Pathogen Reduction | |
Carrying pathogens (viruses, bacteria and parasites) [11, 16,17,18] | |
Inhibiting growth of S. aureus via β-defensins and NETs induction [23,24,25,26] | |
Growth inhibition of plasmodia via PF 4- and Duffy Ag-dependent manner [11] | |
Platelet TLRs | |
Pathogen detection [1] | |
TLR4: LPS-induced platelet-neutrophil aggregation [35, 36], bacterial trapping via NETs in sepsis [13], possible role in thrombopoiesis [29] | |
TLR2: producing ROS which may act directly on bacteria [39] | |
Platelet CD40L (CD154) | |
Inflammatory reactions via interaction with CD40 of endothelial cells: release of adhesion molecules [42] | |
Secreting soluble CD40L, and promoting thrombosis [42] | |
Binding of DCs: inhibiting DC differentiation, suppressing the proinflammatory cytokines | |
IL-12p70 and TNF-α, promoting IL-10 secretion [47] | |
Triggering of T cell responses and migration to inflammatory areas [48, 49] | |
Promoting B cell differentiation and Ab class switching [50] | |
Platelet MHC class I | |
Interference with T cell-mediated cytotoxicity responses [53,54,55] | |
Intracellular MHC class I connection with α granules [56] | |
Platelet cytokines/chemokines | |
Carrying abundant chemokines and cytokines involved in pro/anti-inflammatory pathways [57] | |
PF4: promoting monocytes and neutrophils migration [62], inducing leukocyte pro-inflammatory cytokine release, phagocytosis, chemotaxis, generation of ROS [64] | |
RANTES (CCL5): promoting monocytes and macrophages chemotaxis and recruitment to the endothelium [65,66,67,68,69,70] | |
IL-1β: central to pro-inflammatory cytokine cascade [73], possible role in dengue virus replication in platelets [74, 75] |