IL-33 regulates age-dependency of long-term immune dysfunction induced by sepsis

Sepsis survival in adults is commonly followed by immunosuppression and increased susceptibility to secondary infections. However, the long-term immune consequences of pediatric sepsis are unknown. Here, we compared the frequency of Tregs, the activation of the IL-33/ILC2s axis in M2 macrophages, and the DNA methylation of epithelial lung cells from post-septic infant and adult mice. In contrast to adults, infant mice were resistant to secondary infection and did not show impairment in tumour controls upon melanoma challenge. Mechanistically, increased IL-33 levels, Tregs expansion, and activation of ILC2s and M2-macrophages were observed in post-septic adults but not infant mice. Impaired IL-33 production in post-septic infant mice was associated with increased DNA-methylation on lung epithelial cells. Notably, IL-33 treatment boosted the expansion of Tregs and induced immunosuppression in infant mice. Clinically, adults but not pediatric post-septic patients exhibited higher counts of Tregs and sera IL-33 levels. Hence, we describe a crucial and age-dependent role for IL-33 in post-sepsis immunosuppression.

Macrophages-aPKCɩ-CCL5 Feedback Loop Modulates the Progression and Chemoresistance in Cholangiocarcinoma

Background Recent data indicated that macrophages may mutually interact with cancer cells to promote tumor progression and chemoresistance, but the interaction in cholangiocarcinoma (CCA) is obscure. Methods 10x Genomics single-cell sequencing technology was used to identified the role of macrophages in CCA. Then, we measured the expression and prognostic role of macrophage markers and aPKCɩ in 70 human CCA tissues. Moreover, we constructed monocyte-derived macrophages (MDMs) generated from peripheral blood monocytes (PBMCs) and polarized them into M1/M2 macrophages. A co-culture assay of the human CCA cell lines (TFK-1, EGI-1) and differentiated PBMCs-macrophages was established, and functional studies in vitro and in vivo was performed to explore the interaction between cancer cells and M2 macrophages. Furthermore, we established the cationic liposome-mediated co-delivery of gemcitabine and aPKCɩ-siRNA and detect the antitumor effects in CCA. Results M2 macrophage showed tumor-promoting properties in CCA. High levels of aPKCɩ expression and M2 macrophage infiltration were associated with metastasis and poor prognosis in CCA patients. Moreover, CCA patients with low M2 macrophages infiltration or low aPKCɩ expression benefited from postoperative gemcitabine-based chemotherapy. Further studies showed that M2 macrophages-derived TGFβ1 induced epithelial-mesenchymal transition (EMT) and gemcitabine resistance in CCA cells through aPKCɩ-mediated NF-κB signaling pathway. Reciprocally, CCL5 was secreted more by CCA cells undergoing aPKCɩ-induced EMT and consequently modulated macrophage recruitment and polarization. Furthermore, the cationic liposome-mediated co-delivery of GEM and aPKCɩ-siRNA significantly inhibited macrophages infiltration and CCA progression. Conclusion our study demonstrates the role of Macrophages-aPKCɩ-CCL5 Feedback Loop in CCA, and proposes a novel therapeutic strategy of aPKCɩ-siRNA and GEM co-delivered by liposomes for CCA.

Decrease of IL-1β and TNF in the Spinal Cord Mediates Analgesia Produced by Ankle Joint Mobilization in Complete Freund Adjuvant-Induced Inflammation Mice Model

ObjectiveThis study aims to investigate the effects of ankle joint mobilization (AJM) on mechanical hyperalgesia and peripheral and central inflammatory biomarkers after intraplantar (i.pl.) Complete Freund’s Adjuvant (CFA)-induced inflammation.MethodsMale Swiss mice were randomly assigned to 3 groups (n = 7): Saline/Sham, CFA/Sham, and CFA/AJM. Five AJM sessions were carried out at 6, 24, 48, 72, and 96 h after CFA injection. von Frey test was used to assess mechanical hyperalgesia. Tissues from paw skin, paw muscle and spinal cord were collected to measure pro-inflammatory (TNF, IL-1β) and anti-inflammatory cytokines (IL-4, IL-10, and TGF-β1) by ELISA. The macrophage phenotype at the inflammation site was evaluated by Western blotting assay using the Nitric Oxide Synthase 2 (NOS 2) and Arginase-1 immunocontent to identify M1 and M2 macrophages, respectively.ResultsOur results confirm a consistent analgesic effect of AJM following the second treatment session. AJM did not change cytokines levels at the inflammatory site, although it promoted a reduction in M2 macrophages. Also, there was a reduction in the levels of pro-inflammatory cytokines IL-1β and TNF in the spinal cord.ConclusionTaken together, the results confirm the anti-hyperalgesic effect of AJM and suggest a central neuroimmunomodulatory effect in a model of persistent inflammation targeting the pro-inflammatory cytokines IL-1β and TNF.

