Two independent domains of Factor VIII co-expressed using recombinant vaccinia viruses have procoagulant activity

1987 ◽  
Vol 145 (1) ◽  
pp. 234-240 ◽  
Author(s):  
Andréa Pavirani ◽  
Pierre Meulien ◽  
Huguette Harrer ◽  
Karin Dott ◽  
Fabienne Mischler ◽  
...  
Keyword(s):  
Factor Viii ◽  
Procoagulant Activity ◽  
Recombinant Vaccinia ◽  
Vaccinia Viruses

The Factor VIII Bypassing Activity of Prothrombin Complex Concentrates: The Roles of Factor VIla and of Endothelial Cell Tissue Factor

1991 ◽  
Vol 66 (05) ◽  
pp. 559-564 ◽  
Author(s):  
Jerome M Teitel
Keyword(s):  
Factor Viii ◽  
Tissue Factor ◽  
Factor Viia ◽  
Factor Xa ◽  
Procoagulant Activity ◽  
Tissue Factor Expression ◽  
Prothrombin Complex Concentrates ◽  
Cell Tissue ◽  
Factor Expression ◽  
Necrosis Factor

SummaryAn experimental model incorporating cultured endothelial cells (EC) was used to study the "factor VIII bypassing" activity of prothrombin complex concentrates (PCC), a property exploited in the treatment of hemophiliacs with alloantibodies to factor VIII. Two PCC preparations were ineffective as stimuli of tissue factor expression by EC. However, incubation with a combination of PCC plus endotoxin (lipopolysaccharide, LPS) or tumor necrosis factor (TNF) induced much greater tissue factor expression than was seen in response to either substance alone. PCC expressed an additional direct procoagulant activity at the EC surface, which could not be attributed to either thrombin or factor Xa, and which was diminished by an anti-tissue factor antibody. Therefore factor VIIa, which was detectable in both PCC preparations, likely provided this additional direct procoagulant activity at the EC surface. We also excluded the possibility that coagulation proteases contained in or generated in the presence of PCC are protected from inactivation by AT III. Therefore, PCC can indirectly bypass factor VIII by enhancing induced endothelial tissue factor expression, and also possess direct procoagulant activity, probably mediated by factor VIIa.

Importance of Protease Inhibition in Studies on Purified Factor VIII (Antihaemophilic Factor)

1976 ◽  
Vol 35 (01) ◽  
pp. 186-190 ◽  
Author(s):  
Eugen A. Beck ◽  
Peter Bachmann ◽  
Peter Barbier ◽  
Miha Furlan
Keyword(s):  
Ionic Strength ◽  
Factor Viii ◽  
Gel Filtration ◽  
High Ionic Strength ◽  
Procoagulant Activity ◽  
Carrier Protein ◽  
Protease Inhibition ◽  
Functional Sites ◽  
Molecular Weight Peak ◽  
Von Willebrand

SummaryAccording to some authors factor VIII procoagulant activity may be dissociable from carrier protein (MW~ 2 × 106) by agarose gel filtration, e.g. at high ionic strength. We were able to reproduce this phenomenon. However, addition of protease inhibitor (Trasylol) prevented the appearance of low molecular weight peak of factor VIII procoagulant activity both at high ionic strength and elevated temperature (37°C). We conclude from our results that procoagulant activity and carrier protein (von Willebrand factor, factor VIII antigen) are closely associated functional sites of native factor VIII macro molecule. Consequently, proteolytic degradation should be avoided in functional and structural studies on factor VIII and especially in preparing factor VIII concentrate for therapeutic use.

Protection of mice from respiratory Sendai virus infections by recombinant vaccinia viruses.

1997 ◽  
Vol 71 (1) ◽  
pp. 832-838 ◽  
Author(s):  
S I Takao ◽  
K Kiyotani ◽  
T Sakaguchi ◽  
Y Fujii ◽  
M Seno ◽  
...  
Keyword(s):  
Sendai Virus ◽  
Virus Infections ◽  
Recombinant Vaccinia ◽  
Vaccinia Viruses

scholarly journals Inhibition of human coagulation factor VIII by monoclonal antibodies. Mapping of functional epitopes with the use of recombinant factor VIII fragments

1989 ◽  
Vol 263 (1) ◽  
pp. 187-194 ◽  
Author(s):  
A Leyte ◽  
K Mertens ◽  
B Distel ◽  
R F Evers ◽  
M J M De Keyzer-Nellen ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Factor Viii ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Procoagulant Activity ◽  
Coagulation Factor Viii ◽  
Coagulation Cascade ◽  
Restriction Enzyme Digestion ◽  
Proteolytic Activation

