Human gastric B cell responses can be induced by intestinal immunisation

Area of Science:

• Gastroenterology
• Immunology
• Vaccinology

Background:

• Previous research indicated oral vaccination elicits strong B cell responses in the stomach of Helicobacter pylori infected individuals.
• This study investigated inducing gastric immune responses via intestinal and gastric immunization in H. pylori infected volunteers.

Purpose of the Study:

• To evaluate the efficacy of intestinal and gastric immunization in inducing gastric immune responses in H. pylori infected volunteers.
• To determine if H. pylori infection enhances the gastric mucosa's capacity to express intestinally induced B cell responses.

Main Methods:

• H. pylori infected subjects received two doses of inactivated cholera vaccine either intestinally (endoscopic delivery) or intragastrically.
• Uninfected individuals received the vaccine orally.
• Vaccine-specific antibody-secreting cells in gastric and duodenal biopsies were quantified using the enzyme-linked immunospot assay.

Main Results:

• Intestinal immunization induced specific gastric IgA-secreting cells in 5/8 volunteers and duodenal B cell responses in 7/8.
• Local gastric immunization induced gastric B cell responses in 4/8 volunteers and duodenal responses in all.
• Uninfected volunteers showed duodenal, but not gastric, responses to oral vaccination.

Conclusions:

• Helicobacter pylori infection enhances the gastric mucosa's ability to express intestinally induced B cell responses.
• These findings support the development of a therapeutic H. pylori vaccine that can be delivered along the entire upper gastrointestinal tract.