Previous Article | Next Article 
Infect Immun, March 1998, p. 1181-1189, Vol. 66, No. 3
Department of Medicine,
Received 29 April 1997/Returned for modification 20 June
1997/Accepted 4 December 1997
Neutropenia is considered a significant risk factor for invasive
aspergillosis but is almost always associated with concurrent thrombocytopenia. Studies determined that platelets, like neutrophils, attached to cell walls of the invasive hyphal form of Aspergillus fumigatus. Organisms were damaged as shown by loss of cell wall integrity in scanning laser confocal microscopy and release of defined
hyphal surface glycoproteins. Rapid expression appearance of surface
antigen CD63 and release of markers of platelet degranulation confirmed
activation during attachment to hyphae. Optimal platelet activation
required opsonization of hyphae with fresh or heat-inactivated whole
plasma. These effects of opsonization with whole plasma could not be
duplicated by pooled human serum, immunoglobulin G, or fibrinogen,
whether used separately or combined. Thus, platelets in the presence of
whole plasma have the potential to play an important role in normal
host defenses against invasive aspergillosis.
The crucial role of phagocytic
cells, particularly polymorphonuclear neutrophils (PMN), in host
defenses against invasive aspergillosis is supported by the occurrence
of the disease under well-characterized clinical conditions where these
cells are either dysfunctional (7) or scarce
(37). A large body of in vitro evidence and animal data from
our own (14, 15, 20) and other (30) laboratories
corroborates and helps to explain the frequent association between
neutropenia and disseminated aspergillosis.
However, chemotherapy-induced neutropenia rarely occurs without
concomitant thrombocytopenia. Several clinical and experimental observations suggest that platelets, besides preventing hemorrhage, may
contribute to host defenses against a broad range of infections (6, 5). For example, thrombocytopenic rabbits tend to have larger vegetations and higher density of streptococci in an
experimental model of bacterial endocarditis (32). Platelets
stimulated with Aspergillus hyphae typically invade blood vessels, causing
local thrombosis with consequent distal hemorrhagic infarction. This
characteristic propensity for intravascular invasion preceding and
during dissemination, the association of dissemination with thrombocytopenia, and the known microbicidal capabilities of platelets led us to examine the potential role of platelets in host defenses against infection by Aspergillus fumigatus, the most common
cause of invasive aspergillosis.
Our results established that A. fumigatus hyphae strongly
activated human platelets in vitro and that platelets damaged A. fumigatus hyphae in vitro.
(This work was presented in part at the 34th Annual Meeting of the
Infectious Diseases Society of America, New Orleans, La., 18-20
September 1996 [4a].)
Reagents.
All reagents were purchased from Sigma Chemical,
St. Louis, Mo., unless otherwise stated. Experiments involving PMN were
done in phosphate-buffered saline (PBS; BioWhittaker, Walkersville, Md.) with 5.5 mM glucose, 3.4 mM CaCl2, and 5.25 mM
MgCl2 (supplemented PBS). Platelets were suspended in
buffer containing 3.8 mM HEPES with 140 mM NaCl, 3.75 mM
NaH2PO4, 21 mM KCl, 1 mM CaCl2, and 5.5 mM glucose (HEPES-Ca2+).
Organisms.
As in past experiments (22), A. fumigatus conidia from a clinical isolate were harvested from
culture on Sabouraud dextrose agar slants, then suspended in Sabouraud
dextrose broth at 106/ml, and left overnight at room
temperature on a gyrotatory shaker. The swollen conidia were then
germinated at 37°C for 2.5 h. Under these conditions, Opsonization of hyphae.
Samples of fresh blood were either
anticoagulated with EDTA or left to clot at 37°C and then centrifuged
for preparation of autologous plasma or serum, respectively.
Platelet-poor plasma was obtained by centrifugation (2,000 × g for 10 min). Germinated hyphae were resuspended in glass
tubes at 50 × 106/ml with the following opsonic
solutions: pooled human plasma (BioWhittaker), fresh or
heat-inactivated (30 min at 56°C) autologous plasma or serum,
fibrinogen (3 mg/ml), human immunoglobulin G (IgG; 1 mg/ml), and
various combinations of these opsonins. Following 20 min of incubation
at 37°C, hyphae were washed twice, resuspended in the working buffer,
and kept at room temperature until used.
Fluorescent labeling of A. fumigatus hyphae.
