Inbred or outbred? An evaluation of the functional allogenicity of farm sheep used in cardiac valve studies

Abstract

More than 1 in 3 pairs of sheep is too closely related to elicit an immune response when cross-reacted. This finding may alter the interpretation of studies that base their findings on allogeneic transplantations in sheep without ascertaining the genetic similarities of the animals. Valve transplantation studies in a sheep model should assess the extent of allogenicity of donor and recipient sheep.

Modified Uterine Allotransplantation and Immunosuppression Procedure in the Sheep Model

“…Inbreeding among farm sheep could reduce the variability of MHC polymorphisms between animals. One-third of sheep from a single farm maintaining excellent breeding practices may be too closely related to mount an immune response against donor tissue [ 45 ]. Thus, in the present study, every two sheep were obtained from a single farm.…”

Decellularization reduces immunogenicity of sheep pulmonary artery vascular patches

“…Mixed lymphocyte reaction assays were performed, as previously described, to ensure allogenicity between donor and recipient pairs. 14…”

Functional restoration of endothelial cells of the cryopreserved heart valve

“…27 There were recent reports that ABO antigen expression was not found on the endothelium of cryopreserved allograft valves, and blood group incompatibility was not likely to play a signifi cant role in allograft degeneration. 28,29 Although the relation between graft allogenicity and in vivo durability is controversial, in view of antithrombosis and matrix preservation, endothelial sealing of the luminal surface of the allograft could be associated with a longer-duration allograft. Although the results of HUVECs not being perfectly applicable to heart valves are uncertain, our results imply that functional recovery of endothelial cells in cryopreserved valves seems to be more sluggish than that of other cells comprising the cryopreserved aortic cusps.…”