In JoVE (1)

Other Publications (3)

Articles by Dan Lehmann in JoVE

Other articles by Dan Lehmann on PubMed

Extrapancreatic Autoimmune Manifestations in Type 1 Diabetes Patients and Their First-degree Relatives: a Multicenter Study

Diabetes Care. Apr, 2003  |  Pubmed ID: 12663603

To investigate the prevalence of autoimmune diseases in young patients (probands) with type 1 diabetes and their first-degree relatives, and to determine the spectrum of extrapancreatic manifestations in these subjects.

Gamma-irradiation Enhances Apoptosis Induced by Cannabidiol, a Non-psychotropic Cannabinoid, in Cultured HL-60 Myeloblastic Leukemia Cells

Leukemia & Lymphoma. Oct, 2003  |  Pubmed ID: 14692532

Two non-psychotropic cannabinoids, cannabidiol (CBD) and cannabidiol-dimethylheptyl (CBD-DMH), induced apoptosis in a human acute myeloid leukemia (AML) HL-60 cell line. Apoptosis was determined by staining with bisBenzimide and propidium iodide. A dose dependent increase of apoptosis was noted, reaching 61 and 43% with 8 microg/ml CBD and 15 microg/ml CBD-DMH, respectively, after a 24 h treatment. Prior exposure of the cells to gamma-irradiation (800 cGy) markedly enhanced apoptosis, reaching values of 93 and 95%, respectively. Human monocytes from normal individuals were resistant to either cannabinoids or gamma-irradiation. Caspase-3 activation was observed after the cannabinoid treatment, and may represent a mechanism for the apoptosis. Our data suggest a possible new approach to treatment of AML.

The Role of Skin-derived Dendritic Cells in CD8+ T Cell Priming Following Immunization with Lentivectors

Journal of Immunology (Baltimore, Md. : 1950). May, 2010  |  Pubmed ID: 20357252

Although skin dendritic cells (DCs) have been shown to directly present Ag to CD8(+) T cells after intradermal immunization with lentivectors, the contribution of the different skin DC subsets to this process remains unclear. Using langerin-diphtheria toxin receptor transgenic mice we demonstrated that ablation of langerhans cells and langerin-expressing positive dermal DCs (Ln(+)dDCs) did not interfere with the generation of CD8(+) T cells by lentiviral vectors. Consistent with these findings, the absence of langerhans cells and Ln(+)dDCs did not hamper the presentation level of lentiviral-derived Ag by skin DCs in vitro. We further demonstrated that only dDCs and Ln(+)dDCs were capable of presenting Ag, however, the number of dDCs migrating to the draining lymph nodes was 6-fold higher than that of Ln(+)dDCs. To study how the duration of DC migration influences CD8(+) T cell responses, we analyzed the kinetics of Ag expression at the injection site and manipulated DC migration by excising the injected skin at various times after immunization. A low level of Ag expression was seen 1 wk after the immunization; peaked during week 2, and was considerably cleared by week 3 via a perforin-dependent fas-independent mechanism. Removing the injection site 3 or 5 d, but not 10 d, after the immunization, resulted in a reduced CD8(+) T cell response. These findings suggest that dDCs are the main APCs active after intradermal lentiviral-mediated immunization, and migration of dDCs in the initial 10-d period postimmunization is required for optimal CD8(+) T cell induction.

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