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Various regulatory CD8 + T-cell subsets have been proposed for immune tolerance and have been implicated in controlling autoimmune diseases. However, their phenotypic identities and suppression mechanisms are not yet understood. This study found that coculture of T-cell receptor (TCR)- or interferon (IFN)-β-activated CD8 + T cells significantly suppressed the cytokine production of Th1 and Th17 cells. By experimenting with the experimental autoimmune uveitis (EAU), we found that adoptive transfer of TCR or IFN-β-activated CD8 + T cells significantly lessened disease development in an IFN-γ-dependent manner with a decreased uveitogenic Th1 and Th17 response. Interestingly, after adoptive transfer into the EAU mice, the IFN-γ + CD8 + T cells were recruited more efficiently into the secondary lymphoid organs during the disease-priming phase. This recruitment depends on the IFN-γ-inducible chemokine receptor CXCR3; knocking out CXCR3 abolishes the protective effect of CD8 + T cells in EAU. In conclusion, we identified the critical role of IFN-γ for CD8 + T cells to inhibit Th1 and Th17 responses and ameliorate EAU. CXCR3 is necessary to recruit IFN-γ + CD8 + T cells to the secondary lymphoid organ for the regulation of autoreactive Th1 and Th17 cells., (© 2023 The Authors. European Journal of Immunology published by Wiley-VCH GmbH.)

Tumor microenvironments (TMEs) influence cancer progression but are complex and often differ between patients. Considering that microenvironment variations may reveal rules governing intratumoral cellular programs and disease outcome, we focused on tumor-to-tumor variation to examine 52 head and neck squamous cell carcinomas. We found that macrophage polarity-defined by CXCL9 and SPP1 (CS) expression but not by conventional M1 and M2 markers-had a noticeably strong prognostic association. CS macrophage polarity also identified a highly coordinated network of either pro- or antitumor variables, which involved each tumor-associated cell type and was spatially organized. We extended these findings to other cancer indications. Overall, these results suggest that, despite their complexity, TMEs coordinate coherent responses that control human cancers and for which CS macrophage polarity is a relevant yet simple variable.

Macrophage polarization is influenced by lipids, which also exert significant control over macrophage functions. Lipids and their metabolites are players in intricate signaling pathways that modulate macrophages' responses to pathogens, phagocytosis, ferroptosis, and inflammation. This review focuses on lipid metabolism and macrophage functions and addresses potential molecular targets for the treatment of macrophage-related diseases. While lipogenesis is crucial for lipid accumulation and phagocytosis in M1 macrophages, M2 macrophages likely rely on fatty acid β-oxidation to utilize fatty acids as their primary energy source. Cholesterol metabolism, regulated by factors such as SREBPs, PPARs, and LXRs, is associated with the cholesterol efflux capacity and the formation of foam cells (M2-like macrophages). Foam cells, which are targets for atherosclerosis, are associated with an increase in inflammatory cytokines. Lipolysis and fatty acid uptake markers, such as CD36, also contribute to the production of cytokines. Enhancing the immune system through the inhibition of lipid-metabolism-related factors can potentially serve as a targeted approach against tumor cells. Cyclooxygenase inhibitors, which block the conversion of arachidonic acid into various inflammatory mediators, influence macrophage polarization and have generated attention in cancer research.

Development of a universal influenza vaccine that can provide robust and long-lasting protection against heterologous infections is a global public health priority. A variety of vaccine antigens are designed to increase the antigenicity of conserved epitopes to elicit cross-protective antibodies that often lack virus-neutralizing activity. Given the contribution of antibody effector functions to cross-protection, adjuvants need to be added to modulate antibody effector functions as well as to enhance antibody quantity. We previously showed that post-fusion influenza vaccine antigens elicit non-neutralizing but cross-protective antibodies against conserved epitopes. Here, using a murine model, we comparably assessed the adjuvanticity of the newly developed SA-2 adjuvant containing a synthetic TLR7 agonist DSP-0546 and squalene-based MF59 analog as representative Th1- or Th2-type adjuvants, respectively. Both types of adjuvants in the post-fusion vaccine comparably enhanced cross-reactive IgG titers against heterologous strains. However, only SA-2 skewed the IgG subclass into the IgG2c subclass in association to its Th1-polarizing nature. SA-2-enhanced IgG2c responses exhibited antibody-dependent cellular cytotoxicity against heterologous virus strains, without cross-neutralizing activity. Eventually, the SA-2-adjuvanted vaccination provided protection against lethal infection by heterologous H3N2 and H1N1 viruses. Together, we conclude that the combination with a SA-2 is advantageous for enhancing the cross-protective capability of post-fusion HA vaccines that elicit non-neutralizing IgG antibodies., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yoshimasa Takahashi reports financial support was provided by Japan Agency for Medical Research and Development. Akihisa Fukushima reports financial support was provided by Japan Agency for Medical Research and Development. Takuya Yamamoto reports financial support was provided by Japan Agency for Medical Research and Development. Masamitsu Aoki reports a relationship with Sumitomo Pharma. Co., Ltd. that includes: employment. Akihisa Fukushima reports a relationship with Sumitomo Pharma Co Ltd that includes: employment. Yoshimasa Takahashi has patent pending to Licensee. Yu Adachi has patent pending to Licensee. Akihisa Fukushima has patent pending to Licensee., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Some chemoattractants and leukocytes such as M1 and M2 macrophages are known to be involved in the development of glomerulosclerosis during diabetic nephropathy (DN). In the course of diabetes, an altered and defective cellular metabolism leads to the increase in adenosine levels, and thus to changes in the polarity (M1/M2) of macrophages. MRS1754, a selective antagonist of the A2B adenosine receptor (A2BAR), attenuated glomerulosclerosis and decreased macrophage-myofibroblast transition in DN rats. Therefore, we aimed to investigate the effect of MRS1754 on the glomerular expression/secretion of chemoattractants, the intraglomerular infiltration of leukocytes, and macrophage polarity in DN rats. Kidneys/glomeruli of non-diabetic, DN, and MRS1754-treated DN rats were processed for transcriptomic analysis, immunohistopathology, ELISA, and in vitro macrophage migration assays. The transcriptomic analysis identified an upregulation of transcripts and pathways related to the immune system in the glomeruli of DN rats, which was attenuated using MRS1754. The antagonism of the A2BAR decreased glomerular expression/secretion of chemoattractants (CCL2, CCL3, CCL6, and CCL21), the infiltration of macrophages, and their polarization to M2 in DN rats. The in vitro macrophages migration induced by conditioned-medium of DN glomeruli was significantly decreased using neutralizing antibodies against CCL2, CCL3, and CCL21. We concluded that the pharmacological blockade of the A2BAR decreases the transcriptional expression of genes/pathways related to the immune response, protein expression/secretion of chemoattractants, as well as the infiltration of macrophages and their polarization toward the M2 phenotype in the glomeruli of DN rats, suggesting a new mechanism implicated in the antifibrotic effect of MRS1754.