Biotinylation of hyphal cell wall glycoproteins was performed by a
previously published method (4), with the following modifications. Freshly germinated hyphae were suspended at 3 × 107/ml in 3 ml of 100 mM phosphate buffer (pH 8.0)
containing N-hydroxysuccinimidobiotin (0.1 mg/ml). Following
15 min of incubation at 37°C with gentle shaking, the hyphae were
washed sequentially with 50 mM (pH 6.0) and 10 mM (pH 7.4) phosphate
buffers and were resuspended (3 × 107/ml) in
HEPES-Ca2+. The biotinylated hyphae were then incubated
with 5 µg of 5-([4, 6-dichlorotriazin-2-yl]amino)fluorescein
(DTAF)-conjugated streptavidin (Jackson ImmunoResearch Laboratories,
West Grove, Pa.) per ml for 10 min at room temperature, hand mixed, and
protected from light. Following two washes with supplemented PBS to
remove any excess of DTAF-conjugated streptavidin, hyphae were
resuspended in working buffer and wrapped in aluminum foil until used.
Biotinylation with or without labeling with fluorescent conjugate did
not alter hyphal viability, ability to activate platelets, or
susceptibility to damage by either platelets or neutrophils.
Microscopy.
Transmitted light imaging and fluorescent light
imaging were performed with a Nikon (Garden City, N.Y.) microscope.
Samples obtained at intervals were photographed with a Nikon 2000 camera and Ektachrome film (Eastman Kodak, Rochester, N.Y.). For
selected experiments, hyphal damage was visualized with a Leica laser
scanning confocal microscope (Leica, Lasertechnik, GmbH, Heidelberg,
Germany) equipped with an argon ion laser (2 to 50 mW). The smallest
apertures were applied to the detection pinhole for optimal signal.
Z-series optical sections were recorded at 0.5 to 1.0 µm, using a
63× (numerical aperture = 1.4) oil immersion lens and stored on
optical disks (27, 34). Computer images were generated and
prints were made with Adobe Photoshop software (San Jose, Ca.).
Preparation of PMN and platelets.
As in past experiments,
PMN (20) and platelets (11) were freshly prepared
for each experiment from blood of healthy volunteer donors. Blood was
anticoagulated with either heparin or citrate for PMN or platelet
preparation, respectively. Blood for PMN preparation was diluted 1:1
with isotonic 3% dextran and incubated for 20 min at 37°C to
accelerate erythrocyte sedimentation. Supernatants were then
centrifuged on Ficoll-metrizoate gradients. Residual erythrocytes were
lysed twice with hypotonic NaCl. Yield of functional PMN, assessed by
nitroblue tetrazolium reduction, was >98%. Immediately before use,
PMN were resuspended in supplemented PBS to final concentrations of
3 × 106 to 6 × 106/ml and kept on
ice until used. Platelet-rich plasma was obtained by centrifugation
of citrate anticoagulated blood. Platelets were separated on Sepharose
2B columns (11), then diluted to final concentrations of
6 × 107 to 20 × 107/ml in
HEPES-Ca2+, and kept at 37°C with continuous gentle
rocking until used. Platelets were prepared in this manner to minimize
the potential for spontaneous activation as shown previously
(11). Spontaneous activation of platelets during the
preparation procedure was identified by change in platelet shape,
aggregation, spontaneous degranulation (judged by Platelet degranulation.
Following germination, hyphae were
washed once with HEPES-Ca2+ and resuspended in this buffer
at 4 × 107/ml. Resting platelets were mixed with
germinated hyphae in a 40/1 ratio and incubated for 30 min at 37°C
with gentle mixing. Supernatants were obtained by rapid centrifugation
(twice at 104 × g for 4 min) through 80:20
(vol/vol) Dow Corning Contour oil (Nye Lubricants, New Bedford, Mass.).
Samples were kept frozen at
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Human Platelets Damage Aspergillus
fumigatus Hyphae and May Supplement Killing by
Neutrophils
ABSTRACT
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
INTRODUCTION
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
-thrombin release a cationic protein (platelet
microbicidal protein [PMP]) which is microbicidal to some strains of
Staphylococcus aureus (35) and Candida
albicans (29). Recent data have shown that resistance
of C. albicans to PMP increases the severity of experimental
Candida endocarditis (36). Platelets also are
cytotoxic in vitro against larvae of Schistosoma sp.
(10, 18, 25) and inhibit growth of Plasmodium
malariae in vitro (26).
MATERIALS AND METHODS
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
90%
formed hyphae.
-glucuronidase
release), and lack of response to thrombin stimulation in controls.
Platelets evidencing activation during preparation were discarded.
-thrombin (9 nM) and
incubated for 1 h at 37°C. DTAF-conjugated mouse anti-human
CD42b or DTAF-conjugated mouse anti-human CD63 (Becton Dickinson, San
Jose, Calif.) was added at 5 µg/ml (final concentration). After
incubation for 15 min at 37°C, reactions were stopped with 3.7%
buffered formalin. Samples were compared by fluorescence microscopy.
