Search Results (216)

Human cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) braziliensis is a complex parasitic disease marked by dynamic host–parasite interactions and immunomodulation. Extracellular vesicles (EV) derived from immune cells have emerged as key mediators of intercellular communication and potential biomarkers in infectious diseases. In this study, we combined a modified lymphocyte proliferation assay with nano-flow cytometry to quantify and phenotype EV released by CD4⁺, CD8⁺, and CD14⁺ cells in PBMC cultures from CL patients at different clinical stages: before treatment (PBT), during treatment (PDT), and post-treatment (PET) with antimonial. Healthy individuals (HI) were included as physiological controls. Upon stimulation with L. (V.) braziliensis antigens, we observed a distinct modulation of EV subsets. In the PBT group, CD4⁺ and CD14⁺ EV were significantly reduced, while CD8⁺ EV remained elevated. During PDT and PET, EV concentrations were restored across all subsets. These findings suggest that L. (V.) braziliensis selectively modulates the release of immune cell–derived EV, possibly as an immune evasion mechanism. The restoration of EV release following antimonial therapy highlights their potential as sensitive biomarkers for disease activity and treatment monitoring. This study offers novel insights into the immunoregulatory roles of EV in CL and underscores their relevance in host–parasite interactions. Full article

Background/Objectives: Senecio scandens Buch.-Ham. is a flavonoid-rich traditional medicinal plant with established immunomodulatory properties. However, the mechanisms underlying the immunoregulatory and intestinal protective effects of its flavonoid extract (Senecio scandens flavonoids—SSF) remain unclear. This study characterized SSF’s bioactive components and evaluated its efficacy against cyclophosphamide (CTX)-induced immunosuppression and intestinal injury. Methods: The constituents of SSF were identified using UHPLC/Q-Orbitrap/HRMS. Mice with CTX-induced immunosuppression were treated with SSF (80, 160, 320 mg/kg) for seven days. Immune parameters (organ indices, lymphocyte proliferation, cytokine, and immunoglobulin levels) and gut barrier integrity markers (ZO-1, Occludin, Claudin-1 protein expression; sIgA secretion; microbiota composition) were assessed. Network pharmacology combined with functional assays elucidated the underlying regulatory mechanisms. Results: Twenty flavonoids were identified in SSF, with six prototype compounds detectable in the blood. The SSF treatment significantly ameliorated CTX-induced weight loss and atrophy of the thymus and spleen. It enhanced splenic T- and B-lymphocyte proliferation by 43.6% and 29.7%, respectively; normalized the CD4⁺/CD8⁺ ratio (1.57-fold increase); and elevated levels of IL-2, IL-6, IL-10, TNF-α, IFN-γ, IgM, and IgG. Moreover, SSF reinforced the intestinal barrier by upregulating tight junction protein expression and sIgA levels while modulating the gut microbiota, enriching beneficial taxa (e.g., the Lachnospiraceae_NK4A136_group, Akkermansia) and suppressing pathogenic Alistipes. Mechanistically, SSF activated the TLR/MyD88/NF-κB pathway, with isoquercitrin identified as a pivotal bioactive constituent. Conclusions: SSF effectively mitigates CTX-induced immunosuppression and intestinal damage. These findings highlight SSF’s potential as a dual-functional natural agent for immunomodulation and intestinal protection. Subsequent research should validate isoquercitrin’s molecular targets and assess SSF’s clinical efficacy. Full article

The Akabane virus (AKAV) is a significant member of the Orthobunyavirus genus, with its envelope glycoprotein Gc, focusing on its molecular structural features, immunoregulatory mechanisms, and application value in pathogen diagnosis and vaccine design. As a key structural protein of AKAV, Gc mediates virus adsorption and neutralizing antibody recognition through the N-terminal highly variable region (HVR), while the C-terminal conserved region (CR) dominates the membrane fusion process, and its glycosylation modification has a significant regulatory effect on protein function. In clinical diagnostics, serological assays based on Gc proteins (e.g., ELISA, immunochromatographic test strips) have been standardized; in vaccine development, the neutralizing epitope of Gc proteins has become a core target for subunit vaccine design. Follow-up studies were deeply needed to analyze the structure-function interaction mechanism of Gc proteins to provide theoretical support for the construction of a new type of AKAV prevention and control system. Full article