The epitopes of four monoclonal antibodies against coagulation Factor VIII were mapped with the use of recombinant DNA techniques. Full-length Factor VIII cDNA and parts thereof were inserted into the vector pSP64, permitting transcription in vitro with the use of a promoter specific for SP6 RNA polymerase. Factor VIII DNA inserts were truncated from their 3′-ends by selective restriction-enzyme digestion and used as templates for ‘run-off’ mRNA synthesis. Translation in vitro with rabbit reticulocyte lysate provided defined radiolabelled Factor VIII fragments for immunoprecipitation studies. Two antibodies are shown to be directed against epitopes on the 90 kDa chain of Factor VIII, between residues 712 and 741. The 80 kDa chain appeared to contain the epitopes of the other two antibodies, within the sequences 1649-1778 and 1779-1840 respectively. The effect of antibody binding to these sequences was evaluated at two distinct levels within the coagulation cascade. Both Factor VIII procoagulant activity and Factor VIII cofactor function in Factor Xa generation were neutralized upon binding to the region 1779-1840. The antibodies recognizing the region 713-740 or 1649-1778, though interfering with Factor VIII procoagulant activity, did not inhibit in Factor Xa generation. These findings demonstrate that antibodies that virtually inhibit Factor VIII in coagulation in vitro are not necessarily directed against epitopes involved in Factor VIII cofactor function. Inhibition of procoagulant activity rather than of cofactor function itself may be explained by interference in proteolytic activation of Factor VIII. This hypothesis is in agreement with the localization of the epitopes in the proximity of thrombin-cleavage or Factor Xa-cleavage sites.

scholarly journals Anchoring a secreted plasmodium antigen on the surface of recombinant vaccinia virus-infected cells increases its immunogenicity.

1986 ◽  
Vol 6 (9) ◽  
pp. 3191-3199 ◽  
Author(s):  
C J Langford ◽  
S J Edwards ◽  
G L Smith ◽  
G F Mitchell ◽  
B Moss ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
Poor Response ◽  
Subcellular Location ◽  
Epidemiological Data ◽  
Recombinant Vaccinia Virus ◽  
Live Virus ◽  
Recombinant Vaccinia ◽  
Wide Range ◽  
Vaccinia Viruses ◽  
Infected Cells

We show that the subcellular location of foreign antigens expressed in recombinant vaccinia viruses influences their effectiveness as immunogens. Live recombinant viruses induced very poor antibody responses to a secreted repetitive plasmodial antigen (the S-antigen) in rabbits and mice. The poor response accords with epidemiological data suggesting that S-antigens are poorly immunogenic. Appending the transmembrane domain of a membrane immunoglobulin (immunoglobulin G1) to its carboxy terminus produced a hybrid S-antigen that was no longer secreted but was located on the surface of virus-infected cells. This recombinant virus elicited high antibody titers to the S-antigen. This approach will facilitate the use of live virus delivery systems to immunize against a wide range of foreign nonsurface antigens.

scholarly journals Recombinant Vaccinia Viruses as New Live Vaccines

1984 ◽  
Vol 2 (1) ◽  
pp. 383-407 ◽  
Author(s):  
Geoffrey L. Smith ◽  
Michael Mackett ◽  
Bernard Moss
Keyword(s):  
Recombinant Vaccinia ◽  
Live Vaccines ◽  
Vaccinia Viruses

scholarly journals Construction and characterization of recombinant vaccinia viruses co-expressing a respiratory syncytial virus protein and a cytokine

2001 ◽  
Vol 82 (9) ◽  
pp. 2107-2116 ◽  
Author(s):  
Teresa R. Johnson ◽  
Julie E. Fischer ◽  
Barney S. Graham
Keyword(s):  
Respiratory Syncytial Virus ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Antigen Expression ◽  
Virus Protein ◽  
Recombinant Vaccinia ◽  
Vaccinia Viruses ◽  
Ifn Γ ◽  
Syncytial Virus ◽  
The Impact

Recombinant vaccinia viruses are well-characterized tools that can be used to define novel approaches to vaccine formulation and delivery. While vector co-expression of immune mediators has enormous potential for optimizing the composition of vaccine-induced immune responses, the impact on antigen expression and vector antigenicity must also be considered. Co-expression of IL-4 increased vaccinia virus vector titres, while IFN-γ co-expression reduced vaccinia virus replication in BALB/c mice and in C57BL/6 mice infected with some recombinant viruses. Protection against respiratory syncytial virus (RSV) challenge was similar in mice immunized with vaccinia virus expressing RSV G glycoprotein and IFN-γ, even though the replication efficiency of the vector was diminished. These data demonstrate the ability of vector-expressed cytokine to influence the virulence of the vector and to direct the development of selected immune responses. This suggests that the co-expression of cytokines and other immunomodulators has the potential to improve the safety of vaccine vectors while improving the immunogenicity of vaccine antigens.

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