70°C. Samples were diluted 1:10 in
HEPES-Ca2+ buffer for assays of released platelet granule
constituents. Markers used were platelet factor 4 (PF4) for -granule
release, -glucuronidase for lysosomal granule release, and serotonin
for 
(dense)-granule release.
-glucuronidase release, 100 µl of sample was mixed
with 200 µl of 6 mM
4-methylumbelliferyl--D-glucuronide in 100 mM acetate
buffer (pH 5.0) plus 200 µl of acetate buffer (500 µl, final
volume). Samples were incubated for 30 min at 37°C shielded from
light, 500 µl of 200 mM glycine (pH 10.5) was added to each sample,
and fluorescence was read immediately (excitation, 360 nm; emission,
448 nm; Perkin-Elmer [Weston, Mass.] 650-10S fluorescence
spectrophotometer). -Glucuronidase release was determined as a
fraction of total -glucuronidase content obtained from 0.1% Triton
X-100-lysed platelets corrected for background supernatant fluorescence
prior to stimulation.
5
mCi/ml) for 20 min at 37°C. To prevent serotonin reuptake, the serotonin analog 13.3 nM imipramine was added within 30 s prior to
activation. After stimulation, platelets were centrifuged through contour oil as noted above. After determination of 3H in
each supernatant, serotonin content was expressed as a fraction of
total serotonin content of 0.1% Triton X-100-lysed platelets.
PF4 release was determined by enzyme-linked immunosorbent assay
(ELISA). After centrifugation of platelet supernatants through contour
oil, 10 µl of each supernatant was diluted with 90 µl buffer in
96-well ELISA microtiter plates (Dynatech Laboratories, Inc.,
Chantilly, Va.) and kept at 4°C for 14 to 16 h. Following serial
washes to remove unbound contents, plates were blocked with 3% bovine
serum albumin in PBS and labeled with 0.17 µg of horseradish
peroxidase-bound mouse anti-PF4 antibody (a generous gift from
Repligen, Inc., Needham, Mass.) per ml, incubated, and washed again.
TBM Microwell substrate (Kirkegaard & Perry, Inc., Gaithersburg, Md.)
was used for development, and reactions were stopped with 0.36 N
sulfuric acid. Absorbance was read at 450 nm. Data were normalized to
PF4 release by platelets maximally stimulated with 9 nM -thrombin.
Comparison of hyphal damage by platelets and activated platelet
supernatants.
Resting platelets were split into two batches, one
kept resting and the other maximally stimulated with 9 nM -thrombin
for 5 min. Supernatants were obtained by centrifugation (2,000 × g for 10 min). Following germination and opsonization with
pooled human serum, hyphae were resuspended in HEPES-Ca2+.
([OD570 hyphae + PMN or platelets or PMN + platelets]/OD570 hyphae [OD570 PMN or
platelets or PMN + platelets/OD570 hyphae]) × 100.
Estimate of hyphal damage by PMN and platelets. Triplicate experiments were performed in 1.5-ml polypropylene microcentrifuge tubes. Tubes containing hyphae were filled with 60 µl (6 × 105 hyphae) of organisms in HEPES-Ca2+. PMN and platelets, separately or in combination, were incubated with hyphae. Incubations were performed as noted above. Incubations thus included hyphae alone, PMN alone, platelets alone, and PMN plus platelets combined in each concentration tested (660-µl final volumes in HEPES-Ca2+).
Following 1 h of incubation at 37°C with gentle tumbling, 0.5 ml of ice-cold ddH2O was added to stop reactions. Samples were centrifuged at 104 × g for 2 min at 4°C. Pellets were resuspended with 1 ml of sterile ddH2O, briskly mixed, and allowed to stand at room temperature for 10 min to achieve hypotonic lysis of PMN. Platelets and hyphal pellets were washed again with ddH2O; hyphae were resuspended in 1 ml of fresh Sabouraud dextrose broth and incubated for 0 to 4 h at 37°C with gentle tumbling. Specimens were centrifuged (10 times at 103 × g for 2 min at 4°C), and pellets were resuspended with 0.5 ml of XTT-Co-Q. Following 30 min of incubation at 37°C with mixing, damage was calculated by using the formula stated above.Data analysis. Data were analyzed with Sigmastat 1.0 software (Jandel Scientific, San Rafael, Calif.). The Student t test was used to assess differences of means for normally distributed variables. Results are presented as mean ± standard error of the mean (SEM) of percentage of controls unless otherwise specified.
