Alex Castañeda, M.S. Graduate Group in Immunology University of California Davis
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Transcript of Alex Castañeda, M.S. Graduate Group in Immunology University of California Davis
Exposure to agriculture dust particles during allergen sensitization exacerbates allergic
airway inflammation
Alex Castañeda, M.S.Graduate Group in Immunology
University of California Davis
Dr. Kent PinkertonDirector, Center for Health & the EnvironmentDepartment of Pediatrics, School of Medicine
Professor of Anatomy, Physiology and Cell BiologyUC Davis School of Veterinary Medicine
AsthmaAllergen
Environmental/OccupationalFactors
Genetic FactorsKim et al. 2010. The many pathways to asthma. Nature Immunology 11: 577-584
Ambient Particles
Ovalbumin
Symptoms: Airway inflammation, bronchial constriction, coughing, wheezing, and shortness of breath
Prevalence: 235 million people worldwide (11 million in the US)
In California (San Joaquin Valley) 25% of all children are diagnosed with allergic asthma
Allergic Asthma
Studies have shown a correlation between asthma and high particulate matter exposure-Particular matter exacerbate asthma-The use of source specific ambient particles has not been studied
Particulate Matter:Vehicle emissions (gasoline)Agricultural DustsDiesel exhaust gasesMineral dustsHydrocarbons
Particles Size:Coarse particlesFine ParticlesUltrafine particles (0.1µm in diameter)
Location:Fresno California (Leading agriculture-producing county in the nation)Particles collected during summer nights (2010)
Particle Pollution
Agricultural DustGeneration
Field preparation for crops, fertilization, crop harvest (ex- almonds)
CompositionInorganic (Mineral Dusts)
Silcates (aluminum silicates), quartz, transition metals
Organic (Carbonates)
Toxicity of Inorganic Agricultural DustsCellular toxicityGenerate free radicalsOxidative cellular stressActivation of the immune system towards an inflammatory state -Fibrogenesis
Hypothesis
Exposure to agricultural dust particles during sensitization with an allergen (house dust mites or ovalbumin) will exacerbate airway inflammation in BALB/c mice
MethodsMurine Model- BALB/c mice
Treatments Allergen- OVA, Purified OVA or
Purified House Dust Mites (HDM)Agricultural Dust- Ultrafine Particles (Fresno)
Sensitization (days 1, 3, & 5)OVA & pOVA- 10ug intranasalHDM- 25ug intranasal
Challenge (days 12, 13, & 14)OVA & pOVA- 10ug aerosolized HDM- 10 ug OVA
0 5 10 15
Allergen Sensitization+
Allergen Challenge
Necropsy
Ambient Particles
Groups 1 -Control (No Allergen + Filtered Air)2- OVA + Filtered Air3- OVA + Particulate Matter4- pOVA + Filtered Air5- pOVA + Particulate Matter 6- pHDM + Filtered Air7- pHDM + Particulate Matter
Tissue CollectionBlood Plasma (IgE,IgG1)BALFLung (Homogenize & Fixed)
BALF Cellular ProfliesMacrophages
Neutrophils
Total Cells
Eosinophils
Results- Tissue HistologyControl Allergen and particulate matter
Mucosubstance
Alcian Blue Periodic Acid Schiff’s Stain
Results- Tissue Histology
P MD
µm3
µm2Airway Inflammation:
Volume of Intraepithelial Mucosubstances
Area of Basal Lamina( )
Results- Tissue Histology
P MD
Results- Total Protein
Results- Antibody Production
Results- IL-17-A Production
Barnes et al. 2008. Immunology of asthma and COPD.Nature Reviews Immunology 8, 183-192
Results- IL-17-E Production
SummaryAirway inflammation was exacerbated when
particulate matter was introduced during allergen sensitization (HDM only, not OVA)-Significantly elevated levels of total cells, macrophages, and neutrophils
Based on muco-substance production HDMA causes significantly more airway inflammation over Ova
IL-17A production was elevated in the HDMA model, correlating with increased neutrophils, however there is no correlation to particles
Future Work
Investigate the mechanisms through which agricultural dust enhances airway inflammation-How particles activate the immune system?
Investigate neutrophil infiltration-Do particles increase neutrophilic inflammation?
AcknowledgementsPinkerton Laboratory UC Davis Western Center for Agricultural Health and Safety
Kent Pinkerton, Ph.D. Marc Schenker, M.D. Chris Carosino Sandra FreelandDale Uyeminami All other membersJanice PeakeKatherine Johnson Graduate Group in ImmunologyImelda EspirituAlexa PhamEsther ShinJocelyn ClaudeAll other members