Sepsis is a life-threatening process related to a dysregulated host response to an underlying infection, which results in organ dysfunction and poor outcomes. Therapeutic strategies using mesenchymal stromal cells (MSCs) are under investigation for sepsis, with efforts to improve cellular utility. Syndecan (SDC) proteins are transmembrane proteoglycans involved with cellular signaling events including tissue repair and modulating inflammation. Bone marrow-derived human MSCs express syndecan-2 (SDC2) at a level higher than other SDC family members; thus, we explored SDC2 in MSC function. Administration of human MSCs silenced for SDC2 in experimental sepsis resulted in decreased bacterial clearance, and increased tissue injury and mortality compared with wild-type MSCs. These findings were associated with a loss of resolution of inflammation in the peritoneal cavity, and higher levels of proinflammatory mediators in organs. MSCs silenced for SDC2 had a decreased ability to promote phagocytosis of apoptotic neutrophils by macrophages in the peritoneum, and also a diminished capability to convert macrophages from a proinflammatory to a proresolution phenotype via cellular or paracrine actions. Extracellular vesicles are a paracrine effector of MSCs that may contribute to resolution of inflammation, and their production was dramatically reduced in SDC2-silenced human MSCs. Collectively, these data demonstrate the importance of SDC2 for cellular and paracrine function of human MSCs during sepsis., (© 2021 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Systemic lupus erythematosus (SLE) is an autoimmune disease that attacks almost every organ. The condition mostly happens to adults but is also found in children, and the latter have the most severe manifestations. Among adults, females, especially non-Caucasian, are mostly affected. Even if the etiology of SLE remains unclear, studies show a close relation between this disease and both genetics and environment. Despite the large number of published articles about SLE, we still do not have a clear picture of its pathogenesis, and no specific drug has been found to treat this condition effectively. The implication of macrophages in SLE development is gaining ground, and studying it could answer these gaps. Indeed, both in vivo and in vitro studies increasingly report a strong link between this disease and macrophages. Hence, this review aims to explore the role of macrophages polarization and plasticity in SLE development. Understanding this role is of paramount importance because in-depth knowledge of the connection between macrophages and this systemic disease could clarify its pathogenesis and provide a foundation for macrophage-centered therapeutic approaches., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ahamada, Jia and Wu.)

The development of complex forms of multicellular organisms depends on the spatial arrangement of cellular architecture and functions. The interior design of the cell is patterned by spatially biased distributions of molecules and biochemical reactions in the cytoplasm and/or on the plasma membrane. In recent years, a dynamic change in the cytoplasmic fluid flow has emerged as a key physical process of driving long-range transport of molecules to particular destinations within the cell. Here, recent experimental advances in the understanding of the generation of the various types of cytoplasmic flows and contributions to intracellular patterning are reviewed with a particular focus on feedback mechanisms between the mechanical properties of fluid flow and biochemical signaling during animal cell polarization., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

While largely appreciated for their antimicrobial and repair functions, macrophages have emerged as indispensable for the development, homeostasis, and regeneration of tissue, including regeneration of the neonatal heart. Upon activation, mammalian neonatal macrophages express and secrete factors that coordinate angiogenesis, resolution of inflammation, and ultimately cardiomyocyte proliferation. This is contrary to adult macrophages in the adult heart, which are incapable of inducing significant levels of cardiac regeneration. The underlying mechanisms by which pro-regenerative macrophages are activated and regulated remain vague. A timely hypothesis is that macrophage metabolism contributes to this proliferative and regenerative potential. This is because we now appreciate the significant contributions of metabolites to immune cell programming and function, beyond solely bioenergetics. After birth, the metabolic milieu of the neonate is subject to significant alterations in oxygenation and nutrient supply, which will affect how metabolic substrates are catabolized. In this context, we discuss potential roles for select macrophage metabolic pathways during cardiac regeneration., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Tuberculosis is a chronic infection caused by Mycobacterium tuberculosis (M.tb), which needs proper macrophage activation for control. It has been debated whether the co-infection with helminth will affect the immune response to mycobacterial infection., Objective: To determine the effect of sequential co-infection of Heligmosomoides polygyrus (H.pg) nematodes and M.tb on T cell responses, macrophages polarization and lung histopathological changes., Method: This study used 49 mice divided into 7 treatment groups, with different sequence of infection of M.tb via inhalation and H.pg via oral ingestion for 8 and 16 weeks. T cells response in the lung, intestine, and peripheral blood were determined by flow cytometry. Cytokines (IL-4, IFN-γ, TGB-β1, and IL-10) were measured in peripheral blood using ELISA. Lung macrophage polarization were determined by the expression of iNOS (M1) or Arginase 1 (M2). Mycobacterial count were done in lung tissue. Lung histopathology were measured using Dorman's semiquantitative score assessing peribronchiolitis, perivasculitis, alveolitis, and granuloma formation., Result: M.tb infection induced Th1 response and M1 macrophage polarization, while H.pg infection induced Th2 and M2 polarization. In sequential co-infection, the final polarization of macrophage was dictated by the sequence of co-infection. However, all groups with M.tb infection showed the same degree of mycobacterial count in lung tissues and lung tissue histopathological changes., Conclusion: Sequential co-infection of H.pg and M.tb induces different T cell response which leads to different macrophage polarization in lung tissue. Helminth infection induced M2 lung macrophage polarization, but did not cause different mycobacterial count nor lung histopathological changes., Competing Interests: Conflicts of interest The authors have none to declare., (Copyright © 2020 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.)

Acute graft-versus-host disease (aGVHD) is a lethal complication after allogeneic hematopoietic stem cell transplantation. The mechanism involves the recognition of host antigens by donor-derived T cells which induces augmented response of alloreactive T cells. In this study, we characterized the role of a previously identified novel classical secretory protein with antitumor function-LYG1 (Lysozyme G-like 1), in aGVHD. LYG1 deficiency reduced the activation of CD4 + T cells and Th1 ratio, but increased Treg ratio in vitro by MLR assay. By using major MHC mismatched aGVHD model, LYG1 deficiency in donor T cells or CD4 + T cells attenuated aGVHD severity, inhibited CD4 + T cells activation and IFN-γ expression, promoted FoxP3 expression, suppressed CXCL9 and CXCL10 expression, restrained allogeneic CD4 + T cells infiltrating in target organs. The function of LYG1 in aGVHD was also confirmed using haploidentical transplant model. Furthermore, administration of recombinant human LYG1 protein intraperitoneally aggravated aGVHD by promoting IFN-γ production and inhibiting FoxP3 expression. The effect of rhLYG1 could partially be abrogated with the absence of IFN-γ. Furthermore, LYG1 deficiency in donor T cells preserved graft-versus-tumor response. In summary, our results indicate LYG1 regulates aGVHD by the alloreactivity of CD4 + T cells and the balance of Th1 and Treg differentiation of allogeneic CD4 + T cells, targeting LYG1 maybe a novel therapeutic strategy for preventing aGVHD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Liu, Yu, Tang, Miao, Qin, Li, Liang, Shi, Zhang, Wang, Yan, Song, Ren and Dong.)

