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Deregulation such as overexpression of adhesion molecules influences cancer progression and survival. Metastasis of malignant cells from their primary tumor site to distant organs is the most common reason for cancer-related deaths. Junctional adhesion molecule-C (JAM-C), a member of the immunoglobulin-like JAM family, can homodimerize and aid cancer cell migration and metastasis. Here we show that this molecule is dynamically expressed on multiple myeloma (MM) cells in the bone marrow and co-localizes with blood vessels within the bone marrow of patients and mice. In addition, upregulation of JAM-C inversely correlates with the downregulation of the canonical plasma cell marker CD138 (syndecan-1), whose surface expression has recently been found to dynamically regulate a switch between MM growth in situ and MM dissemination. Moreover, targeting JAM-C in a syngeneic in vivo MM model ameliorates MM progression and improves outcome. Overall, our data demonstrate that JAM-C might serve not only as an additional novel diagnostic biomarker but also as a therapeutic target in MM disease.

We identified STAT1 gain of function (GOF) in a 32-year-old female with pallor, weakness, cough, and dyspnea admitted to our Division of Medicine. She had severe oral ulcers (OU), type 1 diabetes (T1DM), and pancytopenia. Bone marrow (BM) biopsy showed the absence of erythroid precursors. Peripheral blood parameters such as neutrophils C, p.Cys174Arg) of STAT1 was uncovered. Thus, p.Cys174Arg mutation was investigated as potentially responsible for the patient's inborn immunity error and aplastic anemia. Although STAT1 GOF is rare, aplastic anemia is a more common condition; therefore, we explored STAT1 functional role in the pathobiology of BM failure. Interestingly, in a cohort of six patients with idiopathic aplastic anemia, enhanced phospho-STAT1 levels were observed on BM immunostaining. Next, the most remarkable features associated with STAT1 signaling dysregulation were examined: in both pure red cell aplasia and aplastic anemia, CD8+ T cell genetic variants and mutations display enhanced signaling activities related to the JAK-STAT pathway. Inborn errors of immunity may represent a paradigmatic condition to unravel crucial pathobiological mechanisms shared by common pathological conditions. Findings from our case-based approach and the phenotype correspondence to idiopathic aplastic anemia cases prompt further statistically powered prospective studies aiming to elucidate the exact role and theragnostic window for JAK/STAT targeting in this clinical context. Nonetheless, we demonstrate how a comprehensive study of patients with primary immunodeficiencies can lead to pathophysiologic insights and potential therapeutic approaches within a broader spectrum of aplastic anemia cases.

Multiple myeloma remains a largely incurable disease of clonally expanding malignant plasma cells. The bone marrow microenvironment harbors treatment-resistant myeloma cells, which eventually lead to disease relapse in patients. In the bone marrow, CD4+FoxP3+ regulatory T cells (Tregs) are highly abundant amongst CD4+ T cells providing an immune protective niche for different long-living cell populations, e.g., hematopoietic stem cells. Here, we addressed the functional role of Tregs in multiple myeloma dissemination to bone marrow compartments and disease progression. To investigate the immune regulation of multiple myeloma, we utilized syngeneic immunocompetent murine multiple myeloma models in two different genetic backgrounds. Analyzing the spatial immune architecture of multiple myeloma revealed that the bone marrow Tregs accumulated in the vicinity of malignant plasma cells and displayed an activated phenotype. In vivo Treg depletion prevented multiple myeloma dissemination in both models. Importantly, short-term in vivo depletion of Tregs in mice with established multiple myeloma evoked a potent CD8 T cell- and NK cell-mediated immune response resulting in complete and stable remission. Conclusively, this preclinical in-vivo study suggests that Tregs are an attractive target for the treatment of multiple myeloma.

Measurement of minimal residual disease (MRD) by next-generation flow cytometry (NGF) is an important tool to define deep responses in multiple myeloma (MM). However, little is known about the value of combining NGF with functional imaging and its role for MRD-based consolidation strategies in clinical routine. In the present study, we report our experience investigating these issues with 102 patients with newly diagnosed (n = 57) and relapsed/refractory MM (n = 45). Imaging was performed using either positron emission tomography or diffusion-weighted magnetic resonance imaging. In all, 45% of patients achieved MRD-negativity on both NGF and imaging (double-negativity), and 8% and 40% of patients were negative on either NGF or imaging respectively. Thus, in a minority of patients imaging was the only technique to detect residual disease. Imaging-positivity despite negativity on NGF was more common in heavily pretreated disease (four or more previous lines) compared to newly diagnosed MM (p 0.01). Among the 29 patients undergoing MRD-triggered consolidation, 51% responded with MRD conversion and 21% with improved serological response. MRD-triggered consolidation led to superior progression-free survival (PFS) when compared to standard treatment (p = 0.04). In conclusion, we show that combining NGF with imaging is helpful particularly in patients with heavily pretreated MM, and that MRD-based consolidation could lead to improved PFS.

