Age-Related Dopaminergic Innervation Augments T Helper 2-Type Allergic Inflammation in the Postnatal Lung

Associations between agricultural use of pyrethroid insecticides and asthma: AGRICAN cohort results

RATIONALE

Following the withdrawal of organochlorines and organophosphates, pyrethroids have become the most used insecticides in both agricultural and domestic settings.

OBJECTIVES

We analyzed data from the French AGRICAN agricultural cohort to assess associations of occupational pyrethroid exposures and allergic/non-allergic asthma.

METHODS

At enrollment, asthma diagnosed by a doctor was reported by 11 815 participants (7028 classified as non-allergic and 4458 as allergic based on the presence of eczema and/or hay fever). Individual exposures to 17 pyrethroids were defined in 124 992 participants, based on a combination of the history of pesticide treatment of 11 crops (grassland, vineyard, wheat/barley, corn, field peas, potatoes, tobacco, beets, sunflower, rape, fruits) and a crop-exposure matrix.

MEASUREMENTS AND MAIN RESULTS

In men, no association was observed for any of the pyrethroids regardless of asthma phenotype. In contrast, in ever-exposed women, asthma risk was increased with use of any pyrethroid, both for allergic (+80 %) and non-allergic asthma (+40 %). Highest increases were observed for allergic asthma with fenpropathrin (OR = 2.00; 95 %CI:1.38-2.90), tralomethrin (OR = 1.81; 95 %CI:1.28-2.56), fenvalerate (OR = 1.81; 95 %CI:1.38-2.38), permethrin (OR = 1.78; 95 %CI:1.26-2.50) and deltamethrin (OR = 1.76; 95 %CI:1.35-2.29). Stratified analyses on women who reported living on a farm in early life showed stronger associations for non-allergic asthma. For women who reported early life living on vineyards associations with pyrethroids were stronger for both allergic and non-allergic asthma. Associations for women who lived on cattle farms were reduced for some pyrethroids.

CONCLUSION

Occupational pyrethroid exposure was positively associated with both allergic and non-allergic asthma in women but not in men.

Single-cell RNA sequencing of bone marrow reveals the immune response mechanisms of lymphocytes under avian leukosis virus subgroup J infection

Avian Leukosis Virus (ALV) can induce tumorigenesis and immune suppression by acting on lymphocytes in the bone marrow. In this study, single-cell RNA sequencing (scRNA-seq) was used to analyze chicken bone marrow lymphocytes under Avian Leukosis Virus subtype J (ALV-J) infection. Using subgroup-specific marker genes and cell state analysis, we identified 18 distinct cell clusters, including 8 T cell clusters, 2 B cell clusters, 5 tumor-like cell clusters, and 3 unidentified clusters. Gene expression analysis revealed that in the 10 T/B lymphocyte clusters, the differentially expressed genes in double-positive T cells, B1-like B cells, and cytotoxic T cells were highly enriched in pathways related to viral infection and immune response. These three cell populations exhibited high proportions and significant changes after infection, suggesting a strong immune response to ALV-J infection. Additionally, during ALV-J infection, the proportion of regulatory T cells and CTLA4 T cells increased, while immune suppressive factors TGFB1 and IL16 were highly expressed across the cell populations, indicating an immune-suppressive state in bone marrow lymphocytes. Moreover, ALV-J infected all cell populations; however, within the same cluster, only a fraction of the cells expressed ALV-J viral genes. Notably, in all cells expressing ALV-J viral genes, the "Rho family GTPase signaling pathway" associated with antiviral responses was activated. The Rho family, which is a key regulator of cytoskeletal reorganization and cell polarity, also plays a critical role in tumor cell proliferation and metastasis. Further analysis using Ingenuity Pathway Analysis (IPA) software predicted key upstream regulators of immune response, such as MYC and MCYN. In conclusion, this study identifies key genes and signaling pathways involved in immune responses of different lymphocyte subpopulations triggered by ALV-J infection in bone marrow. These findings contribute to a better understanding of the immune mechanisms in ALV-J-infected bone marrow lymphocytes and provide insights for discovering breeding loci for ALV-J resistance.

Neuroimmune Circuits in Allergic Diseases

Communication between the nervous and immune systems is evolutionarily conserved. From primitive eukaryotes to higher mammals, neuroimmune communication utilizes multiple complex and complementary mechanisms to trigger effective but balanced responses to environmental dangers such as allergens and tissue damage. These responses result from a tight integration of the nervous and immune systems, and accumulating evidence suggests that this bidirectional communication is crucial in modulating the initiation and development of allergic inflammation. In this review, we discuss the basic mechanisms of neuroimmune communication, with a focus on the recent advances underlying the importance of such communication in the allergic immune response. We examine neuronal sensing of allergens, how neuropeptides and neurotransmitters regulate allergic immune cell functions, and how inflammatory factors derived from immune cells coordinate complex peripheral and central nervous system responses. Furthermore, we highlight how fundamental aspects of host biology, from aging to circadian rhythm, might affect these pathways. Appreciating neuroimmune communications as an evolutionarily conserved and functionally integrated system that is fundamentally involved in type 2 immunity will provide new insights into allergic inflammation and reveal exciting opportunities for the management of acute and chronic allergic diseases.

Tissue-Resident Th2 Cells in Type 2 Immunity and Allergic Diseases

Type 2 immunity represents a unique immune module that provides host protection against macro-parasites and noxious agents such as venoms and toxins. In contrast, maladaptive type 2 immune responses cause allergic diseases. While multiple cell types play important roles in type 2 immunity, recent studies in humans and murine models of chronic allergic diseases have shown that a distinct population of tissue-resident, CD4+ T helper type 2 (Th2) cells play a critical role in chronic allergic inflammation. The rules regulating Th2 cell differentiation have remained less well defined than other T cell subsets, but recent studies have shed new light into the specific mechanisms controlling Th2 cell biology in vivo. Here, we review our current understanding of the checkpoints regulating the development and function of tissue-resident Th2 cells with a focus on chronic allergic diseases. We discuss evidence for a barrier tissue checkpoint in initial Th2 cell priming, including the role of neuropeptides, damage-associated molecular patterns, and dendritic cell macro-clusters. Furthermore, we review the evidence for a second barrier tissue checkpoint that instructs the development of multi-cytokine producing, tissue-resident Th2 cells that orchestrate allergic inflammation. Lastly, we discuss potential approaches to therapeutically target tissue-resident Th2 cells in chronic allergic diseases.

A novel technique of cryodenervation for murine vagus nerve: implications for acute lung inflammation

BACKGROUND

Neuroimmune interaction is an underestimated mechanism for lung diseases, and cryoablation is a competitive advantageous technique than other non-pharmacologic interventions for peripheral nerve innervating the lung. However, a lack of cryodenervation model in laboratory rodents leads to the obscure mechanisms for techniques used in clinic.

METHOD

Herein, we developed a novel practical method for mouse peripheral nerve cryoablation, named visualized and simple cryodenervation (VSCD). We first estimated the feasibility, safety and effectiveness of the technique via haematoxylin-eosin staining, histochemistry or immunofluorescence staining and immunoblotting assay. We then constructed the acute lung injury (ALI) model triggered by lipopolysaccharide (LPS) to verify the effect of VSCD in the resolution of pulmonary inflammation. Besides, the IL-10 knockout mice were also applied to explain the underlying mechanism of the protective activity of VSCD in ALI mice.

RESULT

We demonstrated that VSCD was able to induce a reliable and stable blockade of innervation, but reversible structural damage of mouse vagus nerve without detectable toxicity to lung tissues. Cholinergic parasympathetic nerve in the mouse lung coming from vagus nerve was activated at the initial stage (1 week) after VSCD, and blocked 3 weeks later. By use of the ALI mouse model, we found that VSCD effectively decreased pulmonary inflammation and tissue damage in the ALI mice. Moreover, the activated cholinergic anti-inflammatory pathway (CAP) and elevated IL-10 expression might explain the protective action of VSCD following LPS challenge.

CONCLUSION

This study fills the gap in the cryoablation for mouse vagus nerve, thereby guiding the application of cryodenervation in clinical management of pulmonary diseases. It also offers evidence of anti-inflammatory potential of VSCD in ALI mouse model and opens therapeutic avenues for the intervention of acute lung inflammation.