| |
RESULTS |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
Platelet adherence and associated loss of hyphal surface proteins. Platelets adhered to surfaces of opsonized A. fumigatus hyphae (Fig. 1 and 2A). In the early period after attachment, platelets retained rounded oval configurations (Fig. 2A). With activation, attached platelets tended to contract and flatten as they spread over hyphal surfaces, imparting a markedly irregular appearance to hyphal surfaces (Fig. 1). In contrast, hyphal surfaces without attached platelets retained their normally smooth, regular appearances (Fig. 2A to C). Over a 1-h incubation period, platelets induced loss of fluorescent hyphal cell wall constituents, as observed by laser scanning confocal microscopy (Fig. 2). Fluorescence of fluorescein isothiocyanate-labeled cell walls in direct contact with attached platelets decreased progressively, whereas fluorescence intensity did not decrease on the surfaces of hyphal walls without attached platelets (Fig. 2B to J). Eventually, hyphae within masses of surrounding, attached platelets lost nearly all fluorescence, while the masses of surrounding platelets accumulated fluorescence in homogeneous patterns (Fig. 2D to J).
|
|
|
) and without (
) platelets. (B) Western
blot showing time-dependent release of biotinylated cell wall surface
glycoproteins into supernatants of hyphae exposed to platelets. Lanes 1 to 3, sequential protein release into supernatants from hyphae
incubated with platelets for 1, 2, and 3 h, respectively; lanes 4 and 5, spontaneous protein release into supernatants from hyphae
incubated for 0 and 3 h without platelets. Consistent with
previously published observations by other investigators
(Platelet activation and degranulation. Adherence to A. fumigatus hyphae resulted in platelet activation. As expected from published data by others (31), the CD42b surface antigen proved to be constitutively expressed on surfaces of both resting and activated platelets (Fig. 4A). Interaction of platelets with hyphae clearly induced expression of the CD63 antigen on platelet surfaces (Fig. 4B), an established antigenic marker for platelet activation (24). In contrast, surfaces of resting platelets with no attached hyphae did not bind antibodies to the CD63 activation antigen, as they remained nonfluorescent.
|
-granules, -glucuronidase from lysosomal granules, and serotonin
from -granules (Fig. 5A). The relative
efficiency of different opsonins in supporting platelet activation was
assessed by comparing hypha-induced -glucuronidase release to
release of that enzyme from platelets after maximal stimulation with
-thrombin (MAX). Optimal opsonization occurred with whole plasma
(Fig. 5B). No significant differences occurred with fresh autologous
plasma (82.4% ± 9.2% of MAX; mean ± SEM of 12 separate
triplicate experiments), heat-inactivated (56°C, 30 min) autologous
plasma (98.8% ± 11.7% of MAX; mean ± SEM of 3 separate
triplicate experiments), or pooled plasma (60.0% ± 8.3% of MAX;
mean ± SEM of 8 separate triplicate experiments). In contrast,
only minimal release from platelet granules was triggered by
unopsonized hyphae or by hyphae which had been opsonized with pooled
human serum, IgG, or fibrinogen, whether used separately or in various
combinations in three or more separate experiments.
|
Platelet and PMN effects on hyphal metabolic responses.
Activated platelets decreased the ability of hyphae to reduce XTT, a
previously established indicator of fungal cell damage (22).
As shown in Fig. 6A, increasing ratios of
platelets to hyphae from 50:1 to 400:1 in incubations induced
progressive declines in the ability of hyphae to reduce XTT. A 50:1
ratio of platelets to hyphae resulted in a 12.5% ± 4.9% decrease in
hyphal reduction of XTT (P <0.01 compared to corresponding
controls incubated for 1 h in buffer with no platelets or to
zero-time controls, i.e., hyphae mixed with platelets but not
incubated). Significantly greater effects occurred with a 200:1 ratio
of platelets to hyphae (P < 0.001 compared to results
obtained with a 50:1 ratio). Prolongation of hyphal incubations with
platelets beyond 1 h did not further alter effects of platelets on
XTT reduction. However, it remained possible that platelet-mediated
effects on hyphal metabolism were reversible, causing only temporary
suppression of the ability of hyphae to reduce XTT. To determine
whether platelets induced sustained suppression of hyphal metabolic
activity, after 1 h of exposure to platelets, incubations of
hyphae with XTT were prolonged for up to 2 h. Platelet/hypha
ratios of 50:1 and 167:1 were used in eight separate experiments, each
performed with two to four replicates. With both ratios,
platelet-induced decrements in hyphal metabolic activity were
sustained, as there was no recovery of the ability to reduce XTT during
more prolonged incubation with the dye (Fig. 6B). In contrast to intact
platelets, supernatants of -thrombin-activated platelets induced no
detectable alterations in the capacity of hyphae to reduce XTT.
