Targeting BMI-1 in B cells restores effective humoral immune responses and controls chronic viral infection.

Ineffective antibody-mediated responses are a key characteristic of chronic viral infection. However, our understanding of the intrinsic mechanisms that drive this dysregulation are unclear. Here, we identify that targeting the epigenetic modifier BMI-1 in mice improves humoral responses to chronic lymphocytic choriomeningitis virus. BMI-1 was upregulated by germinal center B cells in chronic viral infection, correlating with changes to the accessible chromatin landscape, compared to acute infection. B cell-intrinsic deletion of Bmi1 accelerated viral clearance, reduced splenomegaly and restored splenic architecture. Deletion of Bmi1 restored c-Myc expression in B cells, concomitant with improved quality of antibody and coupled with reduced antibody-secreting cell numbers. Specifically, BMI-1-deficiency induced antibody with increased neutralizing capacity and enhanced antibody-dependent effector function. Using a small molecule inhibitor to murine BMI-1, we could deplete antibody-secreting cells and prohibit detrimental immune complex formation in vivo. This study defines BMI-1 as a crucial immune modifier that controls antibody-mediated responses in chronic infection.

Middle cerebral artery hypodense dot sign in iatrogenic air embolism.

Air embolism is a rare cause of stroke, usually associated with medical procedures, with gastrointestinal endoscopy rarely implicated. Here, we present a case of a patient who experienced cerebral air embolism post-gastroscopy, presenting with aphasia and right hemiparesis due to left M2 occlusion with spontaneous and complete recovery. CT scan revealed a hypodense defect in the left Sylvian fissure, representing a "hypodense dot sign" suggestive of an air embolism. The hypodense MCA sign, previously described in fat embolism cases, could also indicate air embolism, supporting prompt diagnosis and proper intervention.

Multiple sclerosis and genetic polymorphisms in fibrinogen-mediated hemostatic pathways: a case-control study.

INTRODUCTION: Blood coagulation constituents might exert immunomodulatory functions in the CNS and may trigger neuroinflammation and demyelination. We evaluated whether particular single-nucleotide polymorphisms (SNPs), thought to be involved in fibrinogen-mediated hemostatic pathways, are overrepresented in patients with MS compared with controls. METHODS: The case-control study consisted of 119 MS patients recruited consecutively at our clinic, and 68 healthy controls. Afterwards, we created a cumulative genetic risk score (CGRS) which included the 5 selected hemostatic risk alleles (Beta-Fibrinogen 455G/A, Glycoprotein IIIa P1A2, Factor V Leiden, Factor V H2R, and Prothrombin 20210G/A). Multivariate ordinal logistic regression and multivariate multinomial logistic regression were applied to evaluate the effect of CGRS on MS susceptibility. RESULTS: The FGB 455 G/A and Factor V H1299R variants might be associated with MS status, in the recessive and dominant model, respectively. A cumulative association of the five SNPs investigated with the disease was observed. DISCUSSION: We found that MS patients carried more pro-hemostatic variants than healthy controls. An increasing number of unfavorable alleles might increase the likelihood of being in the MS group, in the cumulative analysis. Our findings encourage to evaluating these variants in a larger population-based cohort.

Clinical and Genetic Heterogeneity in a Large Family with Pseudoxanthoma Elasticum: MTHFR and SERPINE1 Variants as Possible Disease Modifiers in Developing Ischemic Stroke.