After successful cardiopulmonary resuscitation (CPR), many patients show signs of an overactive immune activation. Monocytes are a heterogeneous cell population that can be distinguished into 3 subsets by flow cytometry (classical monocytes [CM: CD14 ++ CD16 - ], intermediate monocytes [IM: CD14 ++ CD16 + CCR2 + ] and non-classical monocytes [NCM: CD14 + CD16 ++ CCR2 - ]). Fifty-three patients admitted to the medical intensive care unit (ICU) after cardiac arrest were included. Blood was taken on admission and after 72 h. The primary endpoint of this study was survival at 6 months and the secondary endpoint was neurological outcome as determined by cerebral performance category (CPC)-score at 6 months. Median age was 64.5 (49.8-74.3) years and 75.5% were male. Six-month mortality was 50.9% and survival with good neurological outcome was 37.7%. Monocyte subset distribution upon admission to the ICU did not differ according to survival. Seventy-two hours after admission, patients who died within 6 months showed a higher percentage of the pro-inflammatory subset of IM (8.3% [3.8-14.6]% vs. 4.1% [1.5-8.2]%; P = 0.025), and a lower percentage of CM (87.5% [79.9-89.0]% vs. 90.8% [85.9-92.7]%; P = 0.036) as compared to survivors. In addition, IM were predictive of outcome independent of time to ROSC and witnessed cardiac arrest, and correlated with CPC-score at 6 months (R = 0.32; P = 0.043). These findings suggest a possible role of the innate immune system in the pathophysiology of post cardiac arrest syndrome., (© 2020 The Authors. Journal of Leukocyte Biology published by Wiley Periodicals LLC on behalf of Society for Leukocyte Biology.)

Visualizing mRNA in real time in vivo at high resolution is critical for a full understanding of the spatiotemporal dynamics of gene regulation and function. Here, using a PP7/PCP-based mRNA-tagging approach, we construct a collection of tissue-specific and differentially expressed toolkit strains for visualizing mRNAs encoding apical, basolateral, and junctional proteins in Caenorhabditis elegans epithelia. We precisely delineate the spatiotemporal organization and dynamics of these transcripts across multiple subcellular compartments and tissues. Remarkably, all the transcripts exhibit an asymmetric, membrane-associated localization during epithelial polarization and maturation, which suggests that mRNA localization is a prerequisite for epithelial polarization and function. Single-particle tracking reveals striking features of the transport dynamics of the mRNAs in a gene-specific, compartment-linked, and time-resolved manner. The toolkit can be used to identify the cis-regulatory elements and trans-acting factors for mRNA localization. This study provides a valuable resource to investigate complex RNA dynamics in epithelial polarity and morphogenesis., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

T cells form immunological synapses with professional antigen-presenting cells (APCs) resulting in T cell activation and the acquisition of peptide antigen-MHC (pMHC) complexes from the plasma membrane of the APC. They thus become APCs themselves. We investigate the functional outcome of T-T cell antigen presentation by CD4 T cells and find that the antigen-presenting T cells (Tpres) predominantly differentiate into regulatory T cells (Treg), whereas T cells that have been stimulated by Tpres cells predominantly differentiate into Th17 pro-inflammatory cells. Using mice deficient in pMHC uptake by T cells, we show that T-T antigen presentation is important for the development of experimental autoimmune encephalitis and Th17 cell differentiation in vivo. By varying the professional APC:T cell ratio, we can modulate Treg versus Th17 differentiation in vitro and in vivo, suggesting that T-T antigen presentation underlies proinflammatory responses in conditions of antigen scarcity., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Irregular inflammatory responses are a major contributor to tissue dysfunction and inefficient repair. Skin has proven to be a powerful model to study mechanisms that regulate inflammation. In particular, skin wound healing is dependent on a rapid, robust immune response and subsequent dampening of inflammatory signaling. While injury-induced inflammation has historically been attributed to keratinocytes and immune cells, a vast body of evidence supports the ability of non-immune cells to coordinate inflammation in numerous tissues and diseases. In this review, we concentrate on the active participation of tissue-resident adipocytes and fibroblasts in pro-inflammatory signaling after injury, and how altered cellular communication from these cells can contribute to irregular inflammation associated with aberrant wound healing. Furthering our understanding of how tissue-resident mesenchymal cells contribute to inflammation will likely reveal new targets that can be manipulated to regulate inflammation and repair.