Recent breakthroughs in cancer immunotherapy have shown remarkable success, yet treatment efficacy varies significantly among individuals. Emerging evidence highlights the gut microbiota as a key modulator of immunotherapy response, while vitamin D (VD), an immunomodulatory hormone, has garnered increasing attention for its potential interactions with gut microbiota and immunotherapy outcomes. However, the precise mechanisms and clinical applications of VD in this context remain controversial. This study systematically analyzed peer-reviewed evidence from PubMed, Scopus, Web of Science, PsycINFO, and MEDLINE (January 2000–May 2025) to investigate the complex interplay among VD, gut microbiota, and cancer immunotherapy. This review demonstrates that VD exerts dual immunomodulatory effects by directly activating immune cells through vitamin D receptor (VDR) signaling while simultaneously reshaping gut microbial composition to enhance antitumor immunity. Clinical data reveal paradoxical outcomes: optimal VD levels correlate with improved immunotherapy responses and reduced toxicity in some studies yet are associated with immunosuppression and poorer survival in others. The bidirectional VD–microbiota interaction further complicates this relationship: VD supplementation enriches beneficial bacteria, which reciprocally regulate VD metabolism and amplify immune responses, whereas excessive VD intake may disrupt this balance, leading to dysbiosis and compromised therapeutic efficacy. These findings underscore the need to elucidate VD’s dose-dependent and microbiota-mediated mechanisms to optimize its clinical application in immunotherapy regimens. Future research should prioritize mechanistic studies of VD’s immunoregulatory pathways, personalized strategies accounting for host–microbiota variability, and large-scale clinical trials to validate VD’s role as an adjuvant in precision immunotherapy. Full article

Background: Psoriasis, an inflammatory skin disorder, involves pyroptosis—a pro-inflammatory cell death process. However, cell-specific pyroptosis dynamics and immune microenvironment interactions remain unclear. Objective: To investigate cell-type-specific pyroptosis patterns in psoriasis and their immunoregulatory mechanisms. Methods: We integrated 21 transcriptomic datasets (from 2007 to 2020) obtained from the GEO database and two single-cell RNA sequencing datasets to quantify pyroptotic activity using Gene Set Variation Analysis and AUCell algorithms. Immune cell infiltration profiles were evaluated via CIBERSORT, while cell-cell communication networks were analyzed by CellChat. In vitro and in vivo experiments were performed to validate key findings. Results: Our analysis revealed that psoriasis patients exhibited significantly elevated levels of pyroptosis compared to healthy controls, with pyroptotic activity reflecting treatment responses. Notably, monocyte-derived macrophages (MDMs) in psoriatic lesions displayed markedly heightened pyroptotic activity. In vitro experiments confirmed that MDMs derived from psoriasis patients overexpressed pyroptosis-related molecules (Caspase 1 and Caspase 4) as well as pro-inflammatory cytokines (TNFα, IL6, IL1β) when compared to healthy controls. Furthermore, these cells showed increased expression of CXCL16, which might potentially activate Th17 cells through CXCR6 signaling, thereby driving skin inflammation. Inhibition of monocyte migration in an imiquimod-induced psoriasiform dermatitis model significantly alleviated skin inflammation and reduced the proportion of M1 macrophages and Th17 cells in lesional skin. Conclusions: This study revealed that MDMs in psoriatic lesions exhibited a hyperactive pyroptotic state, which contributed to disease progression through CXCL16-mediated remodeling of the immune microenvironment. These findings highlight pyroptosis as a potential therapeutic target for psoriasis. Full article

This study identifies the novel effects of soluble factors derived from murine erythroblasts on lymphoid cell phenotypes. These effects were observed following the treatment of splenic mononuclear cells with erythroblast-conditioned media received from both healthy mice and mice subjected to hematopoiesis-activating conditions (hypoxia, blood loss, and hemolytic anemia), suggesting a common mechanism of action. Using flow cytometry, we elucidated that erythroblast-derived soluble products modulate T cell differentiation by promoting Treg development and increasing PD-1 surface expression on B cells. The immunoregulatory potential of erythroblasts is subpopulation-dependent: CD45+ erythroblasts respond to hemolytic stress by upregulating the surface expression of immunosuppressive molecules PDL1 and Galectin-9, while CD45- erythroblasts primarily increase TGFb production. These findings highlight the regulatory role of erythroblasts in modulating immune responses. Full article