BACKGROUND AND OBJECTIVES: Pseudoxanthoma elasticum (PXE) is a rare autosomal recessive disorder caused by pathogenic variants in the ABCC6 gene. The phenotypic spectrum of PXE is highly variable and includes principally three major features: skin lesions, eye and vascular manifestations, while brain manifestations are less common. To date about 400 different PXE associated variants in ABCC6 gene are described without any evident genotype-phenotype correlation. Herein, we report the clinical and molecular findings of a large PXE family with clinical and genetic intra-familial variability with significant cerebrovascular involvement. METHODS: The analysis of the ABCC6 gene was performed in the proband and her familiars for the definition of genetic background. Then, in order to determine why some affected individuals had more prominent brain involvement, we investigated classic thrombophilic gene variants. RESULTS: Molecular findings disclosed two different ABCC6 mutations, i.e., the recurrent p.(Arg518Gln) and the novel p.(Val1285Met) missense substitution responsible of a pseudo-dominant inheritance. The study of thrombophilic gene variants revealed the presence of 4G/4G SERPINE1 genotype in the proband and in her father, which both developed ischemic stroke. The proband carried also the C677T variant the MTHFR gene. CONCLUSION: We argue, for the first time, that the 4G/4G SERPINE1 genotype could represent an additional risk factor in PXE for developing ischemic stroke, which adds up to the already known predisposing conditions. Therapeutic implications are discussed, we also advise that PXE patients should be adequately screened for cerebral vasculopathy, even more if familial history is suggestive of brain complications.

Disrupting the Code: Epigenetic Dysregulation of Lymphocyte Function during Infectious Disease and Lymphoma Development.

Lymphocyte differentiation and identity are controlled by signals in the microenvironment that ultimately mediate gene expression in the nucleus. Although much focus has centered on the strategic and often unique roles transcription factors play within lymphocyte subsets, it is increasingly clear that another level of molecular regulation is crucial for regulating gene expression programs. In particular, epigenetic regulation is critical for appropriately regulated temporal and cell-type-specific gene expression during immune responses. As such, mutations in epigenetic modifiers are linked with lymphomagenesis. Furthermore, certain infections can remodel the epigenome in host cells, either through the microenvironment or by directly co-opting host epigenetic mechanisms, leading to inappropriate gene expression and/or ineffective cellular behavior. This review will focus on how histone modifications and DNA methylation, and the enzymes that regulate the epigenome, underpin lymphocyte differentiation and function in health and disease.

TRIM22 inhibits influenza A virus infection by targeting the viral nucleoprotein for degradation.

Tripartite motif (TRIM) protein superfamily members are emerging as important effectors of the innate immune response against viral infections. In particular, TRIM22 was reported to exert antiviral activity against RNA viruses, such as hepatitis B virus (HBV), encephalomyocarditis virus (ECMV), and human immunodeficiency virus type 1 (HIV-1). We demonstrate here, for the first time, that TRIM22 is upregulated by influenza A virus (IAV) infection at both mRNA and protein levels in human alveolar epithelial A549 cells. Conversely, TRIM22 potently restricted IAV replication, in that prevention of TRIM22 expression by means of short hairpin RNA led to a 10-fold enhancement of IAV replication in these cells. Depletion of TRIM22 also reduced the anti-IAV activity of alpha interferon (IFN-α), suggesting that TRIM22 is an important IFN-stimulated gene that is required for maximal suppression of IAV by type I IFN. Furthermore, the IAV infectious titer decreased up to 100-fold in MDCK cells expressing exogenous human TRIM22. Restriction of IAV replication was accounted for by the interaction between TRIM22 and the viral nucleoprotein (NP), resulting in its polyubiquitination and degradation in a proteasome-dependent manner. Thus, TRIM22 represents a novel restriction factor upregulated upon IAV infection that curtails its replicative capacity in epithelial cells.

AST: An OpenSim-based tool for the automatic scaling of generic musculoskeletal models.

BACKGROUND AND OBJECTIVES: The paper introduces a tool called Automatic Scaling Tool (AST) designed for improving and expediting musculoskeletal (MSK) simulations based on generic models in OpenSim. Scaling is a crucial initial step in MSK analyses, involving the correction of virtual marker locations on a model to align with actual experimental markers. METHODS: The AST automates this process by iteratively adjusting virtual markers using scaling and inverse kinematics on a static trial. It evaluates the root mean square error (RMSE) and maximum marker error, implementing corrective actions until achieving the desired accuracy level. The tool determines whether to scale a segment with a marker-based or constant scaling factor based on checks on RMSE and segment scaling factors. RESULTS: Testing on three generic MSK models demonstrated that the AST significantly outperformed manual scaling by an expert operator. The RMSE for static trials was one order of magnitude lower, and for gait tasks, it was five times lower (8.5 ± 0.76 mm vs. 44.5 ± 7.5 mm). The AST consistently achieved the desired level of accuracy in less than 100 iterations, providing reliable scaled MSK models within a relatively brief timeframe, ranging from minutes to hours depending on model complexity. CONCLUSIONS: The paper concludes that AST can greatly benefit the biomechanical community by quickly and accurately scaling generic models, a critical first step in MSK analyses. Further validation through additional experimental datasets and generic models is proposed for future tests.

