Local intragraft humoral immune responses in chronic lung allograft dysfunction

BACKGROUND

Donor human leukocyte antigen (HLA)-specific antibodies (DSA) and non-HLA antibodies can cause allograft injury, possibly leading to chronic lung allograft dysfunction (CLAD) after lung transplantation. It remains unclear whether these antibodies are produced locally in the graft or derived solely from circulation. We hypothesized that DSA and non-HLA antibodies are produced in CLAD lungs.

METHODS

Lung tissue was prospectively collected from 15 CLAD patients undergoing retransplantation or autopsy. 0.3 g of fresh lung tissue was cultured for 4 days without or with lipopolysaccharide or CD40L: lung culture supernatant (LCS) was sampled. Protein eluate was obtained from 0.3 g of frozen lung tissue. The mean fluorescence intensity (MFI) of DSA and non-HLA antibodies was measured by Luminex and antigen microarray, respectively.

RESULTS

LCS from all 4 patients who had serum DSA at lung isolation were positive for DSA, with higher levels measured after CD40L stimulation (CD40L+LCS). Of these, only 2 had detectable DSA in lung eluate. MFI of non-HLA antibodies from CD40L+LCS correlated with those from lung eluate but not with those from sera. Flow cytometry showed higher frequencies of activated lung B cells in patients whose CD40L+LCS was positive for DSA (n = 4) or high non-HLA antibodies (n = 6) compared to those with low local antibodies (n = 5). Immunofluorescence staining showed CLAD lung lymphoid aggregates with local antibodies contained larger numbers of IgG+ plasma cells and greater IL-21 expression.

CONCLUSIONS

We show that DSA and non-HLA antibodies can be produced within activated B cell-rich lung allografts.

SNX17 Regulates Antigen Internalisation and Phagosomal Maturation by Dendritic Cells

Antigen cross-presentation is the process whereby small peptides derived from exogenous antigens are attached to MHC-I molecules triggering CD8+ T lymphocyte activation. The endocytic route of dendritic cells (DCs) is highly specialised for cross-presentation to initiate cytotoxic immune responses against numerous intracellular pathogens and tumours. In this study, we identify the endosomal protein sorting nexin (SNX) 17 as a key regulator of antigen internalisation and cross-presentation by DCs. SNX17 expression in DCs guarantees optimal cross-presentation of soluble, particulate, and Toxoplasma gondii-associated antigens. The silencing of SNX17 expression in DCs significantly affected the internalisation of exogenous antigens by fluid-phase endocytosis, phagocytosis, and more strikingly, T. gondii invasion. We show that SNX17 controls proper integrin recycling, actin cytoskeleton organisation, and phagosomal maturation. Altogether, our findings provide compelling evidence that SNX17 plays a central role in the modulation of the DC endocytic network, which is essential for competent antigen cross-presentation.

DNA PAMPs as Molecular Tools for the cGAS-STING Signaling Pathways

Beyond its role as the bearer of genetic material, DNA also plays a crucial role in the activation phase of innate immunity. Pathogen recognition receptors (PRRs) and their homologs, pathogen-associated molecular patterns (PAMPs), form the foundation for driving innate immune activation and the induction of immune responses during infection. In the context of DNA viruses or bacterial infections, specific DNA sequences are recognized and bound by DNA sensors, marking the DNA as a PAMP for host recognition and subsequent activation of innate immunity. The primary DNA sensor pathway known to date is cGAS-STING, which can induce Type I interferons (IFN) and innate immune responses against viruses and bacteria. Additionally, the cGAS-STING pathway has been identified to mediate functions in autophagy and senescence. Herein, we introduce methods for using DNA PAMPs as molecular tools to study the role of cGAS-STING and its signaling pathway in regulating innate immunity, both in vitro and in vivo.

Stable Isotope Tracing Experiments Using LC-MS

Metabolomics has emerged as a pivotal field in understanding cellular function, particularly in the context of disease. In numerous diseases, including cancer, alterations in metabolism play an essential role in disease progression and drug response. Hence, unraveling the metabolic rewiring is of importance to find novel diagnostic and therapeutic strategies. Isotope tracing is a powerful technique for delving deeper into the metabolic wiring of cells. By tracking an isotopically labeled substrate through biochemical reactions in the cell, this technique provides a dynamic understanding of cellular metabolism. This chapter outlines a robust isotope tracing protocol utilizing high-resolution mass spectrometry coupled to liquid chromatography in cell culture-based models. We cover essential aspects of experimental design and analyses, providing a valuable resource for researchers aiming to employ isotopic tracing.

Antigen-specific modulation of chronic experimental autoimmune encephalomyelitis in humanized mice by TCR-like antibody targeting autoreactive T-cell epitope

The development and application of human TCR-like (TCRL) antibodies recognizing disease-specific MHC-peptide complexes may prove as an important tool for basic research and therapeutic applications. Multiple sclerosis is characterized by aberrant CD4 T-cell response to self-antigens presented by MHC class II molecules. This led us to select a panel of TCRL Abs targeting the immunodominant autoantigenic epitope MOG35-55 derived from myelin oligodendrocyte glycoprotein (MOG) presented on HLA-DR2, which is associated with multiple sclerosis (MS). We demonstrate that these TCRL Abs bind with high specificity to human HLA-DR2/MOG35-55-derived MHC class II molecules and can detect APCs that naturally present the MS-associated autoantigen in the humanized EAE transgenic mouse model. The TCRL Abs can block ex vivo and in vivo CD4 T-cell proliferation in response to MOG35-55 stimulation in an antigen-specific manner. Most significantly, administration of TCRL Abs to MOG35-55-induced EAE model in HLA-DR2 transgenic mice both prevents and regresses established EAE. TCRL function was associated with a reduction in autoreactive pathogenic T-cell infiltration into the CNS, along with modulation of activated CD11b+ macrophages/microglial APCs. Collectively, these findings demonstrate the combined action of TCRL Abs in blocking TCR-MHC interactions and modulating APC presentation and activation, leading to a profound antigen-specific inhibitory effect on the neuroinflammatory process, resulting in regression of EAE. Our study constitutes an in vivo proof of concept for the utility of TCR-like antibodies as antigen-specific immunomodulators for CD4-mediated autoimmune diseases such as MS, validating the importance of the TCR-MHC axis as a therapeutic target for various autoimmune and inflammatory diseases.

Is platelet-rich plasma effective in treating uterine inflammation in jennies inseminated with cryopreserved donkey semen?

Despite frozen donkey semen demonstrating high quality after thawing and achieving suitable pregnancy rates in mares, it yields unsatisfactory results in jennies, likely due to a stronger uterine inflammatory response. This study assessed the effects of platelet-rich plasma (PRP) on uterine inflammation and pregnancy rates in jennies inseminated with frozen donkey semen. Estrous cycles from 11 jennies were assigned to three groups: Control (CTR, n = 22) with no treatment; Single PRP infusion (S-PRP, n = 22) administered 30 h after ovulation induction, prior to artificial insemination (AI); and Double PRP infusion (D-PRP, n = 21) with the first infusion at 30 h after ovulation induction and the second 4 h after AI. Insemination was performed with frozen donkey semen (1 billion sperm) deposited deeply in the uterine horn immediately after ovulation. Endometrial edema, intrauterine fluid (IUF), uterine vascularization, and endometrial cytology were evaluated pre-AI (TCt) and post-AI (6, 24, and 48 h). Uterine biopsies were taken at T48 for histopathological and collagen evaluation. Peripheral blood samples were collected on D5 for serum progesterone measurement, and pregnancy was evaluated via ultrasonography on D14. Data were analyzed using GLMMs, ANOVA, Friedman, and Kruskal-Wallis tests in SAS and GraphPad Prism, with significance set at p < 0.05. The S-PRP group showed less IUF accumulation than the CTR group at T6. Other parameters showed no significant differences among the groups. Cytology revealed a high percentage of inflammatory cells at T6 in all groups, which decreased in subsequent evaluations. In the CTR group, neutrophil percentages were similar to TCt at T24, while treated groups reached this similarity only by T48. Eosinophil percentages increased over time only in the treated groups. Pregnancy rates showed no differences among the groups (CTR: 0 %, S-PRP: 0 %, D-PRP: 10 %). Results indicate that PRP treatments were ineffective in modulating uterine inflammation and did not enhance pregnancy rates in jennies inseminated with frozen donkey semen.

