Characterization and Isolation of Very Small Embryonic-like (VSEL) Stem Cells Obtained from Various Human Hematopoietic Cell Sources.

Stem cell transplantation is one of the available treatments for leukemia, lymphoma, hereditary blood diseases and bone marrow failure. Bone marrow (BM), peripheral blood progenitor cells (PBPC), and cord blood (CB) are the predominant sources of stem cells. Recently a new type of stem cell with a pluripotent potential has been identified. These cells were named "very small embryonic like stem cells (VSELs)". It is claimed that VSEL stem cells can be found in adult BM, peripheral blood (PB), CB and other body tissues. This study is designed to characterize and isolate VSEL stem cells from different human hematopoietic sources; CB, PB and apheresis material (PBPC). VSEL stem cells were isolated from MNC and erythrocyte layers for all materials by using centrifugation and ficoll gradient method. We determined embryonic markers by flow cytometry, immunofluorescence and western blotting methods. Results from western blotting and immunofluorescence show high level of NANOG and OCT4 protein expression in PB, apheresis material and CB. Immunofluorescence images showed cytoplasmic and nuclear presence of these proteins. Flow cytometry results exhibited a higher expression of VSELs markers on debris area than CD45- population and higher expression on CB than PB. As a result, these findings have shown that it is necessary to investigate the function of pluripotent stem cell markers in differentiated adult cells. We further conclude that erythrocyte lysis method had the highest cell recovery amount among erythrocyte lysis and ficoll gradient methods. Consequently, this study gives us new information and viewpoints about expression of pluripotent stem cell (PSC) markers in adult tissues.

Oral nickel exposure may induce Type I hypersensitivity reaction in nickel-sensitized subjects.

BACKGROUND: Little is known about the clinical and immunological changes in the nickel allergic patients with systemic symptoms. We aimed to evaluate T helper cell responses of patients with different clinical presentations due to nickel. METHODS: Patients having various allergic symptoms and positive patch test results to nickel and 20 controls underwent skin prick tests with nickel. IL-10, IL-4, IL-5 and IFN-gamma were measured in the culture supernatants of PBMC stimulated by nickel during lymphocyte proliferation test (LTT). RESULTS: 69 patients (56 female, mean age: 49.2 ± 13.1), 97% having nickel containing dental devices and 20 controls (8 female, mean age 34.9 ± 12.06) were evaluated. Skin prick tests with nickel were positive in 70% of the patients (p<0.001), being significantly higher in the patients with urticaria/angioedema (p=0.02). The LTT stimulation index (p<0.0001), IL-4 (p=0.002), IFN-gamma (p=0.01), IL-5 (p=0.04) and IL-10 (p=0.003) were higher in the patient group. LTT stimulation index, IL-4 and IL-10 were significantly elevated in patients having urticaria, angioedema and respiratory symptoms when compared to those who had only oral symptoms or systemic dermatitis (p=0.004, p=0.002 and p=0.01, respectively). CONCLUSION: This study suggests the presence of Type I hypersensitivity in addition to a Type IV immune reaction in patients with chronic systemic symptoms related to nickel. Nickel containing dental alloys and oral nickel intake seem to trigger systemic symptoms in previously nickel sensitized patients.