Apparently isolated CNS involvement in Erdheim-Chester disease: Case report.

We present the case of a 48-year-old-woman with apparently isolated central nervous system Erdheim-Chester disease characterized by brainstem involvement. Erdheim-Chester disease is extremely rare and multisystem impairment should always be sought in the suspicion of such pathology.

Alemtuzumab-Related Lymphocyte Subset Dynamics and Disease Activity or Autoimmune Adverse Events: Real-World Evidence.

BACKGROUND AND OBJECTIVES: alemtuzumab is a monoclonal anti-CD52 antibody acting on B and T cells in highly active multiple sclerosis (MS). We analyzed changes in lymphocyte subsets after alemtuzumab administration in relation to disease activity and autoimmune adverse events. METHODS: lymphocyte subset counts were assessed longitudinally using linear mixed models. Subset counts at baseline and during follow-up were correlated with relapse rate, adverse events, or magnetic resonance (MRI) activity. RESULTS: we recruited 150 patients followed for a median of 2.7 years (IQR: 1.9-3.7). Total lymphocytes, CD4, CD8, and CD20 significantly decreased in all patients over 2 years (p < 0.001). Previous treatment with fingolimod increased the risk of disease activity and adverse events (p = 0.029). We found a higher probability of disease reactivation in males and in patients with over three active lesions at baseline. Higher EDSS scores at baseline and longer disease duration predicted the switch to other treatments after alemtuzumab. DISCUSSION AND CONCLUSIONS: Our real-world study supports data from clinical trials in which lymphocyte subsets were not useful for predicting disease activity or autoimmune disease during treatment. The early use of an induction therapy such as alemtuzumab in patients with a lower EDSS score and short history of disease could mitigate the risk of treatment failure.

Adiponectin in Cerebrospinal Fluid from Patients Affected by Multiple Sclerosis Is Correlated with the Progression and Severity of Disease.

Adiponectin exerts relevant actions in immunity and is modulated in several disorders, such as multiple sclerosis (MS). In this study, we characterized adiponectin expression and profiles in cerebrospinal fluid (CSF) from MS patients to investigate its potential relationship with the severity and progression of the disease. Total adiponectin in CSF was measured by ELISA in 66 unrelated CSF MS patients and compared with 24 age- and sex-matched controls. Adiponectin oligomer profiles were analysed by Western blotting and FPLC chromatography. Total CSF adiponectin was significantly increased in MS patients compared with controls (9.91 ng/mL vs 6.02 ng/mL) (p < 0.001). Interestingly, CSF adiponectin positively correlated with CSF IgG, and CSF/serum albumin directly correlated with CSF/serum adiponectin. Our data demonstrated that CSF adiponectin predicts a worse prognosis: patients with the progressive form of MS had higher levels compared with the relapsing remitting form; patients with higher EDSS at baseline and a higher MS severity score at 4.5-year follow-up had significantly elevated adiponectin levels with respect to patients with a less severe phenotype. Finally, the adiponectin oligomerization profile was altered in CSF from MS patients, with a significant increase in HMW and MMW. The correlation of CSF adiponectin with the severity and prognosis of MS disease confirmed the role of this adipokine in the inflammatory/immune processes of MS and suggested its use as a complementary tool to assess the severity, progression and prognosis of the disease. Further studies on larger MS cohorts are needed to clarify the contribution of adiponectin to the etiopathogenesis of MS.

Epstein-Barr Virus Promotes B Cell Lymphomas by Manipulating the Host Epigenetic Machinery.