Psycho-Neuro-EndocrinE-Immunology Therapy of Cancer, Autoimmunity, Geriatric Disorders, Covid-19, and Hypertension

Despite the great number of experimental investigations in the area of psycho-neuro-endocrine-immunology showing that endocrine, nervous, and immune systems cannot be in vivo physiologically separated, the diagnosis and therapies of the pathologies of these three functional biological systems continue to be separately performed from a clinical practice point of view. The separation between experimental and clinical medicine became dramatic after the discovery of more than 10 human molecules provided by anti-inflammatory and antitumor activity, completely devoid of any toxicity, which may be subdivided into three fundamental classes, consisting of the pineal indole, beta-carboline, and methoxy-kynuramine hormones. Moreover, human systemic diseases, including cancer, autoimmunity, and cardiovascular pathologies, despite their different pathogenesis and symptomatology, are commonly characterized by a progressive decline in the endogenous production of pineal hormones, endocannabinoids, and Ang 1-7, with a consequent inflammatory status and diminished natural resistance against cancer. Then the evaluation of the functional status of the pineal gland, the endocannabinoid system, and ACE2-Ang 1-7 axis should have to be included within the laboratory analyses for the systemic diseases. Finally, the correction of cancer- and autoimmunity-related neuroimmune and neuroendocrine alterations could influence the clinical course of systemic diseases. In fact, preliminary clinical results would demonstrate that the neuroimmune regimen with pineal hormones, cannabinoids, and Ang 1-7 may allow clinical benefits also in patients affected by systemic pathologies, including cancer, autoimmunity, and cardiovascular diseases, who did not respond to the standard therapies.

Histone-acetyl epigenome regulates TGF-β pathway-associated chemoresistance in colorectal cancer

TGF-β signaling pathway has been demonstrated to be closely related to chemoresistance, which is the major cause of recurrence and poor outcome in colorectal cancer (CRC), however, the comprehensive epigenetic landscape that functionally implicates in the regulation of TGF-β pathway-associated chemoresistance has not yet well established in CRC. In our study, chromatin immunoprecipitation sequencing (ChIP-seq) and Western blot were employed to investigate epigenetic modifications for histones in response to TGF-β1 intervene. We found that the activation of the TGF-β pathway was characterized by genome-wide high levels of H3K9ac and H3K18ac. Mechanistically, the activation of the TGF-β signaling pathway leads to the downregulation of the deacetylase HDAC4, resulting in the upregulation of H3K9ac and H3K18ac. Consequently, this cascade induces oxaliplatin chemoresistance in CRC by triggering the anti-apoptotic PI3K/AKT signaling pathway. Our in vivo experiment results confirmed that overexpression of HDAC4 significantly enhances the sensitivity of CRC to oxaliplatin chemotherapy. Moreover, the expression level of HDAC4 was positively correlated with patients' prognosis in CRC. Our data suggest that histone-acetyl modification demonstrates a crucial role in modulating TGF-β pathway-associated chemoresistance in CRC, and HDAC4 would be a biomarker for prognostic prediction and potential therapeutic target for treatment in CRC.

Harnessing Deep Learning Methods for Voltage-Gated Ion Channel Drug Discovery

Voltage-gated ion channels (VGICs) are pivotal in regulating electrical activity in excitable cells and are critical pharmaceutical targets for treating many diseases including cardiac arrhythmia and neuropathic pain. Despite their significance, challenges such as achieving target selectivity persist in VGIC drug development. Recent progress in deep learning, particularly diffusion models, has enabled the computational design of protein binders for any clinically relevant protein based solely on its structure. These developments coincide with a surge in experimental structural data for VGICs, providing a rich foundation for computational design efforts. This review explores the recent advancements in computational protein design using deep learning and diffusion methods, focusing on their application in designing protein binders to modulate VGIC activity. We discuss the potential use of these methods to computationally design protein binders targeting different regions of VGICs, including the pore domain, voltage-sensing domains, and interface with auxiliary subunits. We provide a comprehensive overview of the different design scenarios, discuss key structural considerations, and address the practical challenges in developing VGIC-targeting protein binders. By exploring these innovative computational methods, we aim to provide a framework for developing novel strategies that could significantly advance VGIC pharmacology and lead to the discovery of effective and safe therapeutics.

Perfluorodecanoic acid induces the increase of innate cells in zebrafish embryos by upregulating oxidative stress levels

Several studies reported that the widespread use of perfluoroalkyl and polyfluoroalkyl substances (PFASs) causes increased environmental pollution, subsequently impacting aquatic organisms. Perfluoroalkyl substances such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) reportedly cause cardiotoxicity, neurotoxicity, and developmental toxicity in different organisms. However, whether perfluorodecanoic acid (PFDA), a widely used perfluoroalkyl substance, induces animal embryos developmental toxicity remain unknown. Here, we explored the immunotoxicity and associated mechanisms of PFDA in zebrafish embryos via RNA sequencing, morphological assessment and behavioral alteration detection following exposure to 0.5, 1 and 2 mg/L of PFDA. Interestingly, We found that with the increase of PFDA to drug concentration, including neutrophils and macrophages, significantly increased the number of inherent cells, immune related genes expression. Furthermore, oxidative stress increased in the PFDA-treated embryos in a dose-dependent manner and inhibition of oxidative stress levels effectively rescued the number of neutrophils. Changes in embryonic behavior were observed after exposure to PFDA. Overall, our results suggest that PFDA may induce innate immune response by accumulation of oxidative stress in zebrafish at early developmental stages, and concern is needed about its environmental exposure risks for animals embryos development. ENVIRONMENTAL IMPLICATION: Perfluorinated and polyfluorinated alkyl substances (PFASs) are a class of synthetic organic compounds containing fluorine widely used as lubricants, surfactants, insecticides, etc. The PFDA, a typical perfluorinated compound, is often used as a wetting agent and flame retardant in industries. Several studies showed that PFASs can cause serious environmental pollution, leading to developmental toxicity to various animals, including reproductive toxicity, liver toxicity, heart toxicity, neurotoxicity, and immunotoxicity. However, there are still limited studies on the effects and mechanisms of PFDA on aquatic organisms. Therefore, there is a need to evaluate the ecological risks of PFDA in animals.

Bidirectional interaction between IL and 17A/IL-17RA pathway dysregulation and α-synuclein in the pathogenesis of Parkinson's disease

Parkinson's disease (PD) pathogenesis is characterized by α-synuclein (α-syn) pathology, which is influenced by various factors such as neuroinflammation and senescence. Increasing evidence has suggested a pivotal role for Interleukin-17A(IL-17A) and Interleukin-17 Receptor A (IL-17RA) in PD, yet the trigger and impact of IL-17A/IL-17RA activation in PD remains elusive. This study observed an age-related increase in IL-17A and IL-17RA in the human central nervous system, accompanied by increased α-syn and senescence biomarkers. Interestingly, both levels of IL-17A and IL-17RA in PD patients were significantly elevated compared to age-matched controls, wherein the IL-17A was mainly present in neurons. This abnormal neuronal IL-17A activation in the PD brain was recapitulated in α-syn mouse models. Correspondingly, administration of recombinant IL-17A exacerbated pathological α-syn in both neuron and mouse models. Furthermore, IL-17A/IL-17RA pathway interventions via blocking antibody or shRNA-mediated knockdown can mitigate the effects of pathological α-syn. This study reveals an interplay between dysregulation of the IL-17A/IL-17RA pathway and α-syn, suggesting that regulating the IL-17A/IL-17RA pathway could modify PD progression by disrupting the detrimental cycle.

Immune-epithelial cell interactions in lung development, homeostasis and disease

The importance of the crosstalk between lung epithelial and immune cells, which emerges from early development and lasts throughout life, is corroborated by a growing body of scientific evidence. This communication not only has a role in driving lung morphogenesis during development, but it is also required in adulthood for the maintenance of homeostasis and repair following infection or injury. Disruption of the intricate immune-epithelial crosstalk can lead to diseases such as COPD and IPF. In this review we summarise the current knowledge regarding the communication between various immune and epithelial cells in development, homeostasis, regeneration and disease, while identifying the current gaps in our knowledge required to facilitate the development of more effective therapies.

