Activation of p38 MAPK in CD4 T cells controls IL-17 production and autoimmune encephalomyelitis

Bergenin potentiates BCG efficacy by enriching mycobacteria-specific adaptive memory responses via the Akt-Foxo-Stat4 axis

The extensive inability of the BCG vaccine to produce long-term immune protection has not only accelerated the disease burden but also progressed towards the onset of drug resistance. In our previous study, we have reported the promising effects of Bergenin (Berg) in imparting significant protection as an adjunct immunomodulator against tuberculosis (TB). In congruence with our investigations, we delineated the impact of Berg on T cells, wherein it enhanced adaptive memory responses by modulating key transcription factors, STAT4 and Akt. We translated this finding into the vaccine model of TB and observed a notable reduction in the burden of Mycobacterium tuberculosis (M.tb) in BCG-Berg co-immunized mice as compared to BCG vaccination. Moreover, Berg, along with BCG, also aided in a heightened proinflammatory response milieu that corroborates the host protective immune response against TB. Furthermore, this response aligns with the escalated central and resident memory responses by modulating the Akt-Foxo-Stat4 axis, which plays a crucial role in enhancing the vaccine efficacy of BCG. These findings showcase the utilization of immunomodulator Berg as an immunoprophylactic agent to upgrade immunological memory, making it a more effective defender against TB.

Novel trifluoromethyl ketone derivatives as oral cPLA2/COX-2 dual inhibitors for resolution of inflammation in rheumatoid arthritis

Thirty-five trifluoromethyl hydrazones and seventeen trifluoromethyl oxime esters were designed and synthesized via molecular hybridization. All the target compounds were initially screened for in vitro anti-inflammatory activity by assessing their inhibitory effect on NO release in LPS-stimulated RAW264.7 cells, and the optimal compound was finally identified as 2-(3-Methoxyphenyl)-N'-((6Z,9Z,12Z,15Z)-1,1,1-trifluorohenicosa-6,9,12,15-tetraen-2-ylidene)acetohydrazide (F26, IC50 = 4.55 ± 0.92 μM) with no cytotoxicity. Moreover, F26 potently reduced the production of PGE2 in LPS-stimulated RAW264.7 cells compared to indomethacin. The interaction of F26 with COX-2 and cPLA2 was directly verified by the CETSA technique. F26 was found to modulate the phosphorylation levels of p38 MAPK and NF-κB p65, as well as the protein expression of IκB, cPLA2, COX-2, and iNOS in LPS-stimulated rat peritoneal macrophages. Additionally, F26 was observed to prevent the nuclear translocation of NF-κB p65 in LPS-stimulated rat peritoneal macrophages by immunofluorescence localization. Therefore, the aforementioned in vitro experiments demonstrated that F26 blocked the p38 MAPK and NF-κB pathways by binding to COX-2 and cPLA2. In the adjuvant-induced arthritis model, F26 demonstrated a significant effect in preventing arthritis symptoms and inflammatory status in rats, exerting an immunomodulatory role by regulating the homeostasis between Th17 and Treg through inhibition of the p38 MAPK/cPLA2/COX-2/PGE2 and NF-κB pathways. Encouragingly, F26 caused less acute ulcerogenicity in rats at a dose of 50 mg/kg compared to indomethacin. Overall, F26 is a promising candidate worthy of further investigation for treating inflammation and associated pain with lesser gastrointestinal irritation, as well as other symptoms in which cPLA2 and COX-2 are implicated in the pathophysiology.

Discovery of novel NSAID hybrids as cPLA2/COX-2 dual inhibitors alleviating rheumatoid arthritis via inhibiting p38 MAPK pathway

A series of NSAIDs hybrid molecules were synthesized and characterized, and their ability to inhibit NO release in LPS-induced RAW264.7 macrophages was evaluated. Most of the compounds showed significant anti-inflammatory activity in vitro, of which (2E,6Z,9Z,12Z,15Z)-1,1,1-trifluorohenicosa-2,6,9,12,15-pentaen-2-yl 2-(4-benzoylphenyl) propanoate (VI-60) was the most optimal (IC50 = 3.85 ± 0.25 μΜ) and had no cytotoxicity. In addition, VI-60 notably reduced the production of PGE2 in LPS-stimulated RAW264.7 cells compared to ketoprofen. Futhur more, VI-60 significantly inhibited the expression of iNOS, cPLA2, and COX-2 and the phosphorylation of p38 MAPK in LPS-stimulated RAW264.7 cells. The binding of VI-60 to cPLA2 and COX-2 was directly verified by the CETSA technique. In vivo studies illustrated that VI-60 exerted an excellent therapeutic effect on adjuvant-induced arthritis in rats by regulating the balance between Th17 and Treg through inhibiting the p38 MAPK/cPLA2/COX-2/PGE2 pathway. Encouragingly, VI-60 showed a lower ulcerative potential in rats at a dose of 50 mg/kg compared to ketoprofen. In conclusion, the hybrid molecules of NSAIDs and trifluoromethyl enols are promising candidates worthy of further investigation for the treatment of inflammation, pain, and other symptoms in which cPLA2 and COX-2 play a role in their etiology.

Th17 cells: A new target in kidney disease research

Type 17 T helper (Th17) cells, which are a subtype of CD4+ T helper cells, secrete pro-inflammatory cytokines such as IL-17A, IL-17F, IL-21, IL-22, and GM-CSF, which play crucial roles in immune defence and protection against fungal and extracellular pathogen invasion. However, dysfunction of Th17 cell immunity mediates inflammatory responses and exacerbates tissue damage. This pathological process initiated by Th17 cells is common in kidney diseases associated with renal injury, such as glomerulonephritis, lupus nephritis, IgA nephropathy, hypertensive nephropathy, diabetic kidney disease and acute kidney injury. Therefore, targeting Th17 cells to treat kidney diseases has been a hot topic in recent years. This article reviews the mechanisms of Th17 cell-mediated inflammation and autoimmune responses in kidney diseases and discusses the related clinical drugs that modulate Th17 cell fate in kidney disease treatment.

MAP kinase inhibitor PD98059 regulates Th1, Th9, Th17, and natural T regulatory cells in an experimental autoimmune encephalomyelitis mouse model of multiple sclerosis

Experimental autoimmune encephalitis (EAE), an animal model of multiple sclerosis (MS), provides significant insights into the mechanisms that initiate and drive autoimmunity. MS is a chronic autoimmune disease of the central nervous system, characterized by inflammatory infiltration associated with demyelination. T lymphocyte cells play a crucial role in MS, whereas natural T regulatory (nTreg) cells prevent autoimmune inflammation by suppressing lymphocyte activity. This study sought to investigate the role of PD98059, a selective MAP kinase inhibitor, in Th1, Th9, Th17, and nTreg cells using the SJL/J mouse model of EAE. Following EAE development, the mice were intraperitoneally administered PD98059 (5 mg/kg for two weeks) daily. We evaluated the effects of PD98059 on Th1 (IFN-γ and T-bet), Th9 (IL-9 and IRF4), Th17 (IL-17A and RORγT), and nTreg (FoxP3 and Helios) cells in the spleen using flow cytometry. Moreover, we explored the effects of PD98059 on the IFN-γ, T-bet, IL-9, IRF4, IL-17A, RORγT, FoxP3, and Helios mRNA and protein levels in brain tissues using qRT-PCR and Western blot analyses. PD98059 treatment significantly decreased the proportion of CD4+IFN-γ+, CD4+T-bet+, CD4+IL-9+, CD4+IRF4+, CD4+IL-17A+, CD4+RORγT+, CD4+IL-17A+, and CD4+RORγT+ cells while increasing that of CD4+FoxP3+ and CD4+Helios+ cells. In addition, PD98059 administration decreased the mRNA and protein levels of IFN-γ, T-bet, IL-9, IRF4, IL-17A, and RORγT but increased those of FoxP3 and Helios in the brain tissue of EAE mice. Our findings suggest that PD98059 corrects immune dysfunction in EAE mice, which is concurrent with the modulation of multiple signaling pathways.

Identification of 6 cuproptosis-related genes for active ulcerative colitis with both diagnostic and therapeutic values

Cuproptosis has been reported to affect a variety of diseases. Therefore, we aimed to examine the role of cuproptosis-related genes in active ulcerative colitis (UC). We acquired 2 datasets of active UC from the Gene Expression Omnibus database and created immune cell infiltrations to research immune cell dysregulation. Based on the cuproptosis gene set and differentially expressed genes (DEGs), we identified the differentially expressed genes of cuproptosis (CuDEGs). We then used 2 machine learning methods to screen hub CuDEGs. Subsequently, we performed validation on additional datasets and investigated the relationship between hub CuDEGs and drug treatments. Thirty-five controls with inactive UC and 90 patients with active UC were obtained from the training sets. A total of 9157 DEGs and 27 CuDEGs were identified, respectively. Immune cell infiltration analysis revealed that patients with active UC exhibited higher levels of activated dendritic cells and neutrophils as well as lower levels of CD8+ T cells, regulatory T cells (Tregs), and macrophage M2. A six-gene cuproptosis signature was identified using machine learning algorithms. We further validated that the 6 hub CuDEGs showed a strong correlation with active UC and acted as cuproptosis-related biomarkers of active UC. Moreover, the expression of ATOX1 was downregulated, and SUMF1, MT1G, ATP7B, FDX1, and LIAS expression was upregulated in the colonic mucosa of active UC patients who responded to golimumab or vedolizumab therapy. With the exception of ATP7B, the expression patterns of hub CuDEGs before and after infliximab treatment of patients with active UC were similar to those of golimumab and vedolizumab. Cuproptosis and active UC have a complex relationship, as illustrated in our study. ATOX1, SUMF1, MT1G, ATP7B, FDX1, and LIAS are cuproptosis-related hub genes of active UC. Our study opens new avenues for investigating UC progression and developing novel therapeutic potential targets for the disease.

