Cell transplantation from limb allografts.

A murine model of skeletal tissue transplantation was developed to study the allograft rejection process in mice for limb allograft transplantation. Muscle, bone, and skin have been shown to be strong antigenic stimuli in vascularized allograft models, and cells from these sources were used for transplantation. Using enzymatic digestion, keratinocytes, myocytes, and osteocytes were harvested from B10.A mice tissues, dissociated into single cells, and then grown in culture for 14 to 21 days. Each cell type was marked with an intracellular fluorescent marker before transplantation of the cells into pockets in the rectus abdominis muscle of a syngenic host. All cell types remained viable and were detectable 2 weeks following transplantation when examined histologically and observed under a fluorescent microscope. Transplanted osteocytes were found to produce bone 8 weeks following transplantation. These results demonstrate that individual cells transplanted into muscle pockets survive and have the ability to produce extracellular matrix in this mouse model of skeletal tissue transplantation. Use of this model will allow transplantation of the cellular components comprising limb allografts to study the relative antigenicities and the rejection of the separate cells with the advanced immunologic techniques available for mice. A better understanding of immunologic responses to these individual tissue components may enable specific donor tissue or host immune modification to achieve skeletal tissue transplantation without immunosuppression. These findings are particularly valuable to the field of tissue engineering where allogeneic cells may be used in cell/polymer constructs for reconstructive procedures.