Bacterium-Induced Alteration in Neutrophils Identified

Photo: Lee-Ann AllenDr. Lee-Ann Allen, Professor of Internal Medicine and Microbiology, is the senior author on a recent publication appearing in the prestigious Journal of Immunology. This paper shows for the first time that Helicobacter pylori, a bacterium that infects the stomach of humans and can cause gastric ulcers and gastric cancer, can induce subtype differentiation of human neutrophils, our most abundant white blood cells and fighters of infections.

For Dr. Allen and her co-authors—Dr. Laura Whitmore, a postdoctoral member of Dr. Allen’s lab, and Megan Weems, a medical student working in Dr. Allen’s lab at the time of this research—the road to this discovery began with curiosity about an odd relationship between H. pylori and neutrophils. In many stomach infections, it seemed, Dr. Allen explained, that H. pylori “wants” to be in a neutrophil-rich environment, “surrounded by cells that are trying to kill it, but cannot.”

A few years ago, understanding of neutrophils broadened to see that they were not all identical. But what was causing those changes seems to vary. In instances of H. pylori infection, this article shows that profound nuclear hypersegmentation induces the subtype differentiation in human neutrophils. The cells exhibit surface markers indicative of sustained activation and are pro-inflammatory and cytoxic, evidenced by their destruction of gastric epithelial cells. “In short,” Dr. Allen says, “the data indicate that H. pylori reprograms human neutrophils in a manner that directly favors disease.” Future studies will attempt to understand the underlying mechanism that enables this pathogen capable of turning its enemy against itself. 

This research is funded by an NIH R01, for which Dr. Allen is the principal investigator, in addition to Infectious Diseases and Immunology NIH/NIAID T32 Training Grants, which funded Ms. Weems summer research fellowship and a portion of Dr. Whitmore’s postdoctoral fellowship, respectively. Congratulations to these three on this important discovery and publication.