Background Interactions between multiple myeloma plasma cells (MMPC) and the multiple myeloma (MM) niche control cell proliferation, drug resistance, and disease spreading through various adhesion molecules and chemokine receptors. Among these, junctional adhesion molecule-A (JAM-A) mediates MMPC-endothelial interactions and propagates neovascularization. Here we addressed whether JAM-A signaling mediates MMPC invasive behavior orchestrating intra- and extramedullary MM dissemination. Methods We investigated JAM-A expression with flow cytometry and immunohistochemistry in 60 MM patient bone marrow (BM) aspirates and biopsies at different disease stages with and without extramedullary disease (EMD) manifestation. We compared these results with RNA-Seq data from 647 newly diagnosed MM (NDMM) patients collected in the MMRF CoMMpass study. Using bioinformatics, we investigated JAM-A-related pathways with hierarchical cluster analysis. Subsequently, we functionally validated these JAM-A-related pathways regarding epithelial-mesenchymal transition (EMT), invasion, and MM dissemination in vitro. Results The median OS differed significantly in subjects with elevated membrane JAM-A expression levels, dividing the patients in the EMD JAM-Ahigh group with a median OS of 84.1 months, whereas median OS in JAM-Alow patients was not reached, irrespective of the EMD status (log-rank=4.19, P=.04). Immunohistochemistry analysis of BM biopsies confirmed these findings. RNA-Seq analysis corroborated the prognostic impact of JAM-A (log-rank=3.8, P=.051). High-risk patients with EMD and JAM-A expression displayed a unique gene-expression signature. Additionally, we constructed a novel expression cluster subgroup model, revealing complex molecular disease patterns and associations between clinical traits and expression markers. Strikingly, MM patients clustered by JAM-A expression levels and EMD manifestation revealed properties of epithelial-mesenchymal-transition and induced focal adhesion pathways. Notably, functional knockdown of JAM-A in MMPC in vitro not only reduced cell viability but also diminished MMPC adhesion molecules and CD138 surface expression. Furthermore, mTOR/PI3K in vitro inhibition with BEZ235 significantly downregulated surface expression in JAM-Ahigh MM cells. Interestingly, when we inhibited mTOR/PI3K in JAM-Alow MM cells, we observed JAM-A induction. Finally, ensuing functional shRNA knockdown of JAM-A halted MM invasion (P Conclusions Collectively, these data reveal JAM-A-mediated signaling critical for EMT transition and invasive behavior. Based on these findings we propose JAM-A as a promising biomarker and novel theragnostic target in MM patients.

The identification of regulatory T cells (Treg cells) in human peripheral blood is an important tool in diagnosis, research and therapeutic intervention. As compared to lymphoid tissues, the frequencies of circulating Treg cells identified as CD4+CD25+Foxp3+ are, however, low. We here show that many of these cells remain undetected due to transient down regulation of Foxp3, which rapidly decays in the absence of cytokine-mediated STAT5 signals. Short-term incubation of PBMCs or isolated CD4+ T-cells, but not of lymph node cells, with IL-2, -7, or -15 more than doubles the frequency of Foxp3+CD25+ among CD4+ T-cells detectable by flow cytometry. This increase is not due to cell division but to upregulation of both proteins. At the same time, the uncovered Treg cells up-regulate CD25 and down-regulate CD127, making them accessible to viable cell sorting. “Latent” Treg cells have a demethylated FOXP3 TSDR sequence, are enriched in naive, non-cycling cells, and are functional. The confirmation of our findings in RA and SLE patients shows the feasibility of uncovering latent Treg cells for immune monitoring in clinical settings. Finally, our results suggest that unmasking of latent Treg cells contributes to the increase in circulating CD4+CD25+Foxp3+ cells reported in IL-2 treated patients. This article is protected by copyright. All rights reserved

