<human>:  How does the immune system fight pathogens?
<bot>: The immune system is composed of several different cells and pathways that work together to fight pathogens. The primary function of the immune system is to recognize and destroy any foreign invaders, such as bacteria and viruses. The various cells of the immune system, such as macrophages, B cells, T cells, and neutrophils, help detect, target, and destroy these invaders by producing specialized proteins such as antibodies. These proteins are able to locate and bind to the antigens on the invading pathogens, marking them for destruction by other cells of the immune system. Additionally, the immune system produces a variety of immune cells that are involved in the production of inflammatory chemicals, which help to further destroy any invading pathogens.