Search Results (555)

Background: Targeting tumor-associated macrophages (TAMs) is a promising immunotherapy for cancers, but current strategies are limited due to strategic caveats. PU.1 is a transcription factor required for macrophage generation and differentiation. To date, the effect of PU.1 inhibition on solid tumors is unknown. Methods: This study examines the anti-tumor effect of PU.1 inhibition and its mechanism using the small-molecule DB2313 in mouse melanoma and breast tumor models. Results: We found that inhibition of PU.1 by DB2313 suppresses B16-OVA melanoma and 4T1 breast tumor growth in mice. In the melanoma tumor model, DB2313 enhanced tumor recruitment of CD4⁺ T helper 1 (Th1) and cytotoxic T/natural killer (NK) cells by targeting TAMs. Transcriptome and targeted gene expression analyses revealed that PU.1 inhibition by DB2313 and small-interference RNAs enhances CXCL9 expression in bulk tumors, TAMs, and bone marrow-derived macrophages. The anti-tumor effects of DB2313 were abolished by depleting macrophages with clodronate or inhibiting the CXCL9-CXCR3 chemokine axis using CXCL9- or CXCR3-neutralizing antibodies. Conclusions: These results suggest that pharmacological inhibition of PU.1 suppresses tumor growth by at least promoting the infiltration of lymphocytes into tumors through the CXCL9-CXCR3 chemokine axis. Our study establishes a framework for developing TAM-modulating immunotherapies by targeting the transcriptional factor PU.1. Full article

T lymphocytes in human skin play essential roles in immune surveillance and tissue homeostasis, with distinct populations residing in the epidermal and dermal compartments. To characterize the molecular basis of their compartmentalized functional specialization, we performed proteomic analysis of total T cell populations isolated from healthy human skin, combining flow cytometry and liquid chromatography–tandem mass spectrometry. We quantified 5985 proteins across epidermal and dermal T cell populations, identifying 2177 significantly differentially expressed proteins (FDR < 0.05), including 1008 with >2-fold changes. Compared with dermal T cells, epidermal T cells showed elevated intensity of tissueresidency marker CD69, co-stimulatory protein CD27, complement components (C3, C4a, and Factors B and D), and proteins involved in oxidative phosphorylation and cholesterol metabolism. Epidermal T cells also exhibited higher levels of antimicrobial S100 proteins, chemokine receptor CCR6, IL-18, and MHC class I molecules, while, in contrast, dermal T cells showed increased expression of CXCR4, IL-16, and MHC class II-related proteins. While these distinct proteomic signatures suggest compartment-specific adaptations in metabolism, immune surveillance, and antigen presentation, the results should be interpreted as exploratory, given methodological limitations. Nonetheless, this study provides a valuable molecular resource for understanding the specialization of T cells within different skin layers and offers a basis for future investigations into skin immune biology and its potential implications in disease. 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 reports the use of single-cell RNA sequencing to evaluate B cells in the peripheral blood mononuclear cells (PBMCs) and intrathyroidal blood mononuclear cells of patients with Graves’ disease (GD) undergoing thyroidectomy. These cells were stimulated with overlapping peptides of thyroid autoantigens, including thyroid-stimulating hormone receptor (TSHR), thyroglobulin (Tg), and thyroid peroxidase (TPO). In PBMCs, naive B cells are characterized by IL6 and CXCR5, whereas memory B cells express IGHG1, IGHG2, and CD74. HLA-DMA, HLA-DRB1, IGHG, IGHM, CD74, CD79A, and MS4A1 expression increased in peptide-stimulated naive and memory B cells compared to those in the controls. Thyroid naive B cells are characterized by CD40 and TNFRSF13C, whereas memory B cells express IGHM, CD79A, and MS4A1. Thyroid B cells showed higher DUSP1, DUSP2, CD69, FOSB, RGS1, and immunoglobulin gene expression than control PBMCs and thyroid cells. B-cell receptor analysis revealed frequent IGHV3-23 and IGHV4-34 usage in controls, whereas IGHV4-34/IGHJ4 expression was increased in TSHR-stimulated groups. We concluded that B-cell responses to TSHR, Tg, and TPO differed and that changes in B-cell reactivity also occurred in PBMCs and the thyroid. Additionally, IGHV3-23 and IGHV4-34 may be associated with autoantibody production in GD. Full article