|
, results of
incubations using a 167:1 ratio of platelets to hyphae).
| |
DISCUSSION |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
These data show that platelets adhered to A. fumigatus hyphae, the invasive form of the fungus, and tended to spread over hyphal surfaces. This interaction induced platelet activation. Opsonization of hyphae with whole plasma was required for optimal platelet activation. Plasma would be readily available for any interactions in vivo, since platelets encounter hyphae only in the circulation. Invading hyphae would then be coated with plasma opsonins under such normal conditions. Plasma contains several factors that might potentially serve as opsonins and potentiate platelet adhesion to hyphae and/or activation. Despite the presence of Fc receptors on platelet surfaces (1) which could interact with antibody-coated hyphae, our data indicated that opsonization of hyphae with normal human IgG alone resulted in only weak platelet activation. Although gamma globulins from healthy individuals include anti-Aspergillus antibodies (28), this does not preclude the possibility that higher antibody titers of patients with aspergillosis might improve platelet responses. Nevertheless, our data do not support a major role for immunoglobulins in platelet-mediated host defenses in nonimmunosuppressed individuals.
Fibrinogen also binds to fungal cell surfaces (9) and has been postulated to play a significant role in platelet attachment to C. albicans (21). Nevertheless, opsonization with fibrinogen, even in concentrations exceeding those present in normal plasma, did not trigger optimal platelet activation in our studies. This was not completely surprising, as components of the active platelet fibrinogen receptor are assembled not before, but only during the platelet activation process (17). Even so, fibrinogen opsonization of hyphae still might contribute to platelet activation in vivo. Coactivation processes might lead to fibrinogen receptor assembly which, in turn, might then contribute to further platelet activation after binding its ligand.
Aspergillus hyphae also activate complement (19), and platelets carry complement surface receptors (8). However, heat inactivation of complement did not impair the ability of plasma to support optimum platelet activation.
Supplementation of serum with pooled IgG, fibrinogen, alone or in combination, failed to restore the opsonic effect of whole fresh or heat-treated plasma (Fig. 5). Thus, further studies will be required to define specific plasma factors responsible for optimum opsonization. The nature of hyphal cell wall surface constituents binding these plasma factors also remains to be defined. We have initiated studies of mechanisms involved in these processes.
Taken together, results of confocal microscopic analysis, measurements of biotinylated surface wall glycoprotein release, and changes in ability to reduce the tetrazolium dye XTT indicated that platelets inflicted significant damage to hyphae. Confocal microscopy showed loss of cell wall constituents from hyphal surfaces that were covered by platelets (Fig. 2). Hyphae without surface-adherent platelets did not evidence loss of labeled surface proteins. Assays of biotinylated surface glycoprotein release showed increased shedding of hyphal cell wall components following exposure to platelets. Biotinylation with or without labeling with fluorescent conjugate did not alter hyphal viability, ability to activate platelets, or susceptibility to damage by either platelets or neutrophils. Of course, these data did not establish that shedding of these biotinylated wall constituents necessarily represented the sole sites of platelet-mediated damage. It is certainly possible that other unmeasured constituents of the cell wall or other sites might have sustained damage by platelets as well. Likewise, these data do not allow for quantification of the relative importance of biotinylated surface glycoprotein release compared to damage to or release of other cell wall constituents. Presumably, surface proteins are more likely to undergo biotinylation than deeper wall proteins. Release of these deeper proteins, if present, might go undetected because of absent labeling.
In addition, platelets impaired the capacity of the fungi to reduce XTT, a previously established indicator of the degree of damage to A. fumigatus hyphae (22). Detrimental effects of platelets on XTT reduction by hyphae were significant with ratios of platelets to hyphae between 50:1 and 400:1. Higher ratios of platelets to hyphae resulted in progressively greater declines in XTT reduction, though the increment between ratios of 200:1 and 400:1 were minimal. Hyphae did not show signs of recovering their ability to reduce XTT when incubations of hyphae with the dye were prolonged to 2 h, beyond the usual 1-h time period. Together with previously published data on XTT as an indicator of damage to A. fumigatus hyphae (22), these effects of platelets on XTT reduction are consistent with damage to the organisms by human platelets.