Novel design of potent anti-tumour activity of IL-2 prodrug by FAPα-mediated activation

Interleukin-2 (IL-2) is a T cell growth factor that is essential for the proliferation of T cells and the generation of effector and memory cells. The antitumor activity of high-dose IL-2 therapy requires maintaining the affinity between IL-2 and IL2-Rα, which can also bring serious toxic side effects. To address this issue, we designed ZGP-Cysteamine-IL-2-K64C and (ZGP-Cysteamine)2-IL-2-(K43C, K64C) based on the strategy of FAPα enzyme-activated prodrugs, and investigated their anti-tumour activity and side effects. In vitro FAPα enzyme cleavage results indicated that the side-chain modified ZGP-Cysteamine moiety could be precisely recognized and cleaved by FAPα, thereby restoring the activity of native IL-2 capable of binding to IL-2Rα in the tumour microenvironment, where it promotes the expansion of CD8+ T cells. Meanwhile, surface plasmon resonance analysis revealed that, compared to wt-IL-2, both ZGP-Cysteamine-IL-2-K64C and (ZGP-Cysteamine)2-IL-2-(K43C, K64C) exhibited significantly reduced affinity for IL-2Rα, while their affinity for IL-2Rβγ remained unchanged. Remarkably, ZGP-Cysteamine-IL-2-K64C and (ZGP-Cysteamine)2-IL-2-(K43C, K64C) almost completely eliminated the pulmonary edema and vascular permeability. Furthermore, the combination of ZGP-Cysteamine-IL-2-K64C and PD-1 blockade showed robust anti-tumour activity in mice tumour models. Our study provides new insights into the structural design of IL-2 prodrug with low side effect and robust anti-tumour efficacy.

Expression of two CD83 homologs in macrophage subpopulations isolated from the brain and kidney of ginbuna crucian carp

There are numerous fish diseases that affect the central nervous system. However, few studies have investigated the immune cells and immunological responses of fish brains. Meanwhile, microglial cells, as the brain's first line of defense, play a vital role in neuroimmunology. Furthermore, CD83 is a co-stimulatory protein that regulates immunological responses and the activation of dendritic cells and macrophages. Although CD83 expression has been linked to the initial activation of microglia in various disease scenarios in mammals, its role in teleost microglial biology remains unclear. In a recent investigation, we discovered that Ginbuna crucian carp (Gb) contains two CD83 homologs (GbCD83 and GbCD83-L). In this study, we used modified procedures of mouse-based macrophage culture from the brain and kidney to identify that GbCD83-L is highly expressed by the brain microglia-like cells and kidney-resident macrophages (KRMs) at both the protein and gene levels. Interestingly, GbCD83-L was considerably elevated in the microglia-like cells and KRMs after 24 h of lipopolysaccharide stimulation. These findings provide the first evidence of CD83 as a potential marker for active microglia and KRMs in teleosts, thus making it a crucial regulator in fish neuroimmunology and a candidate for future immunomodulatory applications in aquaculture.

Lympho-myeloid aggregate-infiltrating CD20+ B cells display a double-negative phenotype and correlate with poor prognosis in esophageal squamous cell carcinoma

According to morphological features, tumor-infiltrating B cells (TIL-Bs) can be classified as lympho-myeloid aggregates (LMAs) and tertiary lymphoid structures (TLSs). As a disease with high incidence and mortality, research on esophageal squamous cell carcinoma (ESCC) TIL-Bs is still unclear. Thus, we aimed to investigate the prognostic value and functional involvement of TIL-Bs in ESCC. Based on CD20 immunohistochemical staining of 147 ESCC samples, the TIL-Bs at different anatomic subregions (intra-tumor (T), invasive margin (IM) and peri-tumor (P)) were quantified and correlated with survival by Kaplan-Meier analyses. We found that LMAs were widely distributed throughout the whole section and were associated with poor prognosis, especially those located in the T subregion, which was contrary to the positive clinical significance of TLSs. Based on the number of LMAs and TLSs, a four-level immune type was constructed as an independent predictor for survival. Using multiplexed immunofluorescence (mIF) staining, we found that the main phenotype of infiltrating B cells in LMAs was CD20+IgD-CD27- double-negative (DN) B cells. DN B cells were abundant in ESCC tumor tissue, and their high expression was related to shortened overall survival time. Subsequently, we demonstrate a close relationship between DN B cells and regulatory T cells (Tregs) using single cell RNA-seq data, bulk RNA-seq data and flow cytometry, and verified the spatial proximity of DN B cells and Tregs by mIF staining. Trajectory analysis and flow cytometry revealed that DN B cells highly expressed genes involved in the antigen processing and presentation pathway, such as HLA-DR. The abundance of DN B cells and LMAs in ESCC provides novel potential targets for optimal immunotherapy against ESCC.

A preliminary investigation on the protective effects of β-glucan and mannan induced trained immunity in pufferfish Takifugu obscurus

Immune stimuli are able to trigger long-term protective effects through mechanisms of trained immunity, which has attracted increasing attention. Although the existence of trained immunity has evidenced in teleost fish, while there were no such reports in pufferfish (Takifugu obscurus) so far. Therefore, the present study aimed to evaluate the induction of β-glucan and mannan on the trained immunity and their protective efficacy against Vibrio harveyi re-stimulation in pufferfish. β-glucan and mannan induction of trained immunity in head-kidney primary leukocytes is accompanied by a strong increase in immediate ROS burst, cumulative NO production and lactate concentrations after V. harveyi re-stimulation. In addition, β-glucan and mannan-treated pufferfish exhibited reduced bacterial loads in multiple tissues, a rapid and long-term elevated inflammatory response in head kidney during secondary V. harveyi infection. Notably, immune receptors dectin-1 and dectin-2, and cytokines tnfsf14 and il-1β exhibited comparatively upregulation to the β-glucan training, while NK-lysin and faslg showed stronger response to the mannan training post V. harveyi stimulation, implying the different signaling pathway activated post β-glucan and mannan training. Subsequent markers for immune training including abundance of genes encoding glycolytic enzymes (hk1, pfkla, and ldha) and transcription factors (mtor and hif-1α), as well as increased acetylation levels were elevated in the β-glucan and mannan trained pufferfish, depicting heightened glycolysis following β-glucan and mannan training. These results collectively demonstrated that β-glucan and mannan both induced protective responses against V. harveyi infection probably through mediating distinct signaling pathway in pufferfish, and studies are underway to harness its potential applicability for prime and boost vaccination strategies.

Identifying RNA Sensors in Antiviral Innate Immunity

The innate immune system plays a pivotal role in pathogen recognition and the initiation of innate immune responses through its Pathogen Recognition Receptors (PRRs), which detect Pathogen-Associated Molecular Patterns (PAMPs). Nucleic acids, including RNA and DNA, are recognized as particularly significant PAMPs, especially in the context of viral pathogens. During RNA virus infections, specific sequences in the viral RNA mark it as non-self, enabling host recognition through interactions with RNA sensors, thereby triggering innate immunity. Given that some of the most lethal viruses are RNA viruses, they pose a severe threat to human and animal health. Therefore, understanding the immunobiology of RNA PRRs is crucial for controlling pathogen infections, particularly RNA virus infections. In this chapter, we will introduce a "pull-down" method for identifying RIG-I-like receptors, related RNA helicases, Toll-like receptors, and other RNA sensors.

Psychoneuroimmunology of Mood Disorders

Recent research has shed light on the intricate relationship between mood disorders, such as major depressive disorder (MDD) and bipolar disorder (BD), and inflammation. This chapter explores the complex interplay involving immune and metabolic dysfunction in the pathophysiology of these disorders, emphasizing their association with autoimmunity/inflammatory conditions, chronic low-grade systemic inflammation, T cell overactivation, and immunosenescence. This perspective underscores the notion that MDD and BD are not solely brain disorders, highlighting their nature as multi-system conditions.

Unveiling the therapeutic potential and mechanisms of stanniocalcin-1 in retinal degeneration

Retinal degeneration (RD) is a group of ocular diseases characterized by progressive photoreceptor apoptosis and visual impairment. Mitochondrial malfunction, excessive oxidative stress, and chronic activation of neuroglia collectively contribute to the development of RD. Currently, there is a lack of efficacious therapeutic interventions for RD. Stanniocalcin-1 (STC-1) is a promising candidate molecule to decelerate photoreceptor cell death. STC-1 is a secreted calcium/phosphorus regulatory protein that exerts diverse protective effects. Accumulating evidence suggests that STC-1 protects retinal cells from ischemic injury, oxidative stress, and excessive apoptosis through enhancing the expression of uncoupling protein-2 (UCP-2). Furthermore, STC-1 exerts its antiinflammatory effects by inhibiting the activation of microglia and macrophages, as well as the synthesis and secretion of proinflammatory cytokines, such as TNF-α, IL-1, and IL-6. By employing these mechanisms, STC-1 effectively shields the retinal photoreceptors and optic nerve, thereby slowing down the progression of RD. We summarize the STC-1-mediated therapeutic effects on the degenerating retina, with a particular focus on its underlying mechanisms. These findings highlight that STC-1 may act as a versatile molecule to treat degenerative retinopathy. Further research on STC-1 is imperative to establish optimal protocols for its clinical use.

