Inhalation of Concentrated Ambient Particles from Urban Fresno, California During Allergic Sensitization Yields an Increase in Allergic Airway Inflammation

CHRISTOPHER CAROSINO, Julian Recendez, Kent Pinkerton

University of California, Davis

     Abstract Number: 380
     Last modified: November 9, 2009

Abstract
Recent epidemiological data has drawn correlations between particulate matter exposure and increased asthma symptoms and hospitalizations. The San Joaquin Valley of California has some of the highest particulate matter pollution in the country and asthma symptom prevalence is among the highest in the state. We wished to test the effect of urban particulate matter pollution from Fresno in the San Joaquin Valley on allergic airway inflammation with in-vivo exposures to determine if exposure to San Joaquin Valley particles can alter the allergic response. Two groups of male BALB/c mice were exposed to six days of fine/ultrafine concentrated ambient particulates (CAPs) or filtered air (control) for six hours/day at an urban site in Fresno, California in the San Joaquin Valley. Both groups of mice were intranasally instilled with 10 micrograms of ovalbumin in 50 microliters PBS immediately following exposures on alternating days for 3 days. Both groups were challenged with 1% aerosolized ovalbumin for one hour on days 11-13. On day 14, the animals were sacrificed and tissues collected for analysis. CAPs exposed animals inhaled an average concentration of 123 micrograms/m$^3 fine/ultrafine particles over the 6 days. Bronchoalveolar lavage (BAL) was performed in the control and CAPs exposed animals. Both animals exhibited cellular profiles indicative of a mild allergic response. While total cells recovered were increased in the CAPs exposed group, though not significantly, there were significant increases in leukocytes in the differential analysis of the recovered BAL fluid. Eosinophils increased nearly 5 fold, neutrophils increased 8 fold and lymphocytes increased nearly 3 fold in CAPs-exposed sensitized mice compared with filter air sensitized mice. Exposure during sensitization to fine/ultrafine concentrated ambient particles from Fresno in the San Joaquin Valley of California as compared to filtered air sensitized animals resulted in increased allergic airway inflammation subsequent to challenge. These results indicate that urban San Joaquin Valley concentrated ambient particles are capable of eliciting an exacerbated allergic response through exposure during sensitization alone when later challenged in the absence of particles.