Xenotransplantation of genetically engineered porcine chondrocytes may benefit many patients who suffer cartilage defects. In this work, we sought to elucidate the molecular bases of the cellular response to xenogeneic cartilage. To this end, we isolated pig costal chondrocytes (PCC)
and conducted a series of functional studies. First, we determined by flow cytometry the cell surface expression of multiple immunoregulatory proteins in resting conditions or after treatment with human TNF-α, IL-1α, or IL-1β, which did not induce apoptosis. TNF-α and
to a lesser extent IL-1α led to a marked upregulation of SLA I, VCAM-1, and ICAM-1 on PCC. SLA II and E-selectin remained undetectable in all the conditions assayed. Notably, CD86 was constitutively expressed at moderate levels, whereas CD80 and CD40 were barely detected. To assess their
function, we next studied the interaction of PCC with human monoblastic U937 and Jurkat T cells. U937 cells adhered to resting and in a greater proportion to cytokine-stimulated PCC. Consistent with its expression pattern, pig VCAM-1 was key, mediating the increased adhesion after cytokine
stimulation. We also conducted coculture experiments with U937 and PCC and measured the release of pig and human cytokines. Stimulated PCC secreted IL-6 and IL-8, whereas U937 secreted IL-8 in response to PCC. Finally, coculture of PCC with Jurkat in the presence of PHA led to a marked Jurkat
activation as determined by the increase in IL-2 secretion. This process was dramatically reduced by blocking pig CD86. In summary, CD86 and VCAM-1 on pig chondrocytes may be important triggers of the xenogeneic cellular immune response. These molecules together with TNF could be considered
potential targets for intervention in order to develop xenogeneic therapies for cartilage repair.
No Supplementary Data.
Document Type: Research Article
, 08907 L'Hospitalet de Llobregat, Barcelona,
Publication date: 2009-12-01
More about this publication?
Cell Transplantation publishes original, peer-reviewed research and review articles on the subject of cell transplantation and its application to human diseases. To ensure high-quality contributions from all areas of transplantation, separate section editors and editorial boards have been established. Articles deal with a wide range of topics including physiological, medical, preclinical, tissue engineering, and device-oriented aspects of transplantation of nervous system, endocrine, growth factor-secreting, bone marrow, epithelial, endothelial, and genetically engineered cells, among others. Basic clinical studies and immunological research papers are also featured. To provide complete coverage of this revolutionary field, Cell Transplantation will report on relevant technological advances, and ethical and regulatory considerations of cell transplants. Cell Transplantation is now an Open Access journal starting with volume 18 in 2009, and therefore there will be an inexpensive publication charge, which is dependent on the number of pages, in addition to the charge for color figures. This will allow work to be disseminated to a wider audience and also entitle the corresponding author to a free PDF, as well as prepublication of an unedited version of the manuscript.
Cell Transplantation is now being published by SAGE. Please visit their website for the most recent issues.