Interaction between vaccinia virus and human blood platelets

Abstract The objective of the present study was to characterize the interaction between human platelets and vaccinia virus and to examine possible impairment of platelet functions. The vaccinia virus was selected for our model system because it lacks detectable neuraminidase activity. Platelets were incubated with purified viral particles labeled with 3H- thymidine and binding parameters were analyzed. Binding reached saturation with an average of 5 particles/platelet. It was not affected by the plasma but was sensitive to temperature and to metabolic inhibitors. 3H-thymidine-labeled vaccinia virus and formaldehyde-fixed platelets were used to measure viral adsorption. The adsorption was temperature-independent but was affected by ionic strength, indicating electrostatic interactions. Treatment of the fixed platelets with neuraminidase or with alkaline phosphatase reduced viral adsorption, indicating that sialate and phosphate residues on the platelet surface may be involved in the adsorption. Platelet activities were markedly affected by vaccinia virus. The virus caused a dramatic 14C-serotonin release with no added inducer. The release was inhibited by aspirin, a known inhibitor of serotonin release related to prostaglandin synthesis. Furthermore, the virus inhibited platelet aggregation, induced by either ADP, collagen, or thrombin. This study demonstrates that although vaccinia virus lacks neuraminidase activity, it does bind to platelets and affects their function.

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Interaction between vaccinia virus and human blood platelets

Blood ◽

10.1182/blood.v59.3.482.bloodjournal593482 ◽

1982 ◽

Vol 59 (3) ◽

pp. 482-487 ◽

Cited By ~ 1

Author(s):

T Bik ◽

I Sarov ◽

A Livne

Keyword(s):

Vaccinia Virus ◽

Electrostatic Interactions ◽

Blood Platelets ◽

Human Platelets ◽

Serotonin Release ◽

Metabolic Inhibitors ◽

Platelet Surface ◽

Neuraminidase Activity ◽

Viral Particles ◽

Viral Adsorption

The objective of the present study was to characterize the interaction between human platelets and vaccinia virus and to examine possible impairment of platelet functions. The vaccinia virus was selected for our model system because it lacks detectable neuraminidase activity. Platelets were incubated with purified viral particles labeled with 3H- thymidine and binding parameters were analyzed. Binding reached saturation with an average of 5 particles/platelet. It was not affected by the plasma but was sensitive to temperature and to metabolic inhibitors. 3H-thymidine-labeled vaccinia virus and formaldehyde-fixed platelets were used to measure viral adsorption. The adsorption was temperature-independent but was affected by ionic strength, indicating electrostatic interactions. Treatment of the fixed platelets with neuraminidase or with alkaline phosphatase reduced viral adsorption, indicating that sialate and phosphate residues on the platelet surface may be involved in the adsorption. Platelet activities were markedly affected by vaccinia virus. The virus caused a dramatic 14C-serotonin release with no added inducer. The release was inhibited by aspirin, a known inhibitor of serotonin release related to prostaglandin synthesis. Furthermore, the virus inhibited platelet aggregation, induced by either ADP, collagen, or thrombin. This study demonstrates that although vaccinia virus lacks neuraminidase activity, it does bind to platelets and affects their function.

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Thrombin-Induced Surface Changes of Human Platelets in Plasma: Their Relation to Serotonin Release

10.1055/s-0039-1684431 ◽

1979 ◽

Author(s):

K. Subbarao ◽

V.V. Kakkar

Keyword(s):

Membrane Proteins ◽

Blood Platelets ◽

Polyacrylamide Gel Electrophoresis ◽

Protein Band ◽

Human Platelets ◽

Serotonin Release ◽

Glycoprotein I ◽

Reversible Aggregation ◽

Coomassie Blue ◽

Labeling Pattern

Membrane proteins of both control and thrombin-treated platelets were labeled by NaB3H4, reduction of Schiff bases formed between pyridoxal 5′-phosphate and protein amino groups. Examination of the labeled polypeptides by SDS-polyacrylamide gel electrophoresis and fluorography disclosed a different labeling pattern for thrombin-treated platelets. The distributions of Coomassie blue-stained protein from treated and untreated cells were, by contrast, almost identical. Fluorographs of control platelets showed a single intensely labeled protein band (mol wt 90,000) whereas with cells exposed to thrombin (30-60 milliunits) about 10 protein bands with mol wts ranging from 43,000 to 200,000 were typically present. Among these were: thrombin-sensitive protein (mol wt 188,000), glycoprotein I (mol wt 150,000) and actin (mol wt 43,000). When serotonin release was prevented, either by reversing platelet aggregation with low amounts of ADP (0.1-0.3 μM) or by preincubating with 3',5'-ADP (20 μM), an inhibitor of both ADP- and thrombin-induced platelet function, the labeling patterns on fluorographs were similar to the control. These results indicate that blood platelets can undergo reversible aggregation without major changes in their surface topography, whereas thrombin-induced serotonin release appears related to structural alterations in platelet membrane proteins.

