Academy of Arts,

Moraxella bovis was repeatedly isolated from cerebrospinal fluid in a girl with two episodes of shunt nephritis. Clinical remission of nephritis was achieved only after shunt replacement. A list of about 20 infectious agents reported to date in patients with shunt nephritis is given. M. bovis is yet another agent previously not reported in patients with shunt nephritis.

Background Interleukin-17 (IL-17)-producing cells are increasingly considered to be the major pathogenic population in various autoimmune disorders. The effects of glucocorticoids, widely used as therapeutics for inflammatory and autoimmune disorders, on IL-17 generation have not been thoroughly investigated so far. Therefore, we have explored the influence of methylprednisolone (MP) on IL-17 expression in rat lymphocytes, and compared it to the effect of the drug on interferon (IFN)-γ. Results Production of IL-17 in mitogen-stimulated lymph node cells (LNC) from non-treated rats, as well as in myelin basic protein (MBP)-stimulated draining LNC from rats immunized with spinal cord homogenate and complete Freund's adjuvant was significantly reduced by MP. The reduction was dose-dependent, sustained through the follow-up period of 48 hours, and was not achieved through anti-proliferative effect. Additionally, MP inhibited IL-17 production in purified T cells as well, but to less extent than in LNC. In its influence on IL-17 production MP inhibited Ror-γT transcription factor expression, as well as Jun phosphorylation, but not ERK or p38 activation in mitogen-stimulated LNC. Importantly, MP collaborated with IFN-γ in inhibiting IL-17 generation in LNC. Conclusion The observed difference in the effect of MP on IL-17 and IFN-γ could be important for the understanding of the variability in the efficiency of glucocorticoids in the treatment of autoimmune diseases.

Although astrocytes presumably participate in maintaining the immune privilege of the central nervous system (CNS), the mechanisms behind their immunoregulatory properties are still largely undefined. In this study, we describe the development of regulatory T cells upon contact with astrocytes. Rat T cells pre-incubated with astrocytes completely lost the ability to proliferate in response to mitogenic stimuli. The cells were blocked in G0/G1 phase of the cell cycle, expressed less IL-2R, and produced significantly lower amounts of interferon-γ (IFN-γ), but not interleukin-2 (IL-2), IL-10, or tumor necrosis factor (TNF). These anergic cells completely prevented mitogen-induced growth of normal T lymphocytes, as well as CNS antigen-driven proliferation of autoreactive T cells. The suppressive activity resided in both CD4+ and CD8+ T-cell compartments. Heat-sensitive soluble T-cell factors, not including transforming growth factor-β (TGF-β) or IL-10, were solely responsible for the observed suppression, as well as for the transfer of suppressive activity to normal T cells. The administration of astrocyte-induced regulatory T cells markedly alleviated CNS inflammation and clinical symptoms of CNS autoimmunity in rats with experimental allergic encephalomyelitis. Finally, the cells with suppressive properties were readily generated from human lymphocytes after contact with astrocytes. Taken together, these data indicate that astrocyte-induced regulatory T cells might represent an important mechanism for self-limitation of excessive inflammation in the brain. © 2004 Wiley-Liss, Inc.

In experimental animal models of multiple sclerosis are rare in ONND (3%) and rheumatoid arthritis (10%). Anti-MBP IgG antibodies, however, are a frequent finding demyelinating antibody responses are directed against the in ONND (23%) and rheumatoid arthritis (60%). Our myelin oligodendrocyte glycoprotein (MOG). We have results provide clear evidence that anti-MOG-Ig antiinvestigated whether a similar antibody response is also bodies are common in CNS inflammation. However, in present in multiple sclerosis patients. Using the recom-OIND these antibody responses are transient, whereas binant human extracellular immunoglobulin domain of they persist in multiple sclerosis. We demonstrate that MOG (MOG-Ig) we have screened the sera and CSFs of the serum anti-MOG-Ig response is already established 130 multiple sclerosis patients, 32 patients with other in early multiple sclerosis (multiple sclerosis-R0; 36%). inflammatory neurological diseases (OIND), 30 patients In later multiple sclerosis stages frequencies and titres with other non-inflammatory neurological diseases are comparable with early multiple sclerosis. In contrast, (ONND) and 10 patients with rheumatoid arthritis. We the frequency of anti-MBP antibodies is low in multiple report that 38% of multiple sclerosis patients are serosclerosis-R0 (12%) and increases during disease progrespositive for IgG antibodies to MOG-Ig compared with sion in relapsing-remitting (32%) and chronic progressive 28% seropositive for anti-myelin basic protein (MBP). In multiple sclerosis (40%), thus suggesting that anti-MBP contrast, OIND are characterized by similar frequencies responses accumulate over time. Finally we provide of serum IgG antibody responses to MOG-Ig (53%) and evidence for intrathecal synthesis of IgG antibodies to MOG-Ig in multiple sclerosis.