During the past decade, the rapid development of high-throughput next-generation sequencing technologies has significantly reinforced our understanding of the role of epigenetics in health and disease. Altered functions of epigenetic modifiers lead to the disruption of the host epigenome, ultimately inducing carcinogenesis and disease progression. Epstein-Barr virus (EBV) is an endemic herpesvirus that is associated with several malignant tumours, including B-cell related lymphomas. In EBV-infected cells, the epigenomic landscape is extensively reshaped by viral oncoproteins, which directly interact with epigenetic modifiers and modulate their function. This process is fundamental for the EBV life cycle, particularly for the establishment and maintenance of latency in B cells; however, the alteration of the host epigenetic machinery also contributes to the dysregulated expression of several cellular genes, including tumour suppressor genes, which can drive lymphoma development. This review outlines the molecular mechanisms underlying the epigenetic manipulation induced by EBV that lead to transformed B cells, as well as novel therapeutic interventions to target EBV-associated B-cell lymphomas.

The Histone Methyltransferase DOT1L Is Essential for Humoral Immune Responses.

Histone modifiers are essential for the ability of immune cells to reprogram their gene expression during differentiation. The recruitment of the histone methyltransferase DOT1L (disruptor of telomeric silencing 1-like) induces oncogenic gene expression in a subset of B cell leukemias. Despite its importance, its role in the humoral immune system is unclear. Here, we demonstrate that DOT1L is a critical regulator of B cell biology. B cell development is defective in Dot1lf/fMb1Cre/+ mice, culminating in a reduction of peripheral mature B cells. Upon immunization or influenza infection of Dot1lf/fCd23Cre/+ mice, class-switched antibody-secreting cells are significantly attenuated and germinal centers fail to form. Consequently, DOT1L is essential for B cell memory formation. Transcriptome, pathway, and histological analyses identified a role for DOT1L in reprogramming gene expression for appropriate localization of B cells during the initial stage of the response. Together, these results demonstrate an essential role for DOT1L in generating an effective humoral immune response.

Atypical progressive multifocal leukoencephalopathy in a kidney transplant recipient with improving symptoms after immunocompetence recovery.

Progressive multifocal leukoencephalopathy (PML) is a viral infection due to John Cunningham Virus (JCV) resulting in progressive damage of brain white matter, mostly related to HIV infection or hemato-oncological malignancies. PML onset is usually multifocal with rapid neurological progression and poor prognosis. Here we report an atypical case of PML with monofocal onset and a good outcome in a 64-year-old man who received a kidney transplant for end-stage renal disease (ESRD). The applied antirejection immunosuppressive drug regimen included tacrolimus, prednisone and mycophenolic acid. Three years after the transplant, he complained of right-hand tremor and rapidly progressive right hemiparesis, with prominent involvement of the upper limb. Brain magnetic resonance imaging (MRI) showed a significant demyelinating area in the left frontal lobe, without mass effect and contrast enhancement. Real-time PCR analysis revealed the presence of JCV on cerebrospinal fluid. Consequent immunosuppressive drug suspension resulted in a global improvement of neurological symptoms and a favourable evolution of the neuroradiological findings. Subsequent eight-year follow-up MRI confirmed the stability of imaging findings over time. Therefore, early recognition of PML symptoms and MRI sign along with the rapid suspension of immunosuppressive drugs can modify the natural history of this disease after a kidney transplant.

Mutations Conferring Increased Sensitivity to Tripartite Motif 22 Restriction Accumulated Progressively in the Nucleoprotein of Seasonal Influenza A (H1N1) Viruses between 1918 and 2009.

