Macrophages in host defense mechanisms

Abstract

From an evolutionary point of view, macrophages form an ancient cell population, representing the main host defense mechanism until the development of the immune system. It might be speculated that, during evolution, macrophages have also acquired important functions in the regulation of humoral and cellular immune reactions and in the control of cell functions of various non-phagocytic cells. As a consequence, in mammals, macrophages may be multifunctional cells.