Neuroprotective effect of L-DOPA-induced interleukin-13 on striatonigral degeneration in cerebral ischemia

Levodopa (L-DOPA) treatment is a clinically effective strategy for improving motor function in patients with ischemic stroke. However, the mechanisms by which modulating the dopamine system relieves the pathology of the ischemic brain remain unclear. Emerging evidence from an experimental mouse model of ischemic stroke, established by middle cerebral artery occlusion (MCAO), suggested that L-DOPA has the potential to modulate the inflammatory and immune response that occurs during a stroke. Here, we aimed to demonstrate the therapeutic effect of L-DOPA in regulating the systemic immune response and improving functional deficits in mice with ischemia. Transient MCAO led to progressive degeneration of nigrostriatal dopamine neurons and significant rotational behavior in mice. Exogenous L-DOPA treatment attenuated the striatonigral degeneration and reversed motor behavioral impairment. Notably, treatment with L-DOPA significantly increased IL-13 but reduced IFN-γ in infarct lesions. To investigate the role of IL-13 in motor behavior, we stereotaxically injected anti-IL-13 antibodies into the infarct area of the mouse brain one week after MCAO, followed by L-DOPA treatment. The intervention reduced dopamine, IL-13, and IL-10 levels and exacerbated motor function. IL-13 is potentially expressed on CD4 T cells, while IL-10 is mainly expressed on microglia rather than astrocytes. Finally, IL-13 activates the phagocytosis of microglia, which may contribute to neuroprotection by eliminating degenerating neurons. Our study provides evidence that the L-DOPA-activated dopamine system modulates peripheral immune cells, resulting in the expression of anti-inflammatory and neuroprotective cytokines in mice with ischemic stroke.

Potential pharmaceuticals targeting neuroimmune interactions in treating acute lung injury

BACKGROUND AND MAIN BODY

Although interactions between the nervous and immune systems have been recognized decades ago, it has become increasingly appreciated that neuroimmune crosstalk is among the driving factors of multiple pulmonary inflammatory diseases including acute lung injury (ALI). Here, we review the current understanding of nerve innervations towards the lung and summarize how the neural regulation of immunity and inflammation participates in the onset and progression of several lung diseases, especially ALI. We then present advancements in the development of potential drugs for ALI targeting neuroimmune interactions, including cholinergic anti-inflammatory pathway, sympathetic-immune pathway, purinergic signalling, neuropeptides and renin-angiotensin system at different stages from preclinical investigation to clinical trials, including the traditional Chinese medicine.

CONCLUSION

This review highlights the importance of considering the therapeutic strategy of inflammatory diseases within a conceptual framework that integrates classical inflammatory cascade and neuroimmune circuits, so as to deepen the understanding of immune modulation and develop more sophisticated approaches to treat lung diseases represented by ALI.

KEY POINTS

The lungs present abundant nerve innervations. Neuroimmune interactions exert a modulatory effect in the onset and progression of lung inflammatory diseases, especially acute lung injury. The advancements of potential drugs for ALI targeting neuroimmune crosstalk at different stages from preclinical investigation to clinical trials are elaborated. Point out the direction for the development of neuroimmune pharmacology in the future.

A review of common influencing factors and possible mechanisms associated with allergic diseases complicating tic disorders in children

Over the past few decades, the incidence of childhood allergic diseases has increased globally, and their impact on the affected child extends beyond the allergy itself. There is evidence of an association between childhood allergic diseases and the development of neurological disorders. Several studies have shown a correlation between allergic diseases and tic disorders (TD), and allergic diseases may be an important risk factor for TD. Possible factors influencing the development of these disorders include neurotransmitter imbalance, maternal anxiety or depression, gut microbial disorders, sleep disturbances, maternal allergic status, exposure to tobacco, and environmental factors. Moreover, gut microbial disturbances, altered immunological profiles, and DNA methylation in patients with allergic diseases may be potential mechanisms contributing to the development of TD. An in-depth investigation of the relationship between allergic diseases and TD in children will be important for preventing and treating TD.

DRD1 suppresses cell proliferation and reduces EGFR activation and PD-L1 expression in NSCLC

Dopamine (DA) acts in various key neurological and physiological processes as both a neurotransmitter and circulating hormone. Over the past several decades, the DA signaling network has been shown to regulate the progression of several types of solid tumors, and considerable evidence has shown it is a druggable pathway in the cancer cell context. However, the specific activity and effect of these pathway components appears to be tissue-type and cell-context-dependent. In the present study, expression and methylation of dopamine receptor D1 (DRD1) were measured using RNA sequencing (RNAseq) and reverse transcription polymerase chain reaction (RT-PCR) in non-small cell lung cancer (NSCLC) samples, and validated using publicly available datasets, including The Cancer Genome Atlas (TCGA). In vitro and in vivo functional experiments were performed for cell proliferation and tumor growth, respectively. Mechanistic analyses of the transcriptome and kinome in DRD1-modulated cells informed further experiments, which characterized the effects on the epidermal growth factor receptor (EGFR) pathway and programmed cell death 1 ligand 1 (PD-L1) proteins. Through these experiments, we identified the DRD1 gene as a negative regulator of disease progression in NSCLC. We show that DRD1, as well as other DA pathway components, are expressed in normal human lung tissue, and that loss of DRD1 expression through promoter hypermethylation is a common feature in NSCLC patients and is associated with worse survival. At the cellular level, DRD1 affects proliferation by inhibiting the activation of EGFR and mitogen-activated protein kinase 1/2 (ERK1/2). Interestingly, we also found that DRD1 regulates the expression of PD-L1 in lung cancer cells. Taken together, these results suggest that DRD1 methylation may constitute a biomarker of poor prognosis in NSCLC patients while other components of this pathway could be targeted to improve response to EGFR- and PD-L1-targeted therapies.

Update on asthma biology

This is an exciting time to be conducting asthma research. The recent development of targeted asthma biologics has validated the power of basic research to discover new molecules amenable to therapeutic intervention. Advances in high-throughput sequencing are providing a wealth of "omics" data about genetic and epigenetic underpinnings of asthma, as well as about new cellular interacting networks and potential endotypes in asthma. Airway epithelial cells have emerged not only as key sensors of the outside environment but also as central drivers of dysregulated mucosal immune responses in asthma. Emerging data suggest that the airway epithelium in asthma remembers prior encounters with environmental exposures, resulting in potentially long-lasting changes in structure and metabolism that render asthmatic individuals susceptible to subsequent exposures. Here we summarize recent insights into asthma biology, focusing on studies using human cells or tissue that were published in the past 2 years. The studies are organized thematically into 6 content areas to draw connections and spur future research (on genetics and epigenetics, prenatal and early-life origins, microbiome, immune and inflammatory pathways, asthma endotypes and biomarkers, and lung structural alterations). We highlight recent studies of airway epithelial dysfunction and response to viral infections and conclude with a framework for considering how bidirectional interactions between alterations in airway structure and mucosal immunity can lead to sustained lung dysfunction in asthma.

Neuroimmune recognition and regulation in the respiratory system

Neuroimmune recognition and regulation in the respiratory system is a complex and highly coordinated process involving interactions between the nervous and immune systems to detect and respond to pathogens, pollutants and other potential hazards in the respiratory tract. This interaction helps maintain the health and integrity of the respiratory system. Therefore, understanding the complex interactions between the respiratory nervous system and immune system is critical to maintaining lung health and developing treatments for respiratory diseases. In this review, we summarise the projection distribution of different types of neurons (trigeminal nerve, glossopharyngeal nerve, vagus nerve, spinal dorsal root nerve, sympathetic nerve) in the respiratory tract. We also introduce several types of cells in the respiratory epithelium that closely interact with nerves (pulmonary neuroendocrine cells, brush cells, solitary chemosensory cells and tastebuds). These cells are primarily located at key positions in the respiratory tract, where nerves project to them, forming neuroepithelial recognition units, thus enhancing the ability of neural recognition. Furthermore, we summarise the roles played by these different neurons in sensing or responding to specific pathogens (influenza, severe acute respiratory syndrome coronavirus 2, respiratory syncytial virus, human metapneumovirus, herpes viruses, Sendai parainfluenza virus, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus, amoebae), allergens, atmospheric pollutants (smoking, exhaust pollution), and their potential roles in regulating interactions among different pathogens. We also summarise the prospects of bioelectronic medicine as a third therapeutic approach following drugs and surgery, as well as the potential mechanisms of meditation breathing as an adjunct therapy.

