White blood cells use brute force to dislodge bacteria

(Press-News.org) A vivid new image is taking shape in the world of cell biology: Imagine bacteria adhering to the surface of a cell, perhaps at the site of an injury or wound. In response, a white blood cell arrives at the scene. This cell encircles the pathogen with its membrane, forming a tight, constricting ring. With remarkable force, the white blood cell yanks the pathogen off the wound’s surface. The white blood cell then engulfs the pathogen in a process called phagocytosis, in which it “eats” the foreign invader to neutralize it.

This dramatic process might sound like something out of a science fiction story. 

“But it’s precisely what occurs inside our bodies,” said Xuefeng Wang, an associate professor at the University of Cincinnati’s Hoxworth Blood Center.

One key player in this process is integrin, a protein found on the surface of cells that facilitates adhesion, helping them stick to other surfaces. In this scenario, integrin is what the white blood cell actively works against when it pulls the pathogen away from the wound.

Wang’s biomedical research lab at Hoxworth focuses on understanding integrin and its role in cell biology. Notably, Hoxworth is the only blood center in the United States that houses an academic research arm, and Wang is one of two research professors on Hoxworth’s team. 

Thanks to his work, Wang is now the recipient of a five-year, $2.3 million grant from the National Institutes of Health (NIH). This funding will support his lab's ongoing research into blood platelets and macrophages (a type of white blood cell). He will further investigate how integrin tension — the physical force exerted by this protein — influences cell function. Wang will also delve into how this force affects platelet behavior, particularly in the formation of clots to stop bleeding during injuries. 

Editor's note: This grant was awarded before the current funding freeze went into effect.

 

Wang is the corresponding author of a study published recently in Nature Communications. The study highlights the newly discovered mechanism by which white blood cells use brute force to dislodge bacteria that stick to human tissues. Once detached, the white blood cells engulf and consume the pathogens.

This study was led by Wang, with Subhankar Kundu, a postdoctoral research fellow in his lab, serving as the first author. The research team also included Kaushik Pal and Arghajit Pyne, two other postdoctoral fellows in Wang's lab. Their collective work has far-reaching implications.

For example, consider the impact of environmental pollutants such as dust or smoke when they enter the lungs. These particles can adhere to lung tissue, and macrophages — the white blood cells responsible for cleaning up such intruders — are tasked with removing them. Macrophages dislodge the pollutants from the lung tissue and then ingest them, preventing harm to the respiratory system.

Looking ahead, Wang is hopeful that his research will contribute to the development of pharmaceuticals designed to enhance the ability of white blood cells to effectively target and neutralize pathogens. 

“This research could open up novel treatments that not only combat infections but also accelerate the healing process of wounds,” said Wang, underscoring the real-world impact of his work.

END