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Comprehensive analysis of B cell repopulation in ocrelizumab-treated patients with multiple sclerosis by mass cytometry and proteomics
Get PDFOcrelizumab, an anti-CD20 antibody, depletes CD20+ B cells, which subsequently repopulate over months. Little is known about changes in other immune cell populations and molecular markers associated with B cell repopulation. Here, we performed a comprehensive characterization of immune cells from ocrelizumab-treated patients with multiple sclerosis (MS) using mass cytometry. About 50% of patients showed naive B cell repopulation after 6 months mainly with a transitional phenotype, whereas CD27+ memory B cells only rarely repopulated. This repopulation was associated with a reduction of memory T cells and activated myeloid cells, as well as reduced expression of activation/migration markers in both cell types. A plasma proteomics analysis identified proteins including TNFRSF13C, associated with B cell depletion and repopulation. Plasma levels of neurofilament light-chain protein declined after ocrelizumab treatment was not linked with B cell repopulation. These findings identify potential soluble markers for monitoring of ocrelizumab treatment in MS
Isolated Uhthoff phenomenon as first manifestation of multiple sclerosis: a case report
Get PDFBACKGROUND: The Uhthoff phenomenon (UP) is a temporary worsening of neurological symptoms due to an increase in body temperature, commonly observed in demyelinating diseases, especially multiple sclerosis (MS). CASE PRESENTATION: A 37-year-old female presented with a four-year history of transient vision impairment in the right eye, particularly during dancing. Visual evoked potentials (VEP) revealed prolonged P100 latency and reduced amplitude of the right eye. Optical coherence tomography (OCT) confirmed thinning of the macular ganglion cell and inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) in the right eye with significant inter-eye differences, consistent with a unilateral optic nerve lesion. Magnetic resonance imaging (MRI) findings of periventricular, pons and spinal cord lesions, along with positive oligoclonal bands in cerebrospinal fluid, confirmed MS diagnosis. CONCLUSIONS: This case underscores the importance of recognizing UP as a potential early indicator of MS. Specific diagnostic tools, such as OCT, VEP, and MRI, can be used to objectify optic nerve involvement and should be considered to identify underlying demyelinating conditions. Early diagnosis of MS can facilitate a timely initiation of therapies and improve patient outcomes. It is essential for clinicians to consider UP for better clinical management of MS
Predictive biomarkers of breast ductal carcinoma in situ may underestimate the risk of recurrence due to de novo ipsilateral breast carcinoma development
No full textDevelopment of ipsilateral breast carcinoma following diagnosis of breast ductal carcinoma in situ (DCIS) has been assumed to represent recurrence of the primary tumour. However, this may not be the case and it is important to know how often recurrences are new tumours. Ipsilateral primary-recurrence pairs (n=78) were sequenced to test their clonal relatedness. Shared genetic events were identified from whole exome sequencing (n=54 pairs) using haplotype-specific copy number and phylogenetic analysis. The remaining pairs were sequenced by a targeted panel or low-coverage whole genome sequencing. We included 32 non-recurrent DCIS to compare recurrent and non-recurrent disease. We found that 7% of DCIS recurrences were non-clonal by whole exome sequencing, indicative of a new breast carcinoma. Lower resolution methods detected a higher non-clonality rate (29%). Comparing primary DCIS with their recurrences found that evolution of DCIS to invasive disease was associated with increased ploidy and copy number events. TP53 mutations were enriched in DCIS with clonal recurrence compared with non-recurrent DCIS. Our results verify that de novo “recurrent tumours” of independent origin occur in patients who may be at high risk
The role of serum neurofilament light (sNfL) as a biomarker in multiple sclerosis: insights from a systematic review
Get PDFOBJECTIVE: This systematic literature review (SLR) was conducted to explore the role of serum neurofilament light chain (sNfL) as a biomarker in multiple sclerosis (MS) disease management. METHODS: The review was conducted in accordance with the recommendation laid by the Cochrane Handbook for Systematic Reviews. A comprehensive literature search was performed in key biomedical databases (EMBASE®, MEDLINE®, MEDLINE®-In-Process, and all Evidence-Based Medicine [EBM] Reviews databases) to retrieve studies reporting the association between sNfL and disease activity in patients with MS. Additional evidence was also identified through hand searching of key conference proceedings and gray literature. RESULTS: Following review of 1831 records, 75 studies from 180 publications were included in the review. The studies included in the SLR consistently demonstrated an association between higher sNfL levels and an increased risk of future relapses within 2 years and MS disease progression. Higher levels of sNfL were also linked to an increased likelihood of experiencing gadolinium-enhancing T1 and T2 lesions. Patients with lower sNfL levels had a higher likelihood of achieving no evidence of disease activity status. Furthermore, an inverse correlation was observed between sNfL levels and cognitive impairment as assessed via the Symbol Digit Modalities Test performance and Timed 25-Foot Walk scores. CONCLUSION: This SLR demonstrates the significance of sNfL as a sensitive biomarker for monitoring MS progression. Convenient and reliable sNfL measurement could benefit routine clinical practice, providing clinicians with a simple and effective tool to monitor disease and treatment response