Background: Minimal residual disease (MRD) diagnostics in multiple myeloma (MM) are gaining increasing importance to determine response depth beyond complete remission (CR) since novel agents have shown to induce high rates of deep clinical responses. Moreover, recent reports indicated combining functional imaging with next generation flow cytometry (NGF) could be beneficial in predicting clinical outcome. This applies in particular to the subset of patients suffering from relapsed/refractory multiple myeloma (RRMM) who tend to show a higher incidence of residual focal lesions despite serological response. Here, we report our institutions experience with implementing both functional imaging and NGF-guided MRD diagnostics in clinical practice. Methods: Our study included patients with newly diagnosed multiple myeloma (NDMM) and RRMM achieving VGPR, CR or sCR. Bone marrow aspirates were obtained for MRD-testing according to IMWG 2016 criteria. Samples were collected between July 2019 and July 2020 and analyzed with NGF (according to EuroFlowTM guidelines) at a sensitivity level of 10-5. Results were compared to functional imaging obtained with positron emission tomography (PET) and diffusion-weighted magnetic resonance imaging (DW-MRI). High-risk disease was defined as presence of deletion 17p, translocation (14;16) or (4;14). Results: We included 66 patients with NDMM (n=39) and RRMM (n=27) who achieved VGPR or better. In patients with RRMM the median number of treatment lines was 2 (range 2-11). Fifteen patients suffered from high-risk disease. Median age at NGF diagnostics was 64 years (range 31-83). Among patients achieving VGPR (n=27), CR (n=10) and sCR (n=29) seventeen (26%) were MRD-negative by NGF testing. CR or better was significantly associated NGF MRD-negativity (p=0.04). Notably, rates of NGF MRD-negativity were similar among patients with NDMM (28%) and RRMM (26%). Even some heavily pretreated patients who underwent ≥ 4 lines of therapy achieved MRD-negativity on NGF (2 of 9). Functional imaging was performed in 46 (70%) patients with DW-MRI (n=22) and PET (n=26). Median time between NGF and imaging assessment was 2 days (range 0-147). Combining results from imaging and NGF, 12 out of 46 (26%) patients were MRD-negative with both methods (neg/neg). Three patients displayed disease activity as measured with both, imaging and NGF (pos/pos). Twenty-nine of the remaining patients were MRD-positive only according to NGF (pos/neg), while two patients were positive on imaging only (neg/pos). More patients demonstrated combined MRD-negativity on NGF and imaging (neg/neg) in the NDMM setting than in RRMM (32% versus 19%). We also observed that 30% of the patients with high-risk genetics showed MRD-negativity on both imaging and NGF. Of note, none of the patients with very advanced disease (≥4 previous lines) was MRD-negative on both techniques. Conclusion In the clinical routine, MRD diagnostics could be used to tailor maintenance and consolidation approaches for patients achieving deep responses by traditional IMWG criteria. Our real-world experience highlights that MRD-negativity can be achieved in patients suffering from high-risk disease and also in late treatment lines, supporting its value as endpoint for clinical trials. However, our data also support MRD diagnostics to be combined with functional imaging at least in the RRMM setting to rule out residual focal lesions. Future studies using MRD for clinical decision-making are highly warranted. Disclosures Einsele: Takeda: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; GlaxoSmithKline: Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau. Rasche:Celgene/BMS: Honoraria; GlaxoSmithKline: Honoraria; Oncopeptides: Honoraria; Skyline Dx: Research Funding; Janssen: Honoraria; Sanofi: Honoraria.

In rodents, low doses of CD28-specific superagonistic monoclonal antibodies (CD28 superagonists, CD28SA) selectively activate regulatory T cells (Treg). This observation has recently been extended to humans, suggesting an option for the treatment of autoimmune and inflammatory diseases. However, a mechanistic explanation for this phenomenon is still lacking. Given that CD28SA amplify T cell receptor (TCR) signals, we tested the hypothesis that the weak tonic TCR signals received by conventional CD4+ T cells (Tconv) in the absence of cognate antigen require more CD28 signaling input for full activation than the stronger TCR signals received by self-reactive Treg. We report that in vitro, the response of mouse Treg and Tconv to CD28SA strongly depends on MHC class II expression by antigen-presenting cells. To separate the effect of tonic TCR signals from self-peptide recognition, we compared the response of wild-type Treg and Tconv to low and high CD28SA doses upon transfer into wild-type or H-2M knockout mice, which lack a self-peptide repertoire. We found that the superior response of Treg to low CD28SA doses was lost in the absence of self-peptide presentation. We also tested if potentially pathogenic autoreactive Tconv would benefit from self-recognition-induced sensitivity to CD28SA stimulation by transferring TCR transgenic OVA-specific Tconv into OVA-expressing mice and found that low-dose CD28SA application inhibited, rather than supported, their expansion, presumably due to the massive concomitant activation of Treg. Finally, we report that also in the in vitro response of human peripheral blood mononuclear cells to CD28SA, HLA II blockade interferes with the expansion of Treg by low-dose CD28SA stimulation. These results provide a rational basis for the further development of low-dose CD28SA therapy for the improvement of Treg activity.