Invasive aspergillosis is a vasculotropic infection (37). Our previous studies showed that PMN protected endothelial cells against invasion by C. albicans hyphae (16). Interactions between damaged endothelial cells, platelets, and PMN have been extensively studied over the last decade, focusing essentially on vessel wall injury and degeneration. Since fungi have now been shown to readily interact with vascular endothelium, circulating platelets, and circulating phagocytes, and since all of these types of cell types have modulatory effects on one another (2, 13, 15, 23), it seems crucial to study fungal interactions with each one of them. The abundance of platelets in the circulation, the circumstantial association of thrombocytopenia with the occurrence of invasive aspergillosis, and our current data showing platelet-mediated damage to hyphae suggest that these latter cells may play a significant role in normally potent coordinated host defenses against this common opportunistic infection.
| |
ACKNOWLEDGMENTS |
|---|
This work was supported by National Institutes of Health grants RO1-DK-51478-02 and 2RO1-DK-31056. L. Christin was supported in part by the Evans Memorial Department of Clinical Research, Boston Medical Center, Boston, Mass.
We thank K. K. H. Svoboda, Department of Anatomy and Neurobiology, Boston University School of Medicine, for expert assistance with laser confocal scanning microscopy.
| |
FOOTNOTES |
|---|
* Corresponding author. Mailing address: Boston Medical Center, Room E-336, Section of Infectious Diseases, 88 E. Newton St., Boston, MA 02118. Phone: (617) 638-7909. Fax: (617) 638-8070. E-mail: rdiamond{at}med-med1.bu.edu.
Editor: T. R. Kozel
| |
REFERENCES |
|---|
|
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
|
|---|
| 1. |
Anderson, G. P., and C. L. Anderson.
1990.
Signal transduction by the platelet Fc receptor.
Blood
76:1165-1172 |
| 2. |
Bengtsson, T.,
S. Zalavary,
O. Stendahl, and M. Grenegard.
1996.
Release of oxygen metabolites from chemoattractant-stimulated neutrophils is inhibited by resting platelets: role of extracellular adenosine and actin polymerization.
Blood
87:4411-4423 |
| 3. | Calderone, R. A., R. D. Diamond, J. M. Senet, J. Warmington, S. Filler, and J. E. Edwards. 1994. Host-cell-fungal cell interactions. J. Med. Vet. Mycol. 32(Suppl. 1):151-168. |
| 4. |
Casanova, M.,
J. L. Lopez-Ribot,
J. P. Martinez, and R. Sentandreu.
1992.
Characterization of cell wall proteins from yeast and mycelial cells of Candida albicans by labeling with biotin: comparison with other techniques.
Infect. Immun.
60:4898-4906 |
| 4a. | Christin, L., D. Wysong, T. Meshulam, R. Hastey, E. R. Simons, and R. D. Diamond. 1996. Human platelets damage Aspergillus fumigatus hyphae and potentiate killing by neutrophils. Clin. Infect. Dis. 23:899. (Abstract 214). |
| 5. | Clawson, C. C., G. H. R. Rao, and J. G. White. 1975. Platelet interaction with bacteria. IV. Stimulation of the release reaction. Am. J. Pathol. 81:411-420[Abstract]. |
| 6. | Clawson, C. C., and J. G. White. 1971. Platelet interaction with bacteria. I. Reaction phases and effects of inhibitors. Am. J. Pathol. 65:367-380[Medline]. |
| 7. | Cohen, M. S., R. E. Isturiz, H. L. Malech, R. K. Root, C. M. Wilfert, L. Gutman, and R. H. Buckley. 1981. Fungal infection in chronic granulomatous disease. Am. J. Med. 71:59-66[Medline]. |
| 8. | Cosgrove, L. J., A. J. d'Apice, A. Haddad, J. Pedersen, and I. F. McKenzie. 1987. CR3 receptor on platelets and its role in the prostaglandin metabolic pathway. Immunol. Cell. Biol. 65:453-460. |
| 9. |
Coulot, P.,
J. P. Bouchara,
G. Renier,
V. Annaix,
C. Planchenault,
G. Tronchin, and D. Chabasse.
1994.
Specific interaction of Aspergillus fumigatus with fibrinogen and its role in cell adhesion.
Infect. Immun.
62:2169-2177 |
| 10. | Damonneville, M., J. Wietzerbin, V. Pancré, M. Joseph, A. Delanoye, A. Capron, and C. Auriault. 1988. Recombinant tumor necrosis factors mediate platelet cytotoxicity to Schistosoma mansoni larvae. J. Immunol. 140:3962-3965[Abstract]. |
| 11. | Davies, T. A., D. L. Drotts, G. J. Weil, and E. R. Simons. 1989. Cytoplasmic Ca2+ is necessary for thrombin-induced platelet activation. J. Biol. Chem. 33:19600-19606. |
| 12. | Davies, T. A., E. Katona, V. Vasilescu, E. J. Cragoe, and E. R. Simons. 1987. Sequential sodium-proton exchange in thrombin-induced human platelets. Biochim. Biophys. Acta 903:381-387[Medline]. |
| 13. | Del Maschio, A., E. Corvazier, F. Maillet, M. D. Kazatchkine, and J. Maclouf. 1989. Platelet-dependent induction and amplification of polymorphonuclear leucocyte lysosomal enzyme release. Br. J. Haematol. 72:329-335[Medline]. |
| 14. |
Diamond, R. D., and R. A. Clark.
