Augustine Tracy, Badri Fariada, Murugesan Selvasankar, Espino Guarch Meritxell, Ameen Al-Aghbar Mohammad, El Nahas Rana, Akobeng Anthony, Elawad Mamoun, Al Khodor Souhaila, Adeli Mehdi, van Panhuys Nicholas
Laboratory of Immunoregulation, Sidra Medicine, Doha, Qatar E-mail:
Microbiome and Host-Microbes Interactions Laboratory, Sidra Medicine, Doha, Qatar E-mail:
Qatar Med J. 2022 Apr 4;2022(2):17. doi: 10.5339/qmj.2022.fqac.17. eCollection 2022.
Allergic diseases constitute significant health and economic issues in both developed and developing nations, with epidemiological studies demonstrating a rapid increase in the global prevalence of food allergy among the pediatric population. Cow milk protein allergy (CMPA), one of the most common forms of food allergies observed in early childhood, affects between 2%-6% of infants and children under 3 years of age. CMPA can present as either an IgE-mediated atopic allergy or a non-IgE mediated allergic response. Antigen-specific T cells play a pivotal role in directing the type of inflammatory immune response that occurs as well as in the formation of immunological memory. IgE-mediated CMPA is thought to develop because of an abnormal expansion of allergen-specific type-2 helper T (Th2) cells and a corresponding deficiency in immune regulation by regulatory T cells (Tregs), thereby altering the Th2/Treg balance. The gut microbiota, established very early during childhood through host-microbe interactions, can influence the incidence of allergic diseases. In this study, we aimed to analyze both the microbiome composition and CD4+T cell differentiation patterns in pediatric patients with and without cow milk allergy to establish the association between these factors. Using 16S rRNA sequencing, we analyzed the microbiome composition in stool samples of allergic and non-allergic pediatric patients aged between 1-4 years and identified the microbial species abundant in IgE and non-IgE mediated cow milk allergies. To assess the CD4+T cell differentiation patterns, peripheral blood mononuclear cells (PBMCs) from these patients were re-stimulated with cow milk antigen, and T cell subsets were assessed using flow cytometry. Antigen-specific CD4+T cells were identified and sorted for high throughput sequencing and subsequent gene expression analysis. The CD4+T cell differentiation patterns of the total and antigen-specific T cells were analyzed and statistically compared with controls. The identification of the correlation between the CD4+T cell differentiation patterns and species-specific microbial abundance in IgE and non-IgE mediated cow milk allergies can help in determining how the gut microbiome influences the CD4+T cell immune compartment development, ultimately leading to the development of cow milk allergy in pediatric patients.
过敏性疾病在发达国家和发展中国家都是重大的健康和经济问题，流行病学研究表明，全球儿童食物过敏患病率迅速上升。牛奶蛋白过敏（CMPA）是幼儿期最常见的食物过敏形式之一，影响2%-6%的3岁以下婴幼儿。CMPA可表现为IgE介导的特应性过敏或非IgE介导的过敏反应。抗原特异性T细胞在指导发生的炎症免疫反应类型以及免疫记忆形成中起关键作用。IgE介导的CMPA被认为是由于过敏原特异性2型辅助性T（Th2）细胞异常扩增以及调节性T细胞（Tregs）免疫调节相应缺陷，从而改变了Th2/Treg平衡。通过宿主-微生物相互作用在儿童早期很早就建立起来的肠道微生物群可影响过敏性疾病的发病率。在本研究中，我们旨在分析有和没有牛奶过敏的儿科患者的微生物组组成和CD4+T细胞分化模式，以确定这些因素之间的关联。使用16S rRNA测序，我们分析了1-4岁过敏和非过敏儿科患者粪便样本中的微生物组组成，并确定了IgE和非IgE介导的牛奶过敏中丰富的微生物种类。为了评估CD4+T细胞分化模式，用牛奶抗原重新刺激这些患者的外周血单核细胞（PBMCs），并使用流式细胞术评估T细胞亚群。鉴定并分选抗原特异性CD4+T细胞用于高通量测序和随后的基因表达分析。分析总T细胞和抗原特异性T细胞的CD4+T细胞分化模式，并与对照组进行统计学比较。确定IgE和非IgE介导的牛奶过敏中CD4+T细胞分化模式与物种特异性微生物丰度之间的相关性，有助于确定肠道微生物群如何影响CD4+T细胞免疫区室发育，最终导致儿科患者牛奶过敏的发生。