Interleukin 17 signaling supports clinical benefit of dual CTLA-4 and PD-1 checkpoint inhibition in melanoma

Recent studies suggest that BRAFV600-mutated melanomas in particular respond to dual anti-programmed cell death protein 1 (PD-1) and anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) immune checkpoint inhibition (ICI). Here we identified an over-representation of interleukin (IL)-17-type 17 helper T (TH17) gene expression signatures (GES) in BRAFV600-mutated tumors. Moreover, high baseline IL-17 GES consistently predicted clinical responses in dual-ICI-treated patient cohorts but not in mono anti-CTLA-4 or anti-PD-1 ICI cohorts. High IL-17 GES corresponded to tumor infiltration with T cells and neutrophils. Accordingly, high neutrophil infiltration correlated with clinical response specifically to dual ICI, and tumor-associated neutrophils also showed strong IL-17-TH17 pathway activity and T cell activation capacity. Both the blockade of IL-17A and the depletion of neutrophils impaired dual-ICI response and decreased T cell activation. Finally, high IL-17A levels in the blood of patients with melanoma indicated a higher global TH17 cytokine profile preceding clinical response to dual ICI but not to anti-PD-1 monotherapy, suggesting a future role as a biomarker for patient stratification.

Interplay of Chemokines Receptors, Toll-like Receptors, and Host Immunological Pathways

A comprehensive framework has been established for understanding immunological pathways, which can be categorized into eradicated and tolerable immune responses. Toll-like receptors (TLRs) are associated with specific immune responses. TH1 immunity is related to TLR7, TLR8, and TLR9, while TH2 immunity is associated with TLR1, TLR2, and TLR6. TH22 immunity is linked to TLR2, TLR4, and TLR5, and THαβ (Tr1) immunity is related to TLR3, TLR7, and TLR9. The chemokine receptor CXCR5 is a marker of follicular helper T cells, and other chemokine receptors can also be classified within a framework based on host immunological pathways. On the basis of a literature review on chemokines and immunological pathways, the following associations were identified: CCR5 with TH1 responses, CCR1 with TH1-like responses, CCR4 (basophils) and CCR3 (eosinophils) with TH2 and TH9 responses, CCR10 with TH22 responses, CCR6 with TH17 responses, CXCR3 with THαβ responses, CCR8 with regulatory T cells (Treg), and CCR2 with TH3 responses. These findings contribute to the identification of biomarkers for immune cells and provide insights into host immunological pathways. Understanding the chemokine and Toll-like receptor system is crucial for comprehending the function of the innate immune system, as well as adaptive immune responses.

Biapenem, a Carbapenem Antibiotic, Elicits Mycobacteria Specific Immune Responses and Reduces the Recurrence of Tuberculosis

Tuberculosis (TB) still tops the list of global health burdens even after COVID-19. However, it will sooner transcend the current pandemic due to the prevailing risk of reactivation of latent TB in immunocompromised individuals. The indiscriminate misuse and overuse of antibiotics have resulted in the emergence of deadly drug-resistant variants of Mycobacterium tuberculosis (M.tb). This study aims to characterize the functionality of the carbapenem antibiotic-Biapenem (BPM) in generating long-lasting immunity against TB. BPM treatment significantly boosted the activation status of the innate immune arm-macrophages by augmenting p38 signaling. Macrophages further primed and activated the adaptive immune cells CD4+ and CD8+ T-cells in the lung and spleen of the infected mice model. Furthermore, BPM treatment significantly amplified the polarization of T lymphocytes toward inflammatory subsets, such as Th1 and Th17. The treatment also helped generate a long-lived central memory T-cell subset. The generation of central memory T lymphocyte subset upon BPM treatment in the murine model led to a significant curtailing in the recurrence of TB due to reactivation and reinfection. These results suggest the potentiality of BPM as a potent adjunct immunomodulator to improve host defense against M.tb by enriching long-term protective memory cells. IMPORTANCE Tuberculosis (TB) caused by Mycobacterium tuberculosis (M.tb) tops the list of infectious killers around the globe. The emergence of drug-resistant variants of M.tb has been a major hindrance toward realizing the "END TB" goal. Drug resistance has amplified the global burden toward the quest for novel drug molecules targeting M.tb. Host-directed therapy (HDT) offers a lucrative alternative to tackle emerging drug resistance and disease relapse by strengthening the host's immunity. Through our present study, we have tried to characterize the functionality of the carbapenem antibiotic-Biapenem (BPM). BPM treatment significantly augmented long-lasting immunity against TB by boosting the innate and adaptive immune arms. The generation of long-lived central memory T lymphocyte subset significantly improved the disease outcome and provided sterilizing immunity in the murine model of TB. The present investigation's encouraging results have helped us depict BPM as a potent adjunct immunomodulator for treating TB.

Early urinary candidate biomarkers and clinical outcomes of intervention in a rat model of experimental autoimmune encephalomyelitis

Multiple sclerosis is a chronic autoimmune demyelinating disease of the central nervous system and is difficult to diagnose in early stages. Without homeostatic control, urine was reported to have the ability to accumulate early changes in the body. We expect that urinary proteome can reflect early changes in the nervous system. The early urinary proteome changes in a most employed multiple sclerosis rat model (experimental autoimmune encephalomyelitis) were analysed to explore early urinary candidate biomarkers, and early treatment of methylprednisolone was used to evaluate the therapeutic effect. Twenty-five urinary proteins were altered at day 7 when there were no clinical symptoms and obvious histological changes. Fourteen were reported to be differently expressed in the serum/cerebrospinal fluid/brain tissues of multiple sclerosis patients or animals such as angiotensinogen and matrix metallopeptidase 8. Functional analysis showed that the dysregulated proteins were associated with asparagine degradation, neuroinflammation and lipid metabolism. After the early treatment of methylprednisolone, the incidence of encephalomyelitis in the intervention group was only 1/13. This study demonstrates that urine may be a good source of biomarkers for the early detection of multiple sclerosis. These findings may provide important information for early diagnosis and intervention of multiple sclerosis in the future.

Identification of the Binding Epitope of an Anti-Mouse CCR6 Monoclonal Antibody (C6Mab-13) Using 1× Alanine Scanning

CC chemokine receptor 6 (CCR6) is one of the members of the G-protein-coupled receptor (GPCR) family that is upregulated in many immune-related cells, such as B lymphocytes, effector and memory T cells, regulatory T cells, and immature dendritic cells. The coordination between CCR6 and its ligand CC motif chemokine ligand 20 (CCL20) is deeply involved in the pathogenesis of various diseases, such as cancer, psoriasis, and autoimmune diseases. Thus, CCR6 is an attractive target for therapy and is being investigated as a diagnostic marker for various diseases. In a previous study, we developed an anti-mouse CCR6 (mCCR6) monoclonal antibody (mAb), C₆Mab-13 (rat IgG₁, kappa), that was applicable for flow cytometry by immunizing a rat with the N-terminal peptide of mCCR6. In this study, we investigated the binding epitope of C₆Mab-13 using an enzyme-linked immunosorbent assay (ELISA) and the surface plasmon resonance (SPR) method, which were conducted with respect to the synthesized point-mutated-peptides within the 1-20 amino acid region of mCCR6. In the ELISA results, C₆Mab-13 lost its ability to react to the alanine-substituted peptide of mCCR6 at Asp11, thereby identifying Asp11 as the epitope of C₆Mab-13. In our SPR analysis, the dissociation constants (K_D) could not be calculated for the G9A and D11A mutants due to the lack of binding. The SPR analysis demonstrated that the C₆Mab-13 epitope comprises Gly9 and Asp11. Taken together, the key binding epitope of C₆Mab-13 was determined to be located around Asp11 on mCCR6. Based on the epitope information, C₆Mab-13 could be useful for further functional analysis of mCCR6 in future studies.

Mitogen-activated protein kinase inhibitor PD98059 improves neuroimmune dysfunction in experimental autoimmune encephalomyelitis in SJL/J mice through the inhibition of nuclear factor-kappa B signaling in B cells

Multiple sclerosis (MS) is a severe autoimmune disease leading to demyelination, followed by consequent axonal degeneration, causing sensory, motor, cognitive, and visual symptoms. Experimental autoimmune encephalomyelitis (EAE) is the most well-studied animal model of MS. Most current MS treatments are not completely effective, and severe side effects remain a great challenge. In this study, we report the therapeutic efficacy of PD98059, a potent mitogen-activated protein kinase inhibitor, on proteolipid protein (PLP)_139-151-induced EAE in SJL/J mice. Following the induction of EAE, mice were intraperitoneally treated with PD98059 (5 mg/kg for 14 days) daily from day 14 to day 28. This study investigated the effects of PD98059 on C-C motif chemokine receptor 6 (CCR6), CD14, NF-κB p65, IκBα, GM-CSF, iNOS, IL-6, TNF-α in CD45R⁺ B lymphocytes using flow cytometry. Furthermore, we analyzed the effect of PD98059 on CCR6, CD14, NF-κB p65, GM-CSF, iNOS, IL-6, and TNF-α mRNA and protein expression levels using qRT-PCR analysis in brain tissues. Mechanistic investigations revealed that PD98059-treated in mice with EAE had reduced CD45R⁺CCR6⁺, CD45R⁺CD14⁺, CD45R⁺NF-κB p65⁺, CD45R⁺GM-CSF⁺, CD45R⁺iNOS⁺, CD45R⁺IL-6⁺, and CD45R⁺TNF-α⁺ cells and increased CD45R⁺IκBα⁺ cells compared with vehicle-treated control mice in the spleen. Moreover, downregulation of CCR6, CD14, NF-κB p65, GM-CSF, iNOS, IL-6, and TNF-α mRNA expression level was observed in PD98059-treated mice with EAE compared with vehicle-treated control mice in the brain tissue. The results of this study demonstrate that PD98059 modulates inflammatory mediators through multiple cellular mechanisms. The results of this study suggest that PD98059 may be pursued as a therapeutic agent for the treatment of MS.

