Vagus Nerve Versus Helicobacter pylori: New View on Old Secrets of Gastroduodenal Pathology

Abstract

Despite the long history of research on etiology and pathogenesis of gastroduodenal pathology, there are still a lot of unclear points in this field. Identification of Helicobacter pylori has been widely considered to be a major breakthrough in pathophysiology of gastroduodenal diseases. However, Helicobacter pylori infection, as a host-pathogen interaction, involves bidirectional cross-talk and requires assessment not only in terms of Helicobacter pylori virulence, but the immune reactivity of the host too. One of the major tasks of mucosal immunity is to discriminate between dangerous and harmless antigens, and it depends on neuroimmune cross-talk, which is orchestrated in gastroduodenal area by vagus nerve. In this review, we propose to recall and assess the role of the vagus nerve in the gastroduodenal homeostasis maintenance and anti-Helicobacter pylori fight, focusing on Helicobacter pylori-gastric mucosa-vagus nerve interaction. The following issues are discussed in this review: 1) Vagus nerve regulation of mucins production as a key element of gastrointestinal barrier against Helicobacter pylori colonization; 2) Virulence factors of Helicobacter pylori and cytoprotective effects of vagus nerve; 3) Peculiarities of Helicobacter pylori-induced innate immunity response, involving host cytokine network activation, and vagus nerve effects, realized through cholinergic anti-inflammatory pathway; 4) Modulation of maturation and activity of dendritic cells by Helicobacter pylori and acetylcholine; and 5) Alteration of adaptive immunity during Helicobacter pylori infection and role of acetylcholine. The structural and immune homeostasis of gastroduodenal area can be affected not only by Helicobacter pylori virulence factors, but theoretically by any shifting in vagus nerve reactivity and/or interaction with enteroendocrine and immune cells in gastroduodenal mucosa.