Researchers develop model to study immune response to infections that cause peptic ulcers

September 24, 2013, Virginia Tech
Similar anatomical properties between the stomach of humans and pigs make the pig an excellent model for studying H. pylori-associated disease. Virginia Bioinformatics Institute researchers have demonstrated that H. pylori (arrow) is found in the inner lining of the stomach and near aggregates of immune cells. The picture insert shows the typically spindle-shaped H. pylori magnified 1,000 times.

(Medical Xpress)—Researchers at the Virginia Bioinformatics Institute have developed a new large animal model to study how the immune system interacts with the stomach bacterium Helicobacter pylori, the leading cause of peptic ulcer disease.

The discovery in the October edition of the journal Infection and Immunity may inform changes in the ways doctors treat patients. An estimated 4 million Americans have sores in the stomach lining known as , according to the American Gastroenterological Association.

Although the bacterium is found in more than half the world's population, most people do not develop diseases. However, some experience of the stomach, or gastritis, which can lead to the development of ulcers or cancer.

In addition to its role as a pathogen, the bacteria have beneficial effects, preventing certain chronic inflammatory and metabolic diseases, including Type 2 diabetes, and obesity.

When bacteria reside within host cells, the immune system typically recruits a type of white blood cell called T cells—in this case, CD8+ cytotoxic T cells—to destroy the infected cells.

However, the researchers found that these cells may contribute to tissue damage.

In patients with H. pylori-associated gastritis, higher numbers of cytotoxic T cells are present, indicating that these cells may contribute to the development of gastric lesions.

To study immune responses in H. pylori-mediated disease, researchers at the Virginia Bioinformatics Institute's Nutritional Immunology and Molecular Medicine Laboratory developed a pig model that closely mimics the human gastric environment. When pigs were infected with H. pylori, the researchers observed an increase in another type of immune cells called pro-inflammatory CD4+ T , followed by an increase in CD8+ cytotoxic T cells, according to the study.

Scientists did not observe an increase in CD8+ T cells in mouse and gerbil models of H. pylori infection. However, the rise of the cells in pigs mirrors the recent findings in human clinical studies.

"Pigs have greater anatomic, physiologic and immunologic similarities to humans than mice, the main animal model used in biomedical research," said Raquel Hontecillas, co-director of the Nutritional Immunology and Molecular Medicine Laboratory and the Center for Modeling Immunity to Enteric Pathogens. "The results from our new pig model closely mimic what has been reported in clinical settings, which will allow us to comprehensively and systematically investigate human immune responses to H. pylori."

The discovery will help scientists better understand the complex interactions of H. pylori and its host.

Researchers within the Center for Modeling Immunity to Enteric Pathogens are using results from the pig model and other experimental data to develop a computational model of H. pylori infection. Such modeling efforts aim to develop faster, more efficient ways to predict initiation, progression and outcomes of infection.

Explore further: Stomach bacteria switch off human immune defences to cause disease

More information: iai.asm.org/content/81/10/3803.abstract

Related Stories

Stomach bacteria switch off human immune defences to cause disease

September 1, 2013
Helicobacter pylori is a bacterium that establishes a life-long stomach infection in humans, which in some cases can lead to duodenal ulcers or stomach cancer. New research, presented at this week's Society for General Microbiology ...

Villain stomach bug may have a sweet side: Researchers reveal how 'bad' gut bacteria may help control diabetes

February 8, 2013
A stomach bacterium believed to cause health problems such as gastritis, ulcers, and gastric cancer may play a dual role by balancing the stomach's ecosystem and controlling body weight and glucose tolerance, according to ...

Other stomach microbiota modulate resistance to H. pylori-driven ulcers

March 25, 2013
Mice with different naturally occurring stomach bacteria have distinct susceptibilities to disease caused by Helicobacter pylori, the well-known cause of ulcers in humans, according to a study published online ahead of print ...

Some bacteria may protect against disease caused by stomach infection

March 12, 2013
Half of the world's human population is infected with the stomach bacteria called Helicobacter pylori, yet it causes disease in only about 10 percent of those infected. Other bacteria living in the stomach may be a key factor ...

Ironing out the link between H. pylori infection and gastric cancer

December 21, 2012
H. pylori frequently causes gastric ulcers and is also one of the greatest risk factors for gastric cancer. H. pylori infection is also associated with another gastric cancer risk factor, iron deficiency.

Recommended for you

Improving vaccines for the elderly by blocking inflammation

January 22, 2018
By identifying why skin immunity declines in old age, a UCL-led research team has found that an anti-inflammatory pill could help make vaccines more effective for elderly people.

Novel genomic tools provide new insight into human immune system

January 19, 2018
When the body is under attack from pathogens, the immune system marshals a diverse collection of immune cells to work together in a tightly orchestrated process and defend the host against the intruders. For many decades, ...

First vaccine developed against grass pollen allergy

January 18, 2018
Around 400 million people worldwide suffer in some form or other from a grass pollen allergy (rhinitis), with the usual symptoms of runny nose, cough and severe breathing problems. In collaboration with the Viennese firm ...

Genomics reveals key macrophages' involvement in systemic sclerosis

January 18, 2018
A new international study has made an important discovery about the key role of macrophages, a type of immune cell, in systemic sclerosis (SSc), a chronic autoimmune disease which currently has no cure.

Researchers discover key driver of atopic dermatitis

January 17, 2018
Severe eczema, also known as atopic dermatitis, is a chronic inflammatory skin condition that is driven by an allergic reaction. In their latest study, researchers at La Jolla Institute reveal an important player that promotes ...

Who might benefit from immunotherapy? New study suggests possible marker

January 16, 2018
While immunotherapy has made a big impact on cancer treatment, the fact remains that only about a quarter of patients respond to these treatments.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.