和非敏化剂，对 26 个半抗原、19 个预/前半抗原和 25 个非敏化剂的准确率为 83%。结果表明，有 4 种敏化剂选择性地与赖氨酸反应，其中包括两种强/极端敏化剂和两种弱敏化剂。此外，还发现有 7 种敏化剂对赖氨酸的反应性高于半胱氨酸。大多数敏化化学物质（27/45）对胱氨酸和赖氨酸肽都有反应。根据测试化学物质的浓度来确定相对反应性强度，当该浓度使肽减少到或超过阳性阈值时，就认为该化学物质具有反应性。在这里，我们报告使用 EC15 作为一个例子来说明该模型在筛选新型化学物质的皮肤致敏潜力方面的应用。初步评估结果突出了赖氨酸在评估化学物质引起致敏反应或诱导过敏反应的潜力方面的应用。这种方法有可能在不进行动物测试的情况下，定性和定量评估接触过敏中的一个重要机制，用于危害和定量风险评估。
