Helicobacter chronic stage inflammation undergoes fluctuations that are altered in tlpA mutants

Abstract

Helicobacter pylori colonizes half of the worlds population and is responsible for a significant disease burden by causing gastritis, peptic ulcers, and gastric cancer. The development of host inflammation drives these diseases, but there are still open questions in the field about how H. pylori controls this process. We characterized H. pylori inflammation using an eight month mouse infection time course and comparison of wild type and a previously identified mutant lacking the TlpA chemoreceptor that causes elevated inflammation. Our work shows that H. pylori chronic stage corpus inflammation undergoes surprising fluctuations, with changes in Th17 and eosinophil numbers. The H. pylori tlpA mutant changed the inflammation temporal characteristics, resulting in different inflammation from wild type at some time points. tlpA mutants have equivalent total and gland colonization at late stage infections. During early infection, in contrast, they show elevated gland and total colonization compared to WT. Our results suggest the chronic inflammation setting is dynamic, and may be influenced by colonization properties of early infection. ImportanceHelicobacter pylori established chronic infection in half of the worlds population. This infection initiates during childhood, and leads to later life gastric diseases including gastritis, peptic ulcers, and gastric cancer. These diseases are driven by host inflammation, with more severe inflammation leading to more severe disease. It is not fully understood how H. pylori controls inflammation. In this work, we used an H. pylori mouse infection model and characterized inflammation and colonization of wild-type H. pylori and a mutant that was known to cause elevated inflammation. We found that inflammation in the chronic stage undergoes surprising fluctuations, with related changes in Th17 numbers. H. pylori tlpA mutants caused offset inflammation dynamics, suggesting that H. pylori infection underlies this dynamism. Although there were not colonization dynamics at the time of inflammation fluctuations, there were differences between WT and tlpA mutant colonization at early time points. Our results suggest the chronic inflammation setting is more dynamic than previously thought and may be influenced by colonization properties of early infection.