Debunking a mythology: Atelectasis is not a cause of postoperative fever

Most physicians appreciate that practicing medicine is a commitment to continuous learning. However, "learning" can be mistakenly understood as simply the acquisition of facts and new knowledge. But learning also necessitates the constant re-examination and challenging of one's existing body of knowledge, as misinformation persists when one's beliefs are not challenged or questioned in the light of new information. One example is the pervasive belief that postoperative atelectasis causes fever despite ample evidence to the contrary. Herein we examine the imaging characteristics of atelectasis, and the means of differentiation of atelectasis from consolidation. We also explore the history of this persistent myth and review the existing literature on the actual causes of postoperative fever.

Choroidal macrophages in homeostasis, aging and age-related macular degeneration

With increasing age, the optimal functioning of the choroid is essential for efficient removal of waste products formed from photoreceptor renewal. A decline in regulatory elements of the immune system, termed immunosenescence, and the failure of para-inflammation to restore tissue homeostasis can result in the progression of healthy aging to sight-threatening inflammation of the choroid. Macrophages are uniquely situated between the innate and adaptive immune systems, with a high capacity for phagocytosis, recognition of complement components, as well as antigen presentation. In this review, we provide an overview of macrophages and their properties in the healthy choroid and cover the impact of aging, immunosenescence and inflammaging on the function of choroidal macrophages. We will discuss the impact of age on macrophage phenotype and behaviour in the pathophysiology of age-related macular degeneration.

Regulation of Bacillus Calmette-Guérin-induced macrophage autophagy and apoptosis by the AMPK-mTOR-ULK1 pathway

Tuberculosis (TB) is a chronic wasting infectious disease caused by Mycobacterium tuberculosis (MTB) or Mycobacterium bovis that can be transmitted among people and domestic animals. During the development of TB, macrophages of the innate immune system can act against MTB via autophagy and apoptosis to prevent the spread of the disease. Among the many autophagy regulatory pathways, the adenosine monophosphate (AMP)-activated protein kinase (AMPK)-mammalian rapamycin target protein (mTOR)-Unc-51-like kinase 1 (ULK1) pathway has received considerable attention. This study investigates the regulatory role of the AMPK-mTOR-ULK1 pathway in attenuating M. bovis Bacillus Calmette-Guérin (BCG)-induced autophagy and apoptosis in murine monocyte macrophages (RAW264.7). Changes in macrophage autophagy and apoptosis were analyzed using the AMPK activator AICAR and inhibitor Compound C to interfere with the AMPK-mTOR-ULK1 pathway and siRNA to silence the pathway. Consequently, BCG stimulation of macrophages significantly activated the AMPK-mTOR-ULK1 pathway while BCG-induced macrophage AMPK activation promoted macrophage autophagy and apoptosis. Activation of the AMPK-mTOR-ULK1 pathway by AICAR significantly improved autophagy occurrence in BCG-induced macrophages and increased apoptosis while Compound C with siRNA produced opposing effects by attenuating autophagy and apoptosis in BCG-induced macrophages. Thus, the AMPK-mTOR-ULK1 pathway has a dual regulatory role in BCG-induced macrophage autophagy and apoptosis and may have synergistic effects. This study analyzes the mechanism of resistance of host cells to MTB and provides a theoretical basis for new therapeutic strategies and related drug development.

The Immune Regulatory Functions in B Cells Are Restored by CpG to Reduce Experimental Food Allergy

Dysfunctional immune regulation contributes to the pathogenesis of food allergy (FA). The mechanism behind regulatory B-cell dysfunction is unclear. CpG has immune regulatory functions. The purpose of this study is to use CpG to recover the immune suppressive functions of B cells in mice with FA. An FA mouse model was created using ovalbumin as the specific antigen. Flow cytometry was used to isolate B cells from the intestinal tissues. The immune regulatory functions of B cells were assessed using immunological approaches. The results showed that the FA response was linked to low IL-10 levels in gut lavage fluids of FA mice. FA mouse intestinal B cells produced lower amounts of IL-10 as compared with B cells isolated from naïve control mice. Impaired immune suppressive functions were observed in B cells isolated from the FA mouse intestine. The inducibility of the Il10 expression in naïve B cells of the intestine of FA mice was defective. The induction of Il10 expression in FA B cells could be restored by CpG through regulating the methylation status of the Cmip promoter. CpG promoted the therapeutic efficacy of allergen specific immunotherapy by restoring the induction of IL-10+ B cells in the intestine. The expression of Il10 in B cells of the FA mouse intestine was impaired. Administration of CpG could restore the expression of Il10 in B cells in the intestine and promote immunotherapy for FA.

Autophagy in cancer development, immune evasion, and drug resistance

Macroautophagy/autophagy is a highly conserved evolutionary mechanism involving lysosomes for the degradation of cytoplasmic components including organelles. The constitutive, basal level of autophagy is fundamental for preserving cellular homeostasis; however, alterations in autophagy can cause disease pathogenesis, including cancer. The role of autophagy in cancer is particularly complicated, since this process acts both as a tumor suppressor in precancerous stages but facilitates tumor progression during carcinogenesis and later stages of cancer progression. This shift between anti-tumor and pro-tumor roles may be influenced by genetic and environmental factors modulating key pathways such as those involving autophagy-related proteins, the PI3K-AKT-MTOR axis, and AMPK, which often show dysregulation in tumors. Autophagy regulates various cellular functions, including metabolism of glucose, glutamine, and lipids, cell proliferation, metastasis, and several types of cell death (apoptosis, ferroptosis, necroptosis and immunogenic cell death). These multifaceted roles demonstrate the potential of autophagy to affect DNA damage repair, cell death pathways, proliferation and survival, which are critical in determining cancer cells' response to chemotherapy. Therefore, targeting autophagy pathways presents a promising strategy to combat chemoresistance, as one of the major reasons for the failure in cancer patient treatment. Furthermore, autophagy modulates immune evasion and the function of immune cells such as T cells and dendritic cells, influencing the tumor microenvironment and cancer's biological behavior. However, the therapeutic targeting of autophagy is complex due to its dual role in promoting survival and inducing cell death in cancer cells, highlighting the need for strategies that consider both the beneficial and detrimental effects of autophagy modulation in cancer therapy. Hence, both inducers and inhibitors of autophagy have been introduced for the treatment of cancer. This review emphasizes the intricate interplay between autophagy, tumor biology, and immune responses, offering insights into potential therapeutic approaches that deploy autophagy in the cancer suppression.

Tumor-Infiltrating Immune Cells in Colorectal Cancer

Colorectal cancer encompasses a heterogeneous group of malignancies that differ in pathophysiological mechanisms, immune response and infiltration, therapeutic response, and clinical prognosis. Numerous studies have highlighted the clinical relevance of tumor-infiltrating immune cells among different types of colorectal tumors yet vary in cell type definitions and cell identification strategies. The distinction of immune signatures is particularly challenging when several immune subtypes are involved but crucial to identify novel intercellular mechanisms within the tumor microenvironment. In this review, we compile human and non-human studies on tumor-infiltrating immune cells and provide an overview of immune subtypes, their pathophysiological functions, and their prognostic role in colorectal cancer. We discuss how differentiating immune signatures can guide the development of immunotherapeutic targets and personalized treatment regimens. We analyzed comprehensive human protein biomarker profiles across the entire immune spectrum to improve interpretability and application of tumor studies and to ultimately enhance immunotherapy and advance precision medicine for colorectal cancer patients.

