TL1A and IL-18 synergy promotes GM-CSF-dependent thymic granulopoiesis in mice.

Acute systemic inflammation critically alters the function of the immune system, often promoting myelopoiesis at the expense of lymphopoiesis. In the thymus, systemic inflammation results in acute thymic atrophy and, consequently, impaired T-lymphopoiesis. The mechanism by which systemic inflammation impacts the thymus beyond suppressing T-cell development is still unclear. Here, we describe how the synergism between TL1A and IL-18 suppresses T-lymphopoiesis to promote thymic myelopoiesis. The protein levels of these two cytokines were elevated in the thymus during viral-induced thymus atrophy infection with murine cytomegalovirus (MCMV) or pneumonia virus of mice (PVM). In vivo administration of TL1A and IL-18 induced acute thymic atrophy, while thymic neutrophils expanded. Fate mapping with Ms4a3-Cre mice demonstrated that thymic neutrophils emerge from thymic granulocyte-monocyte progenitors (GMPs), while Rag1-Cre fate mapping revealed a common developmental path with lymphocytes. These effects could be modeled ex vivo using neonatal thymic organ cultures (NTOCs), where TL1A and IL-18 synergistically enhanced neutrophil production and egress. NOTCH blockade by the LY411575 inhibitor increased the number of neutrophils in the culture, indicating that NOTCH restricted steady-state thymic granulopoiesis. To promote myelopoiesis, TL1A, and IL-18 synergistically increased GM-CSF levels in the NTOC, which was mainly produced by thymic ILC1s. In support, TL1A- and IL-18-induced granulopoiesis was completely prevented in NTOCs derived from Csf2rb-/- mice and by GM-CSFR antibody blockade, revealing that GM-CSF is the essential factor driving thymic granulopoiesis. Taken together, our findings reveal that TL1A and IL-18 synergism induce acute thymus atrophy while  promoting extramedullary thymic granulopoiesis in a NOTCH and GM-CSF-controlled manner.

RIPK1 protects naive and regulatory T cells from TNFR1-induced apoptosis.

The T cell population size is stringently controlled before, during, and after immune responses, as improper cell death regulation can result in autoimmunity and immunodeficiency. RIPK1 is an important regulator of peripheral T cell survival and homeostasis. However, whether different peripheral T cell subsets show a differential requirement for RIPK1 and which programmed cell death pathway they engage in vivo remains unclear. In this study, we demonstrate that conditional ablation of Ripk1 in conventional T cells (Ripk1ΔCD4) causes peripheral T cell lymphopenia, as witnessed by a profound loss of naive CD4+, naive CD8+, and FoxP3+ regulatory T cells. Interestingly, peripheral naive CD8+ T cells in Ripk1ΔCD4 mice appear to undergo a selective pressure to retain RIPK1 expression following activation. Mixed bone marrow chimeras revealed a competitive survival disadvantage for naive, effector, and memory T cells lacking RIPK1. Additionally, tamoxifen-induced deletion of RIPK1 in CD4-expressing cells in adult life confirmed the importance of RIPK1 in post-thymic survival of CD4+ T cells. Ripk1K45A mice showed no change in peripheral T cell subsets, demonstrating that the T cell lymphopenia was due to the scaffold function of RIPK1 rather than to its kinase activity. Enhanced numbers of Ripk1ΔCD4 naive T cells expressed the proliferation marker Ki-67+ despite the peripheral lymphopenia and single-cell RNA sequencing revealed T cell-specific transcriptomic alterations that were reverted by additional caspase-8 deficiency. Furthermore, Ripk1ΔCD4Casp8 ΔCD4 and Ripk1ΔCD4Tnfr1-/- double-knockout mice rescued the peripheral T cell lymphopenia, revealing that RIPK1-deficient naive CD4+ and CD8+ cells and FoxP3+ regulatory T cells specifically die from TNF- and caspase-8-mediated apoptosis in vivo. Altogether, our findings emphasize the essential role of RIPK1 as a scaffold in maintaining the peripheral T cell compartment and preventing TNFR1-induced apoptosis.

Single-cell proteomics and transcriptomics capture eosinophil development and identify the role of IL-5 in their lineage transit amplification.

