The outbreak of the new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a public health emergency. Asthma does not represent a risk factor for COVID-19 in several published cohorts. We hypothesized that the SARS-CoV-2 proteome contains T cell epitopes, which are potentially cross-reactive to allergen epitopes. We aimed at identifying homologous peptide sequences by means of two distinct complementary bioinformatics approaches. Pipeline 1 included prediction of MHC Class I and Class II epitopes contained in the SARS-CoV-2 proteome and allergens along with alignment and elaborate ranking approaches. Pipeline 2 involved alignment of SARS-CoV-2 overlapping peptides with known allergen-derived T cell epitopes. Our results indicate a large number of MHC Class I epitope pairs including known as well as de novo predicted allergen T cell epitopes with high probability for cross-reactivity. Allergen sources, such as Aspergillus fumigatus, Phleum pratense and Dermatophagoides species are of particular interest due to their association with multiple cross-reactive candidate peptides, independently of the applied bioinformatic approach. In contrast, peptides derived from food allergens, as well as MHC class II epitopes did not achieve high in silico ranking and were therefore not further investigated. Our findings warrant further experimental confirmation along with examination of the functional importance of such cross-reactive responses.

新的严重急性呼吸系统综合症冠状病毒2（SARS-CoV-2）的爆发是突发公共卫生事件。在一些已发表的队列研究中，哮喘并不代表COVID-19的危险因素。我们假设SARS-CoV-2蛋白质组包含T细胞表位，这些表位可能与过敏原表位发生交叉反应。我们旨在通过两种不同的互补生物信息学方法鉴定同源肽序列。管道1包括SARS-CoV-2蛋白质组和过敏原中包含的MHC I类和II类MHC抗原表位的预测，以及比对和精心设计的排名方法。管道2涉及SARS-CoV-2重叠肽与已知过敏源T细胞表位的比对。我们的结果表明，大量的MHC I类抗原决定簇对包括已知的以及从头预测的过敏原T细胞抗原决定簇，具有很高的交叉反应可能性。过敏源，例如由于它们与多种交叉反应性候选肽相关联，而与所应用的生物信息学方法无关，因此烟曲霉，鼠疫和皮肤癣菌物种特别受关注。相反，源自食物过敏原的肽以及II类MHC表位没有达到很高的计算机等级，因此未作进一步研究。我们的发现需要进一步的实验证实，以及对这种交叉反应反应的功能重要性的检查。