1982.
Damage to Aspergillus fumigatus and Rhizopus oryzae hyphae by oxidative and nonoxidative microbicidal products of human neutrophils in vitro.
Infect. Immun.
38:487-495 |
| 15. | Diamond, R. D. 1993. Interactions of phagocytic cells with Candida and other opportunistic fungi. Arch. Med. Res. 24:361-369[Medline]. |
| 16. |
Edwards, J. E.,
D. Rotrosen,
J. W. Fontaine,
C. C. Haudenschild, and R. D. Diamond.
1987.
Neutrophil-mediated protection of cultured human vascular endothelial cells from damage by growing Candida albicans hyphae.
Blood
69:1450-1457 |
| 17. |
Hantgan, R. R.,
R. G. Taylor, and J. C. Lewis.
1985.
Platelets interact with fibrin only after activation.
Blood
65:1299-1311 |
| 18. | Joseph, M., C. Auriault, A. Capron, H. Vorn, and P. Viens. 1983. A new function for platelets: IgE-dependent killing of schistosomes. Nature 303:810-811[Medline]. |
| 19. |
Kozel, T. R.,
M. A. Wilson,
T. P. Farrell, and S. M. Levitz.
1989.
Activation of C3 and binding to Aspergillus fumigatus conidia and hyphae.
Infect. Immun.
57:3412-3417 |
| 20. | Levitz, S. M., and R. D. Diamond. 1985. A rapid assay of fungal viability with the tetrazolium salt MTT. J. Infect. Dis. 152:938-945[Medline]. |
| 21. |
Maisch, P. A., and R. A. Calderone.
1980.
Adherence of Candida albicans to fibrin-platelet matrix formed in vitro.
Infect. Immun.
27:650-656 |
| 22. | Meshulam, T., S. M. Levitz, L. Christin, and R. D. Diamond. 1995. A simplified new assay for assessment of fungal cell damage with the tetrazolium dye, (2-3)-bis-(2-methoxy-4-nitro-5-sulphenyl)-(2H)-tetrazolium-5-carboxanilide (XTT). J. Infect. Dis. 172:1153-1156[Medline]. |
| 23. | Nagata, K., T. Tsuji, N. Todoroki, Y. Katagiri, K. Tanoue, H. Yamazaki, N. Hanai, and T. Irimura. 1993. Activated platelets induce superoxide anion release by monocytes and neutrophils through P-selectin (CD62). J. Immunol. 151:3267-3273[Abstract]. |
| 24. |
Nieuwenhuis, A. K.,
J. J. G. Van Oosterhout,
E. Rozenmuller,
F. Van Iwaarden, and J. J. Sixma.
1987.
Studies with a monoclonal antibody against activated platelets: evidence that a secreted 53,000-molecular weight lysosome-like granule protein is exposed on the surface of activated platelets in circulation.
Blood
70:838-844 |
| 25. | Pancré, V., M. Joseph, C. Mazingue, J. Wietzerbin, A. Capron, and C. Auriault. 1987. Induction of platelet cytotoxicity by lymphokines: role of interferon-gamma. J. Immunol. 138:4490-4495[Abstract]. |
| 26. | Peyron, F., B. Polack, L. Lamotte, L. Kolodie, and P. Ambroise-Thomas. 1989. Plasmodium falciparum growth inhibition by human platelets in vitro. Parasitology 99:317-322. |
| 27. | Reardon, C. C., S. J. Kim, R. P. Wagner, and H. Kornfeld. 1996. Interferon-gamma reduces the capacity of human alveolar macrophages to inhibit growth of Cryptococcus neoformans in vitro. Am. J. Respir. Cell Mol. Biol. 15:711-715[Abstract]. |
| 28. | Richardson, M. D., P. A. Llewellyn, and D. W. Warnock. 1984. Antibody to Aspergillus fumigatus antigens in normal sera: influence on positive-negative discrimination in ELISA. J. Immunoassay 5:205-220[Medline]. |
| 29. | Robert, R., C. Mahaza, M. Miegeville, J. Ponton, A. Marot-Leblond, and J. M. Senet. 1996. Binding of resting platelets to Candida albicans germ tubes. Infect. Immun. 64:3752-3757[Abstract]. |
| 30. | Schaffner, A., H. Douglas, and A. Braude. 1982. Selective protection against conidia by mononuclear and against mycelia by polymorphonuclear phagocytes in resistance to Aspergillus: observations on these two lines of defense in vivo and in vitro with human and mouse phagocytes. J. Clin. Invest. 69:617-631. |
| 31. |
Stenberg, P.,
R. McEver,
M. Shuman,
Y. Jacques, and D. Bainton.
1985.