The activities, ontogeny, and mechanisms of lineage expansion of eosinophils are less well resolved than those of other immune cells, despite the use of biological therapies targeting the eosinophilia-promoting cytokine interleukin (IL)-5 or its receptor, IL-5Rα. We combined single-cell proteomics and transcriptomics and generated transgenic IL-5Rα reporter mice to revisit eosinophilopoiesis. We reconciled human and murine eosinophilopoiesis and provided extensive cell-surface immunophenotyping and transcriptomes at different stages along the continuum of eosinophil maturation. We used these resources to show that IL-5 promoted eosinophil-lineage expansion via transit amplification, while its deletion or neutralization did not compromise eosinophil maturation. Informed from our resources, we also showed that interferon response factor-8, considered an essential promoter of myelopoiesis, was not intrinsically required for eosinophilopoiesis. This work hence provides resources, methods, and insights for understanding eosinophil ontogeny, the effects of current precision therapeutics, and the regulation of eosinophil development and numbers in health and disease.

Sublingual allergen immunotherapy prevents house dust mite inhalant type 2 immunity through dendritic cell-mediated induction of Foxp3+ regulatory T cells.

Sublingual allergen immunotherapy (SLIT) is an emerging treatment option for allergic asthma and a potential disease-modifying strategy for asthma prevention. The key cellular events leading to such long-term tolerance remain to be fully elucidated. We administered prophylactic SLIT in a mouse model of house dust mite (HDM)-driven allergic asthma. HDM extract was sublingually administered over 3 weeks followed by intratracheal sensitization and intranasal challenges with HDM. Prophylactic SLIT prevented allergic airway inflammation and hyperreactivity with a low lab-to-lab variation. The HDM-specific T helper (Th)2 (cluster of differentiation 4 Th) response was shifted by SLIT toward a regulatory and Th17 response in the lung and mediastinal lymph node. By using Derp1-specific cluster of differentiation 4+ T cells (1-DER), we found that SLIT blocked 1-DER T cell recruitment to the mediastinal lymph node and dampened IL-4 secretion following intratracheal HDM sensitization. Sublingually administered Derp1 protein activated 1-DER T cells in the cervical lymph node via chemokine receptor7+ migratory dendritic cells (DC). DCs migrating from the oral submucosa to the cervical lymph node after SLIT-induced Foxp3+ regulatory T cells. When mice were sensitized with HDM, prior prophylactic SLIT increased Derp1 specific regulatory T cells (Tregs) and lowered Th2 recruitment in the lung. By using Foxp3-diphtheria toxin receptor mice, Tregs were found to contribute to the immunoregulatory prophylactic effect of SLIT on type 2 immunity. These findings in a mouse model suggest that DC-mediated functional Treg induction in oral mucosa draining lymph nodes is one of the driving mechanisms behind the disease-modifying effect of prophylactic SLIT.

Airway remodelling in asthma and the epithelium: on the edge of a new era.

Asthma is a chronic, heterogeneous disease of the airways, often characterised by structural changes known collectively as airway remodelling. In response to environmental insults, including pathogens, allergens and pollutants, the epithelium can initiate remodelling via an inflammatory cascade involving a variety of mediators that have downstream effects on both structural and immune cells. These mediators include the epithelial cytokines thymic stromal lymphopoietin, interleukin (IL)-33 and IL-25, which facilitate airway remodelling through cross-talk between epithelial cells and fibroblasts, and between mast cells and airway smooth muscle cells, as well as through signalling with immune cells such as macrophages. The epithelium can also initiate airway remodelling independently of inflammation in response to the mechanical stress present during bronchoconstriction. Furthermore, genetic and epigenetic alterations to epithelial components are believed to influence remodelling. Here, we review recent advances in our understanding of the roles of the epithelium and epithelial cytokines in driving airway remodelling, facilitated by developments in genetic sequencing and imaging techniques. We also explore how new and existing therapeutics that target the epithelium and epithelial cytokines could modify airway remodelling.

Global status of chiropractic education research: a scoping review protocol.