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Influence of Blood Platelets on Fibrinolysis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654553 ◽

1961 ◽

Vol 6 (02) ◽

pp. 196-214 ◽

Cited By ~ 10

Author(s):

Rudolf Holemans ◽

Rudolf Gross

Keyword(s):

Human Blood ◽

Blood Platelets ◽

Human Platelets ◽

Bovine Blood ◽

Platelet Surface ◽

Inhibiting Effect ◽

Platelet Concentration ◽

Streptokinase Infusion ◽

Human Plasminogen ◽

Human Blood Platelets

Summary1. Human blood platelets contain a considerable amount of proactivator activity but no plasminogen activator activity or plasminogen. In test systems, containing streptokinase, the lysis of bovine fibrin is enhanced, depending upon the amount of platelets present.2. The platelet proactivator is completely destroyed by heating during 15 min at 70° C. Washing of platelets reduces their proactivator activity; however proactivator activity can still be found after ten washings.3. Bovine platelets do not contain proactivator activity. The similarity in the content in proactivator activity in plasma and platelets of both species, as well as the decrease of proactivator activity by washing, strongly suggests that the proactivator activity of human platelets is adsorbed on the platelet surface from the plasma.4. Both in human platelets and in bovine platelets, antifibrinolysin can be found. This factor is thermostable and is only slightly diminished by washing. The platelet antifibrinolysin seems for its larger part to be located in the platelets; only a small fraction may be adsorbed on their surface.5. The platelet antifibrinolytic activity can, depending upon the platelet concentration, be easily determined in systems containing urokinase or plasmin. Also in streptokinase-activated systems, bovine blood platelets have an inhibiting effect; human blood platelets inhibit streptokinase-induced fibrinolysis when their proactivator activity has been destroyed by heating. When streptokinase and unheated human blood platelets are tested on bovine fibrin the inhibitor effect is completely masked by the presence of proactivator.6. The clinical significance of these findings with regard to fibrinolysis occurring spontaneously or induced by streptokinase infusion, as well as their importance for the differentiation of proactivator and human plasminogen are discussed.

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Short communication: possible association of newly absorbed serotonin with nonmetabolic, granule-located adenine nucleotides in human blood platelets

Blood ◽

10.1182/blood.v45.3.413.bloodjournal453413 ◽

1975 ◽

Vol 45 (3) ◽

pp. 413-416

Author(s):

H Holmsen ◽

CA Setkowsky ◽

HJ Day

Keyword(s):

Guinea Pig ◽

Human Blood ◽

Short Communication ◽

Adenine Nucleotides ◽

Blood Platelets ◽

Human Platelets ◽

Serotonin Release ◽

Release Reaction ◽

Human Blood Platelets

[3H]-adenine-labeled human platelets in plasma were incubated with or without nonradioactive serotonin. Release reaction was then induced by ADP, epinephrine, collagen, or thrombin. Platelets that had been incubated with serotonin released four times as much serotonin as platelets incubated without serotonin. The specific radioactivities of the ATP and ADP released to plasma during release reaction induced with all four inducers were the same in both systems. This shows that when serotonin is taken up by human platelets, it enters the compartment containing nonmetabolic, granula-stored ATP, and not the compartment with metabolic extragranular ATP. These results suggest that the mechanism of serotonin storage in human platelets is similar to that in other species investigated, i.e., rabbit, guinea pig, and pig.

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Effects of Lectins on Blood Platelets from Various Species

10.1055/s-0039-1682742 ◽

1977 ◽

Author(s):

O. Tangen ◽

B. Karlstam ◽

S. Bygdeman

Keyword(s):

Shape Change ◽

Blood Platelets ◽

Human Platelets ◽

Serotonin Release ◽

Variable Degree ◽

Con A ◽

Platelet Release ◽

Induced Aggregation ◽

Aggregation Of Platelets ◽

Platelet Shape

Earlier it has been shown that different lectins induce a variable degree of aggregation of platelets. The present study confirmed previous data and demonstrated that wheat germ agglutinin (WGA) was very active, 1eucoagglutinin had about a tenth of the activity of WGA on a concentration basis, and Con A had a weak aggregating effect on human gel filtered platelets (GFP). Soy bean lectin did not aggregate human GFP.The fact that adenosine inhibited WGA- and leucoagglutinin-induced aggregation that WGA and Con A caused serotonin release, and that the aggregation- curves indicated platelet shape change are indications that the lectins influenced glycosyl moieties involving one or more molecules relevant to release and aggregation reaction.GFP were markedly more responsive to the lectins than platelets in plasma, probably due to interfering glycosyl groups amongst the plasma constituents.Platelets from man, rabbit, rat, cow and pig reacted differently towards the lectins, human platelets being the most reactive and bovine and porcine platelets being almost unreactive. These results pose intriguing questions regarding the glycosyl content of platelet membranes in different species and their relation to platelet release and aggregation.

