The birth of innate immunity

Modern immunology has seen an apparent revolution with the recognition that human immune defense is not only the responsibility of bone marrow‐derived leucocytes, but also dependent on a coordinated network of many cell types including epithelial cells, fibroblasts and neural elements. This classic paper by Alexander Fleming and V.D. Allison (British J of Exp Path, 111, 1922, 252) was largely forgotten for 75 years and describes the discovery that epithelia produce a protein with direct antimicrobial activity. Thus, this paper represents the birth of the field now referred to as innate immunity and first describes an antimicrobial protein ( AMP ).