A platelet alpha-granule membrane protein (GMP-140) is expressed on the plasma membrane after activation.
J. Cell Biol.
101:880-886 |
| 32. | Sullam, P. M., F. Uwe, M. R. Yeaman, M. G. Täuber, A. S. Bayer, and H. F. Chambers. 1993. Effect of thrombocytopenia on the early course of streptococcal endocarditis. J. Infect. Dis. 168:910-914[Medline]. |
| 33. | Wosten, H. A., S. M. Moukha, J. H. Sietsma, and J. G. Wessels. 1991. Localization of growth and secretion of proteins in Aspergillus niger. J. Gen. Microbiol. 137:2017-2023[Medline]. |
| 34. | Wu, X. Y., K. K. Svoboda, and V. Trinkaus-Randall. 1995. Distribution of F-actin, vinculin and integrin subunits (alpha 6 and beta 4) in response to corneal substrata. Exp. Eye Res. 60:445-458[Medline]. |
| 35. |
Yeaman, M. R.,
S. M. Puentes,
C. Norman, and A. S. Bayer.
1992.
Partial characterization and staphylocidal activity of thrombin-induced platelet microbicidal protein.
Infect. Immun.
60:1202-1209 |
| 36. | Yeaman, M. R., S. S. Soldan, M. A. Ghannoum, J. E. Edwards, S. G. Filler, and A. S. Bayer. 1996. Resistance to platelet microbicidal protein results in increased severity of experimental Candida albicans endocarditis. Infect. Immun. 64:1379-1384[Abstract]. |
| 37. | Young, R. C., J. E. Bennett, C. L. Vogel, P. P. Carbone, and V. T. DeVita. 1970. Aspergillosis. The spectrum of the disease in 98 patients. Medicine (Baltimore) 49:147-173[Medline]. |
Infect Immun, March 1998, p. 1181-1189, Vol. 66, No. 3
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Lippuner, N., Morell, B., Schaffner, A., Schaer, D. J.
(2007). Proteinase-activated receptors induce nonoxidative, antimicrobial peptides and increased antimicrobial activity in human mononuclear phagocytes. J. Leukoc. Biol.
81: 465-473
[Abstract] [Full Text] -
Scotter, J. M., Chambers, S. T.
(2005). Comparison of Galactomannan Detection, PCR-Enzyme-Linked Immunosorbent Assay, and Real-Time PCR for Diagnosis of Invasive Aspergillosis in a Neutropenic Rat Model and Effect of Caspofungin Acetate. CVI
12: 1322-1327
[Abstract] [Full Text] -
Ellis, M., al-Ramadi, B., Hedstrom, U., Alizadeh, H., Shammas, V., Kristensen, J.
(2005). Invasive fungal infections are associated with severe depletion of circulating RANTES. J Med Microbiol
54: 1017-1022
[Abstract] [Full Text] -
El-Gedaily, A., Schoedon, G., Schneemann, M., Schaffner, A.
(2004). Constitutive and regulated expression of platelet basic protein in human monocytes. J. Leukoc. Biol.
75: 495-503
[Abstract] [Full Text] -
Lass-Florl, C., Fuchs, D., Ledochowski, M., Speth, C., Dierich, M. P., Wurzner, R.
(2003). Antifungal properties of 5-hydroxytryptamine (serotonin) against Candida species in vitro. J Med Microbiol
52: 169-171
[Abstract] [Full Text] -
Nail, S., Robert, R., Dromer, F., Marot-Leblond, A., Senet, J. M.
(2001). Susceptibilities of Cryptococcus neoformans Strains to Platelet Binding In Vivo and to the Fungicidal Activity of Thrombin-Induced Platelet Microbicidal Proteins In Vitro. Infect. Immun.
69: 1221-1225
[Abstract] [Full Text] -
Blease, K., Mehrad, B., Lukacs, N. W., Kunkel, S. L., Standiford, T. J., Hogaboam, C. M.
(2001). Antifungal and Airway Remodeling Roles for Murine Monocyte Chemoattractant Protein-1/CCL2 During Pulmonary Exposure to Asperigillus fumigatus Conidia. J. Immunol.
166: 1832-1842
[Abstract] [Full Text] -
Latge, J.-P.
(1999). Aspergillus fumigatus and Aspergillosis. Clin. Microbiol. Rev.
12: 310-350
[Abstract] [Full Text]
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»