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Effect of anti-P1A1 antibody on human platelets. I. The role of complement

Blood ◽

10.1182/blood.v53.4.567.567 ◽

1979 ◽

Vol 53 (4) ◽

pp. 567-577 ◽

Cited By ~ 26

Author(s):

DB Cines ◽

AD Schreiber

Keyword(s):

Platelet Aggregation ◽

Complement Activation ◽

Platelet Rich Plasma ◽

Plasma Concentrations ◽

Human Platelets ◽

Serotonin Release ◽

Buffer System ◽

Induce Platelet Aggregation ◽

Platelet Surface ◽

Release Reaction

Abstract We studied the interaction of complement with human platelets. Complement was activated by IgG anti-P1A1 antibody obtained from 3 patients with the post-transfusion purpura syndrome. We used a heparin- plasma buffer system that permits complement activation and also preserves platelet function. With this system complement activation was efficient, and platelet immune alteration was extensive. Anti-P1A1 antibody was effective only in the presence of complement, in which case both platelet lysis and serotonin release (release reaction) in the absence of lysis were observed. Platelet lysis, as assessed by 51Cr loss, required 10-fold more antibody than was necessary to induce platelet aggregation and release of 14C-serotonin. This platelet release reaction required an intact classic complement sequence through C6. The extent of platelet serotonin release parallelled the depletion of C1 and C4 from platelet-rich plasma. Concentrations of antibody insufficient to induce platelet aggregation and serotonin release could still activate C1 and deposit increased C3 on the platelet surface. These studies demonstrated that complement activation by anti-P1A1 antibody can alter human platelets in a nonlytic system. Several phases of complement-mediated human platelet alteration are possible, depending on the concentration of anti-P1A1 antibody.

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Platelet aggregation by fibrinogen polymers crosslinked across the E domain

Blood ◽

10.1182/blood.v68.2.363.bloodjournal682363 ◽

1986 ◽

Vol 68 (2) ◽

pp. 363-371

Author(s):

G McManama ◽

JN Lindon ◽

M Kloczewiak ◽

MA Smith ◽

JA Ware ◽

...

Keyword(s):

Platelet Aggregation ◽

Serotonin Release ◽

Metabolic Inhibitors ◽

High Concentration ◽

Platelet Surface ◽

Soluble Polymers ◽

Platelet Receptor ◽

Lysine Residues ◽

Subsequent Activation ◽

Dose Dependent

There is evidence that platelet interactions with artificial surfaces are mediated by plasma proteins, especially fibrinogen, adsorbed on the surfaces. Multiple site interactions between fibrinogen molecules adsorbed in high concentration and receptors in the unactivated platelet may be sufficient for platelet adhesion and subsequent activation. To examine this hypothesis, we prepared soluble polymers of fibrinogen. Polymers produced by interaction of fibrinogen with Fab'2 fragments of antibodies against fibrinogen's E (central) domain (Fg- Fab'2(E] induced, in gel-filtered platelets, aggregation and serotonin release, which were blocked by monoclonal antibodies against the GPIIb/IIIa complex, by Fab fragments against the D domain, and by metabolic inhibitors; aggregation was attenuated but not abolished by enzymatic removal of ADP (with CP/CPK) or by blockage of ADP binding sites (with FSBA), and when secretion was inhibited by aspirin. Fg- Fab'2(E) also induced a dose-dependent elevation in cytoplasmic Ca2+ (measured by Aequorin luminescence) which was attenuated by CP/CPK and by FSBA, and was eliminated by metabolic inhibitors and by anti- IIb/IIIa antibody. Fibrinogen complexes crosslinked with dimethylsuberimidate or Factor XIII neither aggregated gel-filtered platelets nor inhibited platelet aggregation by ADP and fibrinogen, probably because of inaccessibility of lysine residues in the D (terminal) domain of fibrinogen, which are thought to be required for platelet binding. Thus, soluble complexes of fibrinogen having multiple available platelet receptor recognition sites activate gel-filtered platelets and may provide a useful model for platelet-surface interactions mediated by adsorbed fibrinogen.

