Gastric Th17 Cells Specific for H+/K+-ATPase and Serum IL-17 Signature in Gastric Autoimmunity

• Published in: Frontiers in immunology 2022-07, Vol.13, p.952674-952674
• Main Authors: Della Bella, Chiara, Antico, Antonio, Panozzo, Maria Piera, Capitani, Nagaja, Petrone, Luisa, Benagiano, Marisa, D’Elios, Sofia, Sparano, Clotilde, Azzurri, Annalisa, Pratesi, Sara, Cianchi, Fabio, Ortiz-Princz, Diana, Bergman, Mathijs, Bizzaro, Nicola, D’Elios, Mario Milco
• Format: Article
• Language: English
• Subjects: gastric autoantigen; gastric autoimmunity; gastric cancer; H+/K+-ATPase; Immunology; T cells; Th17
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2022.952674

Human gastric autoimmunity [autoimmune gastritis (AIG)] is characterized by inflammation of the gastric mucosa and parietal cell loss. The gastric parietal cell proton pump H + /K + -adenosine triphosphatase (H + /K + -ATPase) is the major autoantigen in AIG. Our work aimed to investigate the gastric H + /K + -ATPase-specific T helper 17 (Th17) responses in AIG and serum interleukin (IL)-17 cytokine subfamily in AIG patients, in healthy subjects [healthy controls (HCs)], and in patients with iron deficiency anemia (IDA) without AIG. We analyzed the activation of gastric lamina propria mononuclear cells (LPMCs) by H + /K + -ATPase and the IL-17A and IL-17F cytokine production in eight patients with AIG and four HCs. Furthermore, we compared serum levels of IL-17A, IL-17F, IL-21, IL-17E, IL-22, and IL-23 in 43 AIG patients, in 47 HCs, and in 20 IDA patients without AIG. Gastric LPMCs from all AIG patients, but not those from HCs, were activated by H + /K + -ATPase and were able to proliferate and produce high levels of IL-17A and IL-17F. AIG patients have significantly higher serum IL-17A, IL-17F, IL-21, and IL-17E (393.3 ± 410.02 pg/ml, 394.0 ± 378.03 pg/ml, 300.46 ± 303.45 pg/ml, 34.92 ± 32.56 pg/ml, respectively) than those in HCs (222.99 ± 361.24 pg/ml, 217.49 ± 312.1 pg/ml, 147.43 ± 259.17 pg/ml, 8.69 ± 8.98 pg/ml, respectively) and those in IDA patients without AIG (58.06 ± 107.49 pg/ml, 74.26 ± 178.50 pg/ml, 96.86 ± 177.46 pg/ml, 10.64 ± 17.70 pg/ml, respectively). Altogether, our results indicate that IL-17A and IL-17F are produced in vivo in the stomach of AIG patients following activation with H + /K + -ATPase and that serum IL-17A, IL-17F, IL-21, and IL-17E levels are significantly elevated in AIG patients but not in patients without AIG. These data suggest a Th17 signature in AIG and that IL-17A, IL-17F, IL-21, and IL-17E may represent a relevant tool for AIG management.