Glycosaminoglycan-protein interactions in inflammatory processes

Lead Research Organisation: MRC Immunochemistry Unit

Abstract

Inflammation is part of the bodys normal immune response, being switched on at the start of an illness/injury and then turned off once the infection or wound has healed. However, in diseases such as arthritis and asthma these processes are not controlled correctly leading to chronic inflammation and tissue damage. We are studying the production of natural anti-inflammatory molecules in our bodies, and what goes wrong in inflammatory disease. One such molecule is a protein called TSG-6, which we have detected in the joints of arthritis patients and the lungs of asthmatics. It is also made during ovulation (a normal process that has much in common with inflammation) where it has an essential role. We are trying to understand how TSG-6 works as a natural inhibitor of inflammation and reduces tissue destruction. This is not a simple task since TSG-6 has many different functions some of which depend on the fine details of its particular location in a tissue (known as the micro-environment). In particular, polysaccharide molecules play an important role in fine-tuning protein functions. We are looking at how TSG-6 and polysaccharides fit together and this information may be helpful in designing novel therapeutic strategies for a wide range of conditions.

Technical Summary

We aim to understand the molecular basis of inflammatory mechanisms involved in diseases such as arthritis and asthma that also occur in normal physiological processes (e.g., ovulation). The work is focused on polysaccharides called glycosaminoglycans that are involved in the regulation of protein function in tissue microenvironments. For example, the interaction of hyaluronan (a high mass glycosaminoglycan) with specific hyaluronan-binding proteins (hyaladherins) is critical for the formation and stability of extracellular matrix (e.g., in cartilage) and is also important in development, ovulation/fertilisation, immune-cell trafficking and tumour metastasis. One of our main goals is to determine the structural basis and molecular regulation of hyaluronan-protein interactions (using NMR, X-ray crystallography, calorimetry and other biophysical techniques in collaboration with groups in Oxford, Lyon and Chapel Hill). In particular, we are interested in a multi-functional protein called TSG-6 that is essential for mammalian ovulation and fertilisation. We have shown it to be involved in the stabilisation of a hyaluronan-rich matrix that forms around the oocyte, which is required for successful ovulation and sperm capture; rapid progress has been made due to our working with collaborators in Cleveland, Houston, Milan, Oxford, and Uppsala. TSG-6 is also produced during inflammatory conditions (e.g., arthritis and asthma) where it has anti-inflammatory properties, such as inhibiting leukocyte migration and down regulation of the protease network, and may play an important role in tissue repair (e.g., of cartilage). We are studying these protective functions of TSG-6 in murine models of arthritis/inflammation in collaboration with scientists in London and Chicago. In addition, TSG-6 is being investigated in tissues from arthritis patients (Oswestry) and asthmatics/smokers (Miami). Other hyaladherins under study are CD44 (the major cell surface receptor for hyaluronan), which is involved in matrix assembly and leukocyte migration, and the extracellular matrix components aggrecan, versican and link protein that are crucial for matrix structure. In addition to hyaluronan, TSG-6 interacts with sulphated glycosaminoglycans (i.e., heparin, chondroitin-4-sulphate and dermatan sulphate) as well as a growing list of proteins (e.g., aggrecan, I I, PTX3) where these interactions have differential effects on its functional activity. This makes TSG-6 an ideal model system to investigate microenvironment control in inflammatory processes both at a structural and functional level. We are developing new tools for glycomics research (with Plasso, Sheffield) to aid our studies into glycosaminoglycan-protein interactions. This research is providing novel insights into inflammation and is hoped to lead to new therapeutic strategies for inflammatory diseases.

Publications

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Title License agreement with Echelon Biosciences Inc. for method to make verscian G1 domain 
Description Developed protocol for expression, refolding and purification of human versican G1 domain. 
Type Of Material Technology assay or reagent 
Year Produced 2011 
Provided To Others? Yes  
Impact License agreement (Protocol for expression, refolding and purification of versican G1 domain) between MRCT and University of Manchester (February 2011). MRCT licensed this technology to Echelon Biosciences Inc. (July 2011). This reagent is available from Echelon Biosciences: https://echelon-inc.com/index.php?module=Products&func=view&category_id=10127 
 
Title Licensing of HA-binding protein (HABP) to Hokudo Co. Ltd. 
Description Recombinant G1 domain of human versican (VG1) was developed as a detection reagent for hyaluronan (HA). 
Type Of Material Technology assay or reagent 
Year Produced 2006 
Provided To Others? Yes  
Impact The human VG1 protein was licensed by MRCT to Hokudo Co. Ltd, Japan. This product is available (as HABP) from Cosmo Bio Co. Ltd and amsbio. http://www.cosmobiousa.com/habp.html http://www.amsbio.com/Proteoglycans-Glycosaminoglycans-HABP.aspx 
 
Title Licensing of anti-bikunin antibody 
Description A rabbit polyclonal antibody against human bikunin. 
Type Of Material Technology assay or reagent 
Year Produced 2015 
Provided To Others? Yes  
Impact This antibody was licensed by MRCT to EMD Millipore in 2015. 
 
Description Collaborationn with Seikagaku 
Organisation Seikagaku Corporation
Country Japan 
Sector Private 
PI Contribution We supplied protein and expertise to allow studies on the potential of our biological drug (Link_TSG6) for the treatment of osteoarthritis to be carried out by Seikagaku Corporation, Japan.
Collaborator Contribution Seikagaku Corporation (Japan) assessed the potential of our protein-based biological for the treatment of osteoarthritis. New discussions are ongoing about the use of Link_TSG6 for treating ocular symptoms associated with Sjogren's syndrome.
Impact No outputs as yet.
Start Year 2016