Gene-selective transcription promotes the inhibition of tissue reparative macrophages by TNF

Anti-TNF therapies are a core anti-inflammatory approach for chronic diseases such as rheumatoid arthritis and Crohn’s Disease. Previously, we and others found that TNF blocks the emergence and function of alternative-activated or M2 macrophages involved in wound healing and tissue-reparative functions. Conceivably, anti-TNF drugs could mediate their protective effects in part by an altered balance of macrophage activity. To understand the mechanistic basis of how TNF regulates tissue-reparative macrophages, we used RNAseq, scRNAseq, ATACseq, time-resolved phospho-proteomics, gene-specific approaches, metabolic analysis, and signaling pathway deconvolution. We found that TNF controls tissue-reparative macrophage gene expression in a highly gene-specific way, dependent on JNK signaling via the type 1 TNF receptor on specific populations of alternative-activated macrophages. We further determined that JNK signaling has a profound and broad effect on activated macrophage gene expression. Our findings suggest that TNF’s anti-M2 effects evolved to specifically modulate components of tissue and reparative M2 macrophages and TNF is therefore a context-specific modulator of M2 macrophages rather than a pan-M2 inhibitor.

Engineering immunomodulatory and osteoinductive implant surfaces via mussel adhesion-mediated ion coordination and molecular clicking

Immune response and new tissue formation are important aspects of tissue repair. However, only a single aspect is generally considered in previous biomedical interventions, and the synergistic effect is unclear. Here, a dual-effect coating with immobilized immunomodulatory metal ions (e.g., Zn2+) and osteoinductive growth factors (e.g., BMP-2 peptide) is designed via mussel adhesion-mediated ion coordination and molecular clicking strategy. Compared to the bare TiO2 group, Zn2+ can increase M2 macrophage recruitment by up to 92.5% in vivo and upregulate the expression of M2 cytokine IL-10 by 84.5%; while the dual-effect of Zn2+ and BMP-2 peptide can increase M2 macrophages recruitment by up to 124.7% in vivo and upregulate the expression of M2 cytokine IL-10 by 171%. These benefits eventually significantly enhance bone-implant mechanical fixation (203.3 N) and new bone ingrowth (82.1%) compared to the bare TiO2 (98.6 N and 45.1%, respectively). Taken together, the dual-effect coating can be utilized to synergistically modulate the osteoimmune microenvironment at the bone-implant interface, enhancing bone regeneration for successful implantation.

Crosstalk between cancer-associated fibroblasts and immune cells in peritoneal metastasis: inhibition in the migration of M2 macrophages and mast cells by Tranilast

Background The role of tumor–stroma interactions in tumor immune microenvironment (TME) is attracting attention. We have previously reported that cancer-associated fibroblasts (CAFs) contribute to the progression of peritoneal metastasis (PM) in gastric cancer (GC), and M2 macrophages and mast cells also contribute to TME of PM. To elucidate the role of CAFs in TME, we established an immunocompetent mouse PM model with fibrosis, which reflects clinical features of TME. However, the involvement of CAFs in the immunosuppressive microenvironment remains unclear. In this study, we investigated the efficacy of Tranilast at modifying this immune tolerance by suppressing CAFs. Methods The interaction between mouse myofibroblast cell line LmcMF and mouse GC cell line YTN16 on M2 macrophage migration was investigated, and the inhibitory effect of Tranilast was examined in vitro. Using C57BL/6J mouse PM model established using YTN16 with co-inoculation of LmcMF, TME of resected PM treated with or without Tranilast was analyzed by immunohistochemistry. Results The addition of YTN16 cell-conditioned medium to LmcMF cells enhanced CXCL12 expression and stimulated M2 macrophage migration, whereas Tranilast inhibited the migration ability of M2 macrophages by suppressing CXCL12 secretion from LmcMF. In PM model, Tranilast inhibited tumor growth and fibrosis, M2 macrophage, and mast cell infiltration and significantly promoted CD8 + lymphocyte infiltration into the tumor, leading to apoptosis of cancer cells by an immune response. Conclusion Tranilast improved the immunosuppressive microenvironment by inhibiting CAF function in a mouse PM model. Tranilast is thus a promising candidate for the treatment of PM.