Macrophages are the most abundant cells in tumor stroma and their polarization within tumor microenvironment exert the key roles in tumorigenesis. Astragaloside IV is a natural extract from traditional Chinese herbal Radix Astragali, and fulfills pleiotropic function in several cancers. Nevertheless, its function in ovarian cancer microenvironment remains elusive. In the present research, astragaloside IV exhibited little cytotoxicity within a certain dose range in THP-1 cells. Moreover, astragaloside IV suppressed the ratio of CD14 + CD206 + cells in IL-4/IL-13-treated THP-1 macrophages and transcripts of M2 macrophage markers (including CD206, CCL24, PPARγ, Arg-1, IL-10), indicating the inhibitory effects of astragaloside IV on IL-4/IL-13-induced macrophage M2 polarization. Intriguingly, astragaloside IV antagonized M2 macrophages coculture-evoked cell proliferation, invasion and migration in ovarian cancer cells. During this process, administration with astragaloside IV restrained the high expression of high-mobility group box1 (HMGB1) and TLR4 in macrophages co-cultured with ovarian cancer cells, concomitant with decreases in release of M2 marker TGF-β, MMP-9 and IL-10. Moreover, targeting the HMGB1 signaling reversed M2 macrophages-induced ovarian cancer cell proliferation, invasion and migration. Noticeably, exogenous HMGB1 overturned the inhibitory efficacy of astragaloside IV against macrophage M2 polarization-evoked malignant potential in ovarian cancer cells. Together, these findings suggest that astragaloside IV may protect against M2 macrophages-evoked malignancy in ovarian cancer cells by suppressing the HMGB1-TLR4 signaling. Therefore, astragaloside may alleviate the progression of ovarian cancer by regulating macrophage M2 polarization within tumor microenvironment, implying a promising therapeutic strategy against ovarian cancer., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Asthma is a chronic airway disease often due to sensitization to aeroallergens, especially house dust mite allergens (HDMs). The Dermatophagoides pteronyssinus group 2 (Der p 2), is one of the most representative HDM allergens and is recognized by more than 90% of HDM-allergic patients. In mouse models, all asthma-related features can be prevented by prophylactic administration of Dermatophagoides pteronyssinus 2-derived peptide (Der p 2.1). However, it is unknown whether it is able to treat well-established asthma in mice and humans. We aimed here to evaluate the efficacy of Der p 2.1 immunotherapy in a mouse, humanized mouse, and asthmatic patients. Asthma related-features were analyzed through airway hyperresponsiveness (AHR), allergen-specific IgE, and lung histology in mice and humanized mice. Immune profile was analyzed using lung and blood from mice and severe asthmatic patients respectively. T cell and dendritic cell (DC) polarization was evaluated using co-culture of bone marrow derived cells (BMDCs) and naïve T cell from naïve mice. Mice and humanized mice both have a reduced AHR, lung tissue alteration, and HDM-specific IgE under Der p 2.1 treatment. Concerning the immune profile, T helper 2 cells (Th2) and T helper 17 cells (Th17) were significantly reduced in both mice and humanized mice lung and in peripheral blood mononuclear cells (PBMCs) from severe asthmatic patients after Der p 2.1 incubation. The downregulation of T cell polarization seems to be linked to an increase of IL-10-secreting DC under Der p 2.1 treatment in both mice and severe asthmatic patients. This study shows that allergen-derived peptide immunotherapy abrogates asthma-related features in mice and humanized mice by reducing Th2 and Th17 cells polarization via IL-10-secreting DC. These results suggest that Der p 2.1 peptide immunotherapy could be a promising approach to treat both Th2 and Th17 immunity in asthma., (Copyright © 2020 Klein, Colas, Cheminant, Brosseau, Sauzeau, Magnan and Bouchaud.)

It has long been known that in vitro polarized macrophages differ in morphology. Stemming from a conventional immunohistology observation, we set out to test the hypothesis that morphology of tumor-associated macrophages (TAMs) in colorectal liver metastasis (CLM) represents a correlate of functional diversity with prognostic significance. Density and morphological metrics of TAMs were measured and correlated with clinicopathological variables. While density of TAMs did not correlate with survival of CLM patients, the cell area identified small (S-TAM) and large (L-TAM) macrophages that were associated with 5-yr disease-free survival rates of 27.8% and 0.2%, respectively (P < 0.0001). RNA sequencing of morphologically distinct macrophages identified LXR/RXR as the most enriched pathway in large macrophages, with up-regulation of genes involved in cholesterol metabolism, scavenger receptors, MERTK, and complement. In single-cell analysis of mononuclear phagocytes from CLM tissues, S-TAM and L-TAM signatures were differentially enriched in individual clusters. These results suggest that morphometric characterization can serve as a simple readout of TAM diversity with strong prognostic significance., Competing Interests: Disclosures: A. Mantovani reported personal fees from Ventana, Pierre Fabre, Verily, AbbVie, Astra Zeneca, Verseau Therapeutics, Compugen, Myeloid Therapeutics, Third Rock Venture, Imcheck Therapeutics, Ellipses, Novartis, Roche, Macrophage Pharma, Biovelocita, Merck, and Principia; grants from Novartis; and "other" from Cedarlane Laboratories Ltd, Hycult Biotechnology, eBioscience, BioLegend, ABCAM Plc, Novus Biologicals, Enzo Life (ex-Alexis Corp.), and Affymetrix outside the submitted work. He is the inventor of patents related to PTX3 and other innate immunity molecules and receives royalties for reagents related to innate immunity. No other disclosures were reported., (© 2020 Donadon et al.)

Background/aim: Glioblastoma multiforme (GBM) is an intractable tumor that has a very poor prognosis despite intensive treatment with temozolomide plus radiotherapy., Patients and Methods: Sixteen newly diagnosed patients with high-grade gliomas were enrolled in a phase II study of the α-type-1 DC vaccine. Briefly, DCs obtained from the culture of enriched monocytes in the presence of a cytokine cocktail, were pulsed with a cocktail of 5 synthetic peptides and cryopreserved until injection into patients., Results: The amount of IL-12 produced by activated DCs was higher than that previously reported. Among 15 evaluable patients, 10 showed positive CTL responses to any peptides in an ELISPOT assay. After 6 years of observation, five patients were still alive, and two of these patients were relapse-free. Moreover, a significant survival-prolonging effect was verified in DC-treated glioma patients., Conclusion: Peptide-cocktail-pulsed α-type-1 DC vaccines have a potential therapeutic effect on survival when used in combination with the standard regimen, which is partly based on IL-12-IFN-γ-mediated T-cell activation., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Macrophages reprogram their metabolism to promote appropriate responses. Proresolving macrophages primarily use fatty acid oxidation as an energy source. Metabolites generated during the catabolism of fatty acids aid in the resolution of inflammation and tissue repair, but the regulatory mechanisms that control lipid metabolism in macrophages are not fully elucidated. Lipin-1, a phosphatidic acid phosphatase that has transcriptional coregulator activity, regulates lipid metabolism in a variety of cells. In this current study, we show that lipin-1 is required for increased oxidative phosphorylation in IL-4 stimulated mouse ( Mus musculus ) macrophages. We also show that the transcriptional coregulatory function of lipin-1 is required for β-oxidation in response to palmitate (free fatty acid) and apoptotic cell (human) stimulation. Mouse bone marrow-derived macrophages lacking lipin-1 have a reduction in critical TCA cycle metabolites following IL-4 stimulation, suggesting a break in the TCA cycle that is supportive of lipid synthesis rather than lipid catabolism. Together, our data demonstrate that lipin-1 regulates cellular metabolism in macrophages in response to proresolving stimuli and highlights the importance of aligning macrophage metabolism with macrophage phenotype., (Copyright © 2020 The Authors.)

Emerging shreds of evidence suggest that tumor-associated macrophages (TAMs) modulate various hallmarks of cancer during tumor progression. Tumor microenvironment (TME) prime TAMs to execute important roles in cancer development and progression, including angiogenesis, matrix metalloproteinases (MMPs) secretion, and extracellular matrix (ECM) disruption. MicroRNAs (miRNAs) are critical epigenetic regulators, which modulate various functions in diverse types of cells, including macrophages associated with TME. In this review article, we provide an update on miRNAs regulating differentiation, maturation, activation, polarization, and recruitment of macrophages in the TME. Furthermore, extracellular miRNAs are secreted from cancerous cells, which control macrophages phenotypic plasticity to support tumor growth. In return, TAMs also secrete various miRNAs that regulate tumor growth. Herein, we also describe the recent updates on the molecular connection between tumor cells and macrophages. A better understanding of the interaction between miRNAs and TAMs will provide new pharmacological targets to combat cancer.

