Galactosyl-knock-out engineered pig as a xenogenic donor source of adipose MSCs for bone regeneration

Biomaterials. 2013 Apr;34(13):3279-89. doi: 10.1016/j.biomaterials.2013.01.057. Epub 2013 Jan 31.

Abstract

Pig adipose mesenchymal stem cells (AMSCs) could be proposed for the improvement of bone substitute. However, these xenogenic cells retain a galactosyl (Gal) epitope that elicits xenorejection. Our work aims to use Gal-Knock-Out (Gal-KO) pig AMSCs to associate cellular immunomodulation, humoral down-elicitation of Gal-KO cells and osteogenic capacity of AMSCs. Human and pig AMSCs were compared for proliferation/differentiation kinetics and bone neoformation in vivo. Humoral reaction against pig Gal+ vs. Gal-KO AMSCs and immunomodulation properties of Gal+ vs. Gal-KO AMSCs were assessed in vitro. Humoral/cellular reactions against Gal+ vs. Gal-KO osteogenic differentiated pig AMSC xenografts were assessed in an immunocompetent rodent model. Expansion/differentiation/bone neoformation was significantly improved with differentiated pig AMSCs compared with human cells. Based on immunohistochemistry and cell-based ELISA, Gal+ AMSCs had higher sensitivity to preformed/induced anti-pig antibodies than Gal-KO AMSCs. In vitro cellular immunomodulation was similar between Gal+ and Gal-KO AMSCs. In vivo, a significant reduction of anti-pig IgG was found at 1 month in rats implanted with Gal-KO AMSCs compared with those implanted with Gal+ AMSCs. Lymphocyte/macrophage infiltration of osteogenic differentiated pig AMSC xenografts was significantly lower at post-operative day (POD) 7 in recipients of Gal-KO vs. Gal+ pig cells. No significant difference was found at POD 28. The combination of the cellular immunomodulation with the Gal-KO phenotype of AMSCs can significantly improve the cellular engraftment of pig osteogenic cells by delaying xenorejection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / cytology*
  • Animals
  • Antigens / immunology
  • Bone Regeneration*
  • Cell Differentiation
  • Cell Proliferation
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes / metabolism
  • Galactose / immunology
  • Galactose / metabolism*
  • Gene Knockout Techniques*
  • Humans
  • Immunity, Humoral / immunology
  • Immunization
  • Immunohistochemistry
  • Immunomodulation / immunology
  • Kinetics
  • Lymphocyte Culture Test, Mixed
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / metabolism
  • Models, Animal
  • Osteogenesis
  • Primates / immunology
  • Rats
  • Rats, Wistar
  • Sus scrofa
  • Transplantation, Heterologous*

Substances

  • Antigens
  • Epitopes
  • Galactose