Albino Oxford (AO) rats are resistant to induction of experimental autoimmune encephalomyelitis (EAE), in contrast to susceptible Dark Agouti (DA) rats. We have previously shown that draining lymph node cells (DLNC) obtained from immunized DA rats before the onset of the clinical disease produced more interferon (IFN)-␥ and interleukin (IL)-17 (signature cytokines of T H 1 and T H 17 responses, respectively) compared to DLNC from AO rats. In this study, we extend our analysis to entire induction phase of EAE with the emphasis on the T H 1 and T H 17-inducing cytokines. As a result, we show that throughout the inductive phase of the disease DLNC of DA rats, not only expressed higher levels of IFN-␥ and IL-17, but also of T H 1-inducing cytokine-IL-12. As for T H 17-inducing cytokines, DLNC of DA rats expressed more mRNA for p19, specific subunit of IL-23, but the expression of transforming growth factor (TGF)-␤ in both strains was similar. Interestingly, the analysis of IL-6 expression revealed striking difference: while all DA DLNC were positive for IL-6 mRNA, cells from none of AO rats expressed detectable levels of mRNA for this cytokine. Taken together, our data suggest that the differential regulation of production of T H 1 and T H 17 cytokines, and IL-6 in particular, during the induction phase of disease could be responsible for the discrepancy in susceptibility to EAE between these two rat strains.

Nitric oxide (NO) is a highly reactive free radical with profound tumoricidal activity, produced by both macrophages and tumor cells. While it has been postulated that necrotic tumor cells can augment macrophage anti-tumor action, we investigated the effect of tumor cell necrosis on NO synthesis and viability of L929 fibrosarcoma and C6 astrocytoma cell lines. The presence of necrotic tumor cells dose-dependently reduced NO production in IFN-c stimulated L929 cells, and rescued them from NO-dependent autotoxicity. This effect was mediated through soluble products, since it was completely preserved after blocking the contact between the necrotic and live cells. On the other hand, apoptotic tumor cells were unable to suppress IFN-c-triggered NO release and subsequent decrease of cell respiration in L929 cultures. Similar results were obtained with C6 astrocytoma cell line. This downregulation of NO synthesis in response to necrotic cell products was not specific for tumor cell lines, since necrotic tumor cells markedly suppressed NO production in cytokine-stimulated primary fibroblasts and astrocytes. In contrast, both murine and rat peritoneal macrophages readily increased their basal or IFN-c-induced NO production when incubated with necrotic tumor cells. Taken together, these results suggest that tumor cell necrosis might promote or restrict tumor growth through suppression or enhancement of NO synthesis in tumor cells and macrophages, respectively, with net effect presumably depending on the extent of macrophage infiltration. Ó

There has been a continuing effort for the discovery of novel platinum(IV)-based antitumor compounds with better therapeutic performances than cisplatin. In the present work, the anticancer action of recently synthesized Pt(IV)-based complex [Pt(HPxSC)Cl 3 ] was investigated using rat and human astrocytoma cell lines C6 and U251. [Pt(HPxSC)Cl 3 ] markedly reduced the number of cultured astrocytoma cells (IC 50 , 80 AM), as determined by crystal violet assay. The Pt(IV) complex induced apoptotic death of tumor cells, as flow cytometry analysis of the propidium iodide-stained cellular DNA revealed approx. 30% of hypodiploid cells in [Pt(HPxSC)Cl 3 ]-treated astrocytoma cell cultures. On the other hand, [Pt(HPxSC)Cl 3 ] at 200 AM did not affect the viability of rat primary astrocytes, unlike the established anticancer drug cisplatin, which displayed high toxicity toward both astrocytoma cells (IC 50 , 15 AM) and primary astrocytes (IC 50 , 20 AM). Moreover, [Pt(HPxSC)Cl 3 ] at 100 AM did not interfere with the ability of rat peritoneal macrophages to produce important antitumor molecules nitric oxide and tumor necrosis factor-a. Finally, we assessed the ability of [Pt(HPxSC)Cl 3 ] to restrain growth of some bacterial and yeast strains, but it showed rather limited antimicrobial activity. D

Because the neurotoxic effects of the antifungal drug amphotericin B (AMB) closely resemble those ascribed to the highly reactive gaseous free radical nitric oxide (NO), we investigated the effect of AMB on NO production in rodent astrocytes. AMB caused a dose-dependent increase of NO generation in interferon-γ (IFN-γ)-stimulated rat and mouse astrocytes, as well as in IFN-γ + tumor necrosis factor-α (TNF-α)-activated rat astrocytoma cell line C6. Treatment of rat astrocytes with AMB markedly potentiated IFN-γ-triggered expression of mRNA for iNOS, but not for its transcription factor IRF-1. The activation of transcription factor NF-κB was apparently required for AMB-induced iNOS mRNA expression, as the latter was abolished by NF-κB inhibitors: pyrrolidine dithiocarbamate and MG132. AMB-mediated enhancement of astrocyte NO production was partly dependent on endogenous IL-1, as shown by partial inhibition of AMB effect with IL-1 receptor antagonist. IFN-γ + AMB treatment led to reduction of astrocyte mitochondrial respiration (measured by MTT assay) that has been completely reverted by selective iNOS inhibitor aminoguanidine. AMB toxicity toward IFN-γ-stimulated astrocytes was dependent on both AMB and NO action, since AMB and NO-releasing substance SNP synergized in inducing astrocyte mitochondrial dysfunction. These results suggest that the enhancement of cytokine-induced iNOS activation in astrocytes and the subsequent release of high amounts of NO might be at least partly responsible for AMB neurotoxicity. GLIA 35:180–188, 2001. © 2001 Wiley-Liss, Inc.