Exosomes comprise extracellular vesicles (EVs) with diameters between 30 and 150 nm. They transfer proteins, RNA, and other molecules from cell to cell, playing an important role in the interactions between cells. The tumor microenvironment (TME) has been found to contain various cells and molecules that have an important impact on tumor development. In the TME, macrophages have been found to have an important relationship with tumor cells, with tumors recruiting and inducing macrophages to become tumor-associated macrophages (TAMs), which promote tumor development. Recently, exosomes have been found to play a critical role in the interaction between tumor cells and macrophages. Thus, in this review, we summarize the roles and mechanisms of exosomes in the interaction between tumor cells and macrophages and the potential methods by which exosomes are used to target the communication between tumor cells and macrophages to treat cancer., (Copyright © 2020 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.)

Atherosclerotic plaque rupture followed by luminal thrombosis is recognized as the main cause of acute cardiovascular events, especially in patients with diabetes. Although previous studies identified stimulation of macrophages polarization with advanced glycation end products (AGEs) results in the rapid progression of atherosclerosis, the underlying mechanisms are not understood fully. The purpose of this study was to investigate the effect of hypoxia-inducible factor-1α (HIF-1α) and pyruvate dehydrogenase kinase 4 (PDK4), critical proteins for regulating glucose metabolism, on macrophages polarization in diabetic atherosclerosis, and relevant mechanisms involved. We found that there is an increased number of M1 macrophages in carotid atherosclerotic tissues of diabetic mice and in AGE-bovine serum albumin (BSA)-treated RAW264.7 cells. Furthermore, we observed that HIF-1α was upregulated in AGE-BSA-induced M1 polarization and that the HIF-1α knockdown reduced macrophage polarization to M1 phenotype caused by AGE-BSA via regulation of PDK4. Thus, our study identified the critical role of HIF-1α/PDK4 axis in AGE-BSA-induced M1 polarization, which reflected the potential association between energy metabolism and inflammation in macrophages., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Inflammation plays a key role in the development and progression of type-2 diabetes (T2D), a disease characterised by peripheral insulin resistance and systemic glucolipotoxicity. Visceral adipose tissue (AT) is the main source of inflammation early in the disease course. Macrophages are innate immune cells that populate all peripheral tissues, including AT. Dysregulated AT macrophage (ATM) responses to microenvironmental changes are at the root of aberrant inflammation and development of insulin resistance, locally and systemically. The inflammatory activation of macrophages is regulated at multiple levels: cell surface receptor stimulation, intracellular signalling, transcriptional and metabolic levels. This review will cover the main mechanisms involved in AT inflammation and insulin resistance in T2D. First, we will describe the physiological and pathological changes in AT that lead to inflammation and insulin resistance. We will next focus on the transcriptional and metabolic mechanisms described that lead to the activation of ATMs. We will discuss more novel metabolic mechanisms that influence macrophage polarisation in other disease or tissue contexts that may be relevant to future work in insulin resistance and T2D.

Cells polarize for growth, motion, or mating through regulation of membrane-bound small GTPases between active GTP-bound and inactive GDP-bound forms. Activators (GEFs, GTP exchange factors) and inhibitors (GAPs, GTPase activating proteins) provide positive and negative feedbacks. We show that a reaction-diffusion model on a curved surface accounts for key features of polarization of model organism fission yeast. The model implements Cdc42 membrane diffusion using measured values for diffusion coefficients and dissociation rates and assumes a limiting GEF pool (proteins Gef1 and Scd1), as in prior models for budding yeast. The model includes two types of GAPs, one representing tip-localized GAPs, such as Rga3; and one representing side-localized GAPs, such as Rga4 and Rga6, that we assume switch between fast and slow diffusing states. After adjustment of unknown rate constants, the model reproduces active Cdc42 zones at cell tips and the pattern of GEF and GAP localization at cell tips and sides. The model reproduces observed tip-to-tip oscillations with periods of the order of several minutes, as well as asymmetric to symmetric oscillations transitions (corresponding to NETO "new end take off"), assuming the limiting GEF amount increases with cell size.

Purpose: To explore the influence of indoleamine 2,3-dioxygenase (IDO) on macrophage recruitment, polarization and phagocytosis in Aspergillus fumigatus keratitis., Methods: A murine model of A. fumigatus keratitis and peritoneal macrophages incubated with the hyphae of A. fumigatus were used. Macrophage recruitment in corneas was evaluated using immunofluorescence staining. The polarization of macrophages, which was stimulated by A. fumigatus and pretreatment with or without 1-methyltryptophan (1-MT), interferon gamma (IFNG), extracellular regulated protein kinases (ERK) antagonist, and p38 antagonist, was determined using reverse-transcription polymerase chain reaction and flow cytometry. P38 and ERK levels were determined using Western blotting. Macrophage phagocytosis was examined using colony-forming units., Results: Compared with the A.F. group, recruitment of macrophages increased, tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) expression decreased, whereas arginase-1 (Arg-1) and interleukin-10 (IL-10) expression increased in the mouse corneas of the 1-MT+A.F. group. The ratio of CD206+/CD86+ macrophages in the corneas and spleens of 1-MT+A.F. group increased. Furthermore, in peritoneal macrophages stimulated by A. fumigatus, 1-MT promoted Arg-1 and IL-10 expression while upregulating the ratio of CD206+/CD86+ macrophages. Conversely, IDO agonist IFNG promoted TNF-α and iNOS expression, inhibited Arg-1 and IL-10 expression and downregulated the ratio of CD206+/CD86+ macrophages. The role of IFNG was reversed by the antagonist of P38 or ERK. P38 and ERK levels were downregulated in corneas of 1-MT+A.F. group. Besides, IFNG inhibited macrophage phagocytosis., Conclusion: IDO inhibited macrophage recruitment and phagocytosis in A. fumigatus keratitis. Mechanistically, IDO is involved in M1 macrophage polarization in A. fumigatus keratitis through a MAPK/ERK-dependent pathway.