The role, targets and mechanisms of traditional Chinese medicine in regulating the balance of T helper type 17/regulatory Tcells in rheumatoid arthritis

Rheumatoid arthritis (RA) is a persistent systemic autoimmune disease, having all the hallmarks of joint swelling, joint tenderness, and progressive joint destruction, with synovitis and pannus formation as the basic pathological changes. T-lymphocyte infiltration is the key to its pathogenesis. During the growth of RA, the share of regulatory T (Treg) cells decreases, while the percentage of T helper type 17 (Th17) cells increases, giving rise to an imbalance of Th17/Treg cells. Modern medicine has made great advances in the treatment of RA and the selection of available drugs, but there are also the disadvantages of gastrointestinal reaction, high price, and low patient compliance. Therapy of RA remains a problem. Traditional Chinese medicine (TCM) has RA therapy developments, both in experimental research and clinical research, and its advantages of lasting effects and less detrimental reactions and fewer adverse effects are accepted by most patients. Numerous clinical and experimental studies have been performed in TCM on regulating Th17/Treg balance. However, the detailed mechanism of TCM intervention in Th17/Treg equilibrium in preventing and treating RA has not been discovered. In this article, the theory of regulating Th17/Treg cell equilibrium in RA is described from the perspectives of single Chinese medicine, active components of Chinese medicine, Chinese medicine compounds, and other therapies of TCM. It was found that TCM can regulate Th17/Treg cell balance and inhibit immunoreaction by intervening in cytokines, transcription factors, and signal pathways. It enables us to comprehensively and deeply understand the mechanism of TCM intervening in Th17/Treg balance in RA; provides direction for clinical therapy of RA; and offers new thoughts for understanding the pathogenesis of RA.

Anti-inflammatory and immunomodulatory effects of polysaccharide extracted from Wuguchong (maggot) on 2,4-dinitrochlorobenzene-induced atopic dermatitis in mice

Atopic dermatitis (AD) is an inflammatory, heterogeneous, chronic skin disorder characterized by recurrent eczematous lesions and intense pruritus, and the pathophysiology mechanism of AD is known for immune dysregulation and inflammatory responses. Wuguchong (maggot) has been widely used in the wound field and found with pharmacological properties of the anti-inflammatory and immunomodulatory function. Recently, some polysaccharides were proven to have beneficial effects on AD skin lesions in mice and humans. However, the effect of the polysaccharide extracted from Wuguchong (PEW) on AD remains to be investigated. In the present study, we examined the anti-inflammatory and immunomodulatory effects of PEW on AD and explored the potential mechanisms. Balb/c mice were orally administrated with PEW to evaluate the therapeutic effect of PEW on 2,4-dinitrochlorobenzene (DNCB)-induced AD. Oral PEW administration significantly ameliorated the lesions and symptoms in AD mice, such as the ear thickness and ear swelling degree, epidermal and dermal thickness, and the infiltration of mast cells. In addition, PEW treatment decreased the levels of serum IgE and histamine, the frequencies of Th1 and Th17 cells, as well as the mRNA expression levels of Th1 and Th17 cytokines and nuclear transcript factors (IFN-γ, T-bet, IL-17A, and ROR-rt). Furthermore, the activation of the NF-κB pathway and the phosphorylation of MAPKs (p38, ERK, and JNK) were significantly suppressed by PEW treatment. Taken together, our study suggests that PEW exerts anti-inflammatory and immunomodulatory effects through inhibition of Th1 and Th17 responses and downregulation of NF-κB and MAPK pathways, PEW would be developed as a promising immune therapy for AD.

Receptor-Mediated Redox Imbalance: An Emerging Clinical Avenue against Aggressive Cancers

Cancer cells are more vulnerable to abnormal redox fluctuations due to their imbalanced antioxidant system, where cell surface receptors sense stress and trigger intracellular signal relay. As canonical targets of many targeted therapies, cell receptors sensitize the cells to specific drugs. On the other hand, cell target mutations are commonly associated with drug resistance. Thus, exploring effective therapeutics targeting diverse cell receptors may open new clinical avenues against aggressive cancers. This paper uses focused case studies to reveal the intrinsic relationship between the cell receptors of different categories and the primary cancer hallmarks that are associated with the responses to external or internal redox perturbations. Cold atmospheric plasma (CAP) is examined as a promising redox modulation medium and highly selective anti-cancer therapeutic modality featuring dynamically varying receptor targets and minimized drug resistance against aggressive cancers.

Th17-cells in depression: Implication in multiple sclerosis

Depression is one of the most common neuropsychological symptoms of multiple sclerosis. However, in addition to mood disorder, depression can also influence on multiple sclerosis course. The mechanism of this dependence is not fully understood. The recent studies suggest the possible common immune mechanisms in the pathogenesis of depression and multiple sclerosis. In particular, it was shown that along with biogenic amines disturbance, neuroinflammation also play an important role in the pathogenesis of depression. Significant attention is drawn to Th17-cells subsets, which are considered as critical players in the pathogenesis of inflammatory diseases of the central nervous system, including multiple sclerosis. This brief report reviews the literature data on the role of neuroinflammation in the reciprocal influence of multiple sclerosis and depression with focus on Th17-cells, which may underlie pathogenetic mechanisms of both this diseases.

Interleukin 22 and its association with neurodegenerative disease activity

It is worth noting that neuroinflammation is well recognized as a symptom of neurodegenerative diseases (NDs). The regulation of neuroinflammation becomes an attractive focus for innovative ND treatment technologies. There is evidence that IL-22 is associated with the development and progression of a wide assortment of NDs. For example, IL-22 can activate glial cells, causing them to generate pro-inflammatory cytokines and encourage lymphocyte infiltration in the brain. IL-22 mRNA is highly expressed in Alzheimer’s disease (AD) patients, and a high expression of IL-22 has also been detected in the brains of patients with other NDs. We examine the role of IL-22 in the development and treatment of NDs in this review, and we believe that IL-22 has therapeutic potential in these diseases.

Comparative Transcriptomic Analyses Revealed the Effects of Poly (I:C) on the Liver and Spleen of Argyrosomus japonicus

Poly (I:C) can work as an immunostimulant and a viral vaccine; however, its functional mechanism in aquatic animals needs to be further investigated. In this study, comparative transcriptomic analyses were performed to investigate the effects of poly (I:C) on Argyrosomus japonicus at 12 h and 48 h postinjection. A total of 194 and 294 differentially expressed genes were obtained in the liver and spleen, respectively. At 12 h, poly (I:C) injection could significantly influence the function of the metabolism-related pathways and immune-related pathways in the liver through the upregulation of the genes GST, LPIN, FOXO1, CYP24A1, ECM1, and SGK1, and the downregulation of the genes IL-1β, CXC19, TNFAIP3, and IRF1. At 48 h, poly (I:C) could enhance the liver energy metabolism by upregulating the genes TXNRD and ECM1, while it also induced some injury in the cells with the downregulation of the genes HBA and CYP24A1. In the spleen, poly (I:C) could regulate the fish immunity and inflammatory response by upregulating the genes DDIT4, C3, EFNA, and MNK, and by downregulating the genes ABCA1, SORT1, TNF, TLR2, IL8, and MHCII at 12 h, and at 48 h, the poly (I:C) had a similar influence as that in the liver. Intersection analyses demonstrated that CYP24A1 and ECM1 were the main functional genes that contributed to the health of the liver. Ten and four genes participated in maintaining the health of the two tissues after 12 h and 48 h, respectively. In summary, our results provided a new insight into ploy (I:C) application in A. japonicus, and it also helped us to better understand the fish response mechanism to the viral vaccine injection.

Oncology Drug Repurposing for Sepsis Treatment

Sepsis involves life-threatening organ dysfunction caused by a dysregulated host response to infection. Despite three decades of efforts and multiple clinical trials, no treatment, except antibiotics and supportive care, has been approved for this devastating syndrome. Simultaneously, numerous preclinical studies have shown the effectiveness of oncology-indicated drugs in ameliorating sepsis. Here we focus on cataloging these efforts with both oncology-approved and under-development drugs that have been repositioned to treat bacterial-induced sepsis models. In this context, we also envision the exciting prospect for further standard and oncology drug combination testing that could ultimately improve clinical outcomes in sepsis.