OBJECTIVE: The objective of this scoping review is to map the volume and nature (topics, study designs, regions) of chiropractic education research relating to chiropractic learners and programs worldwide. INTRODUCTION: Education of the health workforce is critical to reach population health goals. Chiropractic educational programs are expanding globally; however, the state of chiropractic education research is not known. A better understanding of the volume and nature of chiropractic education research will inform education research priorities and development of chiropractic programs, and assist with preparing a stronger chiropractic workforce to address world health goals. INCLUSION CRITERIA: This scoping review will consider articles that study students, faculty, administration, staff, graduates, and programs in any chiropractic education setting, including graduate, clinical, postgraduate, and specialty training, in any country. Articles on non-educational topics or clinical research will be excluded. METHODS: This review will follow the JBI scoping review methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The databases to be searched include PubMed, Scopus, CINAHL, Index to Chiropractic Literature, Biblioteca Virtual em Saúde, and Educational Resources Information Center from their inception. All languages will be considered. Two reviewers will independently screen records using predefined eligibility criteria and extract data using tables. Data extracted from eligible articles will include study design, participants, region, and topics. The results will be presented in a narrative summary with data presented in tabular and diagrammatic formats. REVIEW REGISTRATION: Open Science Framework https://osf.io/9b3ap.

Physicochemical and biological stability of diluted vedolizumab in intravenous infusion bags.

INTRODUCTION: Intravenous vedolizumab is a widely used monoclonal antibody for outpatients with inflammatory bowel disease. Drug preparation is performed on the day of administration, but is time consuming, causing unnecessary in-hospital patient delay and inefficient logistics for preparation and distribution. Storage of vedolizumab ready-to-administer infusions and distribution via pneumatic air tubes could streamline logistics in the outpatient setting. The aim of this study was to test the shelf life and stability of ready-to-administer intravenous infusion bags containing vedolizumab. METHODS: For assessing in-use shelf life, the reconstituted product (300 mg fixed dose) was diluted to a concentration of 1.2 mg/mL in 0.9% NaCl under aseptic conditions, and stored in polyolefin infusion bags at 2-8°C prior to analysis. On replicate samples, we measured concentration, physical and chemical stability using sodium dodecyl sulphate polyacrylamide gel electrophoresis, size exclusion chromatography, and multi-angle laser light scattering, as well as biological activity using a biolayer interferometry assay to study target engagement, and endotoxin content to assess microbiological stability. Stability of ready-to-use vedolizumab was assessed also after transportation via pneumatic tube system. Samples were taken at different time points over an observation period of 30 days on four replicate samples. RESULTS: For all parameters assessed, the ready-to-use solution of vedolizumab remained stable over a period of at least 30 days. There were no signs of protein aggregation, chemical instability, or loss of binding of the antibody to the α4ß7 integrin target. There was no increase in endotoxin concentration over time. No significant difference was seen in antibody structural stability and protein aggregation between samples before and after transportation via pneumatic tube system. CONCLUSION: When prepared under aseptic conditions, dissolved ready-to-administer vedolizumab infusion bags can be stored long term at 2-8°C and transported via pneumatic air tube, without observable loss of antibody stability or binding activity.

Aspergillus and the Lung.

The filamentous fungus Aspergillus causes a wide spectrum of diseases in the human lung, with Aspergillus fumigatus being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of Aspergillus in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.

Ym1 protein crystals promote type 2 immunity.

Spontaneous protein crystallization is a rare event, yet protein crystals are frequently found in eosinophil-rich inflammation. In humans, Charcot-Leyden crystals (CLCs) are made from galectin-10 (Gal10) protein, an abundant protein in eosinophils. Although mice do not encode Gal10 in their genome, they do form pseudo-CLCs, made from the chitinase-like proteins Ym1 and/or Ym2, encoded by Chil3 and Chil4 and made by myeloid and epithelial cells respectively. Here, we investigated the biological effects of pseudo-CLCs since their function is currently unknown. We produced recombinant Ym1 crystals which were shown to have identical crystal packing and structure by X-ray crystallography as in vivo native crystals derived from murine lung. When administered to the airways of mice, crystalline but not soluble Ym1 stimulated innate and adaptive immunity and acted as a type 2 immune adjuvant for eosinophilic inflammation via triggering of dendritic cells (DCs). Murine Ym1 protein crystals found at sites of eosinophilic inflammation reinforce type 2 immunity and could serve as a surrogate model for studying the biology of human CLCs.

Metabolic network alterations as a supportive biomarker in dementia with Lewy bodies with preserved dopamine transmission.

