Abstract

The adaptive immune system protects the body from the ever-changing landscape of foreign microorganisms. The two arms of the adaptive immune system, T cells and B cells, mount specific responses to pathogens by utilizing the diversity of their receptors, generated through hypermutation. B cells generate antibodies that strongly bind and inactivate antigens (toxic targets). Potent antibodies are generated through the process of “Affinity Maturation” which is akin to evolution at a rapid pace. T cells recognize and clear infected hosts when their highly variable receptors bind sufficiently strongly to complexes formed with antigen-derived peptides displayed on the cell surface. To avoid auto-immune responses, a process of “Thymic Selection” ensures that only self-tolerant receptors (binding weakly to self peptides) are engaged. Methods from Statistical Physics can be used to model and elucidate these processes, as will be demonstrated through several examples.