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Background: The synthesis of IgE is regulated by cytokines secreted from T-helper cells. The studies on cytokine secretion by peripheral blood mononuclear cells (PBMC) upon stimulation with antigen or allergen are difficult due to low levels of cytokines, especially of interleukin-4 (IL-4). Objective: In this study we tried to establish a culture system, which could enable the measurement of the cytokine profiles in specifically activated cultures. Methods Three methods to potentiate cytokine secretion were evaluated: PBMC from bee venom or house dust mite (Dermatophagoides pteronyssinus) allergic patients as well as normal subjects were stimulated either with the major bee venom allergen phospholipase A2 (PLA) or with the major D. pteronyssinus allergen (Der p 1) or with the control antigens tetanus toxoid (TT) and purified protein derivate (PPD). After 7 days of culture the cells were restimulated either with plastic bound OKT3 F(ab)2 monoclonal antibodies (MoAbs), with the appropriate antigen + antigen presenting cells or with IL-2. The secretion of cytokines (IL-4, IFNγ) was measured after restimulation of the cultures (day 8). Results While OKT3 F(ab)2 was unable to activate resting T cells, it could restimulate preactivated cells. Restimulation with OKT3 F(ab)2 induced higher IL-4 and IFNγ secretion than restimulation with IL-2 or antigen. TT and PLA stimulated a similar cytokine secretion profile in normal and PLA allergic subjects with substantial levels of both IL-4 and IFNγ. In contrast, PPD induced virtually only IFNγ secretion. Der p 1 stimulated mainly IL-4 secretion but also IFN-γ production in some mite allergic patients. Conclusion We have established a cell culture system, which combines antigen specificity with a strong cytokine inducing signal provided by anti-CD3 MoAbs. TH-1 and TH-2 characteristic cytokine patterns can be observed in short-term PBMC cultures already after 8 days of culture. [ABSTRACT FROM AUTHOR]

In the anagen human hair follicle, the epithelial cells from the infrainfundibular portion and the hair matrix cells express markedly lower numbers of major histocompatibility complex class I molecules than interfollicular epidermal keratinocytes. During the catagen phase of the hair cycle, class I expression on these cells increases, and activated macrophages aggregate around the follicle, which has led to the hypothesis that the cells to be resorbed are recognized by virtue of their low class I antigen expression. In the present study, we showed that, in vitro, outer root sheath cells also maintain a lower constitutive expression of MHC class I molecules compared with epidermal keratinocytes. In contrast, other surface antigens such as HLA-DR, DP and -DQ. ICAM-1, LFA-3 and CD29, which are all known to participate in Ieucocyte keratinocyte interactions, were similarly expressed in both cell types. Furthermore, interferon gamma strongly upregulated MHC class I and II and ICAM-I expression in both cell types, whereas CD29 and LFA-3 remained unaffected. Tumour necrosis factor alpha. to a lesser extent, also upregulated MHC class I and ICAM-I expression, but not class H expression. The differences in constitutive surface antigen expression of infrainfundibular outer root sheath cells compared with interfollicular epidermal keratinocytes emphasizes a distinct role of this cell type In the hair cycle, and possibly also in alopecia areata. [ABSTRACT FROM AUTHOR]

Abstract Background The neuronal microtubule-associated protein tau becomes hyperphosphorylated and forms aggregates in tauopathies but the processes leading to this pathological hallmark are not understood. Because tauopathies are accompanied by neuroinflammation and the complement cascade forms a key innate immune pathway, we asked whether the complement system has a role in the development of tau pathology. Findings We tested this hypothesis in two mouse models, which expressed either a central inhibitor of complement or lacked an inhibitor of the terminal complement pathway. Complement receptor-related gene/protein y is the natural inhibitor of the central complement component C3 in rodents. Expressing a soluble variant (sCrry) reduced the number of phospho-tau (AT8 epitope) positive neurons in the brain stem, cerebellum, cortex, and hippocampus of aged P301L mutant tau/sCrry double-transgenic mice compared with tau single-transgenic littermates (JNPL3 line). CD59a is the major inhibitor of formation of the membrane attack complex in mice. Intrahippocampal injection of adeno-associated virus encoding mutant human P301L tau into Cd59a−/− mice resulted in increased numbers of AT8-positive cells compared with wild-type controls. This was accompanied by neuronal and synaptic loss and reduced dendritic integrity. Conclusions Our data in two independent mouse models with genetic changes in key regulators of the complement system support the hypothesis that the terminal pathway has an active role in the development of tau pathology. We propose that inhibition of the terminal pathway may be beneficial in tauopathies.