During aging, the brain vasculature undergoes significant deterioration characterized by increased arterial tortuosity, compromised blood–brain barrier integrity, and reduced cerebral blood flow, all of which contribute to various neurological disorders. Thus, understanding the mechanisms underlying aging-related cerebrovascular defects is critical for developing strategies to alleviate aging-associated neurological diseases. In this study, we investigated the role of aging-related genes in brain vascular development using zebrafish as an in vivo model. By thoroughly analyzing scRNA-seq datasets of mid- and old-aged brain vascular endothelial cells (human/mouse), we found ribosomal protein S20 (rps20) significantly down-regulated during aging. qPCR analysis and whole-mount in situ hybridization validated a high expression of rps20 during early zebrafish development, which progressively decreased in adult and aged zebrafish brains. Functional studies using the CRISPR/Cas9-mediated knockout of rps20 revealed an impaired growth of central arteries in the hindbrain and a marked increased intracranial hemorrhage incidence. Mechanistically, qPCR analysis demonstrated a significant downregulation of vegfa, cxcl12b, and cxcr4a, key signaling molecules required for hindbrain vascular development, in rps20-deficient embryos. In conclusion, our findings demonstrate that rps20 is essential for proper brain vascular development and the maintenance of vascular homeostasis in zebrafish, revealing a novel mechanism by which aging-related genes regulate brain vascular development. This study provides new insights that may aid in understanding and treating aging-associated vascular malformations and neurological pathologies. Full article

Androgenetic alopecia (AGA) is a common form of hair loss characterized by androgen-driven tissue remodeling, including progressive follicular miniaturization and dermal fibrosis, which is accompanied by low-grade immune activation. However, the molecular mechanisms underlying this fibroimmune dysfunction remain poorly understood. Dermal fibroblasts (DFs) have been suggested as androgen-responsive stromal cells and a potential source of CXCL12, a chemokine implicated in fibroimmune pathology, but their precise role in AGA has not been fully established. In this study, we performed single-cell transcriptomic profiling of a testosterone-induced mouse model of AGA, with or without treatment of CXCL12-neutralizing antibody, to elucidate the pathological role of CXCL12 in mediating stromal-immune interactions. Our analysis suggested that DFs are the primary androgen-responsive population driving CXCL12 expression. Autocrine CXCL12-ACKR3 signaling in DFs activated TGF-β pathways and promoted fibrotic extracellular matrix deposition. In parallel, paracrine CXCL12-CXCR4 signaling reprogrammed Sox2⁺Twist1⁺ dermal papilla cells (DPCs) and promoted the accumulation of pro-fibrotic Trem2⁺ macrophages, contributing to impaired hair follicle regeneration. Notably, CXCL12 blockade attenuated these stromal and immune alterations, restored the regenerative capacity of DPCs, reduced pro-fibrotic macrophage infiltration, and promoted hair regrowth. Together, these findings identify CXCL12 as a central mediator of androgen-induced fibroimmune remodeling and highlight its potential as a therapeutic target in AGA. Full article

Background: Esophageal squamous cell carcinoma (ESCC) is a fatal malignant tumor. Several studies have demonstrated that immune checkpoint inhibitors can provide clinical benefits to patients with ESCC. However, the single-agent efficacy of these agents remains limited. Although combination therapies (e.g., radiotherapy, chemotherapy) can help to overcome immunotherapy resistance in ESCC, their severe side effects limit clinical application. This study aimed to explore new resistance mechanisms to immunotherapy in ESCC and identify novel molecular targets to overcome immunotherapy resistance. Methods: We employed immunohistochemistry staining to examine the p-FGFR1^Y654 in tumor samples obtained from 103 patients with ESCC, in addition to evaluating CD8+ T cell infiltration. In vitro expression, western blotting, CCK-8, 5-bromo-2′-deoxyuridine incorporation assays, and migration assays were used to confirm the impact of AZD4547 on p-FGFR1^Y654 expression and the proliferation and migration in ESCC cell lines. Through RNA sequencing analysis, databases such as the Cancer Genome Atlas (TCGA) and Gene Set Cancer Analysis (GSCA), and the reconstruction of transgenic mice using the humanized immune system, we validated the correlation between the expression of p-FGFR1^Y654 and CD8+ T cell infiltration. We also explored how p-FGFR1^Y654 recruits myeloid-derived suppressor cells (MDSCs) through the CXCL8–CXCR2 axis to suppress the therapeutic efficacy of immunotherapy in ESCC. Finally, the tumor-suppressive effects of AZD4547 combined with immunotherapy were confirmed in vivo in tumor-bearing mice with a humanized immune system. Results: We found that the inhibition of p-FGFR1^Y654 expression in ESCC can enhance CD8+ T cell infiltration by suppressing the CXCL8-–XCR2 recruitment of MDSCs. AZD4547, combined with immunotherapy, further promotes immunotherapeutic efficacy in ESCC. Conclusions: In conclusion, our study presents a promising model for combination therapy in ESCC immunotherapy. Full article