The role of hormones in ILC2-driven allergic airway inflammation

Group 2 innate lymphoid cells (ILC2s) are a type of innate immune cells that produce a large amount of IL-5 and IL-13 and two cytokines that are crucial for various processes such as allergic airway inflammation, tissue repair and tissue homeostasis. It is known that damaged epithelial-derived alarmins, such as IL-33, IL-25 and thymic stromal lymphopoietin (TSLP), are the predominant ILC2 activators that mediate the production of type 2 cytokines. In recent years, abundant studies have found that many factors can regulate ILC2 development and function. Hormones synthesized by the body's endocrine glands or cells play an important role in immune response. Notably, ILC2s express hormone receptors and their proliferation and function can be modulated by multiple hormones during allergic airway inflammation. Here, we summarize the effects of multiple hormones on ILC2-driven allergic airway inflammation and discuss the underlying mechanisms and potential therapeutic significance.

Location versus ID: what matters to lung-resident memory T cells?

Tissue-resident memory T cells (TRM cells) are vital for the promotion of barrier immunity. The lung, a tissue constantly exposed to foreign pathogenic or non-pathogenic antigens, is not devoid of these cells. Lung TRM cells have been considered major players in either the protection against respiratory viral infections or the pathogenesis of lung allergies. Establishment of lung TRM cells rely on intrinsic and extrinsic factors. Among the extrinsic regulators of lung TRM cells, the magnitude of the impact of factors such as the route of antigen entry or the antigen natural tropism for the lung is not entirely clear. In this perspective, we provide a summary of the literature covering this subject and present some preliminary results on this potential dichotomy between antigen location versus antigen type. Finally, we propose a hypothesis to synthesize the potential contributions of these two variables for lung TRM cell development.

Extracellular CIRP induces CD4CD8αα intraepithelial lymphocyte cytotoxicity in sepsis

BACKGROUND

In sepsis, intestinal barrier dysfunction is often caused by the uncontrolled death of intestinal epithelial cells (IECs). CD4CD8αα intraepithelial lymphocytes (IELs), a subtype of CD4+ T cells residing within the intestinal epithelium, exert cytotoxicity by producing granzyme B (GrB) and perforin (Prf). Extracellular cold-inducible RNA-binding protein (eCIRP) is a recently identified alarmin which stimulates TLR4 on immune cells to induce proinflammatory responses. Here, we hypothesized that eCIRP enhances CD4CD8αα IEL cytotoxicity and induces IEC death in sepsis.

METHODS

We subjected wild-type (WT) and CIRP-/- mice to sepsis by cecal ligation and puncture (CLP) and collected the small intestines to isolate IELs. The expression of GrB and Prf in CD4CD8αα IELs was assessed by flow cytometry. IELs isolated from WT and TLR4-/- mice were challenged with recombinant mouse CIRP (eCIRP) and assessed the expression of GrB and Prf in CD4CD8αα by flow cytometry. Organoid-derived IECs were co-cultured with eCIRP-treated CD4CD8αα cells in the presence/absence of GrB and Prf inhibitors and assessed IEC death by flow cytometry.

RESULTS

We found a significant increase in the expression of GrB and Prf in CD4CD8αα IELs of septic mice compared to sham mice. We found that GrB and Prf levels in CD4CD8αα IELs were increased in the small intestines of WT septic mice, while CD4CD8αα IELs of CIRP-/- mice did not show an increase in those cytotoxic granules after sepsis. We found that eCIRP upregulated GrB and Prf in CD4CD8αα IELs isolated from WT mice but not from TLR4-/- mice. Furthermore, we also revealed that eCIRP-treated CD4CD8αα cells induced organoid-derived IEC death, which was mitigated by GrB and Prf inhibitors. Finally, histological analysis of septic mice revealed that CIRP-/- mice were protected from tissue injury and cell death in the small intestines compared to WT mice.

CONCLUSION

In sepsis, the cytotoxicity initiated by the eCIRP/TLR4 axis in CD4CD8αα IELs is associated with intestinal epithelial cell (IEC) death, which could lead to gut injury.

Perfluorooctanoic acid exposure and its neurodegenerative consequences in C57BL6/J mice

Perfluorooctanoic acid (PFOA) is a member of Per- and polyfluoroalkyl substances (PFASs), an industrial pollutant that has been produced for decades and widely used in various industries. Accumulation of this compound in the environment and body of organisms led to increased concerns about this compound. The toxic effects of PFOA on the nervous system are unknown yet. We aimed to assess the myelination and neurogenesis in brain tissue. In this study, PFOA at doses of 1, 5, 10, and 20 mg/kg were injected intraperitoneally into C57BL/6 J mice for 14 days, and the myelin content, CD4 + and CD8 + cell infiltration to brain regions were evaluated. Also, bromodeoxyuridine (BrdU) labeling was performed to compare neurogenesis among the groups. Luxol Fast Blue (LFB) staining revealed a significant decrease in myelin content in both sex at high concentrations (p < 0.001). The BrdU incorporation changes were observed in both sexes especially females which was highly related to the dose of PFOA and region of the brain. The infiltration rates of CD4 + and CD8 + cells to the brain were shown to be decreased; meanwhile the lymphocyte count was not significantly changed among groups over time and vice versa for the monocyte and neutrophils. Our results showed that PFOA had a negative impact on neurogenesis and the myelination process through the specific region of the brain depending on the dose and sex. Also, PFOA could disturb the number of CD4 + and CD8 + cells infiltrating the brain, which plays a crucial role in neurogenesis, leading to toxicity and neurological abnormalities. It seems that more research is needed to determine the exact mechanisms of PFOA neurotoxicity and its long-term behavioral consequences.

Lung dopaminergic nerves facilitate the establishment of TH2 resident memory cells in early life

BACKGROUND

Allergic asthma develops from allergen exposure in early childhood and progresses into adulthood. The central mediator of progressive allergic asthma is allergen-specific, TH2-resident memory cells (TRMs). Although the crosstalk between nerves and immune cells plays an established role in acute allergic inflammation, whether nerves facilitate the establishment of TH2-TRMs in the immature lung following early life allergen exposure is unknown.

OBJECTIVES

The aim of this study was to identify nerve-derived signals that act in TH2 effector cells to regulate the tissue residency in the immature lung.

METHODS

Following neonatal allergen exposure, allergen-specific TH2-TRMs were tracked temporally and spatially in relationship to developing sympathetic nerves in the lung. Functional mediators of dopamine signaling in the establishment of TH2-TRMs were identified by in vitro bulk RNA-sequencing of dopamine-treated TH2 cells followed by in vivo assessment of candidate genes using adoptive transfer of TH2 cells with viral gene knockdown.

RESULTS

This study found that sympathetic nerves produce dopamine and reside in proximity to TH2 effector cells during the contraction phase following neonatal allergen exposure. Dopamine signals via DRD4 on TH2 cells to elevate IL2RA and epigenetically facilitate type 2 cytokine expression. Blockade of dopamine-DRD4 signaling following neonatal allergen exposure impairs lung residence of TH2 cells and ameliorates anamnestic inflammation in adults.

CONCLUSIONS

These results demonstrate that maturing sympathetic nerves enable a dopamine-enriched lung environment in early life that promotes the establishment of allergen-specific TH2-TRMs. The dopamine-DRD4 axis may provide a therapeutic target to modify allergic asthma progression from childhood to adulthood.

Correlation between the dopaminergic system and inflammation disease: a review

The dopaminergic system is inextricably linked with neurological diseases and addiction. In recent years, many studies have found that the dopaminergic system involves in inflammatory diseases, particularly neuroinflammatory diseases development; This review summarizes the studies of dopaminergic system in inflammatory diseases, and specifically highlights the mechanisms of how dopaminergic system regulates inflammation; In addition, we speculate that there are some cavities in current research, including mixed usage of inhibitors, agonists and lack of systematic controls; We expect this review would provide directions to future research of dopaminergic system and inflammatory diseases.