Visceral leishmaniasis (VL)-related mortality and morbidity imposes a great deal of health concern across the globe. The existing anti-leishmanial drug regimen generally fails to eliminate newly emerging resistant isolates of this dreadful parasite. In such circumstances, the development of a prophylactic strategy to impart protection against the disease is likely to take center stage. In order to develop a promising prophylactic vaccine, it is desirable to identify an adequately potential vaccine candidate. In silico analysis of Leishmania tubulin folding cofactor D protein predicted its potential to activate both B- and T-cell repertoires. Furthermore, the ELISA employing anti-peptide 27 (a segment of tubulin folding cofactor D) antibody revealed its proficiency in VL diagnosis and treatment monitoring. The peptide 27 and its cocktail with another Leishmania peptide (peptide 23 ) prompted the up-regulation of pro-inflammatory cytokines, such as IFN-γ, TNF-α, IL-2, IL-17, etc ., and the down-regulation of immune-regulatory cytokines, such as IL-10, in the immunized BALB/c mice. Coherent to the consequence of peptide-specific humoral immune response, peptide cocktail-based immunization ensued in the predominant amplification of pathogen-specific IgG2a over the IgG1 isotype, up-regulated proliferation of T lymphocytes, and enhanced production of nitric oxide, reactive oxygen species, etc . We also established that the peptide cocktail modulated host MAPK signaling to favor the amplification of Th 1 -dominated immune response in the host. The peptide cocktail mediated the activation of the host immune armory, which was eventually translated into a significant decline in parasitic load in the visceral organs of experimental animals challenged with Leishmania donovani ., (Copyright © 2020 Jamal, Singh, Hansa, Pushpanjali, Ahmad, Dikhit, Umar, Bimal, Das, Mujeeb, Singh, Zubair and Owais.)

Macrophage responses contribute to a diverse array of pathologies ranging from infectious disease to sterile inflammation. Polarization of macrophages determines their cellular function within biological processes. Lipin-1 is a phosphatidic acid phosphatase in which its enzymatic activity contributes to macrophage pro-inflammatory responses. Lipin-1 also possesses transcriptional co-regulator activity and whether this activity is required for macrophage polarization is unknown. Using mice that lack only lipin-1 enzymatic activity or both enzymatic and transcriptional coregulator activities from myeloid cells, we investigated the contribution of lipin-1 transcriptional co-regulator function toward macrophage wound healing polarization. Macrophages lacking both lipin-1 activities did not elicit IL-4 mediated gene expression to levels seen in either wild-type or lipin-1 enzymatically deficient macrophages. Furthermore, mice lacking myeloid-associated lipin-1 have impaired full thickness excisional wound healing compared to wild-type mice or mice only lacking lipin-1 enzymatic activity from myeloid cell. Our study provides evidence that lipin-1 transcriptional co-regulatory activity contributes to macrophage polarization and influences wound healing in vivo ., (Copyright © 2020 Chandran, Schilke, Blackburn, Yurochko, Mirza, Scott, Finck and Woolard.)

hScrib and hDlg belong to the PDZ family of proteins. Since the identification of these highly phylogenetically conserved scaffolds, an increasing amount of experiments has elucidated the roles of hScrib and hDlg in a variety of cell functions. Remarkably, their participation during the establishment of polarity in epithelial cells is well documented. Although the role of both proteins in the immune system is scantly known, it has become a growing field of investigation. Here, we summarize the interactions and functions of hScrib and hDlg1, which participate in diverse functions involving cell polarization in immune cells, and discuss their relevance in the immune cell biology. The fundamental role of hScrib and hDlg1 during the establishment of the immunological synapse, hence T cell activation, and the recently described role of hScrib in reactive oxygen species production in macrophages and of hDlg1 in cytokine production by dendritic cells highlight the importance of both proteins in immune cell biology. The expression of these proteins in other leukocytes can be anticipated and needs to be confirmed. Due to their multiple interaction domains, there is a wide range of possible interactions of hScrib and hDlg1 that remains to be explored in the immune system., Competing Interests: The authors declare no commercial or financial conflict of interest., (Copyright © 2020 Dante Barreda et al.)

CD8 + T cells can be polarized into several different subsets as defined by the cytokines they produce and the transcription factors that govern their differentiation. Here, we identified the polarizing conditions to induce an IL22-producing CD8 + Tc22 subset, which is dependent on IL6 and the aryl hydrocarbon receptor transcription factor. Further characterization showed that this subset was highly cytolytic and expressed a distinct cytokine profile and transcriptome relative to other subsets. In addition, polarized Tc22 were able to control tumor growth as well as, if not better than, the traditional IFNγ-producing Tc1 subset. Tc22s were also found to infiltrate the tumors of human patients with ovarian cancer, comprising up to approximately 30% of expanded CD8 + tumor-infiltrating lymphocytes (TIL). Importantly, IL22 production in these CD8 + TILs correlated with improved recurrence-free survival. Given the antitumor properties of Tc22 cells, it may be prudent to polarize T cells to the Tc22 lineage when using chimeric antigen receptor (CAR)-T or T-cell receptor (TCR) transduction-based immunotherapies., (©2020 American Association for Cancer Research.)

Cartilage lesions and osteoarthritis (OA) presents an ever-increasing clinical and socioeconomic burden. Synovial inflammation and articular inflammatory environment are the key factor for chondrocytes apoptosis and hypertrophy, ectopic bone formation and OA progression. To effectively treat OA, it is critical to develop a drug that skews inflammation toward a pro-chondrogenic microenvironment. In this narrative and critical review, we aim to see the potential use of immune cells modulation or cell therapy as therapeutic alternatives to OA patients. Macrophages are immune cells that are present in synovial lining, with different roles depending on their subtypes. These cells can polarize to pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes, being the latter associated with wound-healing by the production of ARG-1 and pro-chondrogenic cytokines, such as IL-10, IL-1RA, and TGF-b. Emerging evidence reveals that macrophage shift can be determined by several stimuli, apart from the conventional in vitro IL-4, IL-13, and IL-10. Evidences show the potential of physical exercise to induce type 2 response, favoring M2 polarization. Moreover, macrophages in contact with oxLDL have effect on the production of anabolic mediators as TGF-b. In the same direction, type II collagen, that plays a critical role in development and maturation process of chondrocytes, can also induce M2 macrophages, increasing TGF-b. The mTOR pathway activation in macrophages was shown to be able to polarize macrophages in vitro , though further studies are required. The possibility to use mesenchymal stem cells (MSCs) in cartilage restoration have a more concrete literature, besides, MSCs also have the capability to induce M2 macrophages. In the other direction, M1 polarized macrophages inhibit the proliferation and viability of MSCs and impair their ability to immunosuppress the environment, preventing cartilage repair. Therefore, even though MSCs therapeutic researches advances, other sources of M2 polarization are attractive issues, and further studies will contribute to the possibility to manipulate this polarization and to use it as a therapeutic approach in OA patients., (Copyright © 2020 Fernandes, Gomoll, Lattermann, Hernandez, Bueno and Amano.)