PURPOSE: Metabolic network analysis of FDG-PET utilizes an index of inter-regional correlation of resting state glucose metabolism and has been proven to provide complementary information regarding the disease process in parkinsonian syndromes. The goals of this study were (i) to evaluate pattern similarities of glucose metabolism and network connectivity in dementia with Lewy bodies (DLB) subjects with subthreshold dopaminergic loss compared to advanced disease stages and to (ii) investigate metabolic network alterations of FDG-PET for discrimination of patients with early DLB from other neurodegenerative disorders (Alzheimer's disease, Parkinson's disease, multiple system atrophy) at individual patient level via principal component analysis (PCA). METHODS: FDG-PETs of subjects with probable or possible DLB (n = 22) without significant dopamine deficiency (z-score < 2 in putamen binding loss on DaT-SPECT compared to healthy controls (HC)) were scaled by global-mean, prior to volume-of-interest-based analyses of relative glucose metabolism. Single region metabolic changes and network connectivity changes were compared against HC (n = 23) and against DLB subjects with significant dopamine deficiency (n = 86). PCA was applied to test discrimination of patients with DLB from disease controls (n = 101) at individual patient level. RESULTS: Similar patterns of hypo- (parietal- and occipital cortex) and hypermetabolism (basal ganglia, limbic system, motor cortices) were observed in DLB patients with and without significant dopamine deficiency when compared to HC. Metabolic connectivity alterations correlated between DLB patients with and without significant dopamine deficiency (R2 = 0.597, p < 0.01). A PCA trained by DLB patients with dopamine deficiency and HC discriminated DLB patients without significant dopaminergic loss from other neurodegenerative parkinsonian disorders at individual patient level (area-under-the-curve (AUC): 0.912). CONCLUSION: Disease-specific patterns of altered glucose metabolism and altered metabolic networks are present in DLB subjects without significant dopaminergic loss. Metabolic network alterations in FDG-PET can act as a supporting biomarker in the subgroup of DLB patients without significant dopaminergic loss at symptoms onset.

Lipid Nanoparticle Encapsulation Empowers Poly(I:C) to Activate Cytoplasmic RLRs and Thereby Increases Its Adjuvanticity.

Poly(I:C) is a synthetic analogue of dsRNA capable of activating both TLR3 and RLRs, such as MDA-5 and RIG-I, as pathogen recognition receptors. While poly(I:C) is known to provoke a robust type I IFN, type III IFN, and Th1 cytokine response, its therapeutic use as a vaccine adjuvant is limited due to its vulnerability to nucleases and poor uptake by immune cells. is encapsulated poly(I:C) into lipid nanoparticles (LNPs) containing an ionizable cationic lipid that can electrostatically interact with poly(I:C). LNP-formulated poly(I:C) triggered both lysosomal TLR3 and cytoplasmic RLRs, in vitro and in vivo, whereas poly(I:C) in an unformulated soluble form only triggered endosomal-localized TLR3. Administration of LNP-formulated poly(I:C) in mouse models led to efficient translocation to lymphoid tissue and concurrent innate immune activation following intramuscular (IM) administration, resulting in a significant increase in innate immune activation compared to unformulated soluble poly(I:C). When used as an adjuvant for recombinant full-length SARS-CoV-2 spike protein, LNP-formulated poly(I:C) elicited potent anti-spike antibody titers, surpassing those of unformulated soluble poly(I:C) by orders of magnitude and offered complete protection against a SARS-CoV-2 viral challenge in vivo, and serum from these mice are capable of significantly reducing viral infection in vitro.

Head-to-head comparison of relative cerebral blood flow derived from dynamic [18F]florbetapir and [18F]flortaucipir PET in subjects with subjective cognitive decline.

