Human platelets attenuate Aspergillus species via granule-dependent mechanisms.

Using laser scanning microscopy, we investigated whether platelets are capable of internalizing Aspergillus conidia and examined Aspergillus-platelet adherence. The influence of platelets on fungal growth was evaluated by assessing galactomannan (GM) release, hyphal elongation, and colony size. A secretion assay with [(3)H]-serotonin (5-hydroxytryptamine [5-HT]) was performed. Exposure to platelets resulted in significantly decreased GM release (p<.05), hyphal elongation (p<.001), colony size, pigmentation, and 5-HT release ( p<.05). A lack of antifungal effects was observed with the microfilament inhibitor cytochalasin D. Platelets attenuate the virulence of Aspergillus species in vitro on the basis of granule-dependent effects.

[1]  W. Burgstaller,et al.  Interaction of 5-hydroxytryptamine (serotonin) against Aspergillus spp. in vitro. , 2007, International journal of antimicrobial agents.

[2]  Timothy J. Foster,et al.  The interaction of bacterial pathogens with platelets , 2006, Nature Reviews Microbiology.

[3]  J. White.  Platelets are covercytes, not phagocytes: Uptake of bacteria involves channels of the open canalicular system , 2005, Platelets.

[4]  S. Balajee,et al.  Detection of galactomannan antigenemia by enzyme immunoassay for the diagnosis of invasive aspergillosis: variables that affect performance. , 2004, The Journal of infectious diseases.

[5]  M. Selsted,et al.  Antimicrobial Peptides from Human Platelets , 2002, Infection and Immunity.

[6]  D. Fuchs,et al.  Antifungal properties of selective serotonin reuptake inhibitors against Aspergillus species in vitro. , 2001, The Journal of antimicrobial chemotherapy.

[7]  Nina Singh,et al.  Thrombocytopenia in liver transplant recipients: predictors, impact on fungal infections, and role of endogenous thrombopoietin. , 2000, Transplantation.

[8]  P. Hengster,et al.  The postantibiotic effect of N-chlorotaurine on Staphylococcus aureus. Application in the mouse peritonitis model. , 1999, The Journal of antimicrobial chemotherapy.

[9]  J. Senet.  Candida adherence phenomena, from commensalism to pathogenicity. , 1998, International microbiology : the official journal of the Spanish Society for Microbiology.

[10]  T. Meshulam,et al.  Human Platelets Damage Aspergillus fumigatus Hyphae and May Supplement Killing by Neutrophils , 1998, Infection and Immunity.

[11]  A. Bayer,et al.  Staphylococcus aureus susceptibility to thrombin-induced platelet microbicidal protein is independent of platelet adherence and aggregation in vitro , 1992, Infection and immunity.

[12]  R. Stroud,et al.  Interaction of Histoplasma capsulatum with human platelets. , 1980, The Journal of infectious diseases.

[13]  R. Colman,et al.  Thrombosis and Haemostasis , 1988 .

[14]  T. Starzl,et al.  THROMBOCYTOPENIA IN LIVER TRANSPLANT RECIPIENTS , 2000 .