Danger signal, Toll-like receptor, and cancer immunotherapy

The danger model is based on the premise that the innate immune system has evolved to recognize danger by activating antigen presenting cells (APCs) in inflammatory tissues, resulting in the induction of adaptive immunity in some cases. Recently, Toll-like receptor-signaling has been highlighted as a signal for growth, activation and maturation of APCs, and is considered to consist of the large part of danger signals. Old BRMs like BCG, OK-432 and PSK that have been used clinically for a long time should be reassessed as to whether or not they are ligands for Toll-like receptors, and reused in cancer immunotherapy, The relationship of Toll-like receptor-signaling and differentiation, activation and maturation of human dendritic cells has also been commented on in detail for future dendritic cell therapy against cancer.