Chemokines are low-molecular-weight peptides classified as cytokines with chemotactic properties. The chemokine CXCL13 and its receptor CXCR5 play a significant role in cardiac remodeling, and their expression is markedly increased in experimental models of heart failure. Increased CXCL13 activity is associated with the expression of fibromodulin, a proteoglycan that binds and cross-links collagen fibers. The stressed heart undergoes intensive remodeling, including fibrosis. In our experiment, we investigated the effect of the most commonly used triple immunosuppressive regimens on the expression of the CXCR5 receptor, the chemokine CXCL13, and fibromodulin in rat heart tissue. For this purpose, we used Western blot analysis and ELISA. The study was started on 36 rats divided into 6 groups, which received drugs for a period of 6 months. Our results suggest that the chronic use of calcineurin inhibitors in combination with mycophenolate mofetil is a significant stress factor for the heart, leading to abnormal remodeling of the extracellular matrix. The use of rapamycin may alleviate the negative effects of immunosuppressive therapy on the heart. Our results are consistent with the results of our previous studies and provide a basis for further work aimed at understanding the pathophysiology of the development of changes in the heart with individual immunosuppressive regimens. Full article

Background/Objectives: In this study, a mouse model of sutured endothelial keratoplasty was established and compared with a traditional penetrating keratoplasty (PKP) model in both syngeneic (BALB/c) and allogeneic (C57/BL6) patterns. Methods: For the endothelial keratoplasty (EK) model, chimeric donor tissues consisting of BALB/c epithelium-stroma combined with either syngeneic (BALB/c) or allogeneic (C57/BL6) stroma-endothelium were transplanted into BALB/c mice. Graft transparency, gene expression, and mRNA levels in the transplanted tissues were assessed using polymerase chain reaction (PCR) and quantitative real-time reverse transcription PCR (qRT-PCR) to evaluate inflammatory status. Results: Allogeneic PKP had a higher opacity score than syngeneic PKP. In contrast, syngeneic EK mice had similar opacity scores to those of allogeneic EK mice. Upregulation of CXCR3, the receptor for CXCL10, was demonstrated by qRT-PCR in allogeneic PKP mice but not in allogeneic EK mice. Conclusions: Comparison between the syngeneic and allogeneic PKP groups revealed differences in CXCR3 mRNA expression, suggesting that CXCR3 could be a potential biomarker for rejection in the PKP mouse model. Additionally, the EK model did not show CXCR3 upregulation despite the opaque cornea due to nonspecific inflammation. Therefore, our mouse model was considered to be a successfully established EK model. Full article

Ferritin is important for cellular iron storage and metabolism. It consists of 24 ferritin heavy- or light-chain subunits surrounding an iron-containing core, but it is also released as an extracellular molecule that shows increased systemic levels during acute-phase reactions. Furthermore, acute myeloid leukemia (AML) is an aggressive bone marrow malignancy that can be associated with increased ferritin levels both at the time of first diagnosis but also during/following anti-AML treatment due to an iron overload. Such high systemic ferritin levels at diagnosis or later allogeneic stem cell transplantation are associated with decreased long-term survival. Extracellular ferritin binds to several receptors expressed by AML cells (e.g., the transferrin receptor and CXCR4 chemokine receptor) and AML-supporting non-leukemic bone marrow cells (e.g., endothelial, mesenchymal or immunocompetent cells). Ferritin can thereby affect the AML cells directly as well as indirectly via AML-supporting neighboring cells. Finally, ferritin should be regarded as a regulator of the dysfunctional iron metabolism that causes increased iron levels in AML cells, and it is important for cell survival through its function during the initial steps of ferroptosis. Thus, ferritin is not only an adverse prognostic biomarker, but also an important regulator of AML cell proliferation, survival and chemosensitivity and the targeting of iron metabolism/ferroptosis is, therefore, a possible strategy in AML therapy. Full article

