Читать книгу Immunology - Richard Coico - Страница 89

The alternative pathway of complement activation can be triggered by almost any foreign substance, and in the absence of specific antibody. Thus, the alternative pathway is a key part of the innate immune defenses, involved early in the response to pathogens. The most widely studied activators include lipopolysaccharides from the cell walls of Gram‐negative bacteria (which are endotoxins), the cell walls of some yeasts, and cobra venom factor, a protein present in some snakes. Some agents that activate the classical pathway—viruses, aggregated immunoglobulins, and necrotic cells—also trigger the alternative pathway.