Hapten Recognition by T Cells: A Functional and Molecular View

T cells specific for haptens determine immunopathology, as for the recognition of the β-lactamic ring by CD4+ T helper cells, responsible for the severe immune response to Penicillin in allergic patients. In this review we report studies that address functional and molecular aspects of hapten recognition by α/β T cells, enlightening the most relevant examples of hapten-specific T cells and their role in vivo. Using Trinitrophenyl as a contact allergen model and tumor associated carbohydrate antigens (TACA) as antigen models in cancer, our laboratory extensively studied T cell recognition by hapten-specific T cells suggesting new, unexplored avenues for T cell-based immunotherapy. In fact, the evidence of hapten recognition by “conventional” α/β T cells is of a critical importance in designing new immunotherapeutic approaches to treat allergies, cancer and chronic viral diseases.