Race for the surface between THP-1 macrophages and Staphylococcus aureus on various titanium implants with well-defined topography and wettability

Gristina et al. (1987) suggested that the fate of a biomaterial is decided in a "race for the surface" between pathogens and the host. To gain deeper insight into the mechanisms behind this concept, we investigated the "race for the surface" across three co-culture scenarios with THP-1 macrophages and Staphylococcus aureus (1:1 ratio), varying the order of addition: (i) simultaneous, (ii) macrophages first, and (iii) S. aureus first, on six Ti6Al4V-ELI surfaces modified with specific topographies and wettability. The outcome of the race for the surface was not influenced by these biomaterials but by the chronological introduction of macrophages and S. aureus. When macrophages and S. aureus arrived simultaneously, macrophages won the race, leading to the lowest number of viable S. aureus through rapid phagocytosis and killing. When macrophages arrived and established first, macrophages still prevailed but under greater challenge resulting from the lower bacterial killing efficiency of adherent macrophages and numerous viable intracellular bacteria, supporting the concept of the so-called immunocompromised zone around implants (upregulation of TLR-2 receptor and pro-inflammatory IL-1β). When S. aureus arrived first establishing a biofilm, bacteria won the race, leading to macrophage dysfunction and cell death (upregulation of FcγR and TLR-2 receptors, NF-κB signaling, NOX2 mediated reactive oxygen species), contributing to a persistent biofilm phenotype (upregulation of clfA, icaA, sarA, downregulation of agrA, hld, lukAB) and intracellular survival of S. aureus (lipA upregulation). The clinical implications are bacterial colonization of the implant and persistence of intracellular bacteria in periprosthetic tissues, which can lead to infection chronicity. STATEMENT OF SIGNIFICANCE: Gristina et al. (1987) suggested that the fate of a biomaterial is decided in a "race for the surface" between bacterial pathogens and host cells. There is a lack of in vitro co-culture models and knowledge on macrophage-S. aureus interactions on biomaterial surfaces, and no studies have evaluated the expression of virulence factors in S. aureus biofilms. We have successfully developed co-culture models and molecular panels, and elucidated important cellular and molecular interactions between macrophages and S. aureus on a broad range of titanium biomaterials with well-defined surface topography and wettability. Our findings highlight the critical role of biofilm formation and the chronological order of bacteria or macrophage arrival in determining the fate of the race for the surface.

Genetic Manipulation and Extended Culture of Human Germinal Center B Cells to Model Lymphomagenesis

The germinal center (GC) is the stage of B cell differentiation that gives rise to a majority of B cell lymphomas. Here, we present an experimental coculture system for the ex vivo expansion and genetic manipulation of human GC B cells purified from discarded tonsil tissue. This system can be used to investigate the impact of defined genetic alterations, either individually or in combination, upon the growth and survival of human GC B cells in vitro. We provide examples of genetic combinations that lead to the immortalized growth of GC B cells in vitro, and others that result in malignant transformation in immunodeficient mice, allowing the creation of genetically bespoke, synthetic, human lymphoma models.

Running exercise decreases microglial activation in the medial prefrontal cortex in an animal model of depression

BACKGROUND

Running exercise effectively ameliorates depressive symptoms in humans and depression-like behaviors in animals, but the underlying mechanisms remain unclear. Microglia-mediated neuroinflammation plays a major role in the development of depression. The medial prefrontal cortex (mPFC) is a key brain region involved in depression and is sensitive to physical activity. Whether the antidepressant effect of running exercise involves changes in mPFC microglia is not understood.

METHODS

The animals were subjected to chronic unpredictable stress (CUS) intervention followed by treadmill running. The sucrose preference test and elevated plus maze test or tail suspension test were used for behavioral assessment of the animals. The number of microglia in the mPFC was quantified by immunohistochemistry and stereology. The density and morphology of microglia were analyzed via immunofluorescence staining combined with three-dimensional laser scanning techniques. The mRNA expressions of inflammatory cytokines in the mPFC were examined via quantitative real-time PCR.

RESULTS

Running exercise effectively alleviated depressive-like behaviors in depression model animals. Running exercise reversed the increase in the number of microglia and the density of activated microglia in the mPFC of CUS animals. Running exercise effectively reversed the changes in microglia (reduced cell body area, total branch length and branch complexity) in the mPFC of CUS animals. Furthermore, running exercise regulated the gene expressions of pro-/antiinflammatory cytokines in the mPFC of CUS animals.

CONCLUSIONS

Our results suggested that the antidepressant effects of running exercise may involve decreasing the number of activated microglia, reversing morphological changes in microglia in the mPFC, and reducing inflammatory responses.

Macrophage‑driven pathogenesis in acute lung injury/acute respiratory disease syndrome: Harnessing natural products for therapeutic interventions (Review)

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is a common respiratory disease characterized by hypoxemia and respiratory distress. It is associated with high morbidity and mortality. Due to the complex pathogenesis of ALI, the clinical management of patients with ALI/ARDS is challenging, resulting in numerous post‑treatment sequelae and compromising the quality of life of patients. Macrophages, as a class of innate immune cells, play an important role in ALI/ARDS. In recent years, the functions and phenotypes of macrophages have been better understood due to the development of flow cytometry, immunofluorescence, single‑cell sequencing and spatial genomics. However, no macrophage‑targeted drugs for the treatment of ALI/ARDS currently exist in clinical practice. Natural products are important for drug development, and it has been shown that numerous natural compounds from herbal medicine can alleviate ALI/ARDS caused by various factors by modulating macrophage abnormalities. In the present review, the natural products from herbal medicine that can modulate macrophage abnormalities in ALI/ARDS to treat ALI/ARDS are introduced, and their mechanisms of action, discovered in the previous five years (2019‑2024), are presented. This will provide novel ideas and directions for further research, to develop new drugs for the treatment of ALI/ARDS.

Immunomodulation by galectin-9: Distinct role in T cell populations, current therapeutic avenues and future potential

Galectins, glycan-binding proteins, have been identified as critical regulators of the immune system. Recently, Galectin-9 (Gal-9) has emerged as biomarker that correlates with disease severity in a range of inflammatory conditions. However, Gal-9 has highly different roles in the context of immunoregulation, with the potential to either stimulate or suppress the immune response. Neutralizing antibodies targeting Gal-9 have been developed and are in early test phase investigating their therapeutic potential in cancer. Despite ongoing research, the mechanisms behind Gal-9 action remain not fully understood, and extrapolating the implications of targeting this molecule from previous studies is challenging. Here, we examine the pleiotropic function of Gal-9 focusing on conventional T lymphocytes, providing a current overview of its immunostimulatory and immunosuppressive roles. In particular, we highlight that Gal-9 differentially regulates immune responses depending on the context. Considering this complexity, further investigation of Gal-9's intricate biology is necessary to define therapeutic strategies in immune disorders and cancer treatment aimed at inducing or inhibiting Gal-9 signaling.

Selected Aspects of the Neuroimmunology of Cell Therapies for Neurologic Disease: Perspective

Neurologic disease remains a cause of incalculable suffering, a formidable public health burden, and a wilderness of complex biology and medicine. At the same time, advances in basic science, technology, and the clinical development toolkit bring meaningful benefit for patients along with realistic hope for those whose conditions remain inadequately treated. This perspective focuses on cell-based therapies for neurologic disease, with particular emphasis on neuroimmunologic disorders and on the immunologic considerations of cell therapy for nonimmune conditions. I will consider the use of chimeric antigen receptor (CAR)-T effector cells and regulatory T-cell therapies for autoimmune conditions. I will briefly discuss the immune aspects of pluripotent stem cell (PSC)-derived neuronal therapies. With apologies for the omission, we do not discuss mesenchymal stem cells, glial progenitor cells, or CAR-NK cells, primarily for space limitations.

Natural killer cell-based therapies in neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid tumor of childhood forming around 15 % of all pediatric tumors. Despite advances in the treatment of NB, high-risk patients still face a grave prognosis. Adoptive cell therapies based on NK cells are becoming an assistive treatment for such cases. Moreover, there is also evidence that NKT-based therapies have promising results in the management of NB. Lower complications in comparison with adoptive T cell therapies, various cell sources, and miscellaneous tumor recognition mechanisms are some of the advantages of NK- and NKT-based therapies. This review is dedicated to searching for recent advances in this field.

γδ T cells in hematological malignancies: mechanisms and therapeutic strategies

γδ T cells are a unique subset of lymphocytes with both innate and adaptive features. They recognize and eradicate various hematological malignancies through different mechanisms, employing factors including γδ TCR, NKR, NKG2D, TRAIL, and perforin/granzyme. They also modulate other immune cells to enhance their antitumor activity. Moreover, γδ T cells have potent antiviral functions after hematopoietic stem cell transplantation (HSCT), which may improve the outcome of patients with hematological malignancies. In this review, we summarize the current knowledge on γδ T cell biology and function in hematological malignancies and HSCT complications. We also discuss the challenges and limitations of the clinical application of γδ T cells, such as their low frequency in peripheral blood and heterogeneity among different subsets. We then highlight some promising strategies for γδ T cell-based therapy, such as using agonist antibodies, cell engagers, or genetic modification technology. Furthermore, we review the recent clinical trials evaluating the safety and efficacy of γδ T-cell therapy in different hematological malignancies. In conclusion, γδ T cells represent a promising immunotherapeutic tool for hematological malignancies that deserves further exploration.

