C3 convertase cleaves C3 in blood plasma, leading to a confo…

C3 convertase cleaves C3 in blood plasma, leading to a conformational change in the C3b fragment that exposes its reactive thioester group. The activated C3b is potentially harmful to the host, if it becomes covalently attached to a host cell, rather than to the surface of a pathogen. This deleterious outcome is largely avoided by:

Mucosal surfaces are found in tissues such as the gastrointe…

Mucosal surfaces are found in tissues such as the gastrointestinal tract, the reproductive tract and the mouth and respiratory tract. While the mouth and respiratory tract are routes of virus but not bacterial infections, the gastrointestinal tract is the route for bacterial but not virus infections.

The inflammatory response is characterized by four classic s…

The inflammatory response is characterized by four classic symptoms: heat, redness, pain, and swelling. In some instances, this response can be triggered by stimuli that are non-infectious such as asbestos. When exposure to the stimulating trigger is persistent, a state of chronic inflammation can result. This process is likely to be detrimental to the health of the host.