Innate and lymphocytic response of birch-allergic patients before and after sublingual immunotherapy.

Functional imbalance in Th1/Th2 cell response toward allergens is a recognized hallmark of allergic patients and a major roleof dendritic cells (DCs) in redirecting T-cell phenotypes after specific immunotherapy has been suggested. This study investigates the proliferative and cytokine responses of T cells cocultured with monocyte-derived DCs (MoDCs) after allergenstimulation in birch-allergic patients compared with controls and investigates whether sublingual immunotherapy (SLIT) could change the DC-driven immune response. T cells were stimulated with the major birch pollen allergen (nBet v1) and MoDCs from eight birch-allergic patients with seasonal allergic rhinitis and eight nonallergic controls. Proliferation and cytokineproduction were measured before and after one course of SLIT with birch allergoid. Significantly lower levels of proinflammatory(IL-1beta, p = 0.027; IL-6, p = 0.030; TNF-alpha, p - 0.019) and Th1 (interferon gamma, p = 0.032; IL-12, p = 0.05) cytokines were measured in supernatants of T cells and MoDCs cultures from allergic patients compared with nonallergiccontrols. After SLIT, significant increase in IL-12 (p = 0.039), IL-1beta (p = 0.040), IL-6 (p = 0.041), TNF- alpha (p = 0.048), and IL-10 (p = 0.048) and significant decrease in IL-13 (p = 0.001) were observed. MoDCs/T-cell cocultures, pulsed with thespecific allergen, produced lower quantities of proinflammatory and Th1 cytokines in allergic patients compared with healthy subjects, suggesting an allergen-specific impairment of natural immunity and Th1 immune response. A single course of SLIT was able to enhance allergen-specific innate immunity and to modify lymphocyte response, promoting Th1 and T-cell regulatory activity.