Cellular and humoral defence mechanisms against bacteria

Host defence to bacterial infection is a complex process of highly efficient effector systems that co-operate to eliminate microbial invaders. The systems not only co-operate, they are also interdependent, as deficiency of one system may cause dysfunction in another. As is so often the case in medicine, the discovery of the various effector systems and their components originated from studies of patients with unusually severe, frequently recurring infections. Modern molecular biology has greatly aided in elucidation of the basic disorders and identification of the corresponding gene defect. This knowledge will hopefully provide us with better tools for causal therapy in the future; at present the only available "cure" is bone marrow transplantation, a treatment modality with many problems of its own.