Immunogenicity characterization of mononucleated cells originated from umbillical cord blood.

Aim Umbilical cord blood mononucleated (UCBMC) cells has been shown to be the stem cells originated from umbilical cord blood. To date, UCBMC has been introduced as an alternative source for stem cells used in autologous and allogeneic transplantations. Several clinical studies have demonstrated that UCBMCs required less stringent selection for HLA matches between donor and recipient with less cases of graft versus host reaction. In this study, UCBMCs are known to contain many stem cells, were characterized and compared to peripheral blood for their immunogenic profile. Method To elucidate the potential of UCBMC alloreactivity, mixed lymphocyte reaction (MLR) assay was performed. The donor and effectors cells were HLA-typed using PCR method to determine their alloreactivity. Further, to distinguish the level of HLA class I and II expression flowcytometry was done using monoclonal antibodies against those molecules. All the analyse were carried out on UCBMCs and peripheral blood mononucleated cells (PBMCs). Results The result of MLR assay showed that there was less IFN-γ secretion detected in the co-cultured medium in the presence of UCBMCs compared to PBMCs counterpart, indicating less possible rejection of UCBMC. Further, we found that there were only 1-3 alleles of HLA match (out of 8 alleles) among the PBMCs and UCBMCs. By using flowcytometry assay, we could further demonstrate lower HLA Class I expression level with less amount of HLA Class II expressing cells in UCBMC compared to those in PBMCs. Conclusion These findings clearly demonstrate the low immunogenicity of UCBMCs, based on the low level of secreted IFN-γ in the MLR assay, low expression level of HLA Class I, and small population of HLA Class II expressing cells. The outcomes from this study would raise a better understanding in the usage of umbilical cord blood as an alternative source of stem cells for allogeneic transplantation.

Application of a modified method for stem cell isolation from lipoaspirates in a basic lab.

Aim Lipoaspirate, a wasted by product from liposuction procedure recently has been shown to contain abundant mesenchymal stem cells (MSCs). MSCs have been studied in many research areas to regenerate many cell lineages including, myogenic, cardiomyogenic, and angiogenic lineages. The large quantity of MSCs in lipoaspirate, makes it an attractive source for stem cells used in research and clinical applications. A simplified method which is suitable to be performed in a basic laboratory will facilitate development of stem cell research in developing countries. Therefore the outcomes from this study are expected to encourage the progress of stem cell research in Indonesia. Methods Lipoaspirate was digested using collagenase type I, followed by a basic filtration method. Purification of MSCs was done by cell culture for 2-3 days followed by supernatant removal. To confirm the homogenous population of MSCs, an analysis using flowcytometry was performed based on the MSCs minimal criteria developed by Mesenchymal and Tissue Stem Cell Committee of the International Society of Cell Therapy. Resuts MSCs were able to be obtained at 16.41 ± 8.22 x 108 cells per 120 ml lipoaspirate. The cultured cells showed fibroblastic morphology which is characteristic for MSCs and were able to be purified from non-MSCs cells. This was confirmed by flowcytometry assay showing expression of CD105 and the absence of HLA-Class II, CD 45, CD 34, CD14, and CD19. Conclusions This study has shown that it was feasible to isolate messenchymal stem cell from human lipoaspirate. The procedure was practicable to be performed within a basic laboratory.