Complete Inhibition of Endotoxin-Induced Coagulation Activation in Chimpanzees with a Monoclonal Fab Fragment against Factor VII/VIIa

1995 ◽  
Vol 73 (02) ◽  
pp. 223-230 ◽  
Author(s):  
Bart J Biemond ◽  
Marcel Levi ◽  
Hugo ten Cate ◽  
Howard R Soule ◽  
Lori D Morris ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Tissue Factor ◽  
Bolus Injection ◽  
Therapeutic Option ◽  
Factor Vii ◽  
Rapid Decline ◽  
Fab Fragment ◽  
Gram Negative ◽  
Fab Fragments

SummaryGram-negative sepsis is oftentimes complicated by activation of coagulation with disseminated intravascular coagulation and microthrombosis. This may contribute to the associated morbidity, multiple organ failure and death. Recent studies have established that the tissue factor-dependent pathway of blood coagulation has a significant participatory role in the initial endotoxin-induced activation of coagulation. Tissue factor (TF), expressed on the surface of activated monocytes and endothelial cells forms cell surface complexes with free circulating factors VII and VIIa. The latter complex proteolytically activates factors X and IX. Recent in vivo experiments have shown that a rapidly neutralizing TF monoclonal antibody prevents and arrests the endotoxin- induced activation of coagulation and similar studies have shown to reduce mortality in baboons. In this study we describe the preparation of a factor VII/VIIa neutralizing monoclonal Fab fragment and characterize its effect on in vivo activation of coagulation during experimental endotoxemia in chimpanzees.Four chimpanzees received a bolus intravenous injection of 4 ng/kg endotoxin in combination with Fab fragments of a factor VII/VIIa neutralizing murine monoclonal antibody (12D10) at a dose of either 50 μg/kg (n = 2) or 100 μfig/kg (n = 2). Four control animals received a bolus injection of endotoxin alone. Administration of the 12D10 Fab fragments, immediately preceding the endotoxin bolus injection, effectively blocked the endotoxin-induced activation of coagulation. Plasma levels of products of in vivo activation, namely F1+2, TAT complexes and FpA remained at baseline values. The administration of 12D10 resulted in a rapid decline in factor VII/VIIa antigen levels which remained below 5 ng/ml for 180-240 min, followed by a rapid return to baseline levels. Endotoxin administration resulted in activation of the fibrinolytic system as reflected by a rapid increase in plasma plasmin- α2-antiplasmin complexes. Administration of 12D10 was without effect on the endotoxin-induced fibrinolytic activation.In conclusion, this study confirmed the importance of the TF: VII complex in the initial, endotoxin-induced activation of coagulation which was completely blocked by neutralizing all free and tissue factor-complexed factor VII/VIIa by a specific monoclonal Fab fragment. Activation of fibrinolysis was not influenced. Therefore, neutralization of factor VII/VIIa might be a promising therapeutic option in preventing endotoxin-induced microthrombosis during Gram-negative sepsis.

The Role of Phospholipids and the Factor VII Gla-Domain in the Interaction of Factor VII with Tissue Factor

1992 ◽  
Vol 67 (06) ◽  
pp. 679-685 ◽  
Author(s):  
Peter Wildgoose ◽  
Tony Jørgensen ◽  
Yutaka Komiyama ◽  
Tomohiro Nakagaki ◽  
Anders Pedersen ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Surface ◽  
Tissue Factor ◽  
Calcium Binding ◽  
Factor Vii ◽  
Dependent Manner ◽  
Amidolytic Activity ◽  
Fab Fragment ◽  
Calcium Dependent ◽  
Gla Domain