Following inconspicuous preclinical testing, the superagonistic anti-CD28 mAb TGN1412 was applied to six study participants who all developed a devastating cytokine storm. We verified that TGN1412 treatment of fresh PBMCs induced only moderate responses, whereas restoration of tissue-like conditions by high-density preculture (HDC) allowed vigorous cytokine production. TGN1412 treatment of T cells isolated from HDC-PBMCs induced moderate cytokine responses, which upon additional anti-IgG crosslinking were significantly boosted. Moreover, coincubation of TGN1412-treated T cells with B cells expressing the intermediate affinity Fcγ receptor IIB (CD32B), or coincubation with CD32B+ transfectants, resulted in robust T cell activation. This was surprising because TGN1412 was expressed as an Ig of the subclass 4 (IgG4), which was shown before to exhibit only minor affinity to FcγRs. Transcriptome analysis of TGN1412-treated T cells revealed that similar gene signatures were induced irrespective of whether T cells derived from fresh or HDC-PBMCs were studied. Collectively, these data indicate that HDC-PBMCs and HDC-PBMC–derived T cells mount rapid TGN1412 responses, which are massively boosted by FcγR crosslinking, in particular by CD32-expressing B cells. These results qualify HDC-PBMCs as a valuable in vitro test system for the analysis of complex mAb functions.

CD28 superagonists (CD28SAs) are potent T-cell-activating monoclonal antibodies (mAbs). In contrast to their benign behavior and marked therapeutic efficacy as activators of regulatory T (Treg) cells in preclinical rodent models, a phase I trial of the human CD28SA TGN1412 (now called TAB08) in 2006 resulted in a life-threatening cytokine release syndrome (CRS). We studied TAB08-mediated Treg-cell activation in a recently developed in vitro system of human PBMCs, which also reproduces the CRS experienced by the healthy volunteers. We show that just as in rodents, CD28SAs are potent activators and expanders of Treg cells from healthy donors and rheumatoid arthritis patients, even under effective blockade of pro-inflammatory cytokine release by a corticosteroid. Moreover, CD28SA titration identifies a dose range where pro-inflammatory cytokine secretion from conventional T cells is absent while appreciable Treg-cell activation is maintained. Finally, we report that low-dose application of TAB08 to healthy volunteers results in dose-dependent systemic release of the Treg-cell signature cytokine IL-10 in the absence of the pro-inflammatory factors associated with the CRS of the 2006 TGN1412 study. These results demonstrate the potential of appropriately dosed CD28SA and corticosteroid comedication to mobilize human Treg cells for the treatment of autoimmune and inflammatory conditions.

Multiple myeloma (MM) plasma cell (MMPC) interactions with the microenvironment control MMPC growth, survival, drug-resistance and intra- and extramedullary dissemination. Dissemination of MMPCs through bone marrow niches and in extra-medullary sites is an active process of invasion involving bone marrow endothelial cells, multiple adhesion molecules and chemokine receptors. Since enhanced angiogenesis characterizes MM, we investigated whether junctional adhesion molecule-A (JAM-A) mediated interactions between MM bone marrow endothelial cells (MMECs) and MMPCs impact disease progression. To this end, we analyzed JAM-A expression levels in MMECs of 312 MM patients in two independent cohorts with flow cytometry, namely 111 newly diagnosed (NDMM) and 201 relapsed/refractory (RRMM) and compared them to 36 monoclonal gammopathy of undetermined significance (MGUS) and healthy subjects. To corroborate our data and investigate at a gene-expression level the prognostic value of deregulated genes (FDR Surface protein expression of JAM-A on MMECs predicted poor overall survival (OS) in NDMM (not reached (NR) vs. 78 months univariate hazards ratio-HR=9.14, 95% CI 2.8-29.76, P Ensuing functional shRNA knockdown of JAM-A reduced MM invasion (P Collectively, our findings pinpoint JAM-A as a key player propagating a vicious cycle of MMECs and MMPCs interaction; the expression of JAM-A and the related adhesion pathways can prognostically stratify patients in the late disease stages impacting two main MM progression processes: angiogenesis and extra-medullary dissemination. Therefore, we propose JAM-A as a promising MM biomarker and novel therapeutic target in advanced disease. Disclosures Klapper: Roche, Takeda, Amgen, Regeneron: Honoraria, Research Funding. Rosenwald:MorphoSys: Consultancy. Cavo:celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

