Malignant gliomas are able to secrete large amounts of immunosuppressive cytokines like transforming growth factor beta 2 (TGF-beta2) and regularly escape from immune surveillance. Many strategies have been developed to induce potent anti-glioma responses, among those the use of dendritic cells (DC) as therapeutic vaccines. Here, we report that both mature DC and IL-12 secretion are necessary to overcome T-cell inhibition by TGF-beta2. Flow cytometric analyses showed that TGF-beta2 does not suppress the upregulation of MHC (major histocompatibility complex) class II molecules and the T cell stimulatory capacity of human DC that were stimulated with a strong cytokine cocktail containing tumor necrosis factor alpha (TNF-alpha), IL-1beta, IL-6 and prostaglandin E2 (PGE2). Moreover, TGF-beta2 signaling studies revealed that these cytokine-matured DC become unresponsive to TGF-beta2. Although both mature and immature DC expressed comparable amounts of the TGF-beta receptor type II, Smad2 phosphorylation and subsequent upregulation of Smad7 was inhibited in mature DC, but not immature DC. However, further analysis revealed that mature DC alone are not sufficient to mediate full T cell activation in the presence of TGF-beta2, unless IL-12 is added to the DC/T-cell coculture. Finally, we demonstrate that MHC class II expression and IL-12 secretion by DC are not disturbed by TGF-beta2 after DC stimulation with a modified maturation cocktail containing the Toll-like receptor (TLR)-ligands Poly I:C or R848, TNF-alpha, IL-1beta and INF-gamma. These data imply that mature DC retaining their capacity to produce IL-12 are of favorable use in glioma immunotherapy and suggest that TLR triggering of DC plays an important role to elicit a strong immune response in the immunosuppressive environment of malignant gliomas.
Tick borne encephalitis (TBE) is an important viral encephalitis in central and eastern Europe. Cerebrospinal fluid (CSF) pleocytosis has been described in all published patients so far. This may be due to selection bias, however, as CSF pleocytosis is often used as a case definition parameter. The frequency of TBE without CSF pleocytosis is unknown. We report two cases who developed severe TBE without CSF pleocytosis. A normal CSF cell count should therefore not discourage from the differential diagnosis of TBE and deter from serological testing in patients with a clinical constellation suggesting TBE.
Progressive multifocal leucoencephalopathy has become a growing concern in natalizumab-treated multiple sclerosis patients. Here, we describe a 35-year-old patient who was treated with 34 infusions of natalizumab before complaining about visual deterioration. MRI was non-diagnostic and JC virus testing initially was negative. Electroencephalography showed severe slowing of the right hemisphere, and neuropsychological testing revealed right frontal and temporal deficits. The diagnosis of progressive multifocal leucoencephalopathy was established 2 months later by typical MRI presentation and detection of JC virus DNA in the cerebrospinal fluid. Functional neurological deficits may precede imaging features and should prompt early consideration of progressive multifocal leucoencephalopathy.
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