SummaryWhether or not the factor VII Gla-domain is involved in the high-affinity interaction of factor VII and tissue factor via calcium-dependent interactions with surrounding phospholipids is unknown. To investigate this, we have purified the factor VII Gla-peptide (FVII-GP) from digested recombinant human factor VII a and assessed its effect on factor VII: tissue factor interactions. FVII-GP inhibited the activation of factor X by factor Vila in the presence of either soluble or cell surface tissue factor halfmaximally at 0.5 μM and 2.7 μM, respectively. However, FVII-GP failed to inhibit the specific binding of factor Vila to cell-surface tissue factor, and did not inhibit the ability of tissue factor to stimulate the amidolytic activity of factor Vila. Unrelipidated tissue factor apoprotein stimulated the amidolytic activity of factor Vila to the same extent as relipidated tissue factor apoprotein. These findings suggest that the factor VII Gla-domain does not directly interact with tissue factor, but rather is important for calcium binding and concomitant expression of other factor VII epitopes necessary for tissue factor recognition and binding. To test this hypothesis, we have prepared a monoclonal antibody against a putative factor VII epitope that participates in the interaction of factor VII with cell-surface tissue factor (peptide 195-206) and assessed its ability to bind to factor VII in the presence and absence of calcium. Binding of this monoclonal antibody (PW-4) to intact factor VII a was calcium-dependent and could be inhibited in a dose-dependent manner by peptide 195-206. The antibody reacted with Gla-domainless factor Vila, but only 37% as compared to intact factor Vila. In addition, PW4 as well as its Fab’ fragment, inhibited factor Vila binding to cell-surface tissue factor. These studies indicate that the factor VII Gla-domain does not provide structural elements that contribute to the formation of a stable factor VII/VII a-tissue factor binary complex. The factor VII Gla-domain appears to be necessary, however, in binding calcium ions and inducing a calcium-dependent conformational change in factor VII/VII a that expresses one or more neoepitopes that participates in the interaction of factor VII/VII a with the extracellular domain of tissue factor apoprotein.

scholarly journals Monocyte tissue factor induction by lipopolysaccharide (LPS): dependence on LPS-binding protein and CD14, and inhibition by a recombinant fragment of bactericidal/permeability-increasing protein

Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2516-2525 ◽  
Author(s):  
K Meszaros ◽  
S Aberle ◽  
R Dedrick ◽  
R Machovich ◽  
A Horwitz ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Binding Protein ◽  
Mononuclear Phagocytes ◽  
Factor Vii ◽  
Peripheral Blood Mononuclear ◽  
Recombinant Fragment

Abstract Mononuclear phagocytes, stimulated by bacterial lipopolysaccharide (LPS), have been implicated in the activation of coagulation in sepsis and endotoxemia. In monocytes LPS induces the synthesis of tissue factor (TF) which, assembled with factor VII, initiates the blood coagulation cascades. In this study we investigated the mechanism of LPS recognition by monocytes, and the consequent expression of TF mRNA and TF activity. We also studied the inhibition of these effects of LPS by rBPI23, a 23-kD recombinant fragment of bactericidal/permeability increasing protein, which has been shown to antagonize LPS in vitro and in vivo. Human peripheral blood mononuclear cells, or monocytes isolated by adherence, were stimulated with Escherichia coli O113 LPS at physiologically relevant concentrations (> or = 10 pg/mL). The effect of LPS was dependent on the presence of the serum protein LBP (lipopolysaccharide-binding protein), as shown by the potentiating effect of human recombinant LBP or serum. Furthermore, recognition of low amounts of LPS by monocytes was also dependent on CD14 receptors, because monoclonal antibodies against CD14 greatly reduced the LPS sensitivity of monocytes in the presence of serum or rLBP. Induction of TF activity and mRNA expression by LPS were inhibited by rBPI23. The expression of tumor necrosis factor showed qualitatively similar changes. Considering the involvement of LPS-induced TF in the potentially lethal intravascular coagulation in sepsis, inhibition of TF induction by rBPI23 may be of therapeutic benefit.

scholarly journals Activation of human factor VII during clotting in vitro

Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 218-226 ◽  
Author(s):  
LV Rao ◽  
SP Bajaj ◽  
SI Rapaport
Keyword(s):  
Tissue Factor ◽  
Glass Tube ◽  
Factor Vii ◽  
Clotting Factor ◽  
Activate Factor ◽  
Factor Xii ◽  
Factor X ◽  
Normal Plasma

Abstract We have studied factor VII activation by measuring the ratio of factor VII clotting to coupled amidolytic activity (VIIc/VIIam) and cleavage of 125I-factor VII. In purified systems, a low concentration of Xa or a higher concentration of IXa rapidly activated 125I-factor VII, yielding a VIIc/VIIam ratio of 25 and similar gel profiles of heavy and light chain peaks of VIIa. On further incubation, VIIa activity diminished and a third 125I-peak appeared. When normal blood containing added 125I- factor VII was clotted in a glass tube, the VIIc/VIIam ratio rose fivefold, and 20% of the 125I-factor VII was cleaved. Clotting normal plasma in an activated partial thromboplastin time (APTT) system yielded a VIIc/VIIam ratio of 25 and over 90% cleavage of 125I-factor VII. Clotting factor XII-deficient plasma preincubated with antibodies to factor X in an APTT system with added XIa yielded a VIIc/VIIam ratio of 19 and about 60% cleavage, which indicates that IXa, at a concentration achievable in plasma, can effectively activate factor VII. Clotting normal plasma with undiluted tissue factor yielded a VIIc/VIIam ratio of 15 to 20 and 60% cleavage of 125I-factor VII, whereas clotting plasma with diluted tissue factor activated factor VII only minimally. We conclude that both Xa and IXa can function as significant activators of factor VII in in vitro clotting mixtures but believe that only small amounts of factor VII may be activated in vivo during hemostasis.