The 90 kDa heat shock proteins (Hsp90) are molecular chaperones that regulate the stability and maturation of numerous client proteins implicated in the regulation of cancer hallmarks. Despite the potential of pan-Hsp90 inhibitors as anticancer therapeutics, their clinical development has been hindered by on-target toxicities, particularly ocular and cardiotoxic effects, as well as the induction of pro-survival, compensatory heat shock responses. Together, these and other complications have prompted the development of isoform-selective Hsp90 inhibitors. In this review, we discuss the molecular bases for Hsp90 function and inhibition and emphasize recent advances in isoform-selective targeting. Importantly, we highlight how Hsp90 inhibition can sensitize tumors to cancer immunotherapy by enhancing antigen presentation, reducing immune checkpoint expression, remodeling the tumor microenvironment, and promoting innate immune activation. Special focus is given to Hsp90β-selective inhibitors, which modulate immunoregulatory pathways without eliciting the deleterious effects observed with pan-inhibition. Preclinical and early clinical data support the integration of Hsp90 inhibitors with immune checkpoint blockade and other immunotherapeutic modalities to overcome resistance mechanisms in immunologically cold tumors. Therefore, the continued development of isoform-selective Hsp90 inhibitors offers a promising avenue to potentiate cancer immunotherapy with improved efficacy. Full article

Monomeric C-reactive protein (mCRP), derived from the dissociation of the native pentameric CRP (pCRP), has been implicated in the pathophysiology of various neurological conditions, particularly intracerebral hemorrhage (ICH) and neurodegenerative diseases. mCRP accumulates in the brain after hemorrhagic stroke, contributing to the formation of the metabolic penumbra and promoting inflammation. Recent studies have linked mCRP to the activation of microglia, endothelial cells, and complement pathways, which collectively intensify neuroinflammation and disrupt tissue repair mechanisms. Additionally, mCRP is associated with cognitive decline, particularly in ICH survivors, by promoting microvascular damage, neurodegeneration, and vascular instability. The presence of mCRP in distant regions of the brain, including the hypothalamus, suggests its potential role in spreading inflammation and exacerbating long-term neurological damage. This review synthesizes findings on the pathogenic role of mCRP in stroke and neurodegeneration, proposing that mCRP could serve as both a biomarker and a therapeutic target for improving outcomes in stroke patients. Emerging immunopharmacological strategies are being actively pursued to mitigate the pathogenic activity of mCRP, a potent pro-inflammatory effector implicated in a variety of immune-mediated and neuroinflammatory conditions. These approaches encompass the inhibition of native pentameric CRP dissociation into its monomeric isoform, the disruption of mCRP’s high-affinity interactions with lipid rafts and cell surface receptors involved in innate immune activation, and the enhancement of its clearance through mechanisms such as solubilization, opsonin-mediated tagging, and phagocytic engagement. Targeting these immunoregulatory pathways offers a compelling therapeutic framework for attenuating mCRP-driven inflammatory cascades in both systemic and CNS-specific pathologies. Full article

Background: Currently, much attention is focused on the interactions between the leukemic and psoriatic cells showing immunosuppressive activity within the microenvironment. Methods: Our study assessed a collective mRNA expression pattern of crucial immuno-regulatory genes: BTLA, CD160, SPN, TIM-3, VISTA, TIGIT, by qRT-PCR, and performed a comparison in two different diseases, chronic lymphocytic leukemia (CLL) and psoriasis (Ps), referring to clinical characteristics. Results: In Ps, all the studied gene expressions, except TIM-3, were higher than in HVs and all the studied gene expressions, except VISTA, were lower than in CLL. However, the expression of TIM-3, a checkpoint inhibitor, was higher in 0 stage of CLL and was lower in advanced stages of the disease, suggesting its possible diagnostic value. Expression of VISTA was higher in Ps than in HVs, as well as in CLL. It is noteworthy that BTLA, CD160 and SPN were overexpressed in CLL and Ps compared to HVs, suggesting its involvement in immune suppression in both diseases. Conclusions: Significant correlations between gene expressions of SPN and BTLA, SPN and TIGIT, CD160 and TIM-3, were observed, indicating a potential shared regulatory mechanism for immune responses which suggests their bidirectional regulatory role on the functioning of immune system cells, depending on the context of inflammatory or neoplastic conditions. Full article