Intravenous Immunoglobulin Therapy Restores the Quantity and Phenotype of Circulating Dendritic Cells and CD4+ T Cells in Children With Acute Kawasaki Disease

Background

Intravenous immunoglobulin (IVIG) showed its therapeutic efficacy on Kawasaki disease (KD). However, the mechanisms by which it reduces systemic inflammation are not completely understood. Dendritic cells (DCs) and T cells play critical roles in the pathogenic processes of immune disorders. Assessing the quantity of DC subsets and T cells and identifying functional molecules present on these cells, which provide information about KD, in the peripheral blood may provide new insights into the mechanisms of immunoglobulin therapy.

Methods

In total, 54 patients with KD and 27 age-matched healthy controls (HCs) were included in this study. The number, percentage, and phenotype of DC subsets and CD4⁺ T cells in peripheral blood were analyzed through flow cytometry.

Results

Patients with KD exhibited fewer peripheral DC subsets and CD4⁺ T cells than HCs. Human leucocyte antigen-DR (HLA-DR) expression was reduced on CD1c⁺ myeloid DCs (CD1c⁺ mDCs), whereas that on plasmacytoid DCs (pDCs) did not change significantly. Both pDCs and CD1c⁺ mDCs displayed significantly reduced expression of co-stimulatory molecules, including CD40, CD86. pDCs and CD1c⁺ mDCs presented an immature or tolerant phenotype in acute stages of KD. Number of circulating pDC and CD1c⁺ mDC significantly inversely correlated with plasma interleukin-6 (IL-6) levels in KD patients pre-IVIG treatment. No significant differences were found concerning the DC subsets and CD4⁺ T cells in patients with KD with and without coronary artery lesions. Importantly, these altered quantity and phenotypes on DC subsets and CD4⁺ T cells were restored to a great extent post-IVIG treatment. T helper (Th) subsets including Th1 and Th2 among CD4⁺ T cells did not show alteration pre- and post-IVIG treatment, although the Th1-related cytokine IFN-γ level in plasma increased dramatically in patients with KD pre-IVIG treatment.

Conclusions

pDCs and CD1c⁺ mDCs presented an immature or tolerant phenotype in acute stages of KD, IVIG treatment restored the quantity and functional molecules of DCs and CD4⁺ T cells to distinct levels in vivo, indicating the involvement of DCs and CD4⁺ T cells in the inflammation in KD. The findings provide insights into the immunomodulatory actions of IVIG in KD.

A tale of two proteins: PACT and PKR and their roles in inflammation

Inflammation is a pathological hallmark associated with bacterial and viral infections, autoimmune diseases, genetic disorders, obesity and diabetes, as well as environmental stresses including physical and chemical trauma. Among numerous proteins regulating proinflammatory signaling, very few such as Protein kinase R (PKR), have been shown to play an all-pervading role in inflammation induced by varied stimuli. PKR was initially characterized as an interferon-inducible gene activated by viral double-stranded RNA with a role in protein translation inhibition. However, it has become increasingly clear that PKR is involved in multiple pathways that promote inflammation in response to stress activation, both dependent on and independent of its cellular protein activator of PKR (PACT). In this review, we discuss the signaling pathways that contribute to the initiation of inflammation, including Toll-like receptor, interferon, and RIG-I-like receptor signaling, as well as inflammasome activation. We go on to discuss the specific roles that PKR and PACT play in such proinflammatory signaling, as well as in metabolic syndrome- and environmental stress-induced inflammation.

p38 MAP Kinase Signaling in Microglia Plays a Sex-Specific Protective Role in CNS Autoimmunity and Regulates Microglial Transcriptional States

Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system, representing the leading cause of non-traumatic neurologic disease in young adults. This disease is three times more common in women, yet more severe in men, but the mechanisms underlying these sex differences remain largely unknown. MS is initiated by autoreactive T helper cells, but CNS-resident and CNS-infiltrating myeloid cells are the key proximal effector cells regulating disease pathology. We have previously shown that genetic ablation of p38α MAP kinase broadly in the myeloid lineage is protective in the autoimmune model of MS, experimental autoimmune encephalomyelitis (EAE), but only in females, and not males. To precisely define the mechanisms responsible, we used multiple genetic approaches and bone marrow chimeras to ablate p38α in microglial cells, peripheral myeloid cells, or both. Deletion of p38α in both cell types recapitulated the previous sex difference, with reduced EAE severity in females. Unexpectedly, deletion of p38α in the periphery was protective in both sexes. In contrast, deletion of p38α in microglia exacerbated EAE in males only, revealing opposing roles of p38α in microglia vs. periphery. Bulk transcriptional profiling revealed that p38α regulated the expression of distinct gene modules in male vs. female microglia. Single-cell transcriptional analysis of WT and p38α-deficient microglia isolated from the inflamed CNS revealed a diversity of complex microglial states, connected by distinct convergent transcriptional trajectories. In males, microglial p38α deficiency resulted in enhanced transition from homeostatic to disease-associated microglial states, with the downregulation of regulatory genes such as Atf3, Rgs1, Socs3, and Btg2, and increased expression of inflammatory genes such as Cd74, Trem2, and MHC class I and II genes. In females, the effect of p38α deficiency was divergent, exhibiting a unique transcriptional profile that included an upregulation of tissue protective genes, and a small subset of inflammatory genes that were also upregulated in males. Taken together, these results reveal a p38α-dependent sex-specific molecular pathway in microglia that is protective in CNS autoimmunity in males, suggesting that autoimmunity in males and females is driven by distinct cellular and molecular pathways, thus suggesting design of future sex-specific therapeutic approaches.

Targeting the non-ATP-binding pocket of the MAP kinase p38γ mediates a novel mechanism of cytotoxicity in cutaneous T-cell lymphoma (CTCL)

We describe here for the first time a lipid‐binding‐domain (LBD) in p38γ mitogen‐activated protein kinase (MAPK) involved in the response of T cells to a newly identified inhibitor, CSH71. We describe how CSH71, which binds to both the LBD and the ATP‐binding pocket of p38γ, is selectively cytotoxic to CTCL Hut78 cells but spares normal healthy peripheral blood mononuclear (PBMC) cells, and propose possible molecular mechanisms for its action. p38γ is a key player in CTCL development, and we expect that the ability to regulate its expression by specifically targeting the lipid‐binding domain will have important clinical relevance. Our findings characterize novel mechanisms of gene regulation in T lymphoma cells and validate the use of computational screening techniques to identify inhibitors for therapeutic development.

Understanding Abnormal c-JNK/p38MAPK Signaling Overactivation Involved in the Progression of Multiple Sclerosis: Possible Therapeutic Targets and Impact on Neurodegenerative Diseases

Demyelination, immune dysregulation, and neuroinflammation are the most common triggers of motor neuron disorders such as multiple sclerosis (MS). MS is a chronic demyelinating neurodegenerative disease of the central nervous system caused by abnormal immune activation, which causes myelin sheath damage. Cell signal transduction pathways are required for a variety of physiological and pathological processes in the brain. When these signaling systems become overactive, they can lead to disease progression. In various physiological conditions, abnormal mitogen-activated protein kinase (MAPK) activation is associated with several physiological dysfunctions that cause neurodegeneration. Previous research indicates that c-JNK and p38MAPK signaling play critical roles in neuronal growth and differentiation. c-JNK/p38MAPK is a member of the MAPK family, which regulates metabolic pathways, cell proliferation, differentiation, and apoptosis that control certain neurological activities. During brain injuries, c-JNK/p38MAPK also affects neuronal elastic properties, nerve growth, and cognitive processing. This review systematically linked abnormal c-JNK/p38MAPK signaling activation to multiple neuropathological pathways in MS and related neurological dysfunctions. MS progression is linked to genetic defects, oligodendrocyte destruction, glial overactivation, and immune dysregulation. We concluded that inhibiting both the c-JNK/p38MAPK signaling pathways can promote neuroprotection and neurotrophic effects against the clinical-pathological presentation of MS and influence other neurological disorders. As a result, the potential benefits of c-JNK/p38MAPK downregulation for the development of disease-modifying treatment interventions in the future could include MS prevention and related neurocomplications.

Exposure to biomass smoke induces pulmonary Th17 cell differentiation by activating TLR2 on dendritic cells in a COPD rat model

Almost three billion people in developing countries are exposed to biomass smoke (BS), which predisposes them to developing chronic obstructive pulmonary disease (COPD). COPD is associated with abnormal innate and adaptive immune responses in the lungs and systemic circulation, but the mechanisms underlying BS-COPD development are uncertain. We investigated the role of dendritic cells (DCs) and interleukin (IL)-17A in BS-COPD. We investigated T helper cell responses in the BS-exposed COPD rat model by flow cytometry, quantitative PCR, and enzyme-linked immunosorbent assays. We conducted ex vivo experiments to determine which antigen-presenting cells induce Th17 cell responses. We evaluated the in vitro effects of BS-related particulate matter (BRPM) (2.5 μm) on the function of bone marrow-derived dendritic cells (BMDCs). We found that BS exposure enhanced Th17 responses in the lungs of the COPD-modelled rats, and the stimulated DCs (but not the macrophages) were sufficient to induce naïve CD4 + T cells to produce IL-17A in ex vivo experiments. BRPM significantly enhanced the maturation and activation of DCs through Toll-like receptor 2 (TLR2), but not TLR4, and induced Th17 responses. Therefore, BS activated lung DCs through TLR2, which led to Th17 responses and emphysema in the rats. This process is possibly therapeutically targetable.

