Distinct Patterns and Magnitude Of T Cell Responses Are Associated With Seasonal Exposure To Timothy Grass Allergens

Abstract

RationaleTimothy grass (TG) pollen is a common seasonal airborne allergen associated with symptoms ranging from mild rhinitis to severe asthma. Our overall goal is to characterize TG-specific T-cell responses as a function of disease severity and also as a function of seasonality. We are further interested in assessing the quantitative differences, in terms of magnitude of the response, but also qualitative differences, in the type of T-cell subsets (TH) involved.MethodsPBMCs samples obtained either during the pollen season or out-of-season, from allergic and non-allergic controls were stimulated either with TG extract or a pool of the 20 previously identified antigenic regions. The production of lymphokines associated with different TH subsets was evaluated.ResultsAs expected, in PBMC samples obtained in-season, the cytokine production was higher in allergic donors as compared to out-of-season, for IFNg, IL-5, IL-10 and IL-17. Memory cells gave a more robust lymphokine response in-season in allergics. In the case of non-allergic individuals, we observed much lower responses in terms of the Th2 associated cytokine IL5, and expected a robust production of Th1-associated IFNg. Strikingly the Th1 responses in normal individuals were decreased in-season when compared to out-of-season. The potential basis of this phenomenon is currently being investigated. It is possible that this phenomenon might reflect differences in tissue homing or in-season allergen stimulation resulting in activation of regulatory cells/mechanisms in non-allergic individuals.ConclusionsOur data suggest that the magnitude and functionality of TH responses differ substantially for in-season versus out-of-season in allergic and non-allergic individuals. RationaleTimothy grass (TG) pollen is a common seasonal airborne allergen associated with symptoms ranging from mild rhinitis to severe asthma. Our overall goal is to characterize TG-specific T-cell responses as a function of disease severity and also as a function of seasonality. We are further interested in assessing the quantitative differences, in terms of magnitude of the response, but also qualitative differences, in the type of T-cell subsets (TH) involved. Timothy grass (TG) pollen is a common seasonal airborne allergen associated with symptoms ranging from mild rhinitis to severe asthma. Our overall goal is to characterize TG-specific T-cell responses as a function of disease severity and also as a function of seasonality. We are further interested in assessing the quantitative differences, in terms of magnitude of the response, but also qualitative differences, in the type of T-cell subsets (TH) involved. MethodsPBMCs samples obtained either during the pollen season or out-of-season, from allergic and non-allergic controls were stimulated either with TG extract or a pool of the 20 previously identified antigenic regions. The production of lymphokines associated with different TH subsets was evaluated. PBMCs samples obtained either during the pollen season or out-of-season, from allergic and non-allergic controls were stimulated either with TG extract or a pool of the 20 previously identified antigenic regions. The production of lymphokines associated with different TH subsets was evaluated. ResultsAs expected, in PBMC samples obtained in-season, the cytokine production was higher in allergic donors as compared to out-of-season, for IFNg, IL-5, IL-10 and IL-17. Memory cells gave a more robust lymphokine response in-season in allergics. In the case of non-allergic individuals, we observed much lower responses in terms of the Th2 associated cytokine IL5, and expected a robust production of Th1-associated IFNg. Strikingly the Th1 responses in normal individuals were decreased in-season when compared to out-of-season. The potential basis of this phenomenon is currently being investigated. It is possible that this phenomenon might reflect differences in tissue homing or in-season allergen stimulation resulting in activation of regulatory cells/mechanisms in non-allergic individuals. As expected, in PBMC samples obtained in-season, the cytokine production was higher in allergic donors as compared to out-of-season, for IFNg, IL-5, IL-10 and IL-17. Memory cells gave a more robust lymphokine response in-season in allergics. In the case of non-allergic individuals, we observed much lower responses in terms of the Th2 associated cytokine IL5, and expected a robust production of Th1-associated IFNg. Strikingly the Th1 responses in normal individuals were decreased in-season when compared to out-of-season. The potential basis of this phenomenon is currently being investigated. It is possible that this phenomenon might reflect differences in tissue homing or in-season allergen stimulation resulting in activation of regulatory cells/mechanisms in non-allergic individuals. ConclusionsOur data suggest that the magnitude and functionality of TH responses differ substantially for in-season versus out-of-season in allergic and non-allergic individuals. Our data suggest that the magnitude and functionality of TH responses differ substantially for in-season versus out-of-season in allergic and non-allergic individuals.