scholarly journals Tissue factor and factor VII messenger RNAs in human alveolar macrophages: effects of breathing ozone

Blood ◽  
1990 ◽  
Vol 75 (1) ◽  
pp. 122-127 ◽  
Author(s):  
MP McGee ◽  
R Devlin ◽  
G Saluta ◽  
H Koren
Keyword(s):  
Alveolar Macrophage ◽  
Tissue Factor ◽  
Alveolar Macrophages ◽  
Factor Vii ◽  
Fibrinopeptide A ◽  
Factor Activity ◽  
Tissue Factor Activity ◽  
Mrna Concentration ◽  
Human Alveolar Macrophages

Abstract This study was performed to determine if genes for tissue factor and factor VII proteins are expressed and regulated in vivo in lung macrophages during inflammation. Human alveolar macrophages and alveolar fluids were obtained 18 hours after healthy male adults were exposed, for 2 hours during intermittent exercise, to either air or air with 0.4 ppm ozone, added as a model toxic respiratory agent. Messenger RNA (mRNA) for both tissue factor and factor VII were demonstrated in macrophages isolated after subjects were exposed to unpolluted control air. With the same subjects examined after breathing ozone, the following changes were observed: tissue factor mRNA concentration in macrophages increased 2.6 +/- 0.47-fold. Factor VII mRNA concentration was reduced 0.64 +/- 0.24-fold. Total numbers of macrophages recovered did not change significantly. Ratios of nuclear:cytoplasmic areas of cytocentrifuged macrophages were augmented by 24.8% +/- 3%, giving morphometric evidence that immature cell forms increased in the population. In the lavage, tissue factor activity was increased 2.1 +/- 0.3-fold, while amounts of lipid phosphorous, which estimate total membrane lipids, and estimated volumes of alveolar fluid were not significantly changed. Factor VII activity and fibrinopeptide A levels in lavage were increased approximately twofold. These results using rapidly isolated, noncultured cells indicate that tissue factor and factor VII mRNA are synthesized in the alveolar macrophage population in vivo. In addition, evidence was found that as a result of breathing ozone, a shift in alveolar macrophage maturity occurred in association with tissue factor mRNA, tissue factor activity, and factor VII activity increases, and with formation of fibrinopeptide A in alveolar fluids.

scholarly journals Feasibility study of the Fab fragment of a monoclonal antibody against tissue factor as a diagnostic tool

2015 ◽  
Vol 47 (6) ◽  
pp. 2107-2114 ◽  
Author(s):  
RYO TSUMURA ◽  
RYUTA SATO ◽  
FUMIAKI FURUYA ◽  
YOSHIKATSU KOGA ◽  
YOSHIYUKI YAMAMOTO ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Tissue Factor ◽  
Feasibility Study ◽  
Diagnostic Tool ◽  
Fab Fragment

scholarly journals Activation of human factor VII during clotting in vitro

Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 218-226 ◽  
Author(s):  
LV Rao ◽  
SP Bajaj ◽  
SI Rapaport
Keyword(s):  
Tissue Factor ◽  
Glass Tube ◽  
Factor Vii ◽  
Clotting Factor ◽  
Activate Factor ◽  
Factor Xii ◽  
Factor X ◽  
Normal Plasma

We have studied factor VII activation by measuring the ratio of factor VII clotting to coupled amidolytic activity (VIIc/VIIam) and cleavage of 125I-factor VII. In purified systems, a low concentration of Xa or a higher concentration of IXa rapidly activated 125I-factor VII, yielding a VIIc/VIIam ratio of 25 and similar gel profiles of heavy and light chain peaks of VIIa. On further incubation, VIIa activity diminished and a third 125I-peak appeared. When normal blood containing added 125I- factor VII was clotted in a glass tube, the VIIc/VIIam ratio rose fivefold, and 20% of the 125I-factor VII was cleaved. Clotting normal plasma in an activated partial thromboplastin time (APTT) system yielded a VIIc/VIIam ratio of 25 and over 90% cleavage of 125I-factor VII. Clotting factor XII-deficient plasma preincubated with antibodies to factor X in an APTT system with added XIa yielded a VIIc/VIIam ratio of 19 and about 60% cleavage, which indicates that IXa, at a concentration achievable in plasma, can effectively activate factor VII. Clotting normal plasma with undiluted tissue factor yielded a VIIc/VIIam ratio of 15 to 20 and 60% cleavage of 125I-factor VII, whereas clotting plasma with diluted tissue factor activated factor VII only minimally. We conclude that both Xa and IXa can function as significant activators of factor VII in in vitro clotting mixtures but believe that only small amounts of factor VII may be activated in vivo during hemostasis.