Superoxide Dismutase 3 Controls the Activation and Differentiation of CD4+T Cells

Superoxide dismutase 3 (SOD3), a well-known antioxidant has been shown to possess immunomodulatory properties through inhibition of T cell differentiation. However, the underlying inhibitory mechanism of SOD3 on T cell differentiation is not well understood. In this study, we investigated the effect of SOD3 on anti-CD3/CD28- or phorbol myristate acetate (PMA) and ionomycin (ION)-mediated activation of mouse naive CD4⁺ T cells. Our data showed that SOD3 suppressed the expression of activation-induced surface receptor proteins such as CD25, and CD69, and cytokines production. Similarly, SOD3 was found to reduce CD4⁺T cells proliferation and suppress the activation of downstream pathways such as ERK, p38, and NF-κB. Moreover, naïve CD4⁺T cells isolated from global SOD3 knock-out mice showed higher expression of CD25, CD69, and CD71, IL-2 production, proliferation, and downstream signals compared to wild-type CD4⁺T cells. Whereas, the use of DETCA, a known inhibitor of SOD3 activity, found to nullify the inhibitory effect of SOD3 on CD4⁺T cell activation of both SOD3 KO and wild-type mice. Furthermore, the expression of surface receptor proteins, IL-2 production, and downstream signals were also reduced in Th2 and Th17 differentiated cells upon SOD3 treatment. Overall, our data showed that SOD3 can attenuate CD4⁺T cell activation through modulation of the downstream signalings and restrict CD4⁺T cell differentiation. Therefore, SOD3 can be a promising therapeutic for T cell-mediated disorders.

miRNA-467b inhibits Th17 differentiation by targeting eIF4E in experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) are neuroinflammatory autoimmune diseases characterized by the axonal loss, demyelination, and neurodegeneration of the central nervous system. Overactivation of CD4⁺ T cells, especially the migration of the Th1 and Th17 subsets into the central nervous system (CNS), leads to the secretion of inflammatory mediators and destruction of the contact between neurons and activated macrophages, which can then result in a series of neurocognitive and motor deficits. In this study, we intended to explore the role of miRNA-467b in regulating Th cell development in EAE. We found that the level of miRNA-467b was decreased and eukaryotic initiation factor 4 F (eIF4E) was increased in lymph nodes and the CNS at EAE peak. eIF4E was confirmed as the direct target of miRNA467b. Overexpression of miRNA-467b could suppress a percentage of CD4⁺ IL-17⁺ cells in EAE CD4 + T cells in vitro. In addition, we also identified miRNA-467b, which could suppress Th17 cell differentiation by targeting eIF4E in vitro. Furthermore, injecting miRNA-467b mimics into the caudal vein of EAE mice contributed to less inflammation in the peripheral lymphoid organs and CNS and alleviated disease severity. Taken together, our findings imply that miRNA-467b inhibits the differentiation and function of Th17 cells by targeting eIF4E, thereby alleviating EAE.

Stress kinases in the development of liver steatosis and hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD) is an important component of metabolic syndrome and one of the most prevalent liver diseases worldwide. This disorder is closely linked to hepatic insulin resistance, lipotoxicity, and inflammation. Although the mechanisms that cause steatosis and chronic liver injury in NAFLD remain unclear, a key component of this process is the activation of stress-activated kinases (SAPKs), including p38 and JNK in the liver and immune system. This review summarizes findings which indicate that the dysregulation of stress kinases plays a fundamental role in the development of steatosis and are important players in inducing liver fibrosis. To avoid the development of steatohepatitis and liver cancer, SAPK activity must be tightly regulated not only in the hepatocytes but also in other tissues, including cells of the immune system. Possible cellular mechanisms of SAPK actions are discussed.

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Hepatic JNK triggers steatosis and insulin resistance, decreasing lipid oxidation and ketogenesis in HFD-fed mice.

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Decreased liver expression of p38α/β in HFD increases lipogenesis.

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Hepatic p38γ/δ drive insulin resistance and inhibit autophagy, which may lead to steatosis.

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Macrophage p38α/β promote cytokine production and M1 polarization, leading to lipid accumulation in hepatocytes.

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Myeloid p38γ/δ contribute to cytokine production and neutrophil migration, protecting against steatosis, diabetes and NAFLD.

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JNK1 and p38γ induce HCC while p38α blocks it. However, deletion of hepatic JNK1/2 induces cholangiocarcinoma.

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SAPK are potential therapeutic target for metabolic disorders, steatohepatitis and liver cancer.

The MAP kinase inhibitor PD98059 reduces chromosomal instability in the autoimmune encephalomyelitis SJL/J-mouse model of multiple sclerosis

Multiple sclerosis (MS), a disease in which the immune system attacks nerve cells, has been associated with both genetic and environmental risk factors. We observed increased micronucleus (MN) formation in SJL/J mouse experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Most of these MN were due to chromosomal loss. Increased activation of MAP kinases, which leads to disruption of the mitotic spindle and improper segregation of chromosomes, is associated with MS. MAP kinase inhibitors, such as PD98059, may therefore be beneficial for MS. In the EAE model, PD98059 treatment reduced adverse effects, including MN formation, lipid peroxidation, and GSH oxidation. Interventions that mitigate chromosomal instability may have therapeutic value in MS.

Inhibition of Ras GTPases prevents Collagen-Induced Arthritis by Reducing the Generation of Pathogenic CD4+ T Cells and the Hyposialylation of Autoantibodies

OBJECTIVE

RasGTPases are master regulators of multiple intracellular signaling cascades. Perturbation of this pathway has been implicated in the pathogenesis of rheumatoid arthritis (RA). In this study we aimed to define the therapeutic potential of a novel RasGTPases inhibitor, farnesylthiosalicylate (FTS), in the preclinical mouse model of collagen-induced arthritis (CIA) and better delineate its immunomodulatory effects both ex vivo and in the mouse.

METHODS

We analyzed in vitro the immunomodulatory effects of FTS on various CD4⁺ T-cell functions such as activation, proliferation, T-helper polarization, and production of proinflammatory cytokines. Using the CIA model, we further determined the efficacy of FTS to inhibit clinical, histopathologic, and diverse immunological outcomes of arthritis.

RESULTS

FTS treatment of CD4⁺ T cells in vitro effectively targeted distinct kinases (extracellular signal-regulated kinase 1/2, p38, protein kinase B/AKT, and mammalian target of rapamycin), the production of interleukin (IL)-17A, IL-22, and granulocyte-macrophage colony-stimulating factor, and Th17 polarization. FTS therapy in the mouse CIA model significantly reduced clinical disease severity and joint inflammation/damage by histology. Importantly, FTS suppressed the in vivo induction of splenic IL-17⁺ IL-22⁺ Th17 cells and the secretion of proinflammatory cytokines. The production of pathogenic autoantibodies and their abnormal hyposialylation was significantly attenuated by FTS therapy. Importantly, in vivo generation of collagen type-II specific effector CD4⁺ T cells was likewise repressed by FTS therapy.

CONCLUSION

The RasGTPases inhibitor FTS attenuates the production of proinflammatory cytokines by in vitro-activated T cells and is a potent immunomodulatory compound in the CIA model, primarily targeting the generation of autoreactive Th17 cells and the production of autoantibodies and their subsequent pathogenic hyposialylation.

Rationalized inhibition of mixed lineage kinase 3 and CD70 enhances life span and antitumor efficacy of CD8+ T cells

BACKGROUND

The mitogen-activated protein kinases (MAPKs) are important for T cell survival and their effector function. Mixed lineage kinase 3 (MLK3) (MAP3K11) is an upstream regulator of MAP kinases and emerging as a potential candidate for targeted cancer therapy; yet, its role in T cell survival and effector function is not known.

METHODS

T cell phenotypes, apoptosis and intracellular cytokine expressions were analyzed by flow cytometry. The apoptosis-associated gene expressions in CD8+CD38+ T cells were measured using RT2 PCR array. In vivo effect of combined blockade of MLK3 and CD70 was analyzed in 4T1 tumor model in immunocompetent mice. The serum level of tumor necrosis factor-α (TNFα) was quantified by enzyme-linked immunosorbent assay.

RESULTS

We report that genetic loss or pharmacological inhibition of MLK3 induces CD70-TNFα-TNFRSF1a axis-mediated apoptosis in CD8+ T cells. The genetic loss of MLK3 decreases CD8+ T cell population, whereas CD4+ T cells are partially increased under basal condition. Moreover, the loss of MLK3 induces CD70-mediated apoptosis in CD8+ T cells but not in CD4+ T cells. Among the activated CD8+ T cell phenotypes, CD8+CD38+ T cell population shows more than five fold increase in apoptosis due to loss of MLK3, and the expression of TNFRSF1a is significantly higher in CD8+CD38+ T cells. In addition, we observed that CD70 is an upstream regulator of TNFα-TNFRSF1a axis and necessary for induction of apoptosis in CD8+ T cells. Importantly, blockade of CD70 attenuates apoptosis and enhances effector function of CD8+ T cells from MLK3-/- mice. In immune-competent breast cancer mouse model, pharmacological inhibition of MLK3 along with CD70 increased tumor infiltration of cytotoxic CD8+ T cells, leading to reduction in tumor burden largely via mitochondrial apoptosis.

CONCLUSION

Together, these results demonstrate that MLK3 plays an important role in CD8+ T cell survival and effector function and MLK3-CD70 axis could serve as a potential target in cancer.

