Platelet GPIb-IX Has Suppressive Effects on Septic Inflammation

Platelets are normally responsible for the arrest of bleeding but this function, for example, their ability to aggregate can contribute to pathological states, such as atherosclerosis and heart disease. In addition to their obvious role in hemostasis/thrombosis, platelets also seem to be firmly rooted with a great deal of other tasks primarily related to inflammatory/immune mechanisms.1 In particular, platelets express many important immune molecules such as T- and B-lymphocyte costimulatory CD154/CD40 molecules, bactericidal proteins, and most of the members of the Toll-like receptor family.1 It is becoming increasingly recognized that these types of molecules empower platelets with the ability to play critical proinflammatory immune-like roles in infectious states such as sepsis. Toll-like receptors are germline pattern recognition receptors and probably the most important immune sentinels of infectious attack, and all 13 members contain a common structural motif in the form of leucine-rich repeat units. Similarly, the GPIb-IX complex on the platelet also contains leucine-rich repeat; however, whether this shared sequence with Toll-like receptors confers anti-infectious properties to GPIb-IX is not clear.2,3 In this issue, Corken …