The role of platelets in defence against pathogens

Summary

Many more platelets are present in healthy mammals than are necessary for routine haemostasis. Thus, they could have other functions. Platelets have many of the attributes of innate immune function including Toll-like receptors. They also contain a wide range of anti-microbial peptides in storage granules. Platelets play an important role in bacterial infections, both in disease progress and in defence mechanisms depending on circumstances. Similar mechanisms are used in defence against fungi. Platelets are also involved in viral diseases, either in protecting from the immune system or in killing viruses that activate platelets. Finally, platelets have a role in defence against parasitic diseases, in particular malaria, that should not be ignored, and may aggravate some of the worst aspects. Platelets also have receptors for IgE and are implicated via parasitic disorders in development and problems of allergy.

Zusammenfassung

Gesunde Säugetiere haben viel mehr Thrombozyten, als für die normale Hämostase notwendig sind. Somit könnten sie weitere Funktionen besitzen. Thrombozyten verfügen über viele Eigenschaften einer angeborenen Immunfunktion (z. B. Toll-like Rezeptoren). Sie enthalten auch ein breites Spektrum an antimikrobiellen Peptiden in Speicherkörnchen. Thrombozyten spielen eine wichtige Rolle bei bakteriellen Infektionen: je nach Situation sowohl bei der Krankheitsprogression als auch bei Abwehrmechanismen. Ähnliche Mechanismen kommen bei der Abwehr von Pilzen zum Tragen. Thrombozyten sind außerdem bei Viruskrankheiten involviert, entweder beim Schutz durch das Immunsystem oder bei der Elimination von Viren, die Thrombozyten aktivieren. Schließlich haben Thrombozyten Bedeutung bei der Abwehr von Parasitenkrankheiten, v. a. Malaria, durch die sich einige der schlimmsten Aspekte verschlechtern könnten. Thrombozyten besitzen auch IgE-Rezeptoren und sind so über Parasitenkrankheiten an der Entstehung von Allergien und den damit verbundenen Problemen beteiligt.

Keywords

Platelets - haemostasis - immunology - bacteria - fungi - viruses - parasites - allergies

Schlüsselwörter

Thrombozyten - Hämostase - Immunologie - Bakterien - Pilze - Viren - Parasiten - Allergien

• References

• 1 Assinger A, Laky M, Schabbauer G. et al. Efficient phagocytosis of periodontopathogens by neutrophils requires plasma factors, platelets and TLR2. J Thromb Haemost 2011; 09: 799-809.
• 2 Alugupalli KR, Michelson AD, Barnard MR. et al. Platelet activation by a relapsing fever spirochaete results in enhanced bacterium–platelet interaction via integrin αIIbβ3 activation. Mol Microbiol 2001; 39: 330-340.
• 3 Bell RG. IgE, allergies and helminth parasites: a new perspective on an old conundrum. Immunol Cell Biol 1996; 74: 337-345.
• 4 Clark SR, Ma AC, Tavener SA. et al. Platelet TLR4 activates neutrophil extracellular traps to ensnare bacteria in septic blood. Nat Med 2007; 13: 463-469.
• 5 Clemetson KJ, Clemetson JM, Proudfoot AE. et al. Functional expression of CCR1, CCR3, CCR4, and CXCR4 chemokine receptors on human platelets. Blood 2000; 96: 4046-4054.
• 6 Cox D, McConkey S. The role of platelets in the pathogenesis of cerebral malaria. Cell Mol Life Sci 2010; 67: 557-568.
• 7 Flaujac C, Boukour S, Cramer EBorde. Platelets and viruses: an ambivalent relationship. Cell Mol Life Sci 2010; 67: 545-556.
• 8 Ghosh K, Gangodkar S, Jain P. et al. Imaging the interaction between dengue 2 virus and human blood platelets using atomic force and electron microscopy. J Electron Microsc (Tokyo) 2008; 57: 113-118.
• 9 Hasegawa S, Tashiro N, Matsubara T. et al. A comparison of FcεRI-mediated RANTES release from human platelets between allergic patients and healthy individuals. Int Arch Allergy Immunol 2001; 125 (Suppl. 01) 42-47.
• 10 Joseph M, Capron A, Ameisen JC. et al. The receptor for IgE on blood platelets. Eur J Immunol 1986; 16: 306-312.
• 11 Kerrigan SW, Cox D. Platelet–bacterial interactions. Cell Mol Life Sci 2010; 67: 513-524.
• 12 Krijgsveld J, Zaat SA, Meeldijk J. et al. Thrombocidins, microbicidal proteins from human blood platelets, are C-terminal deletion products of CXC chemokines. J Biol Chem 2000; 275: 20374-20381.
• 13 McMorran BJ, Marshall VM, de Graaf C. et al. Platelets kill intraerythrocytic malarial parasites and mediate survival to infection. Science 2009; 323: 797-800.
• 14 Matowicka-Karna J, Kemona H, Dymicka-Piekarska V, Butkiewicz A. The secretory activity of blood platelets-β-thromboglobulin and platelet factor 4 in echinococcosis. Pol Merkur Lekarski 2005; 19: 172-174.
• 15 Perkhofer S, Trappl K, Striessnig B. et al. Platelets enhance activity of antimycotic substances against non-Aspergillus fumigatus Aspergillus species in vitro. . Medical Mycology 2011; 49: 157-166.
• 16 Rødland EK, Ueland T, Pedersen TM. et al. Activation of platelets by Aspergillus fumigatus and potential role of platelets in the immunopathogenesis of Aspergillosis. Infect Immun 2010; 78: 1269-1275.
• 17 Semple JW, Italiano JE, Freedman J. Platelets and immune continuum. Nature Immunology Reviews 2011; 11: 264-274.
• 18 Shaw KT, Mawji Y, Stevenson MM, Kongshavn PA. Cells within the vascular system capable of mediating trypanocidal activity in vitro. Infect Immun 1991; 59: 3143-3150.
• 19 Sprague DL, Sowa JM, Elzey BD, Ratliff TL. The role of platelet CD154 in the modulation in adaptive immunity. Immunol Res 2007; 39: 185-193.
• 20 Stanley RG, Ngaiza JR, Wambayi E. et al. Platelets as an innate defence mechanism against Schistosoma mansoni infections in mice. Parasite Immunol 2003; 25: 467-473.
• 21 Sun H, Wang X, Degen JL, Ginsburg D. Reduced thrombin generation increases host susceptibility to group A streptococcal infection. Blood 2009; 113: 1358-1364.
• 22 Tamagawa-Mineoka R, Katoh N, Kishimoto S. Platelets play important roles in the late phase of the immediate hypersensitivity reaction. J Allergy Clin Immunol 2009; 123: 581-587.
• 23 Wiesner J, Vilcinskas A. Antimicrobial peptides: The ancient arm of the human immune system Virulence. 2010; 01: 440-464.
• 24 Yeaman MR. Platelets in defense against bacterial pathogens. Cell Mol Life Sci 2010; 67: 525-544.
• 25 Zander DM, Klinger M. The blood platelets contribution to innate host defense – what they have learned from their big brothers. Biotechnol J 2009; 04: 914-926.