XAF1 is secreted from stressed tumor cells to activate T cell-mediated tumor surveillance via Lck-ERK signaling

X-linked inhibitor of apoptosis-associated factor 1 (XAF1) is a stress-inducible tumor suppressor that is commonly inactivated in multiple types of human malignancies. Nevertheless, the molecular basis for the XAF1-mediated tumor suppression remains largely undefined. Here, we report that XAF1 is secreted from cells under various cytotoxic stress conditions and activates T cell-mediated tumor surveillance. In cancer cells exposed to interferon -γ, tumor necrosis factor -α, and etoposide, XAF1 is elevated and actively secreted through the unconventional endo-lysosomal trafficking pathway and the zinc finger 4 domain of XAF1 plays an essential for this secretion. Secreted XAF1 is internalized into nearby T cells through clathrin-mediated endocytosis and stimulates proliferation, migration, and tumor infiltration of T cells. Internalized XAF1 activates RAF-MEK-ERK signaling through the direct interaction with and phosphorylation of lymphocyte-specific protein tyrosine kinase. In response to interferon -γ injection, Xaf1+/+ tumors display significantly higher regression rate and T cell infiltration compared to Xaf1-/- tumors while Xaf1-/- tumors are markedly reduced by injection of recombinant Xaf1. XAF1 expression is associated with overall survival in T cell-enriched cancer patients and also correlates with prognosis in T cell-based immunotherapies. Together, our study identifies XAF1 as a novel secretory immune-modulatory tumor suppressor, illuminating the mechanistic consequence of its inactivation in tumorigenesis.

Gut‑liver axis in liver disease: From basic science to clinical treatment (Review)

Incidence of a number of liver diseases has increased. Gut microbiota serves a role in the pathogenesis of hepatitis, cirrhosis and liver cancer. Gut microbiota is considered 'a new virtual metabolic organ'. The interaction between the gut microbiota and liver is termed the gut‑liver axis. The gut‑liver axis provides a novel research direction for mechanism of liver disease development. The present review discusses the role of the gut‑liver axis and how this can be targeted by novel treatments for common liver diseases.

Butyrolactone-I from marine fungi alleviates intestinal barrier damage caused by DSS through regulating lactobacillus johnsonii and its metabolites in the intestine of mice

Butyrolactone-I (BTL-1), a secondary metabolite from the marine fungus Aspergillus terreus, exhibits numerous biological activities. Previous research has indicated that Butyrolactone-I alleviates intestinal epithelial inflammation via the TLR4/NF-κB and MAPK pathways. However, the mechanisms underlying its protection against intestinal barrier damage remain unclear. This study aims to further elucidate these mechanisms. We observed that BTL-1 administration increased the abundance of Lactobacillus johnsonii (LJ) in both in vivo and in vitro experiments, prompting an investigation into the effects of LJ and its metabolites on DSS-induced inflammatory bowel disease (IBD). The results demonstrated that BTL-1 significantly upregulated tight junction (TJ) and adherens junction (AJ) proteins, maintained intestinal barrier integrity, and alleviated DSS-induced IBD in mice. These effects were associated with the proliferation of LJ and its metabolites, such as butyric and propionic acids, and the inhibition of the MAPK signaling pathway in the colon. Interestingly, administering LJ alone produced a protective effect against DSS-induced IBD similar to that observed with BTL-1. Furthermore, butyric acid, a metabolite of LJ, also upregulated TJ/AJ proteins in intestinal epithelial cells through the MAPK signaling pathway. Our findings suggest that BTL-1 regulates intestinal flora, promotes LJ proliferation, protects intestinal barrier integrity, increases the concentrations of butyric and propionic acids, and ultimately inhibits the activation of the MAPK signaling pathway in mice to alleviate IBD. Therefore, BTL-1 could potentially be used as a natural drug to prevent IBD and maintain intestinal flora balance. We explored how butyrolactone-I exerts a preventive effect on IBD through intestinal bacteria (Lactobacillus johnsonii).

Cathepsin C exacerbates EAE by promoting the expansion of Tfh cells and the formation of TLSs in the CNS

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) mediated by CD4+ T helper (Th) cells, and characterized by immune cell infiltration, demyelination and neurodegeneration, with no definitive cure available. Thus, it is pivotal and imperative to acquire more profound comprehension of the underlying mechanisms implicated in MS. Dysregulated immune responses are widely believed to play a primary role in the pathogenesis of MS. Recently, a plethora of studies have demonstrated the involvement of T follicular helper (Tfh) cells and tertiary lymphoid-like structures (TLSs) in the pathogenesis and progression of MS. Cathepsin C (CatC) is a cysteine exopeptidase which is crucial for the activation of immune-cell-associated serine proteinases in many inflammatory diseases in peripheral system, such as rheumatoid arthritis and septicemia. We have previously demonstrated that CatC is involved in neuroinflammation and exacerbates demyelination in both cuprizone-induced and experimental autoimmune encephalomyelitis (EAE) mouse models. However, the underlying immunopathological mechanism remains elusive. In the present study, we established a recombinant myelin oligodendrocyte glycoprotein 35-55 peptide-induced EAE model using conditional CatC overexpression mice to investigate the effects of CatC on the alteration of CD4+ Th subsets, including Th1, Th2, Th17, Tfh and T regulatory cells. Our findings demonstrated that CatC particularly enhanced the population of Tfh cell in the brain, resulting in the earlier onset and more severe chronic syndrome of EAE. Furthermore, CatC promoted the formation of TLSs in the brain, leading to persistent neuroinflammation and exacerbating the severity of EAE in the chronic phase. Conversely, treatment with AZD7986, a specific inhibitor of CatC, effectively attenuated the syndrome of EAE and its effects caused by CatC both in vivo and in vitro. These findings provide a novel insight into the critical role of CatC in innate and adaptive immunity in EAE, and specific inhibitor of CatC, AZD7986, may contribute to potential therapeutic strategies for MS.

Innate immune response to bone fracture healing

The field of osteoimmunology has primarily focused on fracture healing in isolated musculoskeletal injuries. The innate immune system is the initial response to fracture, with inflammatory macrophages, cytokines, and neutrophils arriving first at the fracture hematoma, followed by an anti-inflammatory phase to begin the process of new bone formation. This review aims to first discuss the current literature and knowledge gaps on the immune responses governing single fracture healing by encompassing the individual role of macrophages, neutrophils, cytokines, mesenchymal stem cells, bone cells, and other immune cells. This paper discusses the interactive effects of these cellular responses underscoring the field of osteoimmunology. The critical role of the metabolic environment in guiding the immune system properties will be highlighted along with some effective therapeutics for fracture healing in the context of osteoimmunology. However, compared to isolated fractures, which frequently heal well, long bone fractures in over 30 % of polytrauma patients exhibit impaired healing. Clinical evidence suggests there may be distinct physiologic and inflammatory pathways altered in polytrauma resulting in nonunion. Nonunion is associated with worse patient outcomes and increased societal healthcare costs. The dysregulated immunomodulatory/inflammatory response seen in polytrauma may lead to this increased nonunion rate. This paper will investigate the differences in immune response between isolated and polytrauma fractures. Finally, future directions for fracture studies are explored with consideration of the emerging roles of newly discovered immune cell functions in fracture healing, the existing challenges and conflicting results in the field, the translational potential of these studies in clinic, and the more complex nature of polytrauma fractures that can alter cell functions in different tissues.

Analysis of Calcium-Sensing Receptor Signaling Using Dual Luciferase Assays

Luciferases catalyze a reaction that involves the emission of light, a phenomenon referred to as "bioluminescence". The calcium-sensing receptor (CaSR), a G protein-coupled receptor (GPCR), induces characteristic signaling pathways that stimulate extracellular signal-regulated kinase 1/2 (ERK1/2) and Ca2+ mobilization from the endoplasmic reticulum. ERK1/2 causes an activation of the serum response element (SRE), whereas Ca2+ causes an activation of the nuclear factor of activated T-cells response element (NFAT-RE). Transfection of cells with a vector containing a firefly luciferase reporter gene under the control of the SRE or NFAT-RE allows the monitoring of ERK1/2 activation and Ca2+ mobilization, respectively, by measuring luminescence. In a dual luciferase assay, firefly luminescence is normalized by co-transfecting an internal control vector, which contains a constitutively active promoter driving the expression of a second luciferase, namely, Renilla luciferase, whose activity can be quantified within the same sample. Here, a protocol for the analysis of CaSR signaling using dual luciferase assays in HEK293 cells is provided. The assays can, for example, be used to investigate functional consequences of mutations in the CaSR gene.

