Swedish research might point to stomach cancer vaccine

GOTHENBURG, Sweden — New research at Sahlgrenska Academy might be an important step toward creating a vaccine against ulcers and stomach cancer, The Local reported Dec. 30.

Helicobacter pylori, the bacteria that causes ulcers, tricks the immune system so the body can't defend itself against the infection.

“By tricking the immune cells, the bacteria can keep the infection – and itself – alive,” Malin Hansson, a doctoral candidate at Sahlgrenska, told TT news agency.

Almost half of the Earth's population carry H. pylori. The bacteria don’t affect most people, but in some individuals it can lead to ulcers or stomach cancer.

Research has shown that the immune system has a powerful reaction to the bacteria, which somehow entices the immune cells to remain at the site of the infection rather than travelling to the lymph nodes to activate more immune cells. The result is a chronic infection.

“Quite often it means ulcers and gastritis, which in the worst case can develop into cancer,” Hansson said.

Her research also indicates that the antibodies that can protect the body against H. pylori are drawn to the infected tissue by a signaling molecule called MEC.

Many patients with stomach cancer have very low levels of antibodies.

“If antibodies really protect against the development of stomach cancer, it should be possible to develop a vaccine that increases the excretion of MEC, which in turn draws more antibodies to the [infected] tissue,” Hansson said.

“This is basic research. But in the long term, it might mean that we can vaccinate against diseases such as ulcers and stomach cancer,” she added.

Australian researchers Barry Marshall and Robin Warren won the 2005 Nobel Prize in Physiology or Medicine for their discovery of H. pylori, which led to the treatment of ulcers with antibiotics.