Role of dendritic cells in immunologic and smoking-induced lung diseases

Abstract

Dendritic cells (DCs) are part of the specific and innate immune system and present antigens for lymphocytes but also regulate the actions of cells of the innate immune system such as eosinophilic and neutrophilic granulocytes. There are several types of DCs, which might have opposite functions: some enhance an immune reaction, and others activate regulatory T (Treg) lymphocytes and thus can induce tolerance towards an antigen. Normally DCs migrate to regional lymph nodes and there they present modified antigens to cells of the immune system, however, in disease this might not function, resulting in the accumulation of DCs. The role of DCs in lung disease has not gotten much attention in the past, as investigations were predominantly focused on lymphocytes, macrophages, and granulocytes. Only in the last decades, DCs been more recognized. Several investigations are focusing on their role in immunotherapy in lung cancer, another focus is on inflammatory disorders including infections and allergies. In this review, non-tumor and non-infectious lung diseases with a focus on smoking-induced, autoimmune, and allergic diseases are discussed.