American Heart Association estimates that valvular heart disease has a US prevalence of 2.5% and accounts for 20,000 deaths annually. Although replacement of the diseased valve with a xenogeneic glutaraldehyde- fixed valve (e.g., bovine pericardium (BP)) dramatically improves short term outcome, long term immune mediated attack results in calcification and ultimately valve failure (~10 yr lifespan). Deficiencies of curent valve replacements led the National Heart Lung and Blood Institute (NHLBI) cardiac surgery working group to recommend support for heart valve prosthesis biomaterial research. A tissue engineered heart valve utilizing un-fixed BP as a scaffold onto which patients'cells are grown (recellularization), has the potential to produce a potentially ideal heart valve. However, as noted by the NHLBI xenotransplantation working group, components which stimulate a recipient immune response (xenoantigens) represent the critical barrier to expanding clinical use of xenogeneic biomaterials. We propose a combinatorial approach (our novel antigen removal methodology combined with mesenchymal stem cell (MSC) mediated immunomodulation) for production of an immunologically-acceptable xenogeneic biomaterial for heart valve tissue engineering. Antigen removal aims to remove biomaterial xenoantigens, while leaving the extracellular matrix (ECM) intact and compatible with recellularization. We hypothesize that solubilization of xenoantigens is critical to facilitate their removal from the biomaterial. We therefore propose stepwise application of protein chemistry principles to solubilize and consequently removal BP xenoantigens.
Aim 1 : Remove water-soluble xenoantigens from intact BP while maintaining native ECM structure/function relationships and recellularization potential.
Aim 1 will be conducted in two phases. Phase 1 will assess the effect of two novel factors on removal of water-soluble antigens from BP. Phase 2 will ensure that the resulting scaffold retains ECM properties compatible with heart valve tissue engineering.
Aim 2 : Remove lipid-soluble xenoantigens from intact BP in a stepwise manner after initial removal of water-soluble xenoantigens, while maintaining native ECM structure/function relationships and recellularization potential.
Aim 2 will be conducted using the same 2 phased approach, with the exception that factors used in aim 2 are designed to remove lipid-soluble antigens. The resulting BP scaffold (with or without MSC recellularization) must be immunologically-acceptable following implantation in an immunocompetent recipient. We therefore propose:
Aim 3 : Assess the in vivo immune response to BP following stepwise antigen removal of water- and lipid-soluble xenoantigens. Assess effect of allogeneic MSC recellularization of BP following antigen removal (BP-AR) on in vivo immune response towards the biomaterial.
Aim 3 utilizes an immunocompetent rabbit model for assessment of immune response to both BP-AR and MSC recellularized BP-AR. Completion of this proposal will result in a structurally integral, mechanically sound, immunologically- acceptable xenogeneic scaffold compatible with recellularization for heart valve tissue engineering.

Public Health Relevance

The American Heart Association estimates that valvular heart disease has a prevalence of 2.5% in the United States and accounts for 20,000 deaths annually. Replacement of the diseased valve dramatically improves both quality and quantity of life, however, replacement valves are prone to chronic immune mediated degeneration, resulting in calcification and valve failure in the long term (10-15 yrs). The current proposal aim to fulfill recent recommendations made by the NHLBI cardiac surgery working group, by developing a novel methodology for production of a tissue engineered heart valve which retains the benefits of current heart valve replacements, while avoiding their long term negative outcomes.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL115205-01A1
Application #
8503034
Study Section
Bioengineering, Technology and Surgical Sciences Study Section (BTSS)
Program Officer
Lundberg, Martha
Project Start
2013-08-01
Project End
2018-03-31
Budget Start
2013-08-01
Budget End
2014-03-31
Support Year
1
Fiscal Year
2013
Total Cost
$325,866
Indirect Cost
$87,866
Name
University of California Davis
Department
Veterinary Sciences
Type
Schools of Veterinary Medicine
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
Gates, Katherine V; Griffiths, Leigh G (2018) Chronic graft-specific cell-mediated immune response toward candidate xenogeneic biomaterial. Immunol Res 66:288-298
Dalgliesh, Ailsa J; Parvizi, Mojtaba; Lopera-Higuita, Manuela et al. (2018) Graft-specific immune tolerance is determined by residual antigenicity of xenogeneic extracellular matrix scaffolds. Acta Biomater 79:253-264
Gates, Katherine V; Pereira, Naveen L; Griffiths, Leigh G (2017) Cardiac Non-Human Leukocyte Antigen Identification: Techniques and Troubles. Front Immunol 8:1332
Dalgliesh, Ailsa J; Liu, Zhi Zhao; Griffiths, Leigh G (2017) Magnesium Presence Prevents Removal of Antigenic Nuclear-Associated Proteins from Bovine Pericardium for Heart Valve Engineering. Tissue Eng Part A 23:609-621
Gates, Katherine V; Dalgliesh, Ailsa J; Griffiths, Leigh G (2017) Antigenicity of Bovine Pericardium Determined by a Novel Immunoproteomic Approach. Sci Rep 7:2446
Chang, Chia Wei; Dalgliesh, Ailsa J; López, Javier E et al. (2016) Cardiac extracellular matrix proteomics: Challenges, techniques, and clinical implications. Proteomics Clin Appl 10:39-50
Wong, Maelene L; Wong, Janelle L; Vapniarsky, Natalia et al. (2016) In vivo xenogeneic scaffold fate is determined by residual antigenicity and extracellular matrix preservation. Biomaterials 92:1-12
Wong, Maelene L; Wong, Janelle L; Horn, Rebecca M et al. (2016) Effect of Urea and Thiourea on Generation of Xenogeneic Extracellular Matrix Scaffolds for Tissue Engineering. Tissue Eng Part C Methods 22:700-7
Liu, Zhi Zhao; Wong, Maelene L; Griffiths, Leigh G (2016) Effect of bovine pericardial extracellular matrix scaffold niche on seeded human mesenchymal stem cell function. Sci Rep 6:37089
Kol, Amir; Arzi, Boaz; Athanasiou, Kyriacos A et al. (2015) Companion animals: Translational scientist's new best friends. Sci Transl Med 7:308ps21

Showing the most recent 10 out of 12 publications