A Snapshot of Biomarkers in Psoriasis

A persistent long-standing, inflammatory skin condition that is brought on by a variety of factors is psoriasis. It is distinguished by itchy, scaly, reddish plaques, particularly on areas of the body that are frequently chafed, including the extensor sites of the limbs. Recent developments in molecular-targeted therapy that use biologics or small-molecule inhibitors can effectively cure even the worst psoriatic indications. The outstanding clinical outcomes of treatment help to clarify the disease's detrimental consequences on quality of life. Biomarkers that identify deep remission are essential for developing uniform treatment plans. Blood protein markers such as AMPs that are consistently quantifiable can be very helpful in routine clinical practice. The metabolic pathways involve biomarkers that can not only help diagnose psoriasis in a clinical setting but also indicate its severity based on the levels present in the body. Machine learning and AI have made a diagnosis of the expression of genes as biomarkers more accessible. In this article, biomarkers, as well as their key role in psoriasis, are discussed.

Interleukin-2 receptor α (IL-2Rα/CD25) shedding is differentially regulated by N- and O-glycosylation

The cytokine interleukin-2 (IL-2) is a critical regulator of immune responses, with an especially well-characterized role in regulating T-cell homeostasis. IL-2 signaling involves three distinct receptor subunits: the IL-2Rα (CD25), IL-2Rβ, and IL-2Rγ. The intracellular transduction of IL-2-induced signals is strictly dependent on IL-2Rβ and IL-2Rγ, while the IL-2Rα is not directly involved in signaling. Instead, it has the highest affinity towards IL-2 and is thus responsible for regulating the affinity of a cell for IL-2. In addition to the membrane-bound IL-2Rα, a soluble form of the receptor (sIL-2Rα) has been described, which is present in the blood of healthy individuals, increased under various pathological conditions, and able to bind IL-2 and thus modulate its function. The sIL-2Rα is generated by proteolytic cleavage of the membrane-bound receptor. Here, we analyze whether glycosylation of the IL-2Rα regulates its proteolysis. We find that constitutive IL-2Rα shedding is affected by glycosylation and discover distinct roles for N- and O-glycosylation. Furthermore, we show that induced shedding by the metalloproteases ADAM10 and ADAM17 is also differentially regulated by distinct types of glycans. Finally, we identify a specific role for an N-glycan at an exosite in ADAM17-mediated proteolysis that does not affect ADAM10, indicating distinct substrate recognition mechanisms. These results further the understanding of the mechanisms leading to sIL-2Rα generation, and thus offer the opportunity to specifically modulate the generation of the soluble receptor.

Stereoisomers of cannabidiols and their pharmacological activities - A potentially novel direction for cannabinoids

Cannabidiol (CBD), a bicyclic non-psychoactive cannabinoid biosynthesized by Cannabis spp. of plants, has attracted significant interest in the past decade due to its therapeutic properties. In 2018, the US FDA approved Epidiolex®, a CBD-based drug for the treatment of two rare epileptic seizure disorders. CBD possesses two chiral centers at C3 and C4 on its terpenoid moiety and exhibits cis-trans stereoisomerism along the C3-C4 bond axis. (-)-trans-(3R,4R)-CBD, the natural CBD, is biosynthesized by the cannabis plant, while the unnatural (+)-trans-(3S,4S)-CBD is obtained via chemical synthesis. Both trans isomers exhibit broad in vitro and in vivo biological activities; typically, the unnatural stereoisomer (+)-trans-CBD and its derivatives exhibited more potent activities in comparison to the corresponding (-)-trans isomers. On the other hand, cis-CBD isomers have only been reported recently and can undergo epimerization into trans isomers. There is a significant opportunity to explore unique synthetic methods and biological activities of stereoisomers of CBD that may pave the path for the development of novel therapeutics. Herein, as a novel direction in cannabinoids, we review the chemistry of CBD stereoisomers, their structure-activity relationships, target selectivity and efficacy in animal models.

Immune traits in combination with inflammatory proteins revealing the pathogenesis of autoimmune liver diseases: A Mendelian randomization study

BACKGROUND

Prior observational research has shown relationships between immune cells, inflammatory proteins, and autoimmune liver diseases (AILD), but their causal associations remain controversial. Therefore, we aimed to clarify the causal association between them.

METHODS

We carried out a comprehensive Mendelian randomization (MR) analysis to clarify causal associations between 731 immune traits, 91 circulating inflammatory proteins, and AILD, including primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH). A two-step MR analysis was used to explore the mediating role of circulating inflammatory proteins. Additionally, we performed sensitivity analyses to evaluate the robustness of the results.

RESULTS

CD27 on IgD+CD24+B cell, CD27 on IgD-CD38dimB cell, CD27 on unswitched memory B cell, CD27 on switched memory B cell, and CD27 on CD24+CD27+B cell were risk factors for PBC. However, we detected protective effects of CD25 on IgD-CD27-B cell against PBC and CD28 on resting CD4+Treg cell against PSC. Circulating CD40, Interleukin-33, and Delta and Notch-like epidermal growth factor-related receptor were protective factors for PBC. Furthermore, CD40 mediated the association between immune traits and PBC, with the mediated proportions ranging from 18.3 % to 35.4 %. Tumor necrosis factor superfamily member 12 was identified as a risk factor for PSC, and monocyte chemotactic protein 3 was identified as a protective factor for PSC. Additionally, PBC and PSC had effects on eleven immune traits, which are suggested to be the consequences of them. We found no causal association between immune traits, circulating inflammatory proteins, and AIH. Sensitivity analyses demonstrated our results were robust.

CONCLUSIONS

Our results demonstrate the causal roles of immune traits and inflammatory proteins in PBC and PSC, which reveals their pathogenesis. It is necessary to investigate the specific mechanism by which immune cells and inflammatory proteins affecting the occurrence of AILD.

Extremely low-frequency electromagnetic fields targeting spleen modifies the populations of immunocytes in the spleen

Our study focused on investigating the bioeffects of extremely low-frequency electromagnetic fields (ELF-EMFs) on the immune function of the spleen. We designed an electromagnetic instrument that can locally target on spleen, the spleens of mice were locally exposed to the ELF-EMF (50 Hz, 30 mT) for 14 days (4 h/day). Parallelly, the isolated splenic T cells were exposed to ELF-EMF (50 Hz, 15 mT) for 2 h. After the exposure, the splenocyte showed a reduced apoptosis rate. Among the splenocytes, the CD4+ T cells and natural killer cells accumulated, the percentage of B cells decreased. In vitro study demonstrated that ELF-EMF induced the alteration of T cell subsets, showing an increased percentage of CD4+ T cells and a decreased percentage of CD8+ T cells. Within CD4+ T cells, the population of T helper (Th) 17 cells increased, and the population of regulatory T cells (Treg) cells decreased. The enrichment of the nuclear factor (NF)-κB pathway in the splenic T cells was found to be reduced after exposure to ELF-EMF. Our findings suggest that ELF-EMF regulated the immune function of the spleen by changing the proportion of immune cells in the spleen. Specifically, the differentiation of spleen T cells was induced by ELF-EMF toward Th17 cells and inhibited by ELF-EMF into Treg cells. The NF-κB signaling pathway probably accounts for the effects of ELF-EMF on the spleen T cells.

Harnessing cellular therapeutics for type 1 diabetes mellitus: progress, challenges, and the road ahead

Type 1 diabetes mellitus (T1DM) is a growing global health concern that affects approximately 8.5 million individuals worldwide. T1DM is characterized by an autoimmune destruction of pancreatic β cells, leading to a disruption in glucose homeostasis. Therapeutic intervention for T1DM requires a complex regimen of glycaemic monitoring and the administration of exogenous insulin to regulate blood glucose levels. Advances in continuous glucose monitoring and algorithm-driven insulin delivery devices have improved the quality of life of patients. Despite this, mimicking islet function and complex physiological feedback remains challenging. Pancreatic islet transplantation represents a potential functional cure for T1DM but is hindered by donor scarcity, variability in harvested cells, aggressive immunosuppressive regimens and suboptimal clinical outcomes. Current research is directed towards generating alternative cell sources, improving transplantation methods, and enhancing cell survival without chronic immunosuppression. This Review maps the progress in cell replacement therapies for T1DM and outlines the remaining challenges and future directions. We explore the state-of-the-art strategies for generating replenishable β cells, cell delivery technologies and local targeted immune modulation. Finally, we highlight relevant animal models and the regulatory aspects for advancing these technologies towards clinical deployment.

