Magnetic cell sorting and flow cytometry sorting methods for the isolation and function analysis of mouse CD^4+ CD25^+ Treg cells

Objective: In this paper we compared the two methods of cell sorting (magnetic cell sorting and flow cytometry sorting) for the isolation and function analysis of mouse CD4+ CD25+ regulatory T (Treg) cells, in order to inform further studies in Treg cell function. Methods: We separately used magnetic cell sorting and flow cytometry sorting to identify CD4+ CD25+ Treg cells. After magnetic cell separation, we further used flow cytometry to analyze the purity of CD4+ CD25+ Treg cells, trypan blue staining to detect cell viability, and propidium iodide (PI) staining to assess the cell viability. We detected the immune inhibition of CD4+ CD25+ Treg cells in the in vitro proliferation experiments. Results: The results showed that compared to flow cytometry sorting, magnetic cell sorting took more time and effort, but fewer live cells were obtained than with flow cytometry sorting. The CD4+ CD25+ Treg cells, however, obtained with both methods have similar immunosuppressive capacities. Conclusion: The result suggests that both methods can be used in isolating CD4+ CD25+ Treg cells, and one can select the best method according to specific needs and availability of the methodologies.

Continuous purification and culture of rat type 1 and type 2 alveolar epithelial cells by magnetic cell sorting

Purpose:The incidence of acute lung injury(ALI)in severe trauma patients is 48%and the mortality rate following acute respiratory distress syndrome evolved from ALI is up to 68.5%.Alveolar epithelial type 1 cells(AEC1 s)and type 2 cells(AEC2s)are the key cells in the repair of injured lungs as well as fetal lung development.Therefore,the purification and culture of AECls and AEC2s play an important role in the research of repair and regeneration of lung tissue.Methods:Sprague-Dawley rats(3-4 weeks,120-150 g)were purchased for experiment.Dispase and DNase I were jointly used to digest lung tissue to obtain a single-cell suspension of whole lung cells,and then magnetic bead cell sorting was performed to isolate Tla positive cells as AECls from the single-cell suspension by using polyclonal rabbit anti-Tla(a specific AECls membrane protein)antibodies combined with anti-rabbit IgG microbeads.Afterwards,alveolar epithelial cell membrane marker protein EpCAM was designed as a key label to sort AEC2s from the remaining Tla-neg cells by another positive immunomagnetic selection using monoclonal mouse anti-EpCAM antibodies and anti-mouse IgG microbeads.Cell purity was identified by immunofluorescence staining and flow cytometry.Resii沾••The purity of AECls and AEC2s was 88.3%±3.8%and 92.6%±2.7%,respectively.The cell growth was observed as follows:AECls stretched within the 12-16 h,but the cells proliferated slowly;while AEC2s began to stretch after 24 h and proliferated rapidly from the 2nd day and began to differentiate after 3 days.Conclusion:AECls and AEC2s sorted by this method have high purity and good viability.Therefore,our method provides a new approach for the isolation and culture of AECls and AEC2s as well as a new strategy for the research of lung repair and regeneration.

Characterization of hepatic progenitors from human fetal liver using CD34 as a hepatic progenitor marker

AIM: To enrich putative hepatic progenitors from the developing human fetal liver using CD34 as a marker. METHODS: Aborted fetuses of 13-20 wk were used for the isolation of liver cells. The cells were labeled with anti CD34; a marker used for isolating progenitor population and the cells were sorted using magnetic cell sorting. The positive fractions of cells were assessed for specific hepatic markers. Further, these cells were cultured in vitro for long term investigation. RESULTS: Flow cytometric and immunocytochemical analysis for alphafetoprotein (AFP) showed that the majority of the enriched CD34 positive cells were positive for AFP. Furthermore, these enriched cells proliferated in the long term and maintained hepatic characteristics in in vitro culture. CONCLUSION: The study shows that aborted human fetal liver is a potential source for isolation of hepatic progenitors for clinical applications. The study also demonstrates that CD34 can be a good marker for the enrichment of progenitor populations.