CD28 superagonists (CD28SA) are CD28-specific monoclonal antibodies which are able to activate T-cells without overt TCR engagement. In rodents, CD28SA efficiently activate regulatory T-cells and are therapeutically effective in multiple models of autoimmunity, inflammation and transplantation. However, a phase I study of the human CD28SA TGN1412 in 2006 resulted in a life-threatening cytokine storm. This brief review summarises preclinical work before and since the failed phase I trial with an emphasis on understanding the reasons why there had been no warning of toxicity, and how a novel assay paved the way for a new phase I, phase Ib (both completed), and an ongoing phase II study.

Marine sponges and their associated bacteria have been proven to be a rich source of novel secondary metabolites with therapeutic usefulness in cancer, infection, and autoimmunity. In this study, 79 strains belonging to 20 genera of the order Actinomycetales and seven strains belonging to two genera of the order Sphingomonadales were cultivated from 18 different Caribbean sponges and identified by 16S rRNA gene sequencing. Seven of these strains are likely to represent novel species. Crude extracts from selected strains were found to exhibit protease inhibition against cathepsins B and L, rhodesain, and falcipain-2 as well as immunomodulatory activities such as induction of cytokine release by human peripheral blood mononuclear cells. These results highlight the significance of marine sponge-associated bacteria to produce bioactive secondary metabolites with therapeutic potential in the treatment of infectious diseases and disorders of the immune system. Electronic supplementary material The online version of this article (doi:10.1007/s10126-010-9349-0) contains supplementary material, which is available to authorized users.

During the last years, multiple myeloma (MM) has been recognized to present in some patients with extra-medullary disease (EMD) manifestation with different pathophysiological and clinical characteristics. Recently, we reported junctional adhesion molecule-A (JAM-A) as a novel target and a clinical biomarker in MM [Solimando et al. Leukemia 32(3):736-743, 2018]. Here, we hypothesized that alterations in the adhesion molecules, particularly JAM-A expression, on MM plasma cells (MM-PCs) may play a pivotal role in high-risk EMD patients. Therefore, we evaluated JAM-A expression in 60 MM patient bone marrow (BM) aspirates and biopsies at different disease stages with flow cytometry and immunohistochemistry. We compared these results with RNA-Seq data from 647 newly diagnosed MM (NDMM) patients collected in the MMRF (MM Research Foundation) CoMMpass study. Using bioinformatics, we investigated JAM-A related pathways with hierarchical cluster analysis. Subsequently, we functionally tested these JAM-A related pathways regarding epithelial mesenchymal transition, invasion and MM dissemination in vitro. The median OS differed significantly in subjects with elevated membrane JAM-A expression levels, dividing the patients in EMD JAM-Ahighgroup with a median OS of 84.1 months, whereas median OS in JAM-Alowpatients was not reached, irrespective from the EMD status (log-rank=4.19, P=0.04). Immunohistochemistry analysis of BM biopsies confirmed these findings. RNA-Seq analysis corroborated the prognostic impact of JAM-A (log-rank= 3.8, P= 0.051).High-risk myeloma patients with EMD and JAM-A expression displayed a unique gene-expression signature. Additionally, we constructed a novel expression cluster subgroup MM model, revealing complex molecular disease patterns and associations between clinical traits and expression markers. MM patients clustering according to JAM-A expression levels and EMD manifestation revealed a clear link to the epithelial-mesenchymal-transition and focal adhesion pathways. Notably, functional knockdown of JAM-A in vitro not only reduced cell viability, but also diminished MM adhesion molecules and CD138 surface expression. Furthermore, mTOR/PI3K in vitro inhibition with BEZ235 significantly down regulated surface expression in JAM-Ahigh MM cell lines. Interestingly, when we inhibited mTOR/PI3K in JAM-AlowMM cells, we observed JAM-A induction. In the present study we shed more light on the EMD pathophysiology. Conclusively, our results support that JAM-A can serve as promising prognostic marker for high risk EMD MM patients. Our data provide a biological rationale for a JAM-A guided decision-making process to better combine molecular and immunochemo-therapy modalities in the EMD MM patient subset. Disclosures No relevant conflicts of interest to declare.