scholarly journals Factor IX is activated in vivo by the tissue factor mechanism

Blood ◽  
1990 ◽  
Vol 76 (4) ◽  
pp. 731-736 ◽  
Author(s):  
KA Bauer ◽  
BL Kass ◽  
H ten Cate ◽  
JJ Hawiger ◽  
RD Rosenberg
Keyword(s):  
Tissue Factor ◽  
Factor Ix ◽  
Factor Vii ◽  
Factor Xii ◽  
Factor Xi ◽  
Factor Xi Deficiency ◽  
Factor Ixa ◽  
Coagulant Activity ◽  
The Mean

Abstract Despite significant progress in elucidating the biochemistry of the hemostatic mechanism, the process of blood coagulation in vivo remains poorly understood. Factor IX is a vitamin K-dependent glycoprotein that can be activated by factor XIa or the factor VII-tissue factor complex in vitro. To investigate the role of these two pathways in factor IX activation in humans, we have developed a sensitive procedure for quantifying the peptide that is liberated with the generation of factor IXa. The antibody population used for the immunoassay was raised in rabbits and chromatographed on a factor IX-agarose immunoadsorbent to obtain antibody populations with minimal intrinsic reactivity toward factor IX. We determined that the mean level of the factor IX activation peptide (FIXP) in normal individuals under the age of 40 years was 203 pmol/L and that levels increased significantly with advancing age. The mean concentration of FIXP was markedly reduced to 22.7 pmol/L in nine patients with hereditary factor VII deficiency (factor VII coagulant activity less than 7%) but was not significantly different from normal controls in nine subjects with factor XI deficiency (factor XI coagulant activity less than 8%). These data indicate that factor IXa generation in vivo results mainly from the activity of the tissue factor mechanism rather than the contact system (factor XII, prekallikrein, high molecular-weight kininogen, factor XI). Our results may also help to explain the absence of a bleeding diathesis in many patients with deficiencies of the contact factors of coagulation.

scholarly journals Generation of a Neutralizing Human Monoclonal Antibody Fab Fragment to Surface Antigen 1 ofToxoplasma gondiiTachyzoites

2010 ◽  
Vol 79 (1) ◽  
pp. 512-517 ◽  
Author(s):  
Yong-Feng Fu ◽  
Meng Feng ◽  
Kenji Ohnishi ◽  
Tamon Kimura ◽  
Johbu Itoh ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Surface Antigen ◽  
Heavy Chain ◽  
Germ Line ◽  
Human Monoclonal Antibody ◽  
Passive Immunization ◽  
Positive Staining ◽  
Immunoglobulin Gene ◽  
Fab Fragment ◽  
Fab Fragments

ABSTRACTA combinatorial immunoglobulin gene library was constructed from lymphocytes in peripheral blood of a patient with toxoplasmosis and screened for production of human monoclonal antibody Fab fragments to recombinant surface antigen 1 (SAG1) ofToxoplasma gondii. Two Fab clones, Tox203 and Tox1403, which consisted of a common heavy chain and different light chains, showed positive staining on the entire surface of tachyzoites in confocal microscopy. Sequence analysis of the heavy-chain gene revealed that the closest germ line V segments were VH3-23. The germ line D segment was D1-7, and the closest germ line J segment was JH4. In the light-chain genes, the closest germ line V segment was Vκ1-17 with the Jκ1 or Jκ4 segments. The dissociation constants of these Fab fragments with recombinant SAG1 were 3.09 × 10−9M for Tox203 and 2.01 × 10−8M for Tox1403, indicating that the affinity of Tox203 was 7 times higher than that of Tox1403. Preincubation ofT. gondiitachyzoites with Tox203 significantly inhibited their attachment to cultured MDBK cells. Passive immunization of mice with Tox203 also significantly reduced mortality after challenge withT. gondiitachyzoites. This is the first report of bacterial expression of human monoclonal antibody Fab fragments to SAG1 ofT. gondii. These results also demonstrate that human Fab fragments to SAG1 might be applicable for immunoprophylaxis of toxoplasmosis.

Sign in / Sign up

Export Citation Format

Share Document