Abstract Autophagy is the major pathway involved in the degradation of proteins and organelles, cellular remodeling, and survival during nutrient starvation. Autophagosomal dysfunction has been implicated in an increasing number of diseases from cancer to bacterial and viral infections and more recently in neurodegeneration. While a decrease in autophagic activity appears to interfere with protein degradation and possibly organelle turnover, increased autophagy has been shown to facilitate the clearance of aggregation-prone proteins and promote neuronal survival in a number of disease models. On the other hand, too much autophagic activity can be detrimental as well and lead to cell death, suggesting the regulation of autophagy has an important role in cell fate decisions. An increasing number of model systems are now available to study the role of autophagy in the central nervous system and how it might be exploited to treat disease. We will review here the current knowledge of autophagy in the central nervous system and provide an overview of the various models that have been used to study acute and chronic neurodegeneration.

Abstract Background Experimental autoimmune encephalomyelitis is a widely used animal model to understand not only multiple sclerosis but also basic principles of immunity. The disease is scored typically by observing signs of paralysis, which do not always correspond with pathological changes. Methods Experimental autoimmune encephalomyelitis was induced in transgenic mice expressing an injury responsive luciferase reporter in astrocytes (GFAP-luc). Bioluminescence in the brain and spinal cord was measured non-invasively in living mice. Mice were sacrificed at different time points to evaluate clinical and pathological changes. The correlation between bioluminescence and clinical and pathological EAE was statistically analyzed by Pearson correlation analysis. Results Bioluminescence from the brain and spinal cord correlates strongly with severity of clinical disease and a number of pathological changes in the brain in EAE. Bioluminescence at early time points also predicts severity of disease. Conclusion These results highlight the potential use of bioluminescence imaging to monitor neuroinflammation for rapid drug screening and immunological studies in EAE and suggest that similar approaches could be applied to other animal models of autoimmune and inflammatory disorders.

Abstract Background Transforming Growth Factor-β (TGF-β) regulates key biological processes during development and in adult tissues and has been implicated in many diseases. To study the biological functions of TGF-β, sensitive, specific, and convenient bioassays are necessary. Here we describe a new cell-based bioassay that fulfills these requirements. Results Embryonic fibroblasts from Tgfb1-/- mice were stably transfected with a reporter plasmid consisting of TGF-β responsive Smad-binding elements coupled to a secreted alkaline phosphatase reporter gene (SBE-SEAP). Clone MFB-F11 showed more than 1000-fold induction after stimulation with 1 ng/ml TGF-β1, and detected as little as 1 pg/ml TGF-β1. MFB-F11 cells were highly induced by TGF-β1, TGF-β2 and TGF-β3, but did not show induction with related family members activin, nodal, BMP-2 and BMP-6 or with trophic factors bFGF and BDNF. MFB-F11 cells can detect and quantify TGF-β in biological samples without prior enrichment of TGF-βs, and can detect biologically activated TGF-β in a cell co-culture system. Conclusion MFB-F11 cells can be used to rapidly and specifically measure TGF-β with high sensitivity.

Abstract Inflammation of the central nervous system is an important but poorly understood part of neurological disease. After acute brain injury or infection there is a complex inflammatory response that involves activation of microglia and astrocytes and increased production of cytokines, chemokines, acute phase proteins, and complement factors. Antibodies and T lymphocytes may be involved in the response as well. In neurodegenerative disease, where injury is more subtle but consistent, the inflammatory response is continuous. The purpose of this prolonged response is unclear, but it is likely that some of its components are beneficial and others are harmful. Animal models of neurological disease can be used to dissect the specific role of individual mediators of the inflammatory response and assess their potential benefit. To illustrate this approach, we discuss how mutant mice expressing different levels of the cytokine transforming growth factor β-1 (TGF-β1), a major modulator of inflammation, produce important neuroinflammatory phenotypes. We then demonstrate how crosses of TGF-β1 mutant mice with mouse models of Alzheimer's disease (AD) produced important new information on the role of inflammation in AD and on the expression of different neuropathological phenotypes that characterize this disease.