Apigenin Modulates Dendritic Cell Activities and Curbs Inflammation Via RelB Inhibition in the Context of Neuroinflammatory Diseases

Neuroinflammation leads to tissue injury causing many of the clinical symptoms of Multiple Sclerosis, an autoimmune disorder of the central nervous system (CNS). While T cells, specifically T_h1 and T_h17 cells, are the ultimate effectors of this disease, dendritic cells (DCs) mediate T cell polarization, activation, etc. In our previous study, Apigenin, a natural flavonoid, has been shown to reduce EAE disease severity through amelioration of demyelination in the CNS as well as the sequestering of DCs and other myeloid cells in the periphery. Here, we show that Apigenin exerts its effects possibly through shifting DC modulated T cell responses from T_h1 and T_h17 type towards T_reg directed responses evident through the decrease in T-bet, IFN-γ (T_h1), IL-17 (T_h17) and increase in IL-10, TGF-β and FoxP3 (T_reg) expression in cells from both normal human donors and EAE mice. RelB, an NF-κβ pathway protein is central to DC maturation, its antigen presentation capabilities and DC-mediated T cell activation. Apigenin reduced mRNA and protein levels of RelB and also reduced its nuclear translocation. Additionally, siRNA-mediated silencing of RelB further potentiated the RelB-mediated effects of Apigenin thus confirming its role in Apigenin directed regulation of DC biology. These results provide key information about the molecular events controlled by Apigenin in its regulation of DC activity marking its potential as a therapy for neuroinflammatory disease. Graphical Abstract.

The MNK1/2-eIF4E Axis as a Potential Therapeutic Target in Melanoma

: Melanoma is a type of skin cancer that originates in the pigment-producing cells of the body known as melanocytes. Most genetic aberrations in melanoma result in hyperactivation of the mitogen activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) pathways. We and others have shown that a specific protein synthesis pathway known as the MNK1/2-eIF4E axis is often dysregulated in cancer. The MNK1/2-eIF4E axis is a point of convergence for these signaling pathways that are commonly constitutively activated in melanoma. In this review we consider the functional implications of aberrant mRNA translation in melanoma and other malignancies. Moreover, we discuss the consequences of inhibiting the MNK1/2-eIF4E axis on the tumor and tumor-associated cells, and we provide important avenues for the utilization of this treatment modality in combination with other targeted and immune-based therapies. The past decade has seen the increased development of selective inhibitors to block the action of the MNK1/2-eIF4E pathway, which are predicted to be an effective therapy regardless of the melanoma subtype (e.g., cutaneous, acral, and mucosal).

Interleukin-17 Reduces βENaC via MAPK Signaling in Vascular Smooth Muscle Cells

Degenerin proteins, such as the beta epithelial Na⁺ channel (βENaC), are essential in the intracellular signaling of pressure-induced constriction, an important vascular smooth muscle cell (VSMC) function. While certain cytokines reduce ENaC protein in epithelial tissue, it is unknown if interleukin-17 (IL-17), a potent pro-inflammatory cytokine, directly mediates changes in membrane-associated βENaC in VSMCs. Therefore, we tested the hypothesis that exposure to IL-17 reduces βENaC in VSMCs through canonical mitogen-activated protein kinase (MAPK) signaling pathways. We treated cultured rat VSMCs (A10 cell line) with IL-17 (1–100 ng/mL) for 15 min to 16 h and measured expression of βENaC, p38MAPK, c-jun kinase (JNK), and nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). IL-17 reduced βENaC protein expression in a concentration-dependent fashion and increased phosphorylation of p38MAPK by 15 min and JNK by 8 h. NFκB was unaffected by IL-17 in VSMCs. IL-17 treatment reduced VSMC viability but had no effect on cell death. To determine the underlying signaling pathway involved in this response, VSMCs were treated before and during IL-17 exposure with p38MAPK or JNK inhibitors. We found that JNK blockade prevented IL-17-mediated βENaC protein suppression. These data demonstrate that the pro-inflammatory cytokine IL-17 regulates VSMC βENaC via canonical MAPK signaling pathways, raising the possibility that βENaC-mediated loss of VSMC function may occur in inflammatory disorders.

Immune Regulation of TNFAIP3 in Psoriasis through Its Association with Th1 and Th17 Cell Differentiation and p38 Activation

Background

Psoriasis is an immune-mediated chronic inflammatory skin disorder in which the dysregulation of immune cells plays an important role in its development. Tumor necrosis factor- (TNF-) α antagonists affect the immune repertoire, while TNF-α-induced protein 3 (TNFAIP3) has a protective role against the deleterious effects of inflammation and participates in immune regulation.

Objective

We investigated the immune regulation of TNFAIP3 in the pathogenesis of psoriasis and determined whether it is involved in the antipsoriatic effect of TNF-α antagonists.

Methods

mRNA levels were evaluated in blood from patients with moderate-to-severe psoriasis. The effects of TNF-α antagonists were examined in a mouse imiquimod- (IMQ-) induced psoriasis-like dermatitis model. In the mouse model, TNFAIP3 mRNA expression was determined using RT-PCR. Serum levels of IL-17A, IL-23, IFN-γ, TNF-α, phosphorylated ERK1/2, p38, and JNK were measured using ELISA. The proportion of Th1 and Th17 cells in mouse spleens was analyzed using flow cytometry.

Results

mRNA expression levels of TNFAIP3 in the blood were significantly lower in patients with moderate and severe psoriasis (mean ± SD = 0.44 ± 0.25) compared with normal subjects (mean ± SD = 1.00 ± 0.82) (P < 0.01). In the mouse model, IMQ downregulated TNFAIP3 expression levels, which were increased after TNF-α antagonist treatment (P < 0.05). Serum levels of Th17 cytokines (IL-17A and IL-23) and Th1 cytokines (IFN-γ and TNF-α) were significantly higher in the IMQ and IMQ/rat IgG1 groups compared with the control group, and the application of TNF-α antagonists significantly decreased the levels of inflammatory cytokines (P < 0.01). Notably, phosphorylated p38 levels were increased in the IMQ and IMQ/rat IgG1 groups compared with the control group but were downregulated by treatment with TNF-α antagonists (P < 0.05). Th1 and Th17 cells were significantly increased in the IMQ group compared with the control group (P < 0.01).

Conclusion

TNFAIP3 downregulation associated with Th1 and Th17 cell differentiation and p38 activation might contribute in part to the mechanism of immune dysfunction in psoriasis. TNF-α antagonists might partly exert their effects on psoriasis via this pathway.

Mixed lineage kinase 3 inhibition induces T cell activation and cytotoxicity

Mixed lineage kinase 3 (MLK3), also known as MAP3K11, was initially identified in a megakaryocytic cell line and is an emerging therapeutic target in cancer, yet its role in immune cells is not known. Here, we report that loss or pharmacological inhibition of MLK3 promotes activation and cytotoxicity of T cells. MLK3 is abundantly expressed in T cells, and its loss alters serum chemokines, cytokines, and CD28 protein expression on T cells and its subsets. MLK3 loss or pharmacological inhibition induces activation of T cells in in vitro, ex vivo, and in vivo conditions, irrespective of T cell activating agents. Conversely, overexpression of MLK3 decreases T cell activation. Mechanistically, loss or inhibition of MLK3 down-regulates expression of a prolyl-isomerase, Ppia, which is directly phosphorylated by MLK3 to increase its isomerase activity. Moreover, MLK3 also phosphorylates nuclear factor of activated T cells 1 (NFATc1) and regulates its nuclear translocation via interaction with Ppia, and this regulates T cell effector function. In an immune-competent mouse model of breast cancer, MLK3 inhibitor increases Granzyme B-positive CD8+ T cells and decreases MLK3 and Ppia gene expression in tumor-infiltrating T cells. Likewise, the MLK3 inhibitor in pan T cells, isolated from breast cancer patients, also increases cytotoxic CD8+ T cells. These results collectively demonstrate that MLK3 plays an important role in T cell biology, and targeting MLK3 could serve as a potential therapeutic intervention via increasing T cell cytotoxicity in cancer.

Identification and functional analysis of specific MS risk miRNAs and their target genes

BACKGROUND

It has been widely acknowledged that abnormal expression of microRNAs (miRNAs) may lead to the occurrence and development of MS through regulating target genes. Currently, only few studies have comprehensively evaluated the function and relationship between MS-related miRNAs and their target genes.

METHODS

Differentially expressed miRNAs in MS patients' serum and plasma were selected by reviewing numerous literatures manually. Then, thousands of target genes were screened by several online databases, of which 899 MS-related genes were further identified. Gene ontology, protein-protein interaction and KEGG pathway analysis were used to determine high-risk pathways and MS risk genes. Transcriptomic datasets from GEO was analyzed to evaluate these risk genes.

RESULTS

28 MS-related miRNAs were extracted. MiR-30e, miR-93, miR-155 were identified as the most crucial miRNAs through targeting hub genes: PIK3CA, PIK3R1, PIK3R2 and MAPK8. Seven immune pathways were screened out according to KEGG pathway analysis. Six transcriptomic datasets were used to evaluate results, and PIK3CA was differentially expressed in MS patients compared with healthy donors.

CONCLUSIONS

According to our research, MS-related miRNAs and their target genes of MS were identified and comprehensively evaluated. This work may provide a new insight for discovering pathogenesis and possible biomarkers of MS in future studies.