A bio-guided screening against influenza A virus (FLUAV) was carried out with seven Euphorbiaceae species. The results showed that chromatographic fractions from Phyllantus niruri, Euphorbia pulcherrima and Codiaeum variegatum had relevant anti-FLUAV activity, although only chromatographical subfractions from C. variegatum kept the activity. From this plant, the active compound against FLUAV was isolated. Its structure was assigned as 2-(3,4,5)-trihydroxy-6-hydroxymethyltetrahydropyran-2-yloxymethyl)acrylonitrile (1) on the basis of NMR, mass spectrometry and X-ray diffraction analysis. The compound displayed virucidal activity without impairment of haemagglutination properties of the used virus strain. This is the first report indicating antiviral activity of a cyanoglucoside.

Juvenile myoclonic epilepsy (JME) is a common form of generalized epilepsy that starts in adolescence. A major JME susceptibility locus (EJM1) was mapped to chromosomal region 6p21 in three independent linkage studies, and association was reported between JME and a microsatellite marker in the 6p21 region. The critical region for EJM1 is delimited by obligate recombinants at HLA-DQ and HLA-DP. In the present study, we found highly significant linkage disequilibrium (LD) between JME and a core haplotype of five single-nucleotide–polymorphism (SNP) and microsatellite markers in this critical region, with LD peaking in the BRD2 (RING3) gene (odds ratio 6.45; 95% confidence interval 2.36–17.58). DNA sequencing revealed two JME-associated SNP variants in the BRD2 (RING3) promoter region but no other potentially causative coding mutations in 20 probands from families with positive LOD scores. BRD2 (RING3) is a putative nuclear transcriptional regulator from a family of genes that are expressed during development. Our findings strongly suggest that BRD2 (RING3) is EJM1, the first gene identified for a common idiopathic epilepsy. These findings also suggest that abnormalities of neural development may be a cause of common idiopathic epilepsy, and the findings have implications for the generalizability of proposed pathogenetic mechanisms, derived from diseases that show Mendelian transmission, to their complex counterparts.

Objective To report a case of limbic encephalitis (LE) presenting with psychosis. Method Case report. Results A woman with LE initially presented with acute psychotic symptoms. Magnetic resonance imaging (MRI) showed hyperintensity in bilateral temporal lobes. Paraneoplastic and autoimmune antibodies were negative, but symptoms resolved after starting methylprednisolone. Conclusion A greater awareness for and knowledge of LE among all disciplines could help early recognition and management of LE and avoid permanent behavioral deficits.

Background : Miraziridine A, a natural peptide isolated from a marine sponge, is a potent cathepsin B inhibitor with a second-order rate constant of 1.5 x 10 4 M -1 s -1 . In the present study, miraziridine A was isolated from the Red Sea sponge Theonella swinhoei on the basis of chromatographic and spectrometric techniques. We conclude that T. swinhoei from the Red Sea represents an alternative source of the aziridinylpeptide miraziridine A to the previously identified Theonella mirabilis from Japan. We confirmed that the metabolite is produced by marine sponges from different geographical locations. Context : Marine sponges have been proven to be a rich source of secondary metabolites exhibiting a huge diversity of biological activities, including antimicrobial, antitumor and immunomodulatory activities. Theonella species (order Lithistida, Demospongiae) have been shown to be a source of anti-protease and anti-HIV secondary metabolites. Aims : To identify the protease inhibitor mirazirine A in the marine sponge Theonella swinhoei. Material and Methods : The marine sponge Theonella swinhoei was collected by SCUBA diving in the Red Sea in Eilat (Israel). Sponge material was lyophilized and further extracted successively with cyclohexane, dichloromethane and methanol to obtain three crude extracts. LC-MS analysis was performed to confirm the presence of Miraziridine A in the dichloromethane fraction. Results : In the present study, miraziridine A was isolated from the Red Sea sponge T. swinhoei on the basis of chromatographic and spectrophotometric techniques. Conclusions : We conclude that T. swinhoei from the Red Sea represents an alternative source of the aziridinylpeptide miraziridine A to the previously identified Theonella mirabilis from Japan.