Recent concerns regarding the safety of Janus kinase inhibitors (JAKis) have prompted investigation into their impact on immune cell subsets in rheumatoid arthritis (RA) patients. This study aims to analyse alterations in immune cell populations induced by JAKis that may contribute to adverse events, such as infections or malignancies. This study included 78 RA patients meeting ACR/EULAR criteria with an established treatment with JAKis (tofacitinib, baricitinib, upadacitinib, or filgotinib), 20 healthy donors, and 20 RA patients treated with biological disease-modifying antirheumatic drugs (bDMARDs). Peripheral blood mononuclear cells (PBMCs) were immunophenotyped directly after isolation using multiparametric flow cytometry to characterise innate and adaptive immune-cell subsets. JAKi-treated patients showed a significant reduction in cytotoxic NK Dim (CD3−CD56+CD16+) cells and in the percentage of NK Dim cells expressing the activation marker Nkp30. In CD4+ T cells, the percentage of Th17 (CD3+CD4+CD45RA+CCR6+CXCR3−), Th1-17 (CD3+CD4+CD45RA+CCR6+CXCR3+), and central memory (CM, CD3+CD4+CD45RA+CD62L+) cells was lower in the JAKi group, while effector memory (EM, CD3+CD4+CD45RA−CD62L−) and terminally differentiated CD45RA (TEMRA, CD3+CD4+CD45RA+CD62L−) T helper cells were increased compared to healthy and bDMARD-treated controls. The reduction in NK Dim and Th1-17 cells and the increase in exhausted Th subsets suggest a potential compromise in antiviral immunity and balanced immune responses in JAKi-treated RA patients. These alterations may contribute to an increased risk of infections or malignancies. Full article

Background: Allergic rhinitis (AR) is triggered by immunoglobulin E (IgE)-mediated immune responses to airborne allergens. Recent studies highlight the pivotal role of T follicular helper 2 (Tfh2) cells in IgE production. Interleukin-37 (IL-37) has emerged as an intrinsic modulator of innate immunity and inflammatory processes. We aimed to investigate the regulatory effect of IL-37 on Tfh2 cells in the pathogenesis of AR. Methods: Blood samples were collected from AR patients and controls. The IL-37 levels and the frequency of Tfh2 cells were detected by enzyme-linked immunosorbent assay (ELISA) and flow cytometry, respectively. The isolated Tfh2 cells were cultured or cocultured with naive B cells. The regulatory effects of IL-37 on Tfh2/B cells were assessed using ELISA, quantitative real-time polymerase chain reaction (qRT-PCR). Mouse models of ovalbumin (OVA)-induced AR were established to explore the effect of IL-37 in vivo. Results: IL-37 suppressed the production of IL-4 and IL-21 by Tfh2 cells and downregulated C-X-C chemokine receptor type 5 (CXCR5) and B-cell lymphoma 6 protein (Bcl6) mRNA expression while upregulating B lymphocyte-induced maturation protein 1 (Blimp1) and signal transducers and activators of transduction5 (STAT5) mRNA. IL-37 decreased IgE production by B cells significantly, and the addition of anti-IL-18 receptor α alleviated this effect. In mouse models, IL-37 reduced nasal rubbing, sneezing, eosinophil counts, OVA-specific IgE, and Tfh2 proportions. Conclusions: IL-37 plays a crucial role in modulating Tfh2 cell responses in AR, suggesting a potential therapeutic target for this condition. Full article