A statistical framework to identify cell types whose genetically regulated proportions are associated with complex diseases

Finding disease-relevant tissues and cell types can facilitate the identification and investigation of functional genes and variants. In particular, cell type proportions can serve as potential disease predictive biomarkers. In this manuscript, we introduce a novel statistical framework, cell-type Wide Association Study (cWAS), that integrates genetic data with transcriptomics data to identify cell types whose genetically regulated proportions (GRPs) are disease/trait-associated. On simulated and real GWAS data, cWAS showed good statistical power with newly identified significant GRP associations in disease-associated tissues. More specifically, GRPs of endothelial and myofibroblasts in lung tissue were associated with Idiopathic Pulmonary Fibrosis and Chronic Obstructive Pulmonary Disease, respectively. For breast cancer, the GRP of blood CD8+ T cells was negatively associated with breast cancer (BC) risk as well as survival. Overall, cWAS is a powerful tool to reveal cell types associated with complex diseases mediated by GRPs.

H3K27me3-modulated Hofbauer cell BMP2 signalling enhancement compensates for shallow trophoblast invasion in preeclampsia

BACKGROUND

Preeclampsia (PE) is a common hypertensive pregnancy disorder associated with shallow trophoblast invasion. Although bone morphogenetic protein 2 (BMP2) has been shown to promote trophoblast invasion in vitro, its cellular origin and molecular regulation in placenta, as well as its potential role in PE, has yet to be established. Additionally, whether BMP2 and/or its downstream molecules could serve as potential diagnostic or therapeutic targets for PE has not been explored.

METHODS

Placentas and sera from PE and healthy pregnant women were subjected to multi-omics analyses, immunoblots, qPCR, and ELISA assays. Immortalized trophoblast cells, primary cultures of human trophoblasts, and first-trimester villous explants were used for in vitro experiments. Adenovirus expressing sFlt-1 (Ad Flt1)-induced PE rat model was used for in vivo studies.

FINDINGS

We find globally decreased H3K27me3 modifications and increased BMP2 signalling in preeclamptic placentas, which is negatively correlated with clinical manifestations. BMP2 is derived from Hofbauer cells and epigenetically regulated by H3K27me3 modification. BMP2 promotes trophoblast invasion and vascular mimicry by upregulating BMP6 via BMPR1A-SMAD2/3-SMAD4 signalling. BMP2 supplementation alleviates high blood pressure and fetal growth restriction phenotypes in Ad Flt1-induced rat PE model.

INTERPRETATION

Our findings demonstrate that epigenetically regulated Hofbauer cell-derived BMP2 signalling enhancement in late gestation could serve as a compensatory response for shallow trophoblast invasion in PE, suggesting opportunities for diagnostic marker and therapeutic target applications in PE clinical management.

FUNDING

National Key Research and Development Program of China (2022YFC2702400), National Natural Science Foundation of China (82101784, 82171648, 31988101), and Natural Science Foundation of Shandong Province (ZR2020QH051, ZR2020MH039).

MRP8/14 Is a Molecular Signature Triggered by Dopamine in HIV Latent Myeloid Targets That Increases HIV Transcription and Distinguishes HIV+ Methamphetamine Users with Detectable CSF Viral Load and Brain Pathology

There is a significant overlap between HIV infection and substance-use disorders. Dopamine (DA) is the most abundantly upregulated neurotransmitter in methamphetamine abuse, with receptors (DRD1-5) that are expressed by neurons as well as by a large diversity of cell types, including innate immune cells that are the targets of HIV infection, making them responsive to the hyperdopaminergic environment that is characteristic of stimulant drugs. Therefore, the presence of high levels of dopamine may affect the pathogenesis of HIV, particularly in the brain. The stimulation of HIV latently infected U1 promonocytes with DA significantly increased viral p24 levels in the supernatant at 24 h, suggesting effects on activation and replication. Using selective agonists to different DRDs, we found that DRD1 played a major role in activating viral transcription, followed by DRD4, which increased p24 with a slower kinetic rate compared to DRD1. Transcriptome and systems biology analyses led to the identification of a cluster of genes responsive to DA, where S100A8 and S100A9 were most significantly correlated with the early increase in p24 levels following DA stimulation. Conversely, DA increased the expression of these genes' transcripts at the protein level, MRP8 and MRP14, respectively, which form a complex also known as calprotectin. Interestingly, MRP8/14 was able to stimulate HIV transcription in latent U1 cells, and this occurred via binding of the complex to the receptor for an advanced glycosylation end-product (RAGE). Using selective agonists, both DRD1 and DRD4 increased MRP8/14 on the surface, in the cytoplasm, as well as secreted in the supernatants. On the other hand, while DRD1/5 did not affect the expression of RAGE, DRD4 stimulation caused its downregulation, offering a mechanism for the delayed effect via DRD4 on the p24 increase. To cross-validate MRP8/14 as a DA signature with a biomarker value, we tested its expression in HIV+ Meth users' postmortem brain specimens and peripheral cells. MRP8/14+ cells were more frequently identified in mesolimbic areas such as the basal ganglia of HIV+ Meth+ cases compared to HIV+ non-Meth users or to controls. Likewise, MRP8/14+ CD11b+ monocytes were more frequent in HIV+ Meth users, particularly in specimens from participants with a detectable viral load in the CSF. Overall, our results suggest that the MRP8 and MRP14 complex may serve as a signature to distinguish subjects using addictive substances in the context of HIV, and that this may play a role in aggravating HIV pathology by promoting viral replication in people with HIV who use Meth.

Dopamine inhibits group 2 innate lymphoid cell-driven allergic lung inflammation by dampening mitochondrial activity

Neuronal signals have emerged as pivotal regulators of group 2 innate lymphoid cells (ILC2s) that regulate tissue homeostasis and allergic inflammation. The molecular pathways underlying the neuronal regulation of ILC2 responses in lungs remain to be fully elucidated. Here, we found that the abundance of neurotransmitter dopamine was negatively correlated with circulating ILC2 numbers and positively associated with pulmonary function in humans. Dopamine potently suppressed lung ILC2 responses in a DRD1-receptor-dependent manner. Genetic deletion of Drd1 or local ablation of dopaminergic neurons augmented ILC2 responses and allergic lung inflammation. Transcriptome and metabolic analyses revealed that dopamine impaired the mitochondrial oxidative phosphorylation (OXPHOS) pathway in ILC2s. Augmentation of OXPHOS activity with oltipraz antagonized the inhibitory effect of dopamine. Local administration of dopamine alleviated allergen-induced ILC2 responses and airway inflammation. These findings demonstrate that dopamine represents an inhibitory regulator of ILC2 responses in allergic airway inflammation.

Breathing easy: Dopamine quenches the ILC2 flame

Communication between nerves and group 2 innate lymphoid cells (ILC2s) is thought to regulate allergic airway inflammation, but the molecular mechanisms are unclear. In this issue of Immunity, Cao et al. uncover an essential role for dopamine in inhibiting ILC2 function via metabolic restriction, thereby ameliorating key features of asthma pathogenesis.

Dopamine, Immunity, and Disease

The neurotransmitter dopamine is a key factor in central nervous system (CNS) function, regulating many processes including reward, movement, and cognition. Dopamine also regulates critical functions in peripheral organs, such as blood pressure, renal activity, and intestinal motility. Beyond these functions, a growing body of evidence indicates that dopamine is an important immunoregulatory factor. Most types of immune cells express dopamine receptors and other dopaminergic proteins, and many immune cells take up, produce, store, and/or release dopamine, suggesting that dopaminergic immunomodulation is important for immune function. Targeting these pathways could be a promising avenue for the treatment of inflammation and disease, but despite increasing research in this area, data on the specific effects of dopamine on many immune cells and disease processes remain inconsistent and poorly understood. Therefore, this review integrates the current knowledge of the role of dopamine in immune cell function and inflammatory signaling across systems. We also discuss the current understanding of dopaminergic regulation of immune signaling in the CNS and peripheral tissues, highlighting the role of dopaminergic immunomodulation in diseases such as Parkinson's disease, several neuropsychiatric conditions, neurologic human immunodeficiency virus, inflammatory bowel disease, rheumatoid arthritis, and others. Careful consideration is given to the influence of experimental design on results, and we note a number of areas in need of further research. Overall, this review integrates our knowledge of dopaminergic immunology at the cellular, tissue, and disease level and prompts the development of therapeutics and strategies targeted toward ameliorating disease through dopaminergic regulation of immunity. SIGNIFICANCE STATEMENT: Canonically, dopamine is recognized as a neurotransmitter involved in the regulation of movement, cognition, and reward. However, dopamine also acts as an immune modulator in the central nervous system and periphery. This review comprehensively assesses the current knowledge of dopaminergic immunomodulation and the role of dopamine in disease pathogenesis at the cellular and tissue level. This will provide broad access to this information across fields, identify areas in need of further investigation, and drive the development of dopaminergic therapeutic strategies.

