Evasion of pathogens by avoiding recognition or eradication by complement,in part via molecular mimicry

Most pathogens invading the human body are attacked by the host immune syst em directly following entry and usually also during most stages of the dise ase, especially when they are in contact with the blood. However, pathogens have developed an effective battery of specific strategies to overcome imm une defense. This, far from being complete, review concentrates on evasion of pathogens by avoiding recognition or eradication by complement. The latt er is achieved by removal of complement either by shedding it off the micro bial surface, by consuming it away from the target membrane or by destroyin g it. Alternative procedures of avoiding eradication are the inhibition of complement activation or the employment of complement proteins via several highly sophisticated mechanisms, including the imitation of complement-like proteins (molecular mimicry). (C) 1999 Elsevier Science Ltd. All rights re served.