The sex-specific role of p38 MAP kinase in CNS autoimmunity is regulated by estrogen receptor alpha

Biological sex is a critical factor in regulating immune function. A striking example of this is the higher prevalence of autoimmune diseases such as multiple sclerosis (MS) and lupus in females compared to males. While many studies have implicated the role of sex hormones such as estrogens and androgens in these sex differences, surprisingly little is known about other molecular pathways that underlie sex differences or interact with sex hormones. We have previously shown that conditional ablation of p38α MAP kinase signaling in myeloid cells (p38αCKO) was protective in a mouse model of MS, experimental autoimmune encephalomyelitis (EAE), in female but not male mice. This sex difference was dependent on the presence of sex hormones, leading us to hypothesize that the pathogenic function of p38α in EAE depends on estrogen signaling via one of the two nuclear estrogen receptors, encoded by Esr1 and Esr2 . To test this hypothesis, we performed experiments with p38αCKO macrophages, which demonstrated that the effects of estradiol and p38α were independent of one another in vitro . Since many sex hormone effects are lost in vitro, we generated p38αCKO mice lacking either Esr1 or Esr2 , and evaluated their EAE susceptibility in vivo . Myeloid-specific deletion of Esr1 abrogated protection in p38αCKO females, although global deletion of Esr1 and Esr2 did not. Moreover, global or myeloid-specific disruption of Esr1 unexpectedly promoted protection from EAE in p38αCKO males. Mechanistically, Esr1 deletion resulted in partial reprogramming of p38α-dependent transcriptional modules in male macrophages, in particular those regulated by TGFβ, BRD4, and SMARCA4. These results demonstrate that estrogen signaling in myeloid cells plays an important sex-specific role in programming their dependence on specific intracellular signaling pathways in the context of autoimmune disease pathogenesis, suggesting potential avenues for sex-specific therapeutics or combinatorial approaches for the treatment of such diseases.

TNFα-Signaling Modulates the Kinase Activity of Human Effector Treg and Regulates IL-17A Expression

Maintenance of regulatory T cells CD4⁺CD25^highFOXP3⁺ (Treg) stability is vital for proper Treg function and controlling the immune equilibrium. Treg cells are heterogeneous and can reveal plasticity, exemplified by their potential to express IL-17A. TNFα-TNFR2 signaling controls IL-17A expression in conventional T cells via the anti-inflammatory ubiquitin-editing and kinase activity regulating enzyme TNFAIP3/A20 (tumor necrosis factor-alpha-induced protein 3). To obtain a molecular understanding of TNFα signaling on IL-17 expression in the human effector (_effTreg, CD25^highCD45RA⁻) Treg subset, we here studied the kinome activity regulation by TNFα signaling. Using FACS-sorted naïve (_naïveTreg, CD25^highCD45RA⁺) and _effTreg subsets, we demonstrated a reciprocal relationship between TNFα and IL-17A expression; _effTreg (TNFα^low/IL-17A^high) and _naïveTreg (TNFα^high/IL-17A^low). In _effTreg, TNFα-TNFR2 signaling prevented IL-17A expression, whereas inhibition of TNFα signaling by clinically applied anti-TNF antibodies led to increased IL-17A expression. Inhibition of TNFα signaling led to reduced TNFAIP3 expression, which, by using siRNA inhibition of TNFAIP3, appeared causally linked to increased IL-17A expression in _effTreg. Kinome activity screening of CD3/CD28-activated _effTreg revealed that anti-TNF-mediated neutralization led to increased kinase activity. STRING association analysis revealed that the TNF suppression _effTreg kinase activity network was strongly associated with kinases involved in TCR, JAK, MAPK, and PKC pathway signaling. Small-molecule-based inhibition of TCR and JAK pathways prevented the IL-17 expression in _effTreg. Together, these findings stress the importance of TNF-TNFR2 in regulating the kinase architecture of antigen-activated _effTreg and controlling IL-17 expression of the human Treg. These findings might be relevant for optimizing anti-TNF-based therapy and may aid in preventing Treg plasticity in case of Treg-based cell therapy.

Mitogen-Activated Protein Kinase Inhibitors and T-Cell-Dependent Immunotherapy in Cancer

Mitogen-activated protein kinase (MAPK) signaling networks serve to regulate a wide range of physiologic and cancer-associated cell processes. For instance, a variety of oncogenic mutations often lead to hyperactivation of MAPK signaling, thereby enhancing tumor cell proliferation and disease progression. As such, several components of the MAPK signaling network have been proposed as viable targets for cancer therapy. However, the contributions of MAPK signaling extend well beyond the tumor cells, and several MAPK effectors have been identified as key mediators of the tumor microenvironment (TME), particularly with respect to the local immune infiltrate. In fact, a blockade of various MAPK signals has been suggested to fundamentally alter the interaction between tumor cells and T lymphocytes and have been suggested a potential adjuvant to immune checkpoint inhibition in the clinic. Therefore, in this review article, we discuss the various mechanisms through which MAPK family members contribute to T-cell biology, as well as circumstances in which MAPK inhibition may potentiate or limit cancer immunotherapy.

Myeloid loss of Beclin 1 promotes PD-L1hi precursor B cell lymphoma development

Beclin 1 (Becn1) is a key molecule in the autophagy pathway and has been implicated in cancer development. Due to the embryonic lethality of homozygous Becn1-deficient mice, the precise mechanisms and cell type-specific roles of Becn1 in regulating inflammation and cancer immunity remain elusive. Here, we report that myeloid-deficient Becn1 (Becn1ΔM) mice developed neutrophilia, were hypersusceptible to LPS-induced septic shock, and had a high risk of developing spontaneous precursor B cell (pre-B cell) lymphoma with elevated expression of immunosuppressive molecules programmed death ligand 1 (PD-L1) and IL-10. Becn1 deficiency resulted in the stabilization of MEKK3 and aberrant p38 activation in neutrophils, and mediated neutrophil-B cell interaction through Cxcl9/Cxcr3 chemotaxis. Neutrophil-B cell interplay further led to the activation of IL-21/STAT3/IRF1 and CD40L/ERK signaling and PD-L1 expression; therefore, it suppressed CD8+ T cell function. Ablation of p38 in Becn1ΔM mice prevented neutrophil inflammation and B cell tumorigenesis. Importantly, the low expression of Becn1 in human neutrophils was significantly correlated with the PD-L1 levels in pre-B acute lymphoblastic lymphoma (ALL) patients. Our findings have identified myeloid Becn1 as a key regulator of cancer immunity and therapeutic target for pre-B cell lymphomas.

Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Induces Interleukin-17 Production via Activation of the IRAK1-PI3K-p38MAPK-C/EBPβ/CREB Pathways

Porcine reproductive and respiratory syndrome virus (PRRSV) is widely prevalent in pigs, resulting in significant economic losses worldwide. A compelling impact of PRRSV infection is severe pneumonia. In the present study, we found that interleukin-17 (IL-17) was upregulated by PRRSV infection. Subsequently, we demonstrated that PI3K and p38MAPK signaling pathways were essential for PRRSV-induced IL-17 production as addition of phosphatidylinositol 3-kinase (PI3K) and p38MAPK inhibitors dramatically reduced IL-17 production. Furthermore, we show here that deleting the C/EBPβ and CREB binding motif in porcine IL-17 promoter abrogated its activation and that knockdown of C/EBPβ and CREB remarkably impaired PRRSV-induced IL-17 production, suggesting that IL-17 expression was dependent on C/EBPβ and CREB. More specifically, we demonstrate that PRRSV nonstructural protein 11 (nsp11) induced IL-17 production, which was also dependent on PI3K-p38MAPK-C/EBPβ/CREB pathways. We then show that Ser74 and Phe76 amino acids were essential for nsp11 to induce IL-17 production and viral rescue. In addition, IRAK1 was required for nsp11 to activate PI3K and enhance IL-17 expression by interacting with each other. Importantly, we demonstrate that PI3K inhibitor significantly suppressed IL-17 production and lung inflammation caused by HP-PRRSV in vivo, implicating that higher IL-17 level induced by HP-PRRSV might be associated with severe lung inflammation. These findings provide new insights onto the molecular mechanisms of the PRRSV-induced IL-17 production and help us further understand the pathogenesis of PRRSV infection.IMPORTANCE Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) associated with severe pneumonia has been one of the most important viral pathogens in pigs. IL-17 is a proinflammatory cytokine that might be associated with the strong inflammation caused by PRRSV. Therefore, we sought to determine whether PRRSV infection affects IL-17 expression, and if so, determine this might partially explain the underlying mechanisms for the strong inflammation in HP-PRRSV-infected pigs, especially in lungs. Here, we show that PRRSV significantly induced IL-17 expression, and we subsequently dissected the molecular mechanisms about how PRRSV regulated IL-17 production. Furthermore, we show that Ser74 and Phe76 in nsp11 were indispensable for IL-17 production and viral replication. Importantly, we demonstrated that PI3K inhibitor impaired IL-17 production and alleviated lung inflammation caused by HP-PRRSV infection. Our findings will help us for a better understanding of PRRSV pathogenesis.