C-Fiber Degeneration Enhances Alveolar Macrophage-Mediated IFN-α/β Response to Respiratory Syncytial Virus

Stimulation of unmyelinated C fibers, the nociceptive sensory nerves, by noxious stimuli is able to initiate host responses. Host defensive responses against respiratory syncytial virus (RSV) infection rely on the induction of a robust alpha/beta interferon (IFN-α/β) response, which acts to restrict viral production and promote antiviral immune responses. Alveolar macrophages (AMs) are the major source of IFN-α/β upon RSV infection. Here, we found that C fibers are involved in host defense against RSV infection. Compared to the control mice post-RSV infection, degeneration and inhibition of C fibers by blockade of transient receptor potential vanilloid 1 (TRPV1) lowered viral replication and alleviated lung inflammation. Importantly, AMs were markedly elevated in C-fiber-degenerated (KCF) mice post-RSV infection, which was associated with higher IFN-α/β secretion as measured in bronchoalveolar lavage fluid (BALF) samples. Degeneration of C fibers contributed to the production of vasoactive intestinal peptide (VIP), which modulated AM and IFN-α/β levels to protect against RSV infection. Collectively, these findings revealed the key role of C fibers in regulating AM and IFN-α/β responses against RSV infection via VIP, opening the possibility for new therapeutic strategies against RSV. IMPORTANCE Despite continuous advances in medicine, safe and effective drugs against RSV infection remain elusive. As such, host-RSV interactions and host-directed therapies require further research. Unmyelinated C fibers, the nociceptive sensory nerves, play an important role in regulating the host response to virus. In the present study, from the perspective of neuroimmune interactions, we clarified that C-fiber degeneration enhanced the AM-mediated IFN-α/β response against RSV via VIP, providing potential therapeutic targets for the treatment of RSV infection.

Dopaminergic Signalling Enhances IL-2 Production and Strengthens Anti-Tumour Response Exerted by Cytotoxic T Lymphocytes in a Melanoma Mouse Model

Dopamine has emerged as an important regulator of immunity. Recent evidence has shown that signalling through low-affinity dopamine receptors exerts anti-inflammatory effects, whilst stimulation of high-affinity dopamine receptors potentiates immunity in different models. However, the dopaminergic regulation of CD8⁺ T-cells in anti-tumour immunity remains poorly explored. Here, we studied the role of dopamine receptor D3 (DRD3), which displays the highest affinity for dopamine, in the function of CD8⁺ T-cells and its consequences in the anti-tumour immune response. We observed that the deficiency of Drd3 (the gene encoding DRD3) in CD8⁺ T-cells limits their in vivo expansion, leading to an impaired anti-tumour response in a mouse melanoma model. Mechanistic analyses suggest that DRD3 stimulation favours the production of interleukin 2 (IL-2) and the surface expression of CD25, the α-chain IL-2 receptor, which are required for expansion and effector differentiation of CD8⁺ T-cells. Thus, our results provide genetic and pharmacologic evidence indicating that DRD3 favours the production of IL-2 by CD8⁺ T-cells, which is associated with higher expansion and acquisition of effector function of these cells, promoting a more potent anti-tumour response in a melanoma mouse model. These findings contribute to understanding how dopaminergic signalling affects the cellular immune response and represent an opportunity to improve melanoma therapy.

Neuro-epithelial-ILC2 crosstalk in barrier tissues

Group 2 innate lymphoid cells (ILC2s) contribute to the maintenance of mammalian barrier tissue homeostasis. We review how ILC2s integrate epithelial signals and neurogenic components to preserve the tissue microenvironment and modulate inflammation. The epithelium that overlies barrier tissues, including the skin, lungs, and gut, generates epithelial cytokines that elicit ILC2 activation. Sympathetic, parasympathetic, sensory, and enteric fibers release neural signals to modulate ILC2 functions. We also highlight recent findings suggesting neuro-epithelial-ILC2 crosstalk and its implications in immunity, inflammation and resolution, tissue repair, and restoring homeostasis. We further discuss the pathogenic effects of disturbed ILC2-centered neuro-epithelial-immune cell interactions and putative areas for therapeutic targeting.

The Dopamine Gene Receptors (DRD1-5) Expression Alteration in Psoriasis Patients

BACKGROUND

Psoriasis is a chronic inflammatory autoimmune disease that is considered linked to genetic and environmental factors such as stress. Since the neurotransmitter dopamine has a close association with stress configuration, it can be a candidate for relieving psoriasis representation. In addition to the CNS, immune cells can play a decisive role in regulating immune functions through dopamine synthesis and the expression of its receptors. Altered response of immune cells to dopamine as well as a distorted expression of dopamine receptors (DRs) in immune cells have been reported in some chronic inflammatory conditions.

OBJECTIVE

This study aims the evaluation of dopamine receptor (DR1-DR5) gene expression in mononuclear blood cells of psoriatic patients in comparison with normal individuals.

METHODS

We isolated peripheral mononuclear cells (PBMCs) from blood samples followed by total RNA extraction, cDNA synthesis, and real-time PCR using specific primer pairs.

RESULTS

We found that all types of DRs are expressed in the PBMCs of normal and psoriatic individuals. We also concluded that compared to controls, DR2 and DR4 were overexpressed in psoriasis patients while DR3 was low-expressed.

CONCLUSION

Increased expression of DR2 and DR4 along with decreased expression of DR3 in PBMCs of psoriasis patients not only provide new insight into the pathogenesis of psoriasis but may also be effective in designing future therapeutic strategies attributable to psoriasis.

Dopamine signaling promotes tissue-resident memory differentiation of CD8+ T cells and antitumor immunity

Tissue-resident memory CD8+ T (TRM)-cells have been associated with robust protective anti-tumor immune responses and improved prognosis of cancer patients. Therefore, therapeutic strategies that modulate either the production or activity of TRM cells could be effective for treating cancer. Using a high-throughput drug screen, we showed that the neurotransmitter dopamine drives differentiation of CD8+ T cells into CD103+ TRM cells. In murine syngeneic tumor xenograft models and clinical human colon cancer samples, DRD5 served as the major functional dopamine receptor on CD8+ T cells and positively correlated with TRM cell density. DRD5 deficiency led to a failure of CD8+ T cells to accumulate in tissues, resulting in impaired TRM cell formation, reduced effector function, and uncontrolled disease progression. Moreover, dopamine treatment promoted the antitumor activity of CD8+ T cells and suppressed colorectal cancer growth in immunocompentent mouse models, and ex-vivo pre-conditioning with dopamine enhanced the in vivo efficacy of CAR-T cells. Finally, in a colorectal cancer patient cohort, dopamine expression was positively associated with patient survival and CD8+ T cell infiltration. These findings suggest that dopaminergic immunoregulation plays an important role in the differentiation of CD8+ cells into CD103+ TRM cells and thereby modulates TRM-elicited antitumor immunity in colorectal cancer.

Advancing Lung Immunology Research: An Official American Thoracic Society Workshop Report

The mammalian airways and lungs are exposed to a myriad of inhaled particulate matter, allergens, and pathogens. The immune system plays an essential role in protecting the host from respiratory pathogens, but a dysregulated immune response during respiratory infection can impair pathogen clearance and lead to immunopathology. Furthermore, inappropriate immunity to inhaled antigens can lead to pulmonary diseases. A complex network of epithelial, neural, stromal, and immune cells has evolved to sense and respond to inhaled antigens, including the decision to promote tolerance versus a rapid, robust, and targeted immune response. Although there has been great progress in understanding the mechanisms governing immunity to respiratory pathogens and aeroantigens, we are only beginning to develop an integrated understanding of the cellular networks governing tissue immunity within the lungs and how it changes after inflammation and over the human life course. An integrated model of airway and lung immunity will be necessary to improve mucosal vaccine design as well as prevent and treat acute and chronic inflammatory pulmonary diseases. Given the importance of immunology in pulmonary research, the American Thoracic Society convened a working group to highlight central areas of investigation to advance the science of lung immunology and improve human health.