CD8(+) T cell-derived CD40L mediates noncanonical cytotoxicity in CD40-expressing cancer cells
Get PDFT cells and their effector functions, in particular the canonical cytotoxicity of CD8(+) T cells involving perforin, granzymes, Fas ligand (FasL), and tumor necrosis factor related apoptosis inducing ligand (TRAIL), are crucial for tumor immunity. Here, we reveal a previously unidentified mechanism by which CD40L-expressing CD8(+) T cells induce cytotoxicity in cancer cells. In murine models, up to 50% of tumor-specific CD8(+) T cells expressed CD40L, and conditional CD40L ablation in CD8(+) T cells alone led to tumor formation. Mechanistically, CD40L(+)CD8(+) T cells can induce cell death in CD40-expressing cancer cells by triggering caspase-8 activation. We demonstrate that a gene signature for resistance to CD40 signaling-induced cell death strongly correlates with worse survival in different human cancer cohorts. Our results introduce CD40L as a rather counterintuitive, noncanonical cytotoxic factor that complements the capabilities of CD8(+) T cells to combat cancers and has the potential to enhance the efficacy of immunotherapies
Enhanced mutanome analysis towards the induction of neoepitope-reactive T-cell responses for personalized immunotherapy of pancreatic cancer
Get PDFBACKGROUND: Personalized immunotherapy of pancreatic ductal adenocarcinoma (PDAC) through T-cell mediated targeting of tumor-specific, mutanome-encoded neoepitopes may offer new opportunities to combat this disease, in particular by countering recurrence after primary tumor resection. However, the sensitive and accurate calling of somatic mutations in PDAC tissue samples is compromised by the low tumor cell content. Moreover, the repertoire of immunogenic neoepitopes in PDAC is limited due to the low mutational load of the majority of these tumors. METHODS: We developed a workflow involving the combined analysis of next-generation DNA and RNA sequencing data from matched pairs of primary tumor samples and patient-derived xenograft models towards the enhanced detection of driver mutations as well as single nucleotide variants encoding potentially immunogenic T-cell neoepitopes. Subsequently, we immunized HLA/human T-cell receptor (TCR) locus-transgenic mice with synthetic peptides representing candidate neoepitopes, and molecularly cloned the genes encoding TCRs targeting these epitopes. RESULT: Application of our pipeline resulted in the identification of greater numbers of non-synonymous mutations encoding candidate neoepitopes with increased confidence. Furthermore, we provide proof of concept for the successful isolation of HLA-restricted TCRs from humanized mice immunized with different neoepitopes, several of which would not have been selected based on mutanome analysis of PDAC tissue samples alone. These TCRs mediate specific T-cell reactivity against the tumor cells in which the corresponding mutations were identified. CONCLUSION: Enhanced mutanome analysis and candidate neoepitope selection increase the likelihood of identifying therapeutically relevant neoepitopes, and thereby support the optimization of personalized immunotherapy for PDAC and other poorly immunogenic cancers
Targeting RNA adenosine editing and modification enzymes for RNA therapeutics
Get PDFAdenosine-to-inosine (A-to-I) RNA editing, and N6 methyladenosine (m6A) are among the most abundant modifications in eukaryotic messenger RNA, affecting various aspects of RNA metabolism and cellular function, including proliferation, differentiation, responses to stressors, and cell death. Recent preclinical evidence suggests that both modifications play a significant role in multiple disorders, including infections, chronic inflammatory diseases, and cancer, sparking great interest in their therapeutic potential. Structural characterization of ADARs (adenosine deaminases acting on RNA) and key m6A enzymes has enabled the development of small molecule inhibitors modulating their expression, enzymatic activity, or binding to target RNAs. Herein, we review preclinical evidence supporting the therapeutic benefits of targeting ADARs and m6A enzymes in diverse disease contexts. Small molecule inhibitors of RNA modification enzymes have shown potent anti-proliferative and pro-apoptotic effects in cancer cells, and have successfully inhibited tumor growth in vivo, without evident toxicity, while their combination with immuno-/chemotherapeutics displayed synergistic anti-neoplastic action. Adenosine RNA editing via recruitment of endogenous ADARs and usage of guide RNAs showed remarkable efficacy in correcting G-to-A point mutations and restoring the associated protein expression with limited off-target activity. Future studies are warranted to evaluate the safety and clinical efficacy of RNA editing or modification-targeting therapeutics in patients
Contextual modulation and blunted defensive responses to predators in head-fixed and freely moving mice