Adjuvant alum regulates the eIF2a-GATA3 axis in CD4+ T cells to influence allergen immunotherapy

Allergen-specific immunotherapy (AIT) is an aetiology-targeting therapy for allergic diseases. The therapeutic mechanism of AIT is not fully understood yet. Endoplasmic reticulum stress is associated with the pathogenesis of allergic disorders. This study aims to elucidate the effects of AIT on suppressing allergic response through regulating endoplasmic reticulum stress. In this study, patients with perennial allergic rhinitis were recruited. AIT was conducted for the patients. An allergic rhinitis (AR) mouse model was established with mite extracts as allergens. We found that AIT modulated the endoplasmic reticulum stress status in peripheral CD4+ T cells in patients with allergic rhinitis. The intensity of endoplasmic reticulum stress associated the PERK (protein kinase RNA-like endoplasmic reticulum kinase)-eIF2a (eukaryotic translation initiation factor 2a) axis in CD4+ T cells was upregulated by AIT, which was closely associated with the improvement in allergic rhinitis response after AIT. eIF2a interacted with GATA3 to downregulate the IL4 gene transcription in CD4+ T cells. High doses of aluminium hydroxide (alum) in AIT vaccines enhanced the activity of XBP1 to suppress eIF2a in CD4+ T cells. AIT containing a low dose of alum effectively mitigated the experimental allergic rhinitis, while the AIT without alum or a high dose of alum exacerbated the experimental allergic rhinitis. In conclusion, the alum adjuvant in allergen vaccines can regulate the activity of eIF2a to regulate the expression of Th2 cytokines in CD4+ T cells. Manipulating the alum dose in AIT vaccines has the potential to enhance the therapeutic effects of AIT.

Effects of chemokine-binding protein in visceral ovine aphthae on immune regulation response

ORFV of the family poxvirus，which produces a pustular dermatitis both in humans and animals.,Previous studies have found an fatal case caused by the infection of ORFV in the viscera. However, the mechanisms of ORFV how to infect the viscera remain unknown. Our sequencing results revealed that the CBP of the visceral infection strain lacked a 24-base pair segment at position 217 comparison to the oral infection strain. Subsequently, we successfully packaged the recombinant adenoviruses pAd-CBP-K and pAd-CBP-N in HEK-293A cells and carried it to infect lymphocytes. RT-PCR analysis showed that the CBP protein was expressed in lymphocytes, and pAd-CBP-N group exhibited a significantly higher CBP expression level compared to the pAd-CBP-K group. At 4, 8, and 12 hours post-infection, both pAd-CBP-K and pAd-CBP-N were found to downregulate the expression of MIP-1 and CCL-5 in the supernatant of lymphocytes. However, the expression of IL-2, IL-6, IL-8, IL-12, INF-γ, and TNF-α showed a significant up-regulation. Furthermore, the inflammatory factors relative expression levels of IL-2, IL-6, IL-8, IL-8, IL-12, IFN-γ and TNF-α were significantly up-regulated in the both group. Interestingly, a significant increase in the expression of IL-6, IL-8 and TNF-α were detected in the pAd-CBP-N group at both 8 and 12 hours compared to pAd-CBP-N. Taken together, these findings showed that CBP can regulate the expression of free chemokines and activate the expression of inflammatory factors, and provide a basis for follow-up research.

Mitochondrial mechanisms in Treg cell regulation: Implications for immunotherapy and disease treatment

Regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis and preventing autoimmune diseases. Recent advances in immunometabolism have revealed the pivotal role of mitochondrial dynamics and metabolism in shaping Treg functionality. Tregs depend on oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) to support their suppressive functions and long-term survival. Mitochondrial processes such as fusion and fission significantly influence Treg activity, with mitochondrial fusion enhancing bioenergetic efficiency and reducing reactive oxygen species (ROS) production, thereby promoting Treg stability. In contrast, excessive mitochondrial fission disrupts ATP synthesis and elevates ROS levels, impairing Treg suppressive capacity. Furthermore, mitochondrial ROS act as critical signaling molecules in Treg regulation, where controlled levels stabilize FoxP3 expression, but excessive ROS leads to mitochondrial dysfunction and immune dysregulation. Mitophagy, as part of mitochondrial quality control, also plays an essential role in preserving Treg function. Understanding the intricate interplay between mitochondrial dynamics and Treg metabolism provides valuable insights for developing novel therapeutic strategies to treat autoimmune disorders and enhance immunotherapy in cancer.

Targeting tumor-associated macrophages: Novel insights into immunotherapy of skin cancer

BACKGROUND

The incidence of skin cancer is currently increasing, and conventional treatment options inadequately address the demands of disease management. Fortunately, the recent rapid advancement of immunotherapy, particularly immune checkpoint inhibitors (ICIs), has ushered in a new era for numerous cancer patients. However, the efficacy of immunotherapy remains suboptimal due to the impact of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs), a major component of the TME, play crucial roles in tumor invasion, metastasis, angiogenesis, and immune evasion, significantly impacting tumor development. Consequently, TAMs have gained considerable attention in recent years, and their roles have been extensively studied in various tumors. However, the specific roles of TAMs and their regulatory mechanisms in skin cancer remain unclear.

AIM OF REVIEW

This paper aims to elucidate the origin and classification of TAMs, investigate the interactions between TAMs and various immune cells, comprehensively understand the precise mechanisms by which TAMs contribute to the pathogenesis of different types of skin cancer, and finally discuss current strategies for targeting TAMs in the treatment of skin cancer.

KEY SCIENTIFIC CONCEPTS OF OVERVIEW

With a specific emphasis on the interrelationship between TAMs and skin cancer, this paper posits that therapeutic modalities centered on TAMs hold promise in augmenting and harmonizing with prevailing clinical interventions for skin cancer, thereby charting a novel trajectory for advancing the landscape of immunotherapeutic approaches for skin cancer.

Ig or Not Ig? That Is the Question: The Nucleating Supersecondary Structure of the Ig-Fold and the Extended Ig Universe

Observing the omnipresence of the Ig-fold in all domains of life, one may wonder why this fold among all is such a wunderkind of evolution. Culminating in vertebrates, it enables a myriad of functions at the heart of the immune, nervous, vascular, and muscular systems. We suggest the Ig-fold resilience lies in the robust folding of a core supersecondary structure (SSS) that can accommodate a myriad of topological variations. In this chapter, we focus on the core supersecondary structure common to all topostructural variants of the Ig-fold and will see that this pattern can also be found in other β-sandwich folds. It represents a highly resilient central SSS that accommodates a very high plasticity observed among β-sandwiches. We have recently developed a universal numbering system to identify and annotate Ig-domains, Ig-like domains, and what we now call Ig-extended domains, i.e., β-sandwiches that contain and extend the Ig-fold topology (to be published). A universal numbering scheme, common to all topological and structural variants of any domain sharing the Ig-fold, allows a direct comparison of any Ig, Ig-like, and Ig-extended domain in sequence, topology, and structure. This can therefore help understand the robust patterns in Ig-folding and interactions with other Ig or non-Ig proteins, as well as help trace evolutionary patterns of immunoglobulin domains. The universal numbering scheme, called IgStrand, is now at the heart of an algorithm that can label secondary structure elements of the Ig-fold for any topological variant. It is implemented in the open-source web-based iCn3D program from NCBI (Wang, Youkharibache, Zhang, Lanczycki, Geer, Madej, Phan, Ward, Lu, Marchler, Bioinformatics 36:131-135, 2020). Interestingly, that algorithm captures SSS homologies across a very large spectrum of β-sandwiches, and one can envision classifying numerous such sandwiches as "Ig-extended" domains and their variable topological arrangements. In this chapter, we go through examples of Ig, Ig-like, and Ig-extended domains as in a journey through cells: in the cell nucleus, in the cytoplasm, or on extracellular regions of cell surface receptors, and in viruses.