Neuronal-Immune Cell Units in Allergic Inflammation in the Nose

Immune cells and immune-derived molecules, endocrine glands and hormones, the nervous system and neuro molecules form the combined tridirectional neuroimmune network, which plays a significant role in the communication pathways and regulation at the level of the whole organism and local levels, in both healthy persons and patients with allergic rhinitis based on an allergic inflammatory process. This review focuses on a new research paradigm devoted to neuronal-immune cell units, which are involved in allergic inflammation in the nose and neuroimmune control of the nasal mucociliary immunologically active epithelial barrier. The categorization, cellular sources of neurotransmitters and neuropeptides, and their prevalent profiles in constituting allergen tolerance maintenance or its breakdown are discussed. Novel data on the functional structure of the nasal epithelium based on a transcriptomic technology, single-cell RNA-sequencing results, are considered in terms of neuroimmune regulation. Notably, the research of pathogenesis and therapy for atopic allergic diseases, including recently identified local forms, from the viewpoint of the tridirectional interaction of the neuroimmune network and discrete neuronal-immune cell units is at the cutting-edge.

Neuro-Immune Regulation in Inflammation and Airway Remodeling of Allergic Asthma

Allergic asthma is a common chronic inflammation of the airways and causes airway remodeling eventually. For a long time, investigators have been focusing on the immunological mechanism of asthma. However, in recent years, the role of neuro-regulation in the occurrence of asthma has gradually attracted investigators’ attention. In this review, we firstly describe neuro-immune regulation in inflammation of allergic asthma from two aspects: innate immunity and adaptive immunity. Secondly, we introduce neuro-immune regulation in airway remodeling of asthma. Finally, we prospect the role of pulmonary neuroendocrine cells in the development of asthma. In general, the amount of researches is limited. Further researches on the neural regulation during the occurrence of asthma will help us clarify the mechanism of asthma more comprehensively and find more effective ways to prevent and control asthma.

Crosstalk between ILC2s and Th2 CD4+ T Cells in Lung Disease

Cytokine secretion, such as interleukin-4 (IL-4), IL-5, IL-9, IL-13, and amphiregulin (Areg), by type 2 innate lymphoid cells (ILC2s) is indispensable for homeostasis, remodeling/repairing tissue structure, inflammation, and tumor immunity. Often viewed as the innate cell surrogate of T helper type 2 (Th2) cells, ILC2s not only secrete the same type 2 cytokines, but are also inextricably related to CD4⁺T cells in terms of cell origin and regulatory factors, bridging between innate and adaptive immunity. ILC2s interact with CD4⁺T cells to play a leading role in a variety of diseases through secretory factors. Here, we review the latest progress on ILC2s and CD4⁺T cells in the lung, the close relationship between the two, and their relevance in the lung disease and immunity. This literature review aids future research in pulmonary type 2 immune diseases and guides innovative treatment approaches for these diseases.

Chicken Peripheral Blood Mononuclear Cells Response to Avian Leukosis Virus Subgroup J Infection Assessed by Single-Cell RNA Sequencing

Chicken peripheral blood mononuclear cells (PBMCs) exhibit wide-ranging cell types, but current understanding of their subclasses, immune cell classification, and function is limited and incomplete. Here we performed single-cell RNA sequencing (scRNA-seq) of PBMCs in Avian leukosis virus subgroup J (ALV-J) infected and control chickens at 21 days post infection (DPI) to determine chicken PBMCs subsets and their specific molecular and cellular characteristics. Eight cell populations and their potential marker genes were identified in PBMCs. T cell populations had the strongest response to (ALV-J) infection, based on the detection of the largest number of differentially expressed genes (DEGs), and could be further grouped into four subsets: activated CD4⁺ T cells, Th1-like cells, Th2-like cells, and cytotoxic CD8⁺ T cells. Furthermore, pseudotime analysis results suggested that chicken CD4⁺ T cells could potentially differentiate into Th1-like and Th2-like cells. Moreover, ALV-J infection activated CD4⁺ T cell was probably inclined to differentiate into Th1-like cells. Compared to the control PBMCs, ALV-J infection also had an obvious impact on PBMCs composition. B cells showed inconspicuous response and their numbers decreased in PBMCs from ALV-J infected chicken. Proportions of cytotoxic Th1-like cells and CD8⁺ T cells increased in the T cell population of PBMCs from ALV-J infected chicken, which were potentially key mitigating effectors against ALV-J infection. More importantly, our results provide a rich resource of gene expression profiles of chicken PBMCs subsets for a systems-level understanding of their function in homeostatic condition as well as in response to viral infection.

Melatonergic signalling instructs transcriptional inhibition of IFNGR2 to lessen interleukin-1β-dependent inflammation

BACKGROUND

Immunotransmitters (e.g., neurotransmitters and neuromodulators) could orchestrate diverse immune responses; however, the elaborated mechanism by which melatonergic activation governs inflammation remains less defined.

METHODS

Primary macrophages, various cell lines, and Pasteurella multocida (PmCQ2)-infected mice were respectively used to illustrate the influence of melatonergic signalling on inflammation in vitro and in vivo. A series of methods (e.g., RNA-seq, metabolomics, and genetic manipulation) were conducted to reveal the mechanism whereby melatonergic signalling reduces macrophage inflammation.

RESULTS

Here, we demonstrate that melatonergic activation substantially lessens interleukin (IL)-1β-dependent inflammation. Treatment of macrophages with melatonin rewires metabolic program, as well as remodels signalling pathways which depends on interferon regulatory factor (IRF) 7. Mechanistically, melatonin acts via membrane receptor (MT) 1 to increase heat shock factor (Hsf) 1 expression through lowering the inactive glycogen synthase kinase (GSK3) β, thereby transcriptionally inhibiting interferon (IFN)-γ receptor (IFNGR) 2 and ultimately causing defective canonical signalling events [Janus kinase (JAK) 1/2-signal transducer and activator of transcription (STAT) 1-IRF7] and lower IL-1β production in macrophages. Moreover, we find that melatonin amplifies host protective responses to PmCQ2 infection-induced pneumonia.

CONCLUSIONS

Our conceptual framework provides potential therapeutic targets to prevent and/or treat inflammatory diseases associating with excessive IL-1β production.

Analysis of Airway Vagal Neurons

Internal organs, including the airway, are innervated by neurons of the autonomic and sensory nervous systems. The airway-innervating sensory neurons primarily originate from the vagus nerve, whose cell bodies are found, in rodents, in the jugular and nodose ganglia complex (JNC). About half of these sensory neurons expressed the heat-sensing ion channel TRPV1 and evolved to limit tissue damage by detecting chemical, mechanical, or thermal threats and to initiate protective airway reflexes such as coughing and bronchoconstriction. They also help monitor the host homeostasis by sensing nutrients, pressure, and O₂ levels and help mount airway defenses by controlling immune and goblet cell activity. To better appreciate the scope of the physiological role and pathological contributions of these neurons, we will review gain and loss-of-function approaches geared at controlling the activity of these neurons. We will also present a method to study transcriptomic changes in airway-innervating neurons and a co-culture approach designed to understand how nociceptors modulate immune responses.

Dopaminergic stimulation leads B-cell infiltration into the central nervous system upon autoimmunity

BACKGROUND

Recent evidence has shown dopamine as a major regulator of inflammation. Accordingly, dopaminergic regulation of immune cells plays an important role in the physiopathology of inflammatory disorders. Multiple sclerosis (MS) is an inflammatory disease involving a CD4⁺ T-cell-driven autoimmune response to central nervous system (CNS) derived antigens. Evidence from animal models has suggested that B cells play a fundamental role as antigen-presenting cells (APC) re-stimulating CD4⁺ T cells in the CNS as well as regulating T-cell response by mean of inflammatory or anti-inflammatory cytokines. Here, we addressed the role of the dopamine receptor D3 (DRD3), which displays the highest affinity for dopamine, in B cells in animal models of MS.

