ABSTRACT
Equine recurrent airway obstruction (RAO; a term combining both chronic obstructive pulmonary disease (COPD) and summer pasture associated obstructive pulmonary disease (SPAOPD)) is one of the most common equine respiratory diseases with up to 50% of horses affected worldwide. The etiopathogenesis of RAO is unknown although pulmonary hypersensitivity to inhaled mold antigens may be involved. Recent work in our laboratory demonstrating elevated levels of IL-4 and IL-13 mRNA in the airways and peripheral blood of horses with RAO is consistent with an atopic component to RAO. Little is known regarding the earliest phases of RAO in horses. Here we describe the development of a novel airway model for equine RAO that utilizes ovalbumin-coated polystyrene beads for airway sensitization and challenge. Aerosol challenge of sensitized ponies with OVA-coated microbeads resulted in decreased airway compliance, increased percentage of lymphocytes and neutrophils in the bronchoalveolar lavage fluid, and evidence of a Th2 cytokine response in the bronchoalveolar cells. These results suggest that this approach may be useful in describing the initial stages of RAO development in the horse.
Subject(s)
Airway Obstruction/veterinary , Horse Diseases/etiology , Airway Obstruction/etiology , Airway Obstruction/immunology , Animals , Horses , Interleukin-13/genetics , Interleukin-4/genetics , Interleukin-5/genetics , RNA, Messenger/analysis , RecurrenceABSTRACT
BACKGROUND AND PURPOSE: Fatty acid composition of rodent diets can affect baseline immune function as measured in vitro and in vivo. Stress, in a variety of forms, can also affect immune function. Possible interaction between diet and other stressors has not been fully explored. We examined the interaction between sleep deprivation stress and dietary fatty acid composition in altering lymphocyte responses to mitogen stimulation. METHODS: Rats were fed diets containing various sources of fatty acids, then were subjected to sleep deprivation. Splenocytes were harvested and assayed for responsiveness to various mitogens, using a 72-h proliferation assay. RESULTS: Rats subjected to sleep deprivation experienced significant suppression of in vitro proliferative response to various mitogens. This immune suppression was dependent on duration of sleep deprivation. Feeding sleep deprived rats a diet enriched in fatty acids abrogated the effect of sleep deprivation. CONCLUSIONS: The fat content of rodent diets can have a marked effect on baseline and stress-modulated immune responses.
Subject(s)
Dietary Fats/administration & dosage , Sleep Deprivation/diet therapy , Sleep Deprivation/immunology , Animals , Fatty Acids/administration & dosage , Immune Tolerance/drug effects , In Vitro Techniques , Lymphocyte Activation/drug effects , Male , Rats , Rats, Sprague-Dawley , Stress, Physiological/diet therapy , Stress, Physiological/immunologyABSTRACT
Equine influenza virus remains a major health concern for the equine industry in spite of ongoing vaccination programmes. Previous work has shown that the immune system of horses can be affected by strenuous exercise. The possible adverse consequence of exercise-induced alterations in lymphocyte responses measured in vitro was unknown. Here we demonstrate that subjecting vaccinated ponies to a 5 day strenuous exercise programme results in a significant suppression of their T cell-mediated immune response to equine influenza virus as measured by decreased lymphoproliferation and gamma interferon production measured in vitro. These same ponies also demonstrated increased susceptibility to influenza disease following a challenge exposure to the same strain of virus. Rested ponies that had received the same vaccine and challenge were completely protected from disease. Our results demonstrate that exercise-induced suppression of the equine immune response to influenza virus can be associated with an increased susceptibility to disease.