Background: miRNAs are master regulators of signaling pathways critically involved in asthma and are transferred between cells in extracellular vesicles (EV). We aimed to investigate whether the miRNA content of EV secreted by primary normal human bronchial epithelial cells (NHBE) is altered upon asthma development., Methods: NHBE cells were cultured at air-liquid interface and treated with interleukin (IL)-13 to induce an asthma-like phenotype. EV isolations by precipitation from basal culture medium or apical surface wash were characterized by nanoparticle tracking analysis, transmission electron microscopy, and Western blot, and EV-associated miRNAs were identified by a RT-qPCR-based profiling. Significant candidates were confirmed in EVs isolated by size-exclusion chromatography from nasal lavages of children with mild-to-moderate (n = 8) or severe asthma (n = 9), and healthy controls (n = 9)., Results: NHBE cells secrete EVs to the apical and basal side. 47 miRNAs were expressed in EVs and 16 thereof were significantly altered in basal EV upon IL-13 treatment. Expression of miRNAs could be confirmed in EVs from human nasal lavages. Of note, levels of miR-92b, miR-210, and miR-34a significantly correlated with lung function parameters in children (FEV 1 FVC %pred and FEF 25-75%pred ), thus lower sEV-miRNA levels in nasal lavages associated with airway obstruction. Subsequent ingenuity pathway analysis predicted the miRNAs to regulate Th2 polarization and dendritic cell maturation., Conclusion: Our data indicate that secretion of miRNAs in EVs from the airway epithelium, in particular miR-34a, miR-92b, and miR-210, might be involved in the early development of a Th2 response in the airways and asthma., (© 2019 The Authors. Allergy Published by John Wiley & Sons Ltd.)

Calreticulin (CALR) has anti-tumor effects by increasing dendritic cell maturation and tumor antigen presentation. However, whether CALR affects macrophages and modulates progression of acute respiratory distress syndrome/acute lung injury (ARDS/ALI) remains unknown. In this study, we discovered that CALR protein was highly expressed in the mice with LPS-induced ALI and CALR expression level was positively correlated to the severity of ALI. Commercial anti-CALR antibody (aCALR) can neutralize recombinant CALR (rCALR) and suppress the expression of TNF-alpha and IL-6 in the rCALR-treated macrophages. Blocking CALR activity by intraperitoneal (i.p.) administration of aCALR significantly suppressed ALI, accompanied with lower total cell counts, neutrophil and T cell infiltration in bronchoalveolar lavage (BAL) and lung tissues. The expression of CXCL15, IL-6, IL-1beta, TNF-alpha, and CALR were significantly reduced, in association with more polarization of Siglec F+CD206+M2 subtype macrophages in the aCALR-treated mice. Pre-depletion of circulating monocytes did not abolish the aCALR-mediated suppression of ALI. Further analysis in bone marrow-derived macrophages (BMDMs) showed that aCALR suppressed the expression of CD80, IL-6, IL-1beta, IL-18, NLRP3, and p-p38 MAPK; but enhanced the expression of CD206 and IL-10. In addition, we observed more expression and phosphorylation of STAT6 in the aCALR-treated BMDM. Lack of STAT6 resulted in comparable and slightly higher expression of CALR, TNF-alpha and IL-6 in the aCALR-treated STAT6-/- BMDMs than the untreated cells. Therefore, we conclude that CALR is a novel biomarker in the evaluation of ALI. Blocking CALR activity by aCALR effectively suppressed ALI independent of circulating monocytes. Siglec F+CD206+M2 subtype macrophages and p38 MAPK/STAT6 signaling pathway played important role in the immune regulation of aCALR. Blocking CALR activity is a promising therapeutic approach in the treatment of ARDS/ALI., (Copyright © 2020 Jiang, Chen, Hu, Qiu and Zhu.)

Intestinal epithelial cells (IECs) act as a physical barrier separating the commensal-containing intestinal tract from the sterile interior. These cells have found a complex balance allowing them to be prepared for pathogen attacks while still tolerating the presence of bacterial or viral stimuli present in the lumen of the gut. Using primary human IECs, we probed the mechanisms that allow for such a tolerance. We discovered that viral infections emanating from the basolateral side of IECs elicit a stronger intrinsic immune response in comparison to lumenal apical infections. We determined that this asymmetric immune response is driven by the clathrin-sorting adaptor AP-1B, which mediates the polarized sorting of Toll-like receptor 3 (TLR3) towards the basolateral side of IECs. Mice and human IECs lacking AP-1B showed an exacerbated immune response following apical stimulation. Together, these results suggest a model where the cellular polarity program plays an integral role in the ability of IECs to partially tolerate apical commensals while remaining fully responsive to invasive basolateral pathogens.

Background: Egg-induced immune response and granuloma formation are thought to be the basis of central nervous system (CNS)-related clinical symptoms of Schistosoma japonicum. Microglia/macrophages are the major immune cells involved in detection and subsequent elimination of pathogens and injured tissue in the brain. However, little is known about their role in the pathogenesis of neuroschistosomiasis. The main purpose of the study is to clarify the pathological involvement of microglia/macrophages in the pathogenesis of neuroschistosomiasis (NS)., Methods: Staining techniques were applied to the granuloma tissues excised from 4 patients, as well as mice model which was established by microinjecting viable S. japonicum eggs into the brain. Clinical features of the patients and neurological symptoms in mice were also collected and analyzed in terms of their correlation with microglia/macrophages., Results: Microglia/macrophages constituted the major portions of the granulomas surrounding the eggs in both all human cases and S. japonicum egg-injected mice. Granuloma persisted in all patients accompanied by unremitted neurological symptoms, while in mice granuloma formation initiated on day 3, peaked on day 7 and subsided on day 30 post injection with S. japonicum eggs. No neurological abnormalities were observed in egg-injected mice except for significant weight decrease on day 3 compared with saline-injected control. M1 polarization of microglia/macrophages was confirmed in egg-injected mice 3 days post injection and in all human cases. M2 polarization was absent in human patients despite the duration of complaints but dominated in the whole progression of egg-induced pathology in mice until the elimination of eggs and subsidence of neuroinflammation on day 30 post injection., Conclusions: Microglia/macrophages participated actively in the granuloma microenvironment of encephalic schistosomiasis japonicum in both human and mice. The polarization pattern of microglia/macrophages coincided with the symptomatic features in human cases and S. japonicum egg-injected mice, indicating M2 instead of M1 activation as a probably more important mediator in the battle against egg-induced pathology and concomitant manifestations. These new findings will shed light on the pathogenesis of NS from a brand-new perspective, and may contribute to the immunotherapy development for such disease, favoring perhaps M2 polarization of microglia/macrophages as a feasible strategy.