METHODS

Mice harbouring Drd3-deficient or Drd3-sufficient B cells were generated by bone marrow transplantation into recipient mice devoid of B cells. In these mice, we compared the development of experimental autoimmune encephalomyelitis (EAE) induced by immunization with a myelin oligodendrocyte glycoprotein (MOG)-derived peptide (pMOG), a model that leads to CNS-autoimmunity irrespective of the APC-function of B cells, or by immunization with full-length human MOG protein (huMOG), a model in which antigen-specific activated B cells display a fundamental APC-function in the CNS. APC-function was assessed in vitro by pulsing B cells with huMOG-coated beads and then co-culturing with MOG-specific T cells.

RESULTS

Our data show that the selective Drd3 deficiency in B cells abolishes the disease development in the huMOG-induced EAE model. Mechanistic analysis indicates that although DRD3-signalling did not affect the APC-function of B cells, DRD3 favours the CNS-tropism in a subset of pro-inflammatory B cells in the huMOG-induced EAE model, an effect that was associated with higher CXCR3 expression. Conversely, the results show that the selective Drd3 deficiency in B cells exacerbates the disease severity in the pMOG-induced EAE model. Further analysis shows that DRD3-stimulation increased the expression of the CNS-homing molecule CD49d in a B-cell subset with anti-inflammatory features, thus attenuating EAE manifestation in the pMOG-induced EAE model.

CONCLUSIONS

Our findings demonstrate that DRD3 in B cells exerts a dual role in CNS-autoimmunity, favouring CNS-tropism of pro-inflammatory B cells with APC-function and promoting CNS-homing of B cells with anti-inflammatory features. Thus, these results show DRD3-signalling in B cells as a critical regulator of CNS-autoimmunity.

The role of dopamine receptors in lymphocytes and their changes in schizophrenia

Dopamine and its 5 receptors, which are grouped into two families (D1-like and D2-like), modulate functions at a systemic level in both the central nervous system and periphery. The central nervous system and the immune system are the main adaptive systems, which participate in a continuous and functional crosstalk to guarantee homeostasis. On binding to its 5 dopamine receptors, dopamine acts as a co-regulator of the immune system, contributing to the interaction of the central nervous system and inflammatory events and as a source of communication between the different immune cells. Dopaminergic perturbations in the central nervous system are observed in several neurological and psychiatric disorders. Schizophrenia is one of the most common mental disorders with a poorly understood pathoaetiology that includes genetic and environmental components that promote alterations in the dopaminergic system. Interestingly, abnormalities in dopamine receptors expression in lymphocytes of schizophrenia patients have been reported, often significantly correlating with the severity of the psychotic illness. Here, we review the current literature regarding the dopaminergic system in human lymphocytes and its alterations in schizophrenia.

1.

The existence of DA in the bloodstream suggests the presence of dopaminergic components that modulate functions at a systemic level; therefore, its effects are not limited to the CNS and the signalling in the neuronal dopaminergic system should be independent from that of the peripheral systems.

2.

The effects by DA-mediated activation of different DRs on immune cells show different sensitivities to DA, but binding profiles of DA on T cells are similar to those in neuronal membranes, suggesting receptors act similarly to those found in neurons.

3.

All DRs are expressed on the LYM membrane. However, more detailed information is required on the expression patterns of DR in immune cells in healthy conditions and in pathologies.

4.

DA has been observed to influence LYM functions acting in a variety of important processes, like cytokine secretion, cell adhesion, chemotaxis, and cytotoxicity.

5.

In human LYM, DA on D1-like receptors decreases oxidative metabolism and apoptosis, activates the selective secretion of IL-10 and TNFα, and facilitates NK cells. In contrast, most of the immunostimulatory DA effects on LYM depend on stimulation of D2-like receptors including activation, proliferation, differentiation, and suppression of NK cells.

6.

To date, an altered expression or signalling of neurotransmitter receptors is observed in immune cells during psychiatric disorders and, consequently, these cells also markedly respond to antipsychotics.

7.

Numerous technologies have been used in search of biomarkers for SCZ. However, after a century of studying SCZ their application in psychiatry remains rare and there are currently no validated biomarkers for the diagnosis and prognosis of patients with SCZ or the prediction of treatment efficacy.

Primary culture of immature, naïve mouse CD4+ T cells

Primary T-cell culture is an invaluable model for investigating mechanisms underlying T-cell differentiation and function in health and disease. However, different culture conditions are required for immature versus mature CD4+ T cells. Here, we provide an improved culture protocol for immature naïve mouse CD4+ T cells, including details for splenocyte isolation, naïve CD4+ T-cell purification and differentiation, and functional evaluation via flow cytometry. This protocol can also be applied for immature human CD4+ T cells. For complete details on the execution of this protocol, please refer to Wang et al. (2019).

VLM catecholaminergic neurons control tumor growth by regulating CD8+ T cells

We have discovered that the ventrolateral medulla (VLM) catecholaminergic (CA) neurons, a group of neurons that control mouse stress response, are activated in tumor-bearing mice, and the neuronal activity promotes tumor growth in multiple syngeneic and spontaneous mouse tumor models. The tumor-promoting effect of these VLM CA neurons is mediated by cytotoxic T cells. These findings establish an interaction between a tumor and a group of neurons in the mouse brain that influences tumorigenesis and tumor growth by modulating adaptive immunity.

It is known that tumor growth can be influenced by the nervous system. It is not known, however, if tumors communicate directly with the central nervous system (CNS) or if such interactions may impact tumor growth. Here, we report that ventrolateral medulla (VLM) catecholaminergic (CA) neurons in the mouse brain are activated in tumor-bearing mice and the activity of these neurons significantly alter tumor growth in multiple syngeneic and spontaneous mouse tumor models. Specific ablation of VLM CA neurons by a dopamine-β-hydroxylase (DBH) promotor-activated apoptosis-promoting caspase-3 in Dbh-Cre mice as well as inhibition of these neurons by a chemogenetic method slowed tumor progression. Consistently, chemogenetic activation of VLM CA neurons promoted tumor growth. The tumor inhibition effect of VLM CA neuron ablation is mitigated in Dbh-Cre;Rag1^−/− mice, indicating that this regulatory effect is mediated by the adaptive immune system. Specific depletion of CD8⁺ T cells using an anti-CD8⁺ antibody also mitigated the tumor suppression resulting from the VLM CA neuron ablation. Finally, we showed that the VLM CA neuronal ablation had an additive antitumor effect with paclitaxel treatment. Collectively, our study uncovered the role of VLM CA neurons in the mouse brain in controlling tumor growth in the mouse body.

DRD4 (Dopamine D4 Receptor) Mitigate Abdominal Aortic Aneurysm via Decreasing P38 MAPK (mitogen-activated protein kinase)/NOX4 (NADPH Oxidase 4) Axis-Associated Oxidative Stress

[Figure: see text].

VEGF receptor 2 (KDR) protects airways from mucus metaplasia through a Sox9-dependent pathway

Mucus-secreting goblet cells are the dominant cell type in pulmonary diseases, e.g., asthma and cystic fibrosis (CF), leading to pathologic mucus metaplasia and airway obstruction. Cytokines including IL-13 are the major players in the transdifferentiation of club cells into goblet cells. Unexpectedly, we have uncovered a previously undescribed pathway promoting mucous metaplasia that involves VEGFa and its receptor KDR. Single-cell RNA sequencing analysis coupled with genetic mouse modeling demonstrates that loss of epithelial VEGFa, KDR, or MEK/ERK kinase promotes excessive club-to-goblet transdifferentiation during development and regeneration. Sox9 is required for goblet cell differentiation following Kdr inhibition in both mouse and human club cells. Significantly, airway mucous metaplasia in asthmatic and CF patients is also associated with reduced KDR signaling and increased SOX9 expression. Together, these findings reveal an unexpected role for VEGFa/KDR signaling in the defense against mucous metaplasia, offering a potential therapeutic target for this common airway pathology.