Alternative ZAP70-p38 signals prime a classical p38 pathway through LAT and SOS to support regulatory T cell differentiation

T cell receptor (TCR) stimulation activates diverse kinase pathways, which include the mitogen-activated protein kinases (MAPKs) ERK and p38, the phosphoinositide 3-kinases (PI3Ks), and the kinase mTOR. Although TCR stimulation activates the p38 pathway through a "classical" MAPK cascade that is mediated by the adaptor protein LAT, it also stimulates an "alternative" pathway in which p38 is activated by the kinase ZAP70. Here, we used dual-parameter, phosphoflow cytometry and in silico computation to investigate how both classical and alternative p38 pathways contribute to T cell activation. We found that basal ZAP70 activation in resting T cell lines reduced the threshold ("primed") TCR-stimulated activation of the classical p38 pathway. Classical p38 signals were reduced after T cell-specific deletion of the guanine nucleotide exchange factors Sos1 and Sos2, which are essential LAT signalosome components. As a consequence of Sos1/2 deficiency, production of the cytokine IL-2 was impaired, differentiation into regulatory T cells was reduced, and the autoimmune disease EAE was exacerbated in mice. These data suggest that the classical and alternative p38 activation pathways exist to generate immune balance.

Nasal delivery of Fasudil-modified immune cells exhibits therapeutic potential in experimental autoimmune encephalomyelitis

AIM

Multiple sclerosis (MS) is a relapsing-remitting inflammatory demyelinating disease that requires long-term treatment. Although Rho kinase inhibitor Fasudil shows good therapeutic effect in experimental autoimmune encephalomyelitis (EAE), an animal model of MS, certain side effects may limit its clinical use. This study aimed at observing the therapeutic potential of Fasudil-modified encephalitogenic mononuclear cells (MNCs) via nasal delivery in EAE and exploring possible mechanisms of action.

METHODS

Experimental autoimmune encephalomyelitis was induced with myelin oligodendrocyte glycoprotein 35-55 in C57BL/6 mice, and encephalitogenic MNCs were treated with Fasudil in vitro. Mice received 3 × 106  cells/10 μL per nasal cavity on day 3 and 11 postimmunization, respectively.

RESULTS

Fasudil-modified MNCs reduced clinical severity of EAE, improved demyelination, and decreased inflammatory cells in spinal cords. Immunohistochemical results indicated that CD4+ T cells and CD68+ macrophages were barely detected in Fasudil-MNCs group. Fasudil-modified MNCs decreased CD4+ IFN-γ+ and CD4+ IL-17+ T cells, increased CD4+ IL-10+ T cells, restrained M1 markers CD16/32, CCR7, IL-12, CD8a, enhanced M2 markers CD206, CD200, CD14 in spleen. Fasudil-modified MNCs inhibited the activation of inflammatory signaling p-NF-kB/P38, accompanied by the decrease of COX-2 and the increase of Arg-1 in spinal cord, as well as the reduction of IL-17, TNF-α, IL-6 and the elevation of IL-10 in cultured supernatant of splenocytes. Fasudil-modified MNCs enhanced the levels of neurotrophic factors BDNF and NT-3 in spinal cord.

CONCLUSION

Our results indicate that intranasal delivery of Fasudil-modified MNCs have therapeutic potential in EAE, providing a safe and effective cell therapeutic strategy to MS and/or other related disorders.

HIF-1α regulates IL-1β and IL-17 in sarcoidosis

Sarcoidosis is a complex systemic granulomatous disease of unknown etiology characterized by the presence of activated macrophages and Th1/Th17 effector cells. Data mining of our RNA-Seq analysis of CD14⁺monocytes showed enrichment for metabolic and hypoxia inducible factor (HIF) pathways in sarcoidosis. Further investigation revealed that sarcoidosis macrophages and monocytes exhibit higher protein levels for HIF-α isoforms, HIF-1β, and their transcriptional co-activator p300 as well as glucose transporter 1 (Glut1). In situ hybridization of sarcoidosis granulomatous lung tissues showed abundance of HIF-1α in the center of granulomas. The abundance of HIF isoforms was mechanistically linked to elevated IL-1β and IL-17 since targeted down regulation of HIF-1α via short interfering RNA or a HIF-1α inhibitor decreased their production. Pharmacological intervention using chloroquine, a lysosomal inhibitor, decreased lysosomal associated protein 2 (LAMP2) and HIF-1α levels and modified cytokine production. These data suggest that increased activity of HIF-α isoforms regulate Th1/Th17 mediated inflammation in sarcoidosis.

Sarcoidosis is a rare disease that is characterized by the formation of small lumps known as granulomas inside the body. These lumps are made up of clusters of immune cells, and are commonly found in the skin, lung or eye. Other organs of the body can also be affected, and symptoms will vary depending on where in the body lumps form. There is currently no specific treatment for sarcoidosis, as the direct cause of the disease is unknown. The disease is often treated with drugs that suppress the immune system. However, this type of treatment can lead to significant side effects and patients will respond to these drugs in different ways.

Patients with sarcoidosis have a heightened immune response to microbes that can cause infections, and rather than providing protection, this heightened response causes damage and inflammation to the body’s organs. Now, Talreja et al. have identified which genes and proteins control this inflammatory response in immune cells from the lungs and blood of sarcoidosis patients.

Immune cells in the lungs of sarcoidosis patients were found to have higher levels of hypoxia inducible factor (HIF) – a gene-regulating protein that controls the uptake and metabolism of oxygen in mammals. In addition, lung tissue affected with granulomas also expressed increased levels of a specific version of HIF known as HIF-1. Talreja et al. showed that the increased expression of HIF in the immune cells of sarcoidosis patients was mechanistically linked to the production of several molecules that promote inflammation. Inhibiting HIF-1 led to a decrease in the production of these inflammatory molecules, indicating that increased activity of HIF-1 causes inflammation in sarcoidosis patients.

It remains unclear what causes this abundance of HIF-1α. It is possible that specific modifications of this factor prevent it from degrading, resulting in higher levels. By identifying a link between HIF-1 and inflammation, these findings open up potential new avenues of the treatment for sarcoidosis patients.

cIAP1/2 inhibition synergizes with TNF inhibition in autoimmunity by down-regulating IL-17A and inducing Tregs

IL-17 and TNF-α are major effector cytokines in chronic inflammation. TNF-α inhibitors have revolutionized the treatment of rheumatoid arthritis (RA), although not all patients respond, and most relapse after treatment withdrawal. This may be due to a paradoxical exacerbation of T_H17 responses by TNF-α inhibition. We examined the therapeutic potential of targeting cellular inhibitors of apoptosis 1 and 2 (cIAP1/2) in inflammation by its influence on human T_H subsets and mice with collagen-induced arthritis. Inhibition of cIAP1/2 abrogated CD4⁺ IL-17A differentiation and IL-17 production. This was a direct effect on T cells, mediated by reducing NFATc1 expression. In mice, cIAP1/2 inhibition, when combined with etanercept, abrogated disease activity, which was associated with an increase in T_regs and was sustained after therapy retraction. We reveal an unexpected role for cIAP1/2 in regulating the balance between T_H17 and T_regs and suggest that combined therapeutic inhibition could induce long-term remission in inflammatory diseases.

HIF-1α regulates IL-1β and IL-17 in sarcoidosis

Sarcoidosis is a complex systemic granulomatous disease of unknown etiology characterized by the presence of activated macrophages and Th1/Th17 effector cells. Data mining of our RNA-Seq analysis of CD14⁺monocytes showed enrichment for metabolic and hypoxia inducible factor (HIF) pathways in sarcoidosis. Further investigation revealed that sarcoidosis macrophages and monocytes exhibit higher protein levels for HIF-α isoforms, HIF-1β, and their transcriptional co-activator p300 as well as glucose transporter 1 (Glut1). In situ hybridization of sarcoidosis granulomatous lung tissues showed abundance of HIF-1α in the center of granulomas. The abundance of HIF isoforms was mechanistically linked to elevated IL-1β and IL-17 since targeted down regulation of HIF-1α via short interfering RNA or a HIF-1α inhibitor decreased their production. Pharmacological intervention using chloroquine, a lysosomal inhibitor, decreased lysosomal associated protein 2 (LAMP2) and HIF-1α levels and modified cytokine production. These data suggest that increased activity of HIF-α isoforms regulate Th1/Th17 mediated inflammation in sarcoidosis.

Celastrol suppresses experimental autoimmune encephalomyelitis via MAPK/SGK1-regulated mediators of autoimmune pathology

OBJECTIVE AND DESIGN

Multiple sclerosis (MS) is a debilitating autoimmune disease involving immune dysregulation of the pathogenic T helper 17 (Th17) versus protective T regulatory (Treg) cell subsets, besides other cellular aberrations. Studies on the mechanisms underlying these changes have unraveled the involvement of mitogen-activated protein kinase (MAPK) pathway in the disease process. We describe here a gene expression- and bioinformatics-based study showing that celastrol, a natural triterpenoid, acting via MAPK pathway regulates the downstream genes encoding serum/glucocorticoid regulated kinase 1 (SGK1), which plays a vital role in Th17/Treg differentiation, and brain-derived neurotrophic factor (BDNF), which is a neurotrophic factor, thereby offering protection against experimental autoimmune encephalomyelitis (EAE) in mice.

METHODS

We first tested the gene expression profile of splenocytes of EAE mice in response to the disease-related antigen, myelin oligodendrocyte glycoprotein (MOG), and then examined the effect of celastrol on that profile.

RESULTS

Interestingly, celastrol reversed the expression of many MOG-induced genes involved in inflammation and immune pathology. The MAPK pathway involving p38MAPK and ERK was identified as one of the mediators of celastrol action. It involved suppression of SGK1 but upregulation of BDNF, which then contributed to protection against EAE.

CONCLUSION

Our results not only provide novel insights into disease pathogenesis, but also offer promising therapeutic targets for MS.