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Identification and quantitation of protein S in human platelets

Blood ◽

10.1182/blood.v66.6.1452.bloodjournal6661452 ◽

1985 ◽

Vol 66 (6) ◽

pp. 1452-1455 ◽

Cited By ~ 1

Author(s):

HP Schwarz ◽

MJ Heeb ◽

JD Wencel-Drake ◽

JH Griffin

Keyword(s):

Plasma Protein ◽

Anticoagulant Activity ◽

Limited Proteolysis ◽

Activated Protein C ◽

Protein S ◽

Human Platelets ◽

Immunofluorescent Staining ◽

Metabolic Inhibitors ◽

Platelet Surface ◽

Platelet Protein

Gel filtered human platelets contaminated with less than 0.02% of plasma protein S contained 490 ng of protein S antigen per 3 X 10(8) platelets, equivalent to 2.5% of protein S in whole blood. Three patients with heterozygous plasma protein S deficiency, a congenital disorder associated with venous thrombotic disease, had platelet protein S antigen levels that were 40% of the mean platelet level in ten normal volunteers. In immunoblotting analysis, platelet protein S was indistinguishable from plasma protein S. Thrombin stimulation of platelets caused release of 63% of total protein S antigen and this release was abolished when platelets were preincubated with metabolic inhibitors. Thrombin effected limited proteolysis of platelet protein S and this reaction was inhibited by calcium ions. Immunofluorescent staining of platelets using protein S antibodies demonstrated that protein S colocalized with fibrinogen, an established alpha-granule protein. Thus, human platelets contain protein S in alpha granules that can be released by thrombin stimulation. The released protein S may bind to stimulated platelets and thereby promote and localize the anticoagulant activity of activated protein C on the platelet surface.

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Short communication: possible association of newly absorbed serotonin with nonmetabolic, granule-located adenine nucleotides in human blood platelets

Blood ◽

10.1182/blood.v45.3.413.413 ◽

1975 ◽

Vol 45 (3) ◽

pp. 413-416 ◽

Cited By ~ 7

Author(s):

H Holmsen ◽

CA Setkowsky ◽

HJ Day

Keyword(s):

Guinea Pig ◽

Human Blood ◽

Short Communication ◽

Adenine Nucleotides ◽

Blood Platelets ◽

Human Platelets ◽

Serotonin Release ◽

Release Reaction ◽

Human Blood Platelets

Abstract [3H]-adenine-labeled human platelets in plasma were incubated with or without nonradioactive serotonin. Release reaction was then induced by ADP, epinephrine, collagen, or thrombin. Platelets that had been incubated with serotonin released four times as much serotonin as platelets incubated without serotonin. The specific radioactivities of the ATP and ADP released to plasma during release reaction induced with all four inducers were the same in both systems. This shows that when serotonin is taken up by human platelets, it enters the compartment containing nonmetabolic, granula-stored ATP, and not the compartment with metabolic extragranular ATP. These results suggest that the mechanism of serotonin storage in human platelets is similar to that in other species investigated, i.e., rabbit, guinea pig, and pig.

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Effect of anti-P1A1 antibody on human platelets. I. The role of complement

Blood ◽

10.1182/blood.v53.4.567.bloodjournal534567 ◽

1979 ◽

Vol 53 (4) ◽

pp. 567-577

Author(s):

DB Cines ◽

AD Schreiber

Keyword(s):

Platelet Aggregation ◽

Complement Activation ◽

Platelet Rich Plasma ◽

Plasma Concentrations ◽

Human Platelets ◽

Serotonin Release ◽

Buffer System ◽

Induce Platelet Aggregation ◽

Platelet Surface ◽

Release Reaction

We studied the interaction of complement with human platelets. Complement was activated by IgG anti-P1A1 antibody obtained from 3 patients with the post-transfusion purpura syndrome. We used a heparin- plasma buffer system that permits complement activation and also preserves platelet function. With this system complement activation was efficient, and platelet immune alteration was extensive. Anti-P1A1 antibody was effective only in the presence of complement, in which case both platelet lysis and serotonin release (release reaction) in the absence of lysis were observed. Platelet lysis, as assessed by 51Cr loss, required 10-fold more antibody than was necessary to induce platelet aggregation and release of 14C-serotonin. This platelet release reaction required an intact classic complement sequence through C6. The extent of platelet serotonin release parallelled the depletion of C1 and C4 from platelet-rich plasma. Concentrations of antibody insufficient to induce platelet aggregation and serotonin release could still activate C1 and deposit increased C3 on the platelet surface. These studies demonstrated that complement activation by anti-P1A1 antibody can alter human platelets in a nonlytic system. Several phases of complement-mediated human platelet alteration are possible, depending on the concentration of anti-P1A1 antibody.

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