Chemical properties and protective effect of Rosmarinus officinalis: mitigation of lipid peroxidation and DNA-damage from arsenic exposure

Recent studies have implicated dietary factors in the cause and prevention of important diseases, with strong evidence that plant’s compounds can protect against these diseases. Moreover, food security and environmental contamination are topics in focus at the moment. In this view, contamination by arsenic (As) has received much attention as well as some spices with medicinal properties. Among these plants, the use of Rosmarinus officinalis L. has demonstrated antioxidant properties besides being used for circulatory disorders. Therefore, we measured the mitotic index of Allium cepa L. and characterized the antioxidant effects to determine the capacity of R. officinalis to ameliorate arsenic-induced DNA damage. R. officinalis extract showed no mutagenic effects and exhibited antimutagenic potential, reducing the DNA damage, anaphase-telophase briges and micronuclei chromosome aberrations that result from treatment with the arsenic. Additionally, reduction in arsenic- induced lipid peroxidation was also observed

A specific, glycomimetic Langerin ligand for human Langerhans cell targeting

Langerhans cells are a subset of dendritic cells residing in the epidermis of the human skin. As such, they are key mediators of immune regulation and have emerged as prime targets for novel transcutaneous cancer vaccines. Importantly, the induction of protective T cell immunity by these vaccines requires the efficient and specific delivery of both tumor-associated antigens and adjuvants. Langerhans cells uniquely express Langerin (CD207), an endocytic C-type lectin receptor. Here, we report the discovery of a specific, glycomimetic Langerin ligand employing a heparin-inspired design strategy that integrated NMR spectroscopy and molecular docking. The conjugation of these glycomimetics to liposomes enabled the specific and efficient targeting of Langerhans cells in the human skin. This delivery platform provides superior versatility and scalability over antibody-based approaches and thus addresses current limitations of dendritic cell-based immunotherapies

Notch-mediated generation of monocyte-derived Langerhans cells: Phenotype and function

Langerhans cells (LCs) in the skin are a first line of defense against pathogens but also play an essential role in skin homeostasis. Their exclusive expression of the C-type lectin receptor Langerin/CD207 makes them prominent candidates for immunotherapy. For vaccine testing, an easily accessible cell platform would be desirable as an alternative to the time-consuming purification of LCs from human skin. Here we present such a model and demonstrate that monocytes in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), transforming growth factor (TGF)-β1 and the Notch ligand Delta-like 4 (DLL4) differentiate within 3 days into CD1a+Langerin+cells containing Birbeck granules. RNA-sequencing (RNA-seq) of these monocyte-derived LCs (moLCs) confirmed gene expression of LC-related molecules, pattern recognition receptors and enhanced expression of the antigen-presenting machinery. On protein level, moLCs showed low expression of costimulatory molecules but prominent expression of C-type lectin receptors. MoLCs can be matured, secrete IL-12p70 and TNF-α and stimulate proliferation and cytokine production in allogeneic CD4+ and CD8+ T cells. In regard to vaccine testing, a recently characterized glycomimetic Langerin ligand conjugated to liposomes demonstrated specific and fast internalization into moLCs. Hence, these short-term in vitro-generated moLCs represent an interesting tool to screen LC-based vaccines in the future