In the adult central nervous system (CNS), myelin regeneration primarily occurs through the differentiation of oligodendrocyte progenitor cells into mature oligodendrocytes. In men, declining testosterone levels accelerate the progression of multiple sclerosis (MS), while in women, menopause worsens MS-related disability. We previously demonstrated that functional testes and testosterone are required for the spontaneous remyelination of a focal lysolecithin (LPC)-induced demyelinating lesion in the spinal cords of male mice. Testosterone-dependent myelin repair was dependent on the induction of the chemokine receptor CXCR4 in astrocytes that repopulated the lesion and on cooperation between androgen-receptor signaling and CXCR4 signaling. In the present study, we investigated whether ovaries and estradiol have a comparable key role in female mice. Ovariectomy prevents, the appearance of astrocytes, while treatment with estradiol enhances astrocyte numbers and promotes remyelination by oligodendrocytes within the LPC-demyelinated lesion. Unlike testosterone, estradiol did not induce CXCR4 expression, and its effects remained unaffected by the CXCR4 inhibitor AMD3100. As was seen with testosterone treatment, the presence of astrocytes and myelinating oligodendrocytes within the LPC lesion of estradiol-treated females prevented the incursion of Schwann cells. These findings highlight estradiol’s crucial role in CNS remyelination in females, providing a strong rationale for estrogen-replacement therapy in estrogen-deficient and menopausal women with MS. Full article

CXCL1 (Gro-α, MGSA) is a chemokine functionally similar to CXCL8/IL-8, as both activate the same receptor, CXCR2. CXCL1 levels are frequently elevated in tumors compared to healthy tissue, where they play a key role in promoting cancer cell migration, angiogenesis, and neutrophil recruitment. While the involvement of CXCL1 in tumor progression is well established, its relevance to cancer therapy remains underexplored. This review examines the therapeutic potential of targeting CXCL1 and its receptor, CXCR2, in cancer treatment. It discusses anti-CXCL1 antibodies and CXCR2 antagonists, including AZD5069, SB225002, SCH-479833, navarixin/SCH-527123, ladarixin/DF2156A, and reparixin, as well as strategies to enhance CXCR2 expression in lymphocytes during adoptive cell therapy to improve immunotherapy outcomes. Particular attention is given to the role of CXCL1 in treatment resistance, including resistance to chemotherapy, radiotherapy, and anti-angiogenic therapy. Cancer therapies often upregulate CXCL1 expression, which in turn drives treatment resistance. Additionally, this review explores the contribution of CXCL1 to therapy-induced side effects, such as chemotherapy-induced metastasis, neuropathy, nephrotoxicity, diarrhea, and cardiotoxicity. CXCR2 inhibitors are well tolerated by patients in clinical trials. However, the limited number of studies evaluating these agents in combination with standard chemotherapy precludes any definitive conclusions. Full article

Introduction: In mouse models of chronic lymphocytic leukemia (CLL), an effective anti-leukemia immune response was obtained by depleting a specific regulatory T-cell (Treg) subset. While STAT5 signaling could alter the homeostasis of naïve (nTreg) and activated (aTreg) subsets, which are capable of suppressing also CLL patients’ responses to microbial antigens, perturbed STAT3 signaling could drive CXCR5 expression in circulating T-follicular regulatory cells (Tfr) and their entry into the lymph node/tumor microenvironment. Materials and Methods: By using phospho-specific flow cytometry, we monitored STAT signaling/phosphorylation (pSTAT), in vitro responses to Sars-Cov2-antigen-specific stimulation, and circulating Treg subsets in relation to Binet stage and total tumor mass/tumor distribution (TTM/TD) scoring in 62 patients with CLL. Results: The percentage of CXCR5⁺ Treg significantly increased in patients with Binet stage B disease, and Tfr-like subsets were associated with higher TTM and lower TD. The pSTAT3 levels in CD4⁺ T-cells were only significantly increased in patients undergoing therapy. Lower nTreg percentages correlated with increased disease duration, and an increased aTreg/nTreg ratio correlated with SARS-CoV-2-antigen-induced STAT5 signaling responses. Conclusions: The results show increased amounts of circulating CXCR5⁺ Tfr-like subsets in patients with extensive lymph node involvement and augmented STAT3 signaling in patients on therapy. While STAT5 responses may drive nTreg differentiation into aTreg, nTreg decline is associated with increased disease duration. Full article