BACKGROUND: Dynamic PET imaging studies provide accurate estimates of specific binding, but also measure the relative tracer delivery (R1), which is a proxy for relative cerebral blood flow (rCBF). Recently, studies suggested that R1 obtained from different tracers could be used interchangeably and is irrespective of target tissue. However, the similarities or differences of R1 obtained from different PET tracers still require validation. Therefore, the goal of the current study was to compare R1 estimates, derived from dynamic [18F]florbetapir (amyloid) and [18F]flortaucipir (tau) PET, in the same subjects with subjective cognitive decline (SCD). RESULTS: Voxel-wise analysis presented a small cluster (1.6% of the whole brain) with higher R1 values for [18F]flortaucipir compared to [18F]florbetapir in the Aß-negative group. These voxels were part of the hippocampus and the left middle occipital gyrus. In part of the thalamus, midbrain and cerebellum, voxels (2.5% of the whole brain) with higher R1 values for [18F]florbetapir were observed. In the Aß-positive group, a cluster (0.2% of the whole brain) of higher R1 values was observed in part of the hippocampus, right parahippocampal gyrus and in the left sagittal stratum for [18F]flortaucipir compared to [18F]florbetapir. Furthermore, in part of the thalamus, left amygdala, midbrain and right parahippocampal gyrus voxels (0.4% of the whole brain) with higher R1 values for [18F]florbetapir were observed. Despite these differences, [18F]florbetapir R1 had high correspondence with [18F]flortaucipir R1 across all regions of interest (ROIs) and subjects (Aß-:r2 = 0.79, slope = 0.85, ICC = 0.76; Aß+: r2 = 0.87, slope = 0.93, ICC = 0.77). CONCLUSION: [18F]flortaucipir and [18F]florbetapir showed similar R1 estimates in cortical regions. This finding, put together with previous studies, indicates that R1 could be considered a surrogate for relative cerebral blood flow (rCBF) in the cortex and may be used interchangeably, but with caution, regardless of the choice of these two tracers.

Association between spinal and non-spinal health conditions reported in epidemiological studies: a scoping review protocol.

INTRODUCTION: The increasing prevalence of coexisting health conditions poses a challenge to healthcare providers and healthcare systems. Spinal pain (eg, neck and back pain) and spinal pathologies (eg, osteoporotic fractures and degenerative spinal disease) exist concurrently with other non-spinal health conditions (NSHC). However, the scope of what associations may exist among these co-occurring conditions is unclear. Therefore, this scoping review aims to map the epidemiological literature that reports associations between spine-related pain and pathologies (SPPs) and NSHCs. METHODS AND ANALYSIS: This scoping review will follow the JBI protocol and Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews. We will systematically search the literature using key words and MeSH terms for SPPs and NSHCs. Terminology/vocabulary for NSHCs will include those for communicable and non-communicable diseases as reported by WHO Global Burden of Disease reports. Five databases will be searched from inception: MEDLINE, EMBASE, APA PsycInfo, Scopus and Web of Science Core Collection. Papers published in English, in peer-reviewed journals, including measures of association between SPPs and NSHCs and using observational epidemiologic study designs will be included. Excluded will be studies of cadaveric, animal or health behaviours; studies with no measures of association and non-observational epidemiologic studies. Results will include the number of studies, the studies that have evaluated the measures of association and the frequency of the studied associations between SPPs and NSHCs. Results will be reported in tables and diagrams. Themes of comorbidities will be synthesised into a descriptive report. ETHICS AND DISSEMINATION: This scoping review was deemed exempt from ethics review. This review will provide a comprehensive overview of the literature that reports associations between SPPs and NSHCs to inform future research initiatives and practices. Results will be disseminated through publication in peer-reviewed journals and research conferences. REGISTRATION DETAILS: https://osf.io/w49u3.

Protein citrullination and NET formation do not contribute to the pathology of A20/TNFAIP3 mutant mice.

A20 serves as a critical brake on NF-κB-dependent inflammation. In humans, polymorphisms in or near the TNFAIP3/A20 gene have been linked to various inflammatory disorders, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Experimental gene knockout studies in mice have confirmed A20 as a susceptibility gene for SLE and RA. Here, we examine the significance of protein citrullination and NET formation in the autoimmune pathology of A20 mutant mice because autoimmunity directed against citrullinated antigens released by neutrophil extracellular traps (NETs) is central to the pathogenesis of RA and SLE. Furthermore, genetic variants impairing the deubiquitinase (DUB) function of A20 have been shown to contribute to autoimmune susceptibility. Our findings demonstrate that genetic disruption of A20 DUB function in A20 C103R knockin mice does not result in autoimmune pathology. Moreover, we show that PAD4 deficiency, which abolishes protein citrullination and NET formation, does not prevent the development of autoimmunity in A20 deficient mice. Collectively, these findings provide experimental confirmation that PAD4-dependent protein citrullination and NET formation do not serve as pathogenic mechanisms in the development of RA and SLE pathology in mice with A20 mutations.