Systemic sclerosis (SSc) is an autoimmune fibrotic disorder affecting the skin and internal organs, categorized as either limited cutaneous SSc, where distal areas of skin are involved, or diffuse cutaneous SSc, where more extensive proximal skin involvement is seen. Vascular remodelling and internal organ involvement are frequent complications in both subsets. Multiple pathogenic mechanisms have been demonstrated, including production of disease-specific autoantibodies, endothelial cell damage at an early stage, infiltration of involved tissues by immune cells, as well as environmental factors triggering the onset such as solvents and viruses. Although not strongly familial, susceptibility to SSc is associated with multiple single nucleotide polymorphisms in immunoregulatory genes relevant to antigen presentation, T cell signalling and adaptive immunity, as well as innate immunity. In addition, several lines of evidence demonstrate abnormalities within the epithelial cell layer in SSc. Macroscopically, the SSc epidermis is pigmented, thickened and stiff and strongly promotes myofibroblasts in co-culture. Moreover, multiple activating factors and pathways have been implicated in the disease epidermis, including wound healing responses, induction of damage associated molecular patterns (DAMPS) and the release of pro-fibrotic growth factors and cytokines. Similar to SSc, data from studies of cutaneous wound healing indicate a major role for epidermal keratinocytes in regulating local fibroblast responses during repair of the wound defect. Since the epithelium is strongly exposed to environmental factors and richly populated with protective immune cells, it is possible that disease-initiating mechanisms in SSc involve dysregulated immunity and tissue repair within this cell layer. Treatments designed to restore epithelial homeostasis or else disrupt epithelial–fibroblast cross-talk could be of benefit in this severe and resistant disease. Accordingly, single cell analysis has confirmed an active signature in SSc keratinocytes, which was partially reversed following a period of JAK inhibitor therapy. Full article

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease that affects various organs, including the kidneys. Despite recent advancements, effective treatment options for renal involvement in SLE remain limited. Rebamipide, originally developed as a gastroprotective agent, has been reported to exert immunomodulatory effects in rheumatic diseases. Here, we aimed to evaluate the therapeutic potential of rebamipide in SLE using an animal model and to elucidate its mechanisms of action. We administered rebamipide or vehicle control to lupus-prone MRL/lpr mice and evaluated its efficacy on lupus-like phenotypes, including renal manifestations and immune cell profiles. Additionally, we investigated potential therapeutic mechanisms through in vitro treatment of murine immune cells and podocytes with rebamipide. Oral administration of rebamipide in lupus-prone mice significantly reduced kidney size, weight, and histopathological inflammation. Among circulating immune cell subsets, only regulatory T cells were significantly increased by rebamipide. In vivo treatment with rebamipide enhanced the expression of podocyte structural proteins, such as Synaptopodin, in kidney tissues, accompanied by the recovery of antioxidative factors, including nuclear factor erythroid 2-related factor 2 (Nrf2). Similarly, in vitro treatment of murine immune cells and podocytes with rebamipide replicated its immunoregulatory and antioxidative effects. Rebamipide is proposed as a potential therapeutic candidate for managing renal involvement in SLE through its antioxidative effects on podocytes. Full article

Background/Objectives: Ivy leaf extract has been shown to alleviate bronchial infection symptoms through various mechanisms, including anti-inflammatory effects. However, its impact on adaptive immunity, particularly dendritic cell (DC)/T-cell interactions, remains unexplored. This study investigated the immunomodulatory potential of ivy leaf extract (EA 575^®) using human monocyte-derived DCs (MoDCs). Methods: Immature MoDCs (imMoDCs) were differentiated with IL-4/GM-CSF and matured with LPS/IFN-γ (mMoDCs). MoDCs, treated with EA 575^® during differentiation, were co-cultured with purified T cells. Results: EA 575^® (non-cytotoxic up to 100 µg/mL) inhibited MoDC differentiation and maturation by reducing the expression of CD1a, CD83, CD40, CD86, HLA-DR, Dectin-1, CD206, CD209, HIF-1α, and proinflammatory cytokines (IL-12, IL-23, IL-27, IL-1β, IL-6, TNF-α). EA 575^®-treated mMoDCs suppressed allogeneic T-cell proliferation and reduced Th1 (IFN-γ), Th17 (IL-17A, IL-22), Th9 (IL-9), Th21 (IL-21), TNF-α, and IL-6 responses. Effects were dose-dependent, with higher concentrations (100 µg/mL) showing stronger inhibition. At lower concentrations (20 µg/mL), EA 575^® increased Th2 (IL-4, IL-5) and IL-10 responses, and the frequencies of CD4+ T cells with Treg properties, such as CD25hiFoxp3+, Tr1 (IL-10+Foxp3−), and IL-35+ Foxp3+ cells. Immunoregulatory mechanisms mediated by EA 575^®-treated mMoDCs correlated with the upregulation of tolerogenic markers (PD-L1, ILT3, ILT4, IDO1) on mMoDCs and the increased frequency of exhausted CD4+ T cells (PD-1+CD69+) and cytotoxic T cells (Granzyme B+PD-1+). Conclusions: EA 575^® induces tolerogenic DCs with significant anti-inflammatory and immunoregulatory properties, a previously undescribed phenomenon. Lower concentrations primarily enhance immunoregulatory responses, while higher concentrations exert more pronounced anti-inflammatory effects. Full article