The integration of quantitative trait loci (QTLs) with disease genome-wide association studies (GWASs) has proven successful in prioritizing candidate genes at disease-associated loci. QTL mapping has been focused on multi-tissue expression QTLs or plasma protein QTLs (pQTLs). We generated a cerebrospinal fluid (CSF) pQTL atlas by measuring 6,361 proteins in 3,506 samples. We identified 3,885 associations for 1,883 proteins, including 2,885 new pQTLs, demonstrating unique genetic regulation in CSF. We identified CSF-enriched pleiotropic regions on chromosome (chr)3q28 near OSTN and chr19q13.32 near APOE that were enriched for neuron specificity and neurological development. We integrated our associations with Alzheimer's disease (AD) through proteome-wide association study (PWAS), colocalization and Mendelian randomization and identified 38 putative causal proteins, 15 of which have drugs available. Finally, we developed a proteomics-based AD prediction model that outperforms genetics-based models. These findings will be instrumental to further understand the biology and identify causal and druggable proteins for brain and neurological traits., Competing Interests: Competing interests C.C. has received research support from GSK and Eisai. The funders of the study had no role in the collection, analysis or interpretation of data; in the writing of the report; or in the decision to submit the paper for publication. C.C. is a member of the advisory board of Circular Genomics and owns stocks in this company. D.J.P. is an employee of GSK and holds stock in GSK. M.d.C.M. has been an invited speaker at Eisai. M.d.C.M. is an associate editor at Alzheimer’s Research and Therapy. B.T. and P.J.V. are inventors on a patent (WO2020197399A1, owned by Stichting VUmc). C.E.T. has a collaboration contract with ADx Neurosciences, Quanterix and Eli Lilly and performed contract research or received grants from AC Immune, Axon Neuroscience, BioConnect, Bioorchestra, Brainstorm Therapeutics, Celgene, EIP Pharma, Eisai, Grifols, Novo Nordisk, PeopleBio, Roche, Toyama and Vivoryon. She serves on editorial boards of Medidact Neurologie–Springer, Alzheimer’s Research and Therapy and Neurology: Neuroimmunology and Neuroinflammation and is an editor of the Neuromethods book (Springer). She had speaker contracts for Roche, Grifols and Novo Nordisk. The rest of the authors declare no competing interest., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

In this high-throughput proteomic study of autosomal dominant Alzheimer's disease (ADAD), we sought to identify early biomarkers in cerebrospinal fluid (CSF) for disease monitoring and treatment strategies. We examined CSF proteins in 286 mutation carriers (MCs) and 177 non-carriers (NCs). The developed multi-layer regression model distinguished proteins with different pseudo-trajectories between these groups. We validated our findings with independent ADAD as well as sporadic AD datasets and employed machine learning to develop and validate predictive models. Our study identified 137 proteins with distinct trajectories between MCs and NCs, including eight that changed before traditional AD biomarkers. These proteins are grouped into three stages: early stage (stress response, glutamate metabolism, neuron mitochondrial damage), middle stage (neuronal death, apoptosis), and late presymptomatic stage (microglial changes, cell communication). The predictive model revealed a six-protein subset that more effectively differentiated MCs from NCs, compared with conventional biomarkers., Competing Interests: Declaration of interests C.C. has received research support from GSK and EISAI. C.C. is a member of the advisory board of Circular Genomics and owns stocks in these companies. C.C. is on the advisory board of ADmit. J.L. reports speaker fees from Bayer Vital, Biogen, EISAI, TEVA, Zambon, Merck, and Roche; consulting fees from Axon Neuroscience, EISAI, and Biogen; author fees from Thieme medical publishers and W. Kohlhammer GmbH medical publishers; and is inventor in a patent “Oral Phenylbutyrate for Treatment of Human 4-Repeat Tauopathies” (EP 23 156 122.6). He receives compensation for serving as chief medical officer for MODAG GmbH and is a beneficiary of the phantom share program of MODAG GmbH. E.M. reports research support received from NIA (U01AG059798), Anonymous Foundation, GHR, Alzheimer Association, Eli Lilly Eisai, and Hoffmann-La Roche and paid consulting for Eli Lilly, Alector, Alzamend, Sanofi, AstraZeneca, Hoffmann-La Roche, Grifols, and Merck., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The recent unprecedented progress in ageing research and drug discovery brings together fundamental research and clinical applications to advance the goal of promoting healthy longevity in the human population. We, from the gathering at the Aging Research and Drug Discovery Meeting in 2023, summarised the latest developments in healthspan biotechnology, with a particular emphasis on artificial intelligence (AI), biomarkers and clocks, geroscience, and clinical trials and interventions for healthy longevity. Moreover, we provide an overview of academic research and the biotech industry focused on targeting ageing as the root of age-related diseases to combat multimorbidity and extend healthspan. We propose that the integration of generative AI, cutting-edge biological technology, and longevity medicine is essential for extending the productive and healthy human lifespan.