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@#LSCs(limbal stem cells)are one of the adult unipotent stem cells located in the Vogt palisade area of the limbal cornea. It can supplement the repair of corneal epithelium by self renewal and play an important role in maintaining normal corneal epithelial integrity, corneal transparency and maintaining normal vision. The lack of corneal limbus stem cells caused by various reasons will lead to corneal turbid, ocular surface vascularization, and final blindness. The main methord to treat related diseases is to cultivate corneal limbal stem cells <i>in vitro</i> and retransplantation. How to effectively expand the limbal stem cells <i>in vitro</i> is the key to the success of the treatment. The location, acquisition methods and expansion methods of limbal stem cells were reviewed.
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Objective To isolate HIV-specific T cell clone and to expand them in vitro through the activation-induced expression of CD137 molecule.Methods The peripheral blood mononuclear cells were isolated from HIV-infected patients and HIV Gag specific CD3+CD8+CD137+T cell subset were sorted to 96-well plate in 1 cell/well by multicolor flowcytometry and single cell sorting.After 14 days in vitro culture with feeder cells and cytokines, the numbers and phenotypes of the cultured HIV-specific T cells were calcu-lated and identified.Results The CD137 expression was low on rested T cells but up regulated by the stim-ulation with Gag peptide pool.The CD8+CD137+T cells could secret IFN-γ.The number of CD8 T cells reached to 106 after 14 days in culture and expanded to 107-108 cells after 28 days of culture in vitro 100%of the cells remained activated upon Gag stimulation.Conclusion In stead of using IFN-γ, CD137 could be utilized as a novel molecule to isolate and expand HIV specific T cells in vitro.The expanded antigen spe-cific T cell clones could maintain good activation status.
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Background: Though the transplantation of human corneal endothelial tissue (CET) separated from cadaver cornea is in practice, its transportation has not been reported. We report the successful transportation of CET in varying Indian climatic conditions without cool preservation and the in vitro expansion of Human Corneal Endothelial Precursor Cells (HCEPCs) using a novel Thermo‑reversible gelation polymer (TGP). Materials and Methods: CET from cadaver corneas (n = 67), unsuitable for transplantation, were used. In phase I, CET was transported in Basal Culture Medium (Group I) and TGP (Group II) and in Phase II, in TGP cocktail alone, from three hospitals 250‑2500 km away, to a central laboratory. The transportation time ranged from 6 h to 72 h and the outdoor temperature between 20°C and 41°C. On arrival, CET were processed, cells were expanded upto 30 days in basal culture medium (Group A) and TGP scaffold (Group B). Cell viability and morphology were documented and Reverse transcription polymerase chain reaction (RT‑PCR) characterization undertaken. Results: In Phase I, TGP yielded more viable cells (0.11 × 106 cells) than Group I (0.04 × 106 cells). In Phase II, the average cell count was 5.44 × 104 cells. During expansion, viability of HCEPCs spheres in TGP was maintained for a longer duration. The cells from both the groups tested positive for B‑3 tubulin and negative for cytokeratins K3 and K12, thereby proving them to be HCEPCs. Conclusion: TGP preserves the CET during transportation without cool preservation and supports in vitro expansion, with a higher yield of HCEPCs, similar to that reported in clinical studies.