A Study on the Correlation Between M2 Macrophages and Regulatory T Cells in the Progression of Colorectal Cancer

Background: M2 macrophages and regulatory T cells (Tregs) can promote tumors and development by inhibiting the anti-tumor immune response. This study investigated the number of CD163‐positive M2 macrophages and Foxp3-positive Tregs in the progression of colorectal cancer. It also investigated the correlation and of M2 macrophages and Tregs.Methods: Postoperative tissue specimens and clinical data were collected from 197 patients with colorectal cancer who underwent initial surgical treatment in The Second Ward of Colorectal Surgery of the First Affiliated Hospital of Jinzhou Medical University from March 2020 to December 2020. Use immunohistochemical methods to detect the expression levels of CD163 protein-labeled M2 macrophages and Foxp3 protein-labeled Tregs in colorectal cancer tissues, matched paracancer tissues and lymph node tissues. Analyze the correlation between CD163 and Foxp3 in cancer tissues and lymph node tissues, as well as the relationship between clinicopathological characteristics and preoperative tumor markers. Results: M2 macrophages and Tregs were significantly positively correlated in cancer and lymph node tissues, which significantly increased in cancer and metastatic lymph node tissues. Interestingly, M2 macrophages in non-metastatic lymph nodes also increased significantly in patients with metastatic lymph nodes. Tregs stage I+II is higher than stage III+IV in paraneoplastic tissues. In addition, both CD163 and Foxp3 were upregulated with increasing tumor TNM stage, depth of infiltration, lymphatic metastasis, and depth of infiltration, and both were positively correlated with CEA. Conclusion: M2 macrophages and Tregs are important indicators of colorectal cancer progression and lymph node metastasis. There is a certain correlation between the two types of cells. It is possible that M2 macrophages, together with suppressor cells Tregs, promote an immunosuppressive environment.

Macrophage-Derived Exosomes Promote Bone Mesenchymal Stem Cells Towards Osteoblastic Fate Through microRNA-21a-5p

The effective healing of a bone defect is dependent on the careful coordination of inflammatory and bone-forming cells. In the current work, pro-inflammatory M1 and anti-inflammatory M2 macrophages were co-cultured with primary murine bone mesenchymal stem cells (BMSCs), in vitro, to establish the cross-talk among polarized macrophages and BMSCs, and as well as their effects on osteogenesis. Meanwhile, macrophages influence the osteogenesis of BMSCs through paracrine forms such as exosomes. We focused on whether exosomes of macrophages promote osteogenic differentiation. The results indicated that M1 and M2 polarized macrophage exosomes all can promote osteogenesis of BMSCs. Especially, M1 macrophage-derived exosomes promote osteogenesis of BMSCs through microRNA-21a-5p at the early stage of inflammation. This research helps to develop an understanding of the intricate interactions among BMSCs and macrophages, which can help to improve the process of bone healing as well as additional regenerative processes by local sustained release of exosomes.

microRNA-155-3p delivered by M2 macrophages-derived exosomes enhances the progression of medulloblastoma through regulation of WDR82

Objective Exosomes, membranous nanovesicles, naturally bringing proteins, mRNAs, and microRNAs (miRNAs), play crucial roles in tumor pathogenesis. This study was to investigate the role of miR-155-3p from M2 macrophages-derived exosomes (M2-Exo) in promoting medulloblastoma (MB) progression by mediating WD repeat domain 82 (WDR82). Methods miR-155-3p expression was detected by RT-qPCR. The relationship of miR-155-3p with clinicopathological features of MB patients was analyzed. M2-Exo were isolated and identified by TEM, NTA and Western blot. CCK-8 assay, colony formation assay, flow cytometry, wound healing assay, and Transwell assay were performed to explore the role of miR-155-3p-enriched M2-Exo on the progression of MB cells. Luciferase assay were used to identify the relationship between miR-155-3p and WDR82. The effect of miR-155-3p-enriched M2-Exo on tumorigenesis of MB was confirmed by the xenograft nude mice model. Results miR-155-3p was up-regulated in MB tissues of patients and MB cell lines. High miR-155-3p expression was correlated with the pathological type and molecular subtype classification of MB patients. WDR82 was a direct target of miR-155-3p. miR-155-3p was packaged into M2-Exo. miR-155-3p-enriched M2-Exo promoted the progression of Daoy cells. miR-155-3p-enriched M2-Exo promoted in vivo tumorigenesis. Conclusion The study highlights that miR-155-3p-loaded M2-Exo enhances the growth of MB cells via down-regulating WDR82, which might provide a deep insight into MB mechanism.