Department of Laboratory Medicine, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, China.
Department of Digestive Endoscopy Center, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, China.
Helicobacter. 2023 Jun;28(3):e12959. doi: 10.1111/hel.12959. Epub 2023 Feb 24.
Although Helicobacter pylori is recognized as an extracellular infection bacterium, it can lead to an increase in the number of CD8 T cells after infection. At present, the characteristics of H. pylori antigen-specific CD8 T cells and the epitope response have not been elucidated. This study was focused on putative protective antigen UreB to detect specific CD8 T-cell responses in vitro and screen for predominant response epitopes.
The PBMCs collected from H. pylori-infected individuals were stimulated by UreB peptide pools in vitro to identify the immunodominant CD8 T-cell epitopes. Furthermore, their HLA restriction characteristics were detected accordingly by NGS. Finally, the relationship between immunodominant responses and appearance of gastric symptoms after H. pylori infection was conducted.
UreB-specific CD8 T-cell responses were detected in H. pylori-infected individuals. Three of UreB dominant epitopes (A-2 (UreB : GVKPNMIIK), B-4 (UreB : SEYVGSVEV), and C-1 (UreB : SRKEYVSMY)) were firstly identified and mainly presented by HLA-A1101, HLA-B4001 and HLA-C*0702 alleles, respectively. C-1 responses were mostly occurred in H. pylori-infected subjects without gastric symptoms and may alleviate the degree of gastric inflammation.
The UreB dominant epitope-specific CD8 T-cell response was closely related to the gastric symptoms after H. pylori infection, and the C-1 (UreB ) dominant peptides may be protective epitopes.
虽然幽门螺杆菌被认为是一种细胞外感染菌，但它可以在感染后导致 CD8 T 细胞数量增加。目前，尚未阐明幽门螺杆菌抗原特异性 CD8 T 细胞的特征和表位反应。本研究聚焦于假定保护性抗原 UreB，以体外检测幽门螺杆菌感染个体中特定的 CD8 T 细胞反应，并筛选主要的反应表位。
从幽门螺杆菌感染个体中收集 PBMCs，体外用 UreB 肽库刺激，以鉴定免疫优势 CD8 T 细胞表位。此外，通过 NGS 检测相应的 HLA 限制特征。最后，研究免疫优势反应与幽门螺杆菌感染后出现胃症状之间的关系。
在幽门螺杆菌感染个体中检测到 UreB 特异性 CD8 T 细胞反应。首次鉴定了 UreB 三个优势表位（A-2（UreB：GVKPNMIIK）、B-4（UreB：SEYVGSVEV）和 C-1（UreB：SRKEYVSMY）），分别主要由 HLA-A1101、HLA-B4001 和 HLA-C*0702 等位基因呈递。C-1 反应主要发生在无胃症状的幽门螺杆菌感染个体中，可能减轻胃炎症的程度。
UreB 优势表位特异性 CD8 T 细胞反应与幽门螺杆菌感染后的胃症状密切相关，C-1（UreB）优势肽可能是保护性表位。
