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Published on: December 20, 2017
Recombinant full-length tissue factor pathway inhibitor fails to bind to the cell surface: implications for
1Department of Pediatrics, Washington University School of Medicine and St. Louis Children's Hospital, St Louis, MO 63110, USA.
Abstract:
Tissue factor pathway inhibitor (TFPI) plays a key role in the regulation of tissue factor-initiated blood coagulation secondary to loss of the integrity of the blood vessel wall. TFPI is a naturally occurring Kunitz-type protease inhibitor that inhibits coagulation factor Xa and, in a factor Xa-dependent manner, mediates feedback inhibition of the factor VIIa/tissue factor catalytic complex. In vivo full-length TFPI is thought to be primarily bound to the vascular endothelium and the high affinity binding requires an intact carboxy terminus. Here we describe a full-length TFPI molecule, expressed in mouse C127 cells (TFPI(C127)), which exhibits virtually no cellular binding yet contains the intact carboxy terminus. This TFPI (TFPI(C127)) is neither internalized nor degraded via the TFPI endocytic receptor, LDL-receptor-related protein. Pharmacokinetic studies of TFPI(C127 )in vivo demonstrate a 10-fold prolongation in the plasma half-life, compared with that of bacterial recombinant TFPI. (Blood. 2000;95:1973-1978)
Insights
A novel full-length tissue factor pathway inhibitor (TFPI) molecule, TFPI(C127), shows significantly prolonged plasma half-life in vivo. This engineered TFPI exhibits reduced cellular binding and degradation, offering potential therapeutic advantages.
Area of Science:
- Biochemistry
- Hematology
- Molecular Biology
Background:
- Tissue factor pathway inhibitor (TFPI) regulates blood coagulation initiated by tissue factor.
- TFPI is a Kunitz-type protease inhibitor targeting factor Xa and the factor VIIa/tissue factor complex.
- In vivo, full-length TFPI typically binds to the vascular endothelium, requiring an intact carboxy terminus.
Purpose of the Study:
- To characterize a novel full-length TFPI molecule (TFPI(C127)) expressed in mouse C127 cells.
- To investigate the cellular binding, internalization, and degradation properties of TFPI(C127).
- To evaluate the pharmacokinetic profile of TFPI(C127) in vivo.
Main Methods:
- Expression of full-length TFPI in mouse C127 cells (TFPI(C127)).
- Assessment of cellular binding and internalization assays.
- Evaluation of degradation pathways, including the LDL-receptor-related protein.
- In vivo pharmacokinetic studies comparing TFPI(C127) with bacterial recombinant TFPI.
Main Results:
- TFPI(C127) exhibited minimal cellular binding despite having an intact carboxy terminus.
- TFPI(C127) was not internalized or degraded via the LDL-receptor-related protein.
- Pharmacokinetic studies revealed a 10-fold longer plasma half-life for TFPI(C127) compared to bacterial recombinant TFPI.
Conclusions:
- Engineered TFPI(C127) demonstrates significantly altered cellular interaction and pharmacokinetic properties.
- Reduced cellular binding and degradation contribute to a prolonged plasma half-life.
- TFPI(C127) represents a potentially improved form of TFPI for therapeutic applications in coagulation disorders.
