Use of heparinase to decrease inflammatory responses

Abstract

Heparinase enzymes can be used as a medical treatment to reduce localized inflammatory responses. Treatment of activated endothelium with heparinase inhibits leukocyte rolling, adhesion and extravasation. Most of the heparin and heparan sulfate on endothelial cell surfaces and in basement membranes is degraded by exposure to heparinase. In addition, immobilized chemokines, which are attached to heparin / heparan sulfate on activated endothelium are solubilized by heparinase digestion. Heparinase can be infused into the vascular system to inhibit accumulation of leukocytes in inflamed tissue and decrease damage resulting from localized inflammations. Targeting of heparinase to activated endothelium can be accomplished through localized administration and / or use of genetically engineered heparinase containing endothelium ligand-binding domains.

Description

[0001] This application is related to U.S. provisional application Ser. No. 60 / 004,622, filed 29 Sep. 1995, which is expressly incorporated herein by reference.FIELD OF THE INVENTION [0002] This invention is in the field of medical treatments and is directed to the use of heparinase enzyme as a treatment or prophylactic for reducing localized inflammatory responses. BACKGROUND OF INVENTION [0003] An inflammatory response is local response to cellular injury that is marked by capillary dilation, leukocytic infiltration, redness, heat, and pain and serves as a mechanism initiating the elimination of noxious agents and of damaged tissue. [0004] A generalized inflammatory response within a tissue occurs by the recruitment of leukocytes to the tissue. Destruction of bacteria, foreign materials and / or damaged cells occurs through phagocytosis and / or extracellular degranulation (secretion of degradative enzymes, antimicrobial proteins and myeloperoxidase, which forms superoxides from secre...

AI Technical Summary

Benefits of technology

[0021] In addition, when heparin and heparan sulfate moieties are removed from the surface of activated endothelial cells and from their basement membrane, chemokines, which are bound to the heparin and heparan sulfate, are released from the cell surfaces and basement membrane. The loss of bound chemokines decreases the localized concentration of chemokines and disrupts the chemokine gradient produced by activated endothelium, thereby inhibiting chemokine activation of rolling leukocytes, which is required for firm adhesion, and preventing extravasation of leukocytes along the chemokine gradient. By this invention, decreased leukocyte rolling, activation and extravasation can inhibit localized tissue inflammatory responses by interfering with fundamental mechanisms of leukocyte recruitment.

[0022] Heparinase enzyme can be targeted to specific cell types, tissues or organs by the selected method of administration, which deliver localized high concentrations of the enzymes or physically limit the dispersal of the enzymes. Additionally, according to this invention heparinase can be targeted by fusion of the enzymes to binding domains from antibodies, growth factors or adhesion molecules. The fusion proteins are produced by construction and expression of gene fusions in recombinant organisms. As examples, the binding domains can recognize cell surface molecules on activated endothelium (e.g., ICAM-1, VCAM-1, P-selectin, E-selectin), or on endothelial cell subtypes (e.g., GlyCAM-1). Targeted fusion enzymes can increase the number and specificity of indications, while decreasing the amounts of enzyme required for efficacy and possible side-effects 1 resulting from treatments.

Problems solved by technology

While most localized inflammatory responses are beneficial, harmful inflammatory responses can occur.

Many harmful inflammatory responses also involve accumulation of leukocytes within a tissue.

This accumulation results in the destruction of viable cells and tissue.

In addition to damaging tissue, these responses are detrimental to, or debilitating for, the afflicted individual.

Because of difficulty in distinguishing regions of heparin and heparan sulfate on the same carbohydrate chain, little data exists on the binding preference of chemokines for either heparin or heparan sulfate moieties.

The antibodies interfere with the function of the adhesion molecules and block or reduce leukocyte recruitment.

The presence of soluble chemokine can interfere with adhesion and migration along a bound chemokine gradient.

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