CD300 family members are immunoglobulin superfamily receptors that regulate immune cell function through either activating or inhibitory signals. Among them, CD300a is a prototypical inhibitory receptor, highly expressed in both myeloid and lymphoid lineages, and plays a pivotal role in the pathogenesis of inflammation and tumor immunity. CD300a transduces inhibitory signals in several immune cells—including mast cells, eosinophils, monocytes, dendritic cells (DCs), neutrophils, and natural killer (NK) cells—by recruiting SHP-1 phosphatase to immunoreceptor tyrosine-based inhibitory motifs (ITIMs) and suppressing activation pathways such as Toll-like receptor (TLR)-MyD88 and FcεRI signaling. Recent studies suggest that tumor cells may hijack CD300a-associated pathways to establish an immunosuppressive microenvironment that facilitates immune evasion, tumor survival, and potentially metastatic spread. Proposed mechanisms include reduced DC-mediated type I interferon (IFN) production, diminished NK cell cytotoxicity, and negative regulation of mast cell– and eosinophil-dependent anti-tumor responses. Although some of these findings are derived from in vivo models, the cumulative evidence positions CD300a as a critical immune checkpoint in tumor-associated immune regulation. In addition to its established roles in hematologic malignancies—including chronic lymphocytic leukemia, acute lymphoblastic leukemia, and acute myeloid leukemia—CD300a has also been implicated in modulating tumor-associated immune responses in other pathological contexts. While most studies emphasize its immune cell–mediated effects, emerging evidence suggests that CD300a may directly influence tumor progression by regulating immune homeostasis, intracellular signaling, and tumor microenvironment interactions. Collectively, these findings establish CD300a as a pleiotropic immunoregulatory molecule in both hematologic and non-hematologic malignancies, underscoring the need to further explore its broader relevance and therapeutic potential in cancer immunology. Full article

Neurodegenerative diseases are characterised by the progressive loss of neurons, leading to a decline in specific brain functions. Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the most prevalent, affecting approximately 60 million people worldwide. The pathogenesis of these diseases is complex, combining inflammatory, oxidative, and excitotoxic processes that result in neuronal dysfunction and death. Despite recent advances, there is currently no cure for AD and PD. Available therapies demonstrate limited efficacy, highlighting the continuing need for novel therapeutic approaches. Ergolide, a naturally occurring sesquiterpene lactone from the Inula brittanica plant, has shown immunoregulatory properties in systemic immune cells and potential applications in certain cancers. This study examines whether the therapeutic effects of ergolide extend to the brain. We explored its mechanisms of action in vitro, and its capacity to restore behavioural integrity in zebrafish models of inflammation and neurotoxicity in vivo. We report the ability of ergolide to attenuate inflammatory cytokine and nitric oxide (NO) production from microglia in response to toll-like receptor activation. We further propose a role for the NFκB and cysteinyl leukotriene (CysLT) pathways in ergolide-mediated regulation of microglial activation. Ergolide did not protect against oxidative-induced neuronal death in vitro or mitigate seizure activity in zebrafish. Instead, we revealed a pro-oxidant and cytotoxic effect on neuroblastoma cells. Importantly, ergolide improved survival and alleviated the dysfunction in sensorimotor behaviour in a zebrafish model of inflammation. Our findings reveal a neuroprotective effect of ergolide, likely stemming from its immunoregulatory capacity. We also support further investigation of the CysLT pathway as a therapeutic target for neuroinflammatory-related disease. Full article

Tumor necrosis factor (TNF) is a key immunoregulatory cytokine with a dual role in the host response to Mycobacterium tuberculosis. While essential for granuloma formation, macrophage activation, and containment of latent infection, TNF can also contribute to tissue damage and immune pathology. This review systematically analyzes over 300 peer-reviewed studies published between 1980 and 2024, highlighting the molecular and cellular mechanisms of TNF action in tuberculosis (TB). Particular attention is given to TNF receptor signaling pathways, the balance between protective and pathological immune responses, and the modulation of TNF activity during anti-TNF therapy in patients with autoimmune diseases. We discuss how different TNF inhibitors vary in their capacity to interfere with host defense mechanisms, with monoclonal antibodies carrying a higher reactivation risk than receptor-based agents. To enhance conceptual clarity, we provide newly developed schematic representations that integrate current knowledge on TNF-driven immune dynamics, including its interaction with other cytokines, effects on granuloma stability, and role in intracellular bacterial control. Understanding the pleiotropic functions of TNF in tuberculosis pathogenesis is crucial for developing safe immunomodulatory strategies and optimizing the clinical management of patients at risk of latent TB reactivation. Full article