Researchers at The University of Texas Medical Branch (UTMB) at Galveston have made a remarkable discovery that may have direct implications on how seasonal allergy sufferers are successfully treated. Their study entitled “Pollen-induced Innate Recruitment of Neutrophils Facilitates Induction of Allergic Sensitization and Airway Inflammation” aimed to evaluate how neutrophils may control and regulate the allergic responses and inflammation seen in response to inhaled ragweed pollen. The results were recently published in the American Journal of Respiratory Cell and Molecular Biology.
- Antigen: is any foreign substance such as viruses that causes the immune system to respond by producing antibodies to get rid of it (i.e.,. pollen).
- Neutrophil: a component of the immune response that is essential in protecting the body against disease and infections by removing and destroying some types of bacteria, wastes, foreign substances, and other cells.
- Cytokines: proteins that have important cell signaling/communication functions required for a healthy immune system response to disease.
- Oxidative stress: is a disturbance in the body’s balance between the production of reactive oxygen species (free radicals) and antioxidant defenses
About the Study:
The researchers conducted this evaluation in the laboratory by exposing two groups of mice to ragweed pollen extract (RWPE): healthy mice and mice that were genetically modified to lack a gene that triggers chemokine production, and then comparing the levels of chemokines, neutrophils, and allergic sensitization in the presence of the allergen. The findings showed that, in comparison to the healthy mice with no genetic modification, the modified mice had higher levels of chemokines, neutrophils or allergic sensitization when they were exposed to RWPE. This means that inhibiting pollen-induced recruitment of neutrophils may be a successful strategy to prevent initiation of pollen-induced seasonal allergies.
In a University press release about the study’s findings, Dr. Sanjiv Sur, MD, professor in the department of internal medicine, division of allergy and immunology, and professor in pediatrics and microbiology and immunology, UTMB, and senior study author, explained, “The study reported a remarkable paradigm-shifting observation: repeated administration of neutrophils to the airways along with ragweed pollen recreates allergic sensitization in these genetically modified mice. These data suggest that when the body is forced to react to the presence of pollen in the airways, it recruits neutrophils that induce a state of continuous oxidative stress in the airways. This type of cellular stress from any cause can worsen allergic asthma.”
“We suggest that inhibiting recruitment of neutrophils by blocking chemokines may be a unique strategy for preventing pollen-induced allergic disorders,” Dr. Sur added.
Dr. Sur’s colleague and study lead author Koa Hosoki agrees with this observation and shared his insight on future research directions: “Until now, neutrophil recruitment after exposure to pollens was considered to be a non-specific event. In this study, we demonstrated for the first time that this crucial event initiates allergic sensitization to pollens. Future studies will have to determine if neutrophil recruitment is a universal mechanism of allergic sensitization to all inhaled allergens.”