The immune system is commonly divided into innate and adaptive immune system. However, innate T cells bridge these two branches, as they share features with innate NK cells and of adaptive memory T cells. The most frequent and arguably the most important innate T cells are invariant Natural Killer (iNKT) cells and mucosal NKT (mNKT or MAIT) cells. Both cell types are very potent and important effector cells in a variety of immune responses. Furthermore, basically, all iNKT and mNKT cells in every human being express an almost identical antigen receptor and respond to the same antigens in a similar fashion. Therefore, their therapeutic potential is immense as one effective treatment could, in theory, be applied to every human. However, many important aspects of iNKT and mNKT cell biology have not been uncovered. Furthermore, the potential of innate T cells for therapeutic applications for a chronic inflammatory disease has not been explored so far.
1) The role of iNKT cells in the lung: iNKT cells play a potent, but surprisingly dichotomous role in lung inflammation: Whereas, following lung infections their Th1 response is protective, during allergic responses, like asthma, their Th2 response is deleterious. We study both types of lung inflammation side-by-side to understand how the initial iNKT cell response in the lung is regulated. As an experimental model, infection with Streptococcus pneumonia and an allergen-induced airway hypersensitivity model are used. Uncovering key regulatory mechanisms in directing iNKT cell responses in the lung will provide novel drug candidates for therapeutic applications.