Fig. 2

Platelet immune receptors and functions. Schematic representation of the crucial roles of platelets in inflammatory processes. 1) The binding of IgG-pathogen complex to IgG receptor (FcγRIIA) leads to pathogen engulfment and reduction. 2,3) Platelets can express TLRs that bind to bacterial LPS and specific PAMPs. 4) Interaction of platelet CD40L with different immune cells has an important role in leukocyte recruitment and activation. 5) Platelet MHC class I molecules are located in intracellular space but upon activation these molecules expressed on cell membrane and can activate antigen-specific CD8+ T cells. 6) Activation of TLR7 that distinguish ssRNAs leads to P-selectin as a platelet activation marker and CD154 receptor. 7) Platelets contain many proinflammatory and anti-inflammatory cytokines and chemokines and be can released from these cells to the extracellular space. 8) Soluble form of CD40L (sCD40L) enhances platelet activation, aggregation, and platelet-leukocyte attachment [3, 6, 42]