A Novel Mouse Model of Whole Pollen Grain Induced Rhinitis

Abstract

RATIONALE: Mouse models mimicking human rhinitis are important tools to study the mechanisms behind the disease. We have established a murine model of rhinitis in which mice are both sensitized and challenged with Phleum Pratense (Phl p) pollen.METHODS: Mice were sensitized intranasally for 1-3 weeks, rested for 1-2 weeks and then challenged intranasally for 1-3 weeks with Phl p pollen. During challenge the number of sneezes was counted. Following sacrifice the mice were analyzed for specific antibodies and T-cell reactivity.RESULTS: Mice sensitized for 3 weeks, rested for 2 weeks and challenged for 3 weeks displayed clear signs of rhinitis such as increased serum IgE, increased sneezing, which could be down regulated with anti-histamine and increased T-cell reactivity in cervical lymph nodes. The IgE response was dependent on the dose of pollen whereas the T-cell reactivity was less influenced. Sensitizing for less than 3 weeks did not lead to increased levels of IgE demonstrating that the duration of sensitization is important for development of rhinitis. Resting the mice for 1 week instead of 2 weeks led to lower IgE levels, indicating that the duration of the pause is important. In contrast, both 1, 2 and 3 weeks of challenge led to high levels of IgE.CONCLUSIONS: We here present a murine model of rhinitis in which mice are both sensitized and challenged by intranasal administration of Phl p pollen grains. This model has many similarities to human rhinitis and may be useful in studies of the pathogenesis of allergic airway hyper reactivity. RATIONALE: Mouse models mimicking human rhinitis are important tools to study the mechanisms behind the disease. We have established a murine model of rhinitis in which mice are both sensitized and challenged with Phleum Pratense (Phl p) pollen. METHODS: Mice were sensitized intranasally for 1-3 weeks, rested for 1-2 weeks and then challenged intranasally for 1-3 weeks with Phl p pollen. During challenge the number of sneezes was counted. Following sacrifice the mice were analyzed for specific antibodies and T-cell reactivity. RESULTS: Mice sensitized for 3 weeks, rested for 2 weeks and challenged for 3 weeks displayed clear signs of rhinitis such as increased serum IgE, increased sneezing, which could be down regulated with anti-histamine and increased T-cell reactivity in cervical lymph nodes. The IgE response was dependent on the dose of pollen whereas the T-cell reactivity was less influenced. Sensitizing for less than 3 weeks did not lead to increased levels of IgE demonstrating that the duration of sensitization is important for development of rhinitis. Resting the mice for 1 week instead of 2 weeks led to lower IgE levels, indicating that the duration of the pause is important. In contrast, both 1, 2 and 3 weeks of challenge led to high levels of IgE. CONCLUSIONS: We here present a murine model of rhinitis in which mice are both sensitized and challenged by intranasal administration of Phl p pollen grains. This model has many similarities to human rhinitis and may be useful in studies of the pathogenesis of allergic airway hyper reactivity.