Group 2 Innate Lymphoid Cells: Team Players in Regulating Asthma

Type 2 immunity helps protect the host from infection, but it also plays key roles in tissue homeostasis, metabolism, and repair. Unfortunately, inappropriate type 2 immune reactions may lead to allergy and asthma. Group 2 innate lymphoid cells (ILC2s) in the lungs respond rapidly to local environmental cues, such as the release of epithelium-derived type 2 initiator cytokines/alarmins, producing type 2 effector cytokines such as IL-4, IL-5, and IL-13 in response to tissue damage and infection. ILC2s are associated with the severity of allergic asthma, and experimental models of lung inflammation have shown how they act as playmakers, receiving signals variously from stromal and immune cells as well as the nervous system and then distributing cytokine cues to elicit type 2 immune effector functions and potentiate CD4⁺ T helper cell activation, both of which characterize the pathology of allergic asthma. Recent breakthroughs identifying stromal- and neuronal-derived microenvironmental cues that regulate ILC2s, along with studies recognizing the potential plasticity of ILC2s, have improved our understanding of the immunoregulation of asthma and opened new avenues for drug discovery.

Is acupuncture effective in the treatment of COVID-19 related symptoms? Based on bioinformatics/network topology strategy

Acupuncture is an important part of Chinese medicine that has been widely used in the treatment of inflammatory diseases. During the coronavirus disease 2019 (COVID-19) epidemic, acupuncture has been used as a complementary treatment for COVID-19 in China. However, the underlying mechanism of acupuncture treatment of COVID-19 remains unclear. Based on bioinformatics/topology, this paper systematically revealed the multi-target mechanisms of acupuncture therapy for COVID-19 through text mining, bioinformatics, network topology, etc. Two active compounds produced after acupuncture and 180 protein targets were identified. A total of 522 Gene Ontology terms related to acupuncture for COVID-19 were identified, and 61 pathways were screened based on the Kyoto Encyclopedia of Genes and Genomes. Our findings suggested that acupuncture treatment of COVID-19 was associated with suppression of inflammatory stress, improving immunity and regulating nervous system function, including activation of neuroactive ligand–receptor interaction, calcium signaling pathway, cancer pathway, viral carcinogenesis, Staphylococcus aureus infection, etc. The study also found that acupuncture may have additional benefits for COVID-19 patients with cancer, cardiovascular disease and obesity. Our study revealed for the first time the multiple synergistic mechanisms of acupuncture on COVID-19. Acupuncture may play an active role in the treatment of COVID-19 and deserves further promotion and application. These results may help to solve this pressing problem currently facing the world.

Neuroimmune regulatory networks of the airway mucosa in allergic inflammatory disease

Communication between the nervous and immune systems serves a key role in host‐protective immunity at mucosal barrier sites including the respiratory tract. In these tissues, neuroimmune interactions operate in bidirectional circuits that can sense and respond to mechanical, chemical, and biologic stimuli. Allergen‐ or helminth‐induced products can produce airway inflammation by direct action on nociceptive afferents and adjacent tissues. The activity of nociceptive afferents can regulate innate and adaptive immune responses via neuropeptides and neurotransmitter signaling. This review will summarize recent work investigating the role of neuropeptides CGRP, VIP, neuromedins, substance P, and neurotransmitters dopamine and the B2‐adrenoceptor agonists epinepherine/norepinepherine, each of which influence type 2 immunity by instructing mast cell, innate lymphoid cell type 2, dendritic cell, and T cell responses, both in the airway and the draining lymph node. Afferents in the airway also contain receptors for alarmins and cytokines, allowing their activity to be modulated by immune cell secreted products, particularly those secreted by mast cells. Taken together, we propose that further investigation of how immunoregulatory neuropeptides shape respiratory inflammation in experimental systems may reveal novel therapeutic targets for addressing the increasing prevalence of chronic airway disease in humans.

Serotonin and dopamine receptors profile on peripheral immune cells from patients with temporal lobe epilepsy

The role of inflammation and immune cells has been demonstrated in neurological diseases, including epilepsy. Leukocytes, as well as inflammatory mediators, contribute to abnormal processes that lead to a reduction in seizure threshold and synaptic reorganization. In this sense, identifying different phenotypes of circulating immune cells is essential to understanding the role of these cells in epilepsy. Immune cells can express a variety of surface markers, including neurotransmitter receptors, such as serotonin and dopamine. Alteration in these receptors expression patterns may affect the level of inflammatory mediators and the pathophysiology of epilepsy. Therefore, in the current study, we evaluated the expression of dopamine and serotonin receptors on white blood cells from patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Blood samples from 17 patients with TLE-HS and 21 controls were collected. PBMC were isolated and stained ex vivo for flow cytometry. We evaluated the expression of serotonin (5-HT_1A, 5-HT_1B, 5-HT₂, 5-HT_2B, 5-HT_2C, 5-HT₃, 5-HT₄), and dopamine receptors (D₁, D₂, D₃, D₄, and D₅) on the cell surface of lymphocytes and innate immune cells (monocytes and granulocytes). Our results demonstrated that innate cells and lymphocytes from patients with TLE-HS showed high mean fluorescent intensity (MFI) for 5-HT_1A, 5-HT_1B, 5-HT_2A, and 5-HT₄ compared to controls. No difference was observed for 5-HT_2B. For dopamine receptors, the expression of D₁, D₂, D_4, and D₅ receptors was higher on innate cells from patients with TLE-HS when compared to controls for the MFI. Regarding lymphocytes population, D₂ expression was increased in patients with TLE-HS. In conclusion, there are alterations in the expression of serotonin and dopamine receptors on immune blood cells of patients with TLE-HS. Although the biological significance of these findings still needs to be further investigated, these changes may contribute to the understanding of TLE-HS pathophysiology.

The Role of the Renal Dopaminergic System and Oxidative Stress in the Pathogenesis of Hypertension

The kidney is critical in the long-term regulation of blood pressure. Oxidative stress is one of the many factors that is accountable for the development of hypertension. The five dopamine receptor subtypes (D₁R–D₅R) have important roles in the regulation of blood pressure through several mechanisms, such as inhibition of oxidative stress. Dopamine receptors, including those expressed in the kidney, reduce oxidative stress by inhibiting the expression or action of receptors that increase oxidative stress. In addition, dopamine receptors stimulate the expression or action of receptors that decrease oxidative stress. This article examines the importance and relationship between the renal dopaminergic system and oxidative stress in the regulation of renal sodium handling and blood pressure. It discusses the current information on renal dopamine receptor-mediated antioxidative network, which includes the production of reactive oxygen species and abnormalities of renal dopamine receptors. Recognizing the mechanisms by which renal dopamine receptors regulate oxidative stress and their degree of influence on the pathogenesis of hypertension would further advance the understanding of the pathophysiology of hypertension.

DRD1 downregulation contributes to mechanical stretch-induced lung endothelial barrier dysfunction

Rationale: The lung-protective effects of dopamine and its role in the pathology of ventilator-induced lung injury (VILI) are emerging. However, the underlying mechanisms are still largely unknown.

Objective: To investigate the contribution of dopamine receptor dysregulation in the pathogenesis of VILI and therapeutic potential of dopamine D1 receptor (DRD1) agonist in VILI.

Methods: The role of dopamine receptors in mechanical stretch-induced endothelial barrier dysfunction and lung injury was studied in DRD1 knockout mice, in isolated mouse lung vascular endothelial cells (MLVECs), and in lung samples from patients who underwent pulmonary lobectomy with mechanical ventilation for different time periods.

Measurements and Main Results: DRD1 was downregulated in both surgical patients and mice exposed to mechanical ventilation. Prophylactic administration of dopamine or DRD1 agonist attenuated mechanical stretch-induced lung endothelial barrier dysfunction and lung injury. By contrast, pulmonary knockdown or global knockout of DRD1 exacerbated these effects. Prophylactic administration of dopamine attenuated mechanical stretch-induced α-tubulin deacetylation and subsequent endothelial hyperpermeability through DRD1 signaling. We identified that cyclic stretch-induced glycogen-synthase-kinase-3β activation led to phosphorylation and activation of histone deacetylase 6 (HDAC6), which resulted in deacetylation of α-tubulin. Upon activation, DRD1 signaling attenuated mechanical stretch-induced α-tubulin deacetylation and subsequent lung endothelial barrier dysfunction through cAMP/exchange protein activated by cAMP (EPAC)-mediated inactivation of HDAC6.

Conclusions: This work identifies a novel protective role for DRD1 against mechanical stretch-induced lung endothelial barrier dysfunction and lung injury. Further study of the mechanisms involving DRD1 in the regulation of microtubule stability and interference with DRD1/cAMP/EPAC/HDAC6 signaling may provide insight into therapeutic approaches for VILI.