Get PDFBehavioral responses to threats — such as fleeing, freezing, or fighting — can be either innate or shaped by learning and context. Here, we investigated whether mice exhibit fear of predators across four experimental contexts: one in a novel head-fixed condition and three in established, freely moving scenarios. In head-fixed mice, we measured the behavioral outcome and response to a live rat. Mice were water-deprived and habituated to walk on a treadmill that controlled a virtual environment and reward delivery. After meeting performance criteria, baseline data were collected in one session, followed by a test session in which the mice were exposed to a live rat. Despite the presence of the predator, most (5 out of 7) mice continued to forage at baseline levels; however, individual mice showed significant alterations in one or more of the following measures: running speed, pupil size, eye movement, and posture. To assess how behavioral context and physical restraint influence predator responses, we exposed 36 naive, freely moving mice to fear-inducing stimuli — including looming visual cues, rat odor, and a live rat. Even in these conditions, a substantial proportion of mice failed to exhibit classical defensive responses such as avoidance or escape. Notably, when presented with a freely moving rat, only about half of the mice displayed avoidance behavior. Together, these findings suggest that mice do not universally express innate fear behaviors such as avoidance or fleeing, even in ethologically relevant predator encounters. Instead, their responses appear to be context-dependent and variable, challenging common assumptions about automatic defensive reactions in rodents
Inhibition of lysosomal degradation increases expression of mutant ADA2 in DADA2 monocytes
Get PDFBACKGROUND: Deficiency of adenosine deaminase 2 (DADA2) is an inborn error of immunity causing vasculitis and bone marrow failure. Bone marrow failure is mostly unresponsive to TNF-α inhibitors. The limited understanding of the pathomechanisms driving the disease impedes the development of new treatment options. Unlike cellular model systems expressing pathogenic ADA2 variants, primary monocytes from patients with DADA2 lack ADA2 protein expression. OBJECTIVES: This study aimed to analyze the role of protein degradation in the pathogenesis of DADA2 and the therapeutic potential of the lysosomotropic drug hydroxychloroquine in the treatment of patients with DADA2. METHODS: ADA2 protein expression in CD14(+) monocytes from healthy controls (n = 8) and patients with DADA2 (n = 11) was determined by Western blot after inhibition of lysosomal and proteasomal degradation, as well as after hydroxychloroquine treatment in vivo in 1 patient with DADA2. Lipidation of microtubule associated protein 1 light chain 3 beta (LC3B) was analyzed as a measure of autophagic activity. Clinical and laboratory data were recorded in cytopenic patients with DADA2 treated with hydroxychloroquine, 200 mg per day. RESULTS: We demonstrated that inhibition of lysosomal degradation restores ADA2 protein expression in DADA2 monocytes in vitro. DADA2 monocytes exhibited increased autophagic activity. We observed clinical improvement in 2 cytopenic patients with DADA2 who were treated with hydroxychloroquine, and we showed a concomitant increase in ADA2 protein levels in monocytes from one of these patients in vivo. CONCLUSION: We identified lysosomal protein degradation of ADA2 as a pathomechanism of DADA2 and introduced hydroxychloroquine as a potential treatment option in patients with DADA2 with refractory cytopenia
Physiological serum uric acid concentrations correlate with arterial stiffness in a sex-dependent manner
Get PDFBACKGROUND: In humans, uric acid is a product of purine metabolism that impacts the vascular system. In addition to effects on arterial vascular tone, associations between serum uric acid concentrations-even in the physiological range-and arterial hypertension and vascular-mediated end-organ damage due to an impact on vascular stiffness have been postulated. METHODS: Therefore, we aim to investigate a possible cross-sectional association between serum uric acid concentrations in the physiological range and differences in arterial pulse wave velocity (PWV), an indicator of vascular remodeling, with a focus on possible differences between female and male individuals. We analyzed cross-sectional phenotypic and laboratory parameters, including PWV from 70,649 individuals in the population-based German National Cohort (NAKO) in a sex-specific manner. In parallel, we applied a machine learning approach to identify and quantify factors associated with PWV in a hypothesis-free manner. RESULTS: Our analysis uncovered a positive association between serum uric and PWV which was detected even if only individuals with urate values in the physiological range were included (n = 64,095). This correlation was more pronounced in women than in men. In multivariable linear regression models, we observed an association of uric acid (mmol/l) with PWV (m/s) of β = 1.12 (95% confidence interval (CI): 0.78; 1.45) in males and β = 1.35 (1.05; 1.66) in females, independent of other factors known to affect vascular stiffness. In addition, the machine learning approach identified uric acid as a major factor associated with PWV. The positive association was not restricted to hyperuricemia but evident even in the physiological concentration range. Based on the data from studies on the impact of aging on PWV, it is estimated that an increase in serum uric acid concentration by 0.1 mmol/l corresponds to an increase of approx. 7 years of age in females and of 4 years in males. CONCLUSIONS: Already in the physiological concentration range, uric acid is positively associated with parameters of arterial stiffness. This association is more pronounced in females as compared to males. This finding provides a mechanistic explanation for the increased risk of vascular end-organ damage associated with higher serum uric acid concentrations and supports the observed greater benefit of therapeutic uric acid lowering in female. Future intervention studies have to address the mechanistic causality of the observed effect