Chiropractic Day 2023: A Report and Qualitative Analysis of How Thought Leaders Celebrate the Present and Envision the Future of Chiropractic.

Objective: This study aimed to (1) collect and analyze statements about how to celebrate chiropractic in the present and roles that chiropractors may fulfill in the future, (2) identify if there was congruence among the themes between present and future statements, and (3) offer a model about the chiropractic profession that captures its complex relationships that encompass its interactions within microsystem, mesosystem, exosystem, and macrosystem levels. Methods: For this qualitative analysis, we used pattern and grounded theory approaches. A purposive sample of thought leaders in the chiropractic profession were invited to answer the following 2 open-ended questions: (1) envision the chiropractor of the future, and (2) recommendations on how to celebrate chiropractic. Information was collected during April 2023 using Survey Monkey. The information was entered into a spreadsheet and analyzed for topic clusters, which resulted in matching concepts with social-ecological themes. The themes between the responses to the 2 questions were analyzed for congruence. We used the Standards for Reporting Qualitative Research to report our findings. Results: Of the 54 experts invited, 32 (59%) participated. Authors represented 7 countries and have a median of 32 years of chiropractic experience, with a range of 5 to 51 years. Nineteen major topics in the future statements and 23 major topics in statements about celebrating chiropractic were combined in a model. The topics were presented using the 4 levels of the social-ecological framework. Individual (microsystem): chiropractors are competent, well-educated experts in spine and musculoskeletal care who apply evidence-based practices, which is a combination of the best available evidence, clinical expertise, and patient values. Interpersonal relationships (mesosystem): chiropractors serve the best interests of their patients, provide person-centered care, embrace diversity, equity, and inclusion, consider specific health needs and the health of the whole person. Community (exosystem): chiropractors provide care within integrated health care environments and in private practices, serve the best interests of the public through participation in their communities, participate through multidisciplinary collaboration with and within the health care system, and work together as a profession with a strong professional identity. Societal (macrosystem): chiropractors contribute to the greater good of society and participate on a global level in policy, leadership, and research. There was concordance between both the future envisioning statements and the present celebration recommendations, which suggest logical validity based on the congruence of these concepts. Conclusion: A sample of independent views, including the perceptions from a broad range of chiropractic thought leaders from various backgrounds, philosophies, diversity characteristics, and world regions, were assembled to create a comprehensive model of the chiropractic profession. The resulting model shows an array of intrinsic values and provides the roles that chiropractors may provide to serve patients and the public. This study offers insights into the roles that future chiropractors may fulfill and how these are congruent with present-day values. These core concepts and this novel model may have utility during dialogs about identity, applications regarding chiropractic in policy, practice, education, and research, and building positive relationships and collaborations.

A conversation on allergy: recognizing the past and looking to the future.

Allergy is an ever-evolving group of disorders, which includes asthma, atopic dermatitis, rhinitis and food allergies and that currently affects over 1 billion people worldwide. This group of disorders has exploded in incidence since around the start of the 20th century, implying that genetics is not solely responsible for its development but that environmental factors have an important role. Here, Fabio Luciani and Jonathan Coquet, in their role as editors at Immunology & Cell Biology, asked nine prominent researchers in the field of allergy to define the term 'allergy', discuss the role of genetics and the environment, nominate the most important discoveries of the past decade and describe the best strategies to combat allergy at the population level going forward.

Lipid Nanoparticle Delivery Alters the Adjuvanticity of the TLR9 Agonist CpG by Innate Immune Activation in Lymphoid Tissue.

Pharmacological strategies to activate innate immune cells are of great relevance in the context of vaccine design and anticancer immune therapy, to mount broad immune responses able to clear infection and malignant cells. Synthetic CpG oligodeoxynucleotides (CpG-ODNs) are short single-stranded DNA molecules containing unmethylated CpG dinucleotides and a phosphorothioate backbone. Class B CpG ODNs activate robust innate immune responses through a TLR9-dependent NF-κB signaling pathway. This feature is attractive to exploit in the context of vaccine design and cancer immunotherapy. Soluble CpG-ODNs cause hepatic toxicity, which reduces its therapeutic applicability. The formulation of class B CpG ODN1826 in lipid nanoparticles (LNPs) containing an ionizable cationic lipid that complexes CpG through electrostatic interaction is reported. Upon local administration, LNP-formulated CpG drains to lymph nodes and triggers robust innate immune activation. Unformulated, soluble, CpG, by contrast, is unable to induce robust innate activation in draining lymph nodes and is distributed systemically. In a vaccination setting, LNP-formulated CpG, admixed with a protein antigen, induces higher antigen-specific antibody titers and T cell responses than antigen admixed with unformulated soluble CpG.

