Mechanisms of inflammation: the good, the bad and the ugly

To the general public, the term, inflammation, is associated with pain, swelling, fever and a general sense of unease ranging from mere nuisance to debilitating illness. Under normal circumstances, the process of inflammation is actually a protective response designed to ward off invasion of the person by pathogens such as bacteria, viruses and/or parasites. The immune system of higher mammals (e.g. humans) is comprised of two distinct, arms, termed the innate and the adaptive systems. While these two components play unique roles in controlling pathogens, each relies, in some part, upon the effective function of the other in order to efficiently eliminate invading microorganisms. There are however situations in which this complex system is unable to properly function leading to unresolved infections and/or chronic states of inflammation. This review will summarize the basic mechanisms involved in the inflammatory process as well as discuss some of the key mediators and modulators of this process.