Influenza A viruses (IAVs) can cause zoonotic infections with pandemic potential when most of the human population is immunologically naive. After a pandemic, IAVs evolve to become seasonal in the human host by acquiring adaptive mutations. We have previously reported that the interferon (IFN)-inducible tripartite motif 22 (TRIM22) protein restricts the replication of seasonal IAVs by direct interaction with the viral nucleoprotein (NP), leading to its polyubiquitination and proteasomal degradation. Here we show that, in contrast to seasonal H1N1 IAVs, the 2009 pandemic H1N1 strain as well as H1N1 strains from the 1930s are resistant to TRIM22 restriction. We demonstrate that arginine-to-lysine substitutions conferring an increased sensitivity to TRIM22-dependent ubiquitination accumulated progressively in the NP of seasonal influenza A (H1N1) viruses between 1918 and 2009. Our findings suggest that during long-term circulation and evolution of IAVs in humans, adaptive mutations are favored at the expense of an increased sensitivity to some components of the innate immune response.IMPORTANCE We have uncovered that long-term circulation of seasonal influenza A viruses (IAV) in the human population resulted in the progressive acquisition of increased sensitivity to a component of the innate immune response: the type I interferon-inducible TRIM22 protein, which acts as a restriction factor by inducing the polyubiquitination of the IAV nucleoprotein (NP). We show that four arginine residues present in the NP of the 1918 H1N1 pandemic strain and early postpandemic strains were progressively substituted for by lysines between 1918 and 2009, rendering NP more susceptible to TRIM22-mediated ubiquitination. Our observations suggest that during long-term evolution of IAVs in humans, variants endowed with increased susceptibility to TRIM22 restriction emerge, highlighting the complexity of selection pressures acting on the NP.

c-Myb Regulates the T-Bet-Dependent Differentiation Program in B Cells to Coordinate Antibody Responses.

Humoral immune responses are tailored to the invading pathogen through regulation of key transcription factors and their networks. This is critical to establishing effective antibody-mediated responses, yet it is unknown how B cells integrate pathogen-induced signals to drive or suppress transcriptional programs specialized for each class of pathogen. Here, we detail the key role of the transcription factor c-Myb in regulating the T-bet-mediated anti-viral program. Deletion of c-Myb in mature B cells significantly increased serum IgG2c and CXCR3 expression by upregulating T-bet, normally suppressed during Th2-cell-mediated responses. Enhanced expression of T-bet resulted in aberrant plasma cell differentiation within the germinal center, mediated by CXCR3 expression. These findings identify a dual role for c-Myb in limiting inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Identifying such intrinsic regulators of specialized antibody responses can assist in vaccine design and therapeutic intervention in B-cell-mediated immune disorders.

Otherness in Autism: From the Fellow Human-Being to the Other Synthesis / A Alteridade no Autismo: do Próximo ao Outro de Síntese

Abstract The present article investigates an essential question raised by the experience of the psychoanalytic clinic of autism: otherness. The goal of this research is to establish the specificity and the variety of forms of otherness in autism. From the Freudian premise of the complex of the 'fellow human being' (Nebenmensch) to the distinction between this and the Other as a place of language, this research examines the forms of otherness that can arise in autism, such as identified by J.-C. Maleval. They are as follow: the autistic object, the double, and the synthetic Other. For this purpose, this paper finds support on life events narrated by autistics as well as clinical fragments from the specialized literature.

Resumo O presente artigo investiga uma problemática suscitada pela experiência clínica e essencial à psicanálise com autistas: a alteridade. O objetivo da pesquisa consistiu em estabelecer a especificidade e a variedade das formas de alteridade nesses casos. Partindo da premissa freudiana do complexo do próximo (Nebenmensch) e passando pela distinção entre o próximo e o Outro enquanto lugar da linguagem, a pesquisa percorre as formas de alteridade suscetíveis de se delinearem no autismo, tais como identificadas por J.-C. Maleval: o objeto autístico, o duplo e o Outro de síntese. Para tal, recorre a relatos de vida narrados pelos autistas e a fragmentos clínicos da literatura especializada.

Lentiviral Effector Pathways of TRIM Proteins.

The human tripartite motif (TRIM) family, composed of more than 77 members, encompasses an emerging group of innate antiviral factors. Most TRIM proteins are characterized by being E3 ubiquitin ligases, but also engage in specific interactions with a variety of cellular and viral partners. They are involved in many cellular processes, including cell differentiation, transcriptional regulation, cytoskeleton remodeling, intracellular trafficking, membrane repair, and oncogenesis. In regard to antiviral immunity, they restrict both retroviruses and lentiviruses as well as other DNA and RNA viruses. This review will focus on the TRIM members endowed with anti-retroviral and anti-lentiviral activities and, in particular, human immunodeficiency virus.