The Immunological Properties Of Mesenchymal Stem Cells From Bone Marrow Was Effected By Leukemia Cell Line K562

Objective : Mesenchymal stem cells have unique ability of immunoregulation. The immunomodulatory effect of MSCs is under dispute because of diverse damaged tissue types, different microenvironments and the source of MSCs. Accordingly, the multiple mechanisms of immunoregulation still need to be explored. In this research, we establish an indirect co-culture system in vitro, to explore the impact of chronic myeloid leukemia cell line k562 on the immunological properties of SD-rats derived BMMSCs, providing a new theory to investigate the impact of BMMSCs in tumor microenvironment on the process of hemotologic tumor.Methods: The whole bone marrow adhesion assay was performed to isolate MSCs from SD rat bone marrow of femur and tibia,characteristics of cytomorphology were observed under optical microscope,flow cytometry was used to detect cell surface markers,osteoblasts and adipocytes were induced to identify MSCs.Transwell Chambers were uesd to establish indirect co-culture system of K562 and MSCs,we group three concentrations of K562 and co-culture time, RT-PCR was performed to test IL-6 m RNA and IL-10 m RNA finding different changes under various circumstances; mmunofluorescence technology was carried out to detect the expression of i NOS in MSCs;low concentration of TLR3 agonists Poly(I: C) and TLR4 agonist LPS were used to stimulate MSCs for 1 hour separately,we perform RT-PCR to test m RNA levels of IL-6,IL-1β,IL-10 and i NOS,respectively.Result: MSCs were successfully isolated from bone marrow using whole bone marrow adhesion assay. After indirect co-culture with K562, more expression of IL-6 and IL-10 in MSCs were detected by RT-PCR compared with non-intervention group. i NOS expression is performed through immunofluorescence technique after co-culture with K562.More IL-6,IL-1β,i NOS in MSCs were expressed under the stimulation of TLR4 agonist LPS while more Il-10 in MSCs were expressed under the stimulation of TLR3 agonists Poly(I:C),revealing the immune plasity of MSCs and this plasity can be changed by K562.Conclusion: Chronic myeloid leukemia cell line K562 can change the immunological properties of mesenchymal stem cell, we can go on exploring the specific mechanism which is related with Toll-like receptor to get a better understanding of the immune ability of MSCs especially during the pathological process in CML.