ABSTRACT

Our environment contains a large variety of infectious microorganisms and other potentially harmful substances. A complex and elaborate immune system, comprised of innate and acquired effector mechanisms, has evolved to evoke a rapid and efficient reactions to combat these invading pathogens. The mechanisms of innate resistance and acquired immunity are interdependent and regulate each other. The host defence response against viral infections is characterised by an early non- specific phase predominantly involving macrophages and natural killer cells, followed by an antigen-specific response mediated through the activation of T helper cells, cytotoxic T lymphocytes, and the production of virus-specific antibodies. Macrophages form an important bridge between innate and acquired antiviral immune responses, through their ability to remove viral particles by phagocytosis, their secretion of inflammatory and immunomodulating cytokines and their function as antigen presenting cell. This review describes the role of macrophages in the induction and regulation of acquired cytotoxic T lymphocyte responses against viral infections.