Learn More
In mammals, the regulation of local tryptophan concentrations by the IFN-gamma-i inducible enzyme IDO is a prominent antimicrobial and immunoregulatory effector mechanism. Here, we show for the first time that another tryptophan-degrading enzyme, the liver-specific tryptophan 2,3-dioxygenase (TDO), is also capable of mediating antimicrobial and(More)
Human multipotent mesenchymal stromal cells (MSCs) exhibit multilineage differentiation potential, support hematopoiesis, and inhibit proliferation and effector function of various immune cells. On the basis of these properties, MSC are currently under clinical investigation in a range of therapeutic applications including tissue repair and immune-mediated(More)
Pneumonia caused by bacterial, viral and parasitic pathogens is one of the most common clinical problems facing primary and secondary care physicians. Staphylococcus aureus is a common cause of lung abscesses in humans and, in immunocompromised patients, herpes simplex virus type I and Toxoplasma gondii can cause severe life-threatening pneumonia. The(More)
Tryptophan metabolism occurs via the protohemoprotein enzymes tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO), the latter action of which has a number of effects in the body including both antimicrobial defence and immune regulation. Whilst the antimicrobial action of IDO is largely due to depletion of the essential amino acid(More)
Multipotent mesenchymal stromal cells (MSCs) are bone marrow-derived cells of nonhematopoietic origin with immunoregulatory properties. Although some functions of MSCs have been identified, there are still features that are not explained thus far. The aim of the present study was to identify novel factors involved in MSC-mediated inhibition of T-cell(More)
Neospora caninum is an apicomplexan parasite closely related to Toxoplasma gondii. In nature this parasite is found especially in dogs and cattle, but it may also infect other livestock. The growth of N. caninum, which is an obligate intracellular parasite, is controlled mainly by the cell-mediated immune response. During infection the cytokine gamma(More)
Human fibroblasts provide immunosuppressive functions that are partly mediated by the tryptophan-catabolizing enzyme indoleamine-2,3-dioxygenase (IDO). Moreover, upon stimulation with inflammatory cytokines human fibroblasts exhibit broad-spectrum antimicrobial effector functions directed against various clinically relevant pathogens and these effects are(More)
The interferon (IFN)-gamma-inducible tryptophan degrading enzyme indoleamine 2,3-dioxygenase (IDO) has not only been recognized as a potent antimicrobial effector molecule for the last 25 years but was recently found also to have potent immunoregulatory properties. In this study, we provide evidence that both tryptophan starvation and production of toxic(More)
In infectious diseases, interferon-gamma (IFN-gamma) is generally accepted as one of the most important inducers of antimicrobial and immunoregulatory effects, and both seemingly contradictory effects, can be mediated by the same effector molecules. In detail, several IFN-gamma induced enzymes such as the inducible nitric oxide synthase (iNOS) as well as(More)
Human mesenchymal stromal cells (MSC) possess immunosuppressive and antimicrobial effects that are partly mediated by the tryptophan-catabolizing enzyme indoleamine-2,3-dioxygenase (IDO). Therefore MSC represent a promising novel cellular immunosuppressant which has the potential to control steroid-refractory acute graft versus host disease (GvHD). In(More)