Performance of a [18F]Flortaucipir PET Visual Read Method Across the Alzheimer Disease Continuum and in Dementia With Lewy Bodies.

BACKGROUND AND OBJECTIVES: Recently, the US Food and Drug Administration approved the tau-binding radiotracer [18F]flortaucipir and an accompanying visual read method to support the diagnostic process in cognitively impaired patients assessed for Alzheimer disease (AD). Studies evaluating this visual read method are limited. In this study, we evaluated the performance of the visual read method in participants along the AD continuum and dementia with Lewy bodies (DLB) by determining its reliability, accordance with semiquantitative analyses, and associations with clinically relevant variables. METHODS: We included participants who underwent tau-PET at Amsterdam University Medical Center. A subset underwent follow-up tau-PET. Two trained nuclear medicine physicians visually assessed all scans. Inter-reader agreement was calculated using Cohen κ. To examine the concordance of visual read tau positivity with semiquantification, we defined standardized uptake value ratio (SUVr) positivity using different threshold approaches. To evaluate the prognostic value of tau-PET visual read, we performed linear mixed models with longitudinal Mini-Mental State Examination (MMSE). RESULTS: We included 263 participants (mean age 68.5 years, 45.6% female), including 147 cognitively unimpaired (CU) participants, 97 amyloid-positive participants with mild cognitive impairment or AD dementia (AD), and 19 participants with DLB. The visual read inter-reader agreement was excellent (κ = 0.95, CI 0.91-0.99). None of the amyloid-negative CU participants (0/92 [0%]) and 1 amyloid-negative participant with DLB (1/12 [8.3%]) were tau-positive. Among amyloid-positive participants, 13 CU participants (13/52 [25.0%]), 85 with AD (85/97 [87.6%]), and 3 with DLB (3/7 [42.9%]) were tau-positive. Two-year follow-up visual read status was identical to baseline. Tau-PET visual read corresponded strongly to SUVr status, with up to 90.4% concordance. Visual read tau positivity was associated with a decline on the MMSE in CU participants (ß = -0.52, CI -0.74 to -0.30, p < 0.001) and participants with AD (ß = -0.30, CI -0.58 to -0.02, p = 0.04). DISCUSSION: The excellent inter-reader agreement, strong correspondence with SUVr, and longitudinal stability indicate that the visual read method is reliable and robust, supporting clinical application. Furthermore, visual read tau positivity was associated with prospective cognitive decline, highlighting its additional prognostic potential. Future studies in unselected cohorts are needed for a better generalizability to the clinical population. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that [18F]flortaucipir visual read accurately distinguishes patients with low tau-tracer binding from those with high tau-tracer binding and is associated with amyloid positivity and cognitive decline.

A complement atlas identifies interleukin-6-dependent alternative pathway dysregulation as a key druggable feature of COVID-19.

Improvements in COVID-19 treatments, especially for the critically ill, require deeper understanding of the mechanisms driving disease pathology. The complement system is not only a crucial component of innate host defense but can also contribute to tissue injury. Although all complement pathways have been implicated in COVID-19 pathogenesis, the upstream drivers and downstream effects on tissue injury remain poorly defined. We demonstrate that complement activation is primarily mediated by the alternative pathway, and we provide a comprehensive atlas of the complement alterations around the time of respiratory deterioration. Proteomic and single-cell sequencing mapping across cell types and tissues reveals a division of labor between lung epithelial, stromal, and myeloid cells in complement production, in addition to liver-derived factors. We identify IL-6 and STAT1/3 signaling as an upstream driver of complement responses, linking complement dysregulation to approved COVID-19 therapies. Furthermore, an exploratory proteomic study indicates that inhibition of complement C5 decreases epithelial damage and markers of disease severity. Collectively, these results support complement dysregulation as a key druggable feature of COVID-19.