Context: β-Sitosterol (BS), the primary constituent of plants and vegetables, exhibits multiple biological effects., Objective: This study explores its effect of immune-regulation on macrophages and its potential for rheumatoid arthritis (RA) therapy., Materials and Methods: In vitro, bone marrow-derived macrophages (BMDMs) were treated with 5, 25 and 50 μM BS in the M1 or M2 polarization conditions. In vivo, either i.p. injection with 20 or 50 mg/kg BS every 2 d after boost immunization of collagen-induced arthritis (CIA) or adoptive transfer of 2 × 10 6 BS-treated BMDMs (BS-BMDMs) at the day before CIA were adopted in mice to test the therapeutic effect. IL-10 antibody depletion was used in the period of above treatments to discuss the underlying mechanism., Results: The phenotypes and function of BMDMs showed that 5, 25 and 50 μM BS significantly repressed the M1 polarization and augmented M2 polarization dependent upon concentration. The expression of iNOS, IL-1β, CD86 and MHCII in 25 μM BS-treated M1-polarized BMDMs was reduced by 50.2, 47.1, 87.1 and 31.3%, respectively. In contrast, the expression of arginase-1, IL-10, CD163 and CD206 in 25 μM BS-treated M2-polarized BMDMs was increased by 65.6, 107.4, 23.5 and 51.3%, respectively. In CIA mice, either i.p. injection with BS or adoptive transfer of BS-BMDMs could alleviate the symptoms of ankle swelling (vehicle group: 3.13 ± 0.102 mm; 20 mg/kg BS group: 2.64 ± 0.043 mm; 50 mg/kg BS group: 2.36 ± 0.084 mm; BMDMs group: 3.09 ± 0.174 mm; BS-BMDMs group: 2.43 ± 0.042 mm), reduce the levels of collagen-specific antibodies (IgG and IgG1, but not IgG2c, p < 0.05) and inhibit the production of pro-inflammatory cytokines (p < 0.05). Depletion of IL-10 counteracted the effect of BS treatment (α-IL-10 vs. RatIgG1, p < 0.01 on day 16), highlighting the role of IL-10 in the anti-inflammatory response., Conclusions: These results suggested that BS could modulate the functions of macrophages and might be a promising agent for RA therapy.

Inflammasomes are cytoplasmic protein complexes that regulate the secretion of pro-inflammatory cytokines including IL-1β and IL18, thereby playing a crucial role in inflammatory and chronic diseases. Plant compound Withaferin A (WFA) has been demonstrated to possess numerous biological activities including anti-inflammatory and anti-cancer effects. However, the effect of WFA on macrophage polarization and inflammasome expression in polarized macrophages has not been documented. In this study, cultured THP-1 macrophages were polarized into M1/M2 phenotypes. Subsequently, macrophage characterization was tested for M1 markers (CXCL10 and CXCL9) and M2 markers (CCL20 and CCL13). NOD-like receptor protein 3 (NLRP3) and Absent in melanoma (AIM2) inflammasome gene and protein expressions were measured by RTqPCR and Western blot respectively. Colocalization of both proteins in polarized macrophages was analyzed by immunofluorescence. Our results show that M1 polarized macrophages express elevated NLRP3 and AIM2 gene expressions. Furthermore, WFA treatment stimulated AIM2 and caspase-1 protein expression in M2W macrophages in comparison to M2 cells. ELISA analysis of the cell culture supernatant showed that WFA treatment of M2 macrophages inhibited the secretion of TGF-β in comparison to M1. Immunofluorescence studies showed NLRP3/ASC colocalized in the cytoplasm in M1 macrophages, which was not the case in M2 and M2W cells. AIM2/ASC were found colocalized in M1 and M2W cells, indicating an activation of inflammasome. These results provide basis for better understanding the effect of WFA in inflammatory diseases and some cancers by modulating macrophage polarization and inflammasome activation., (Copyright © 2019. Published by Elsevier Inc.)

Background: T helper 17 (Th17) cells, which are differentiated from CD4 + T cells, drive inflammation, leading to autoimmune diseases such as psoriasis, rheumatoid arthritis, and inflammatory bowel disease. Therefore, inhibiting Th17 polarization could be a therapeutic target for inflammatory diseases., Purpose: We investigated the inhibitory effect of Fraxinus rhynchophylla (Oleaceae) on Th17 differentiation and found its active component., Study Design: The activity of F. rhynchophylla and its active constituent was verified using CD4 + cells extracted from C57BL/6 mice., Methods: Micro-environment for Th17 polarization was provided to CD4 + cells and the effect of treatment with samples was measured by enzyme linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and Western blot., Results: The extract of F. rhynchophylla Hance and its chemical constituent, α-amyrin acetate, which was isolated via bioassay-guided isolation, significantly inhibited Th17 polarization as revealed when interleukin (IL)-17, a characteristic cytokine produced by Th17 cells, was measured. Furthermore, the inhibitory effect of α-amyrin acetate was compared to the amyrin derivatives, α-amyrin and β-amyrin. All displayed a suppressive effect on Th17 polarization and all reduced the expression of single transducer and activator of transcription 3 (STAT3) and retinoic acid receptor-related orphan receptor γt (RORγt), which are crucial transcription factors regulating Th17 differentiation. α-Amyrin acetate, however, exhibited the most prominent effects, which indicates that the functional group, acetate, might strengthen the inhibitory effect on Th17 differentiation., Conclusion: Taken together, these results suggest that the extract of F. rhynchophylla and its active constituent, α-amyrin acetate, could be applied as a potential therapeutic agent for autoimmune disorders such as rheumatoid arthritis., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

PDZ proteins are highly conserved through evolution; the principal function of this large family of proteins is to assemble protein complexes that are involved in many cellular processes, such as cell-cell junctions, cell polarity, recycling, or trafficking. Many PDZ proteins that have been identified as targets of viral pathogens by promoting viral replication and spread are also involved in epithelial cell polarity. Here, we briefly review the PDZ polarity proteins in cells of the immune system to subsequently focus on our hypothesis that the viral PDZ-dependent targeting of PDZ polarity proteins in these cells may alter the cellular fitness of the host to favor that of the virus; we further hypothesize that this modification of the cellular fitness landscape occurs as a common and widespread mechanism for immune evasion by viruses and possibly other pathogens.-Gutiérrez-González, L. H., Santos-Mendoza, T. Viral targeting of PDZ polarity proteins in the immune system as a potential evasion mechanism.

Macrophage-targeted therapy offers new options for intractable pancreatic ductal adenocarcinoma (PDAC), which has a low 5-year survival rate. However, the factors regulating the biological function and phenotype of macrophages in PDAC are incompletely understood. Here, we found that CD51 was positively associated with the poor prognosis of PDAC patients and was highly expressed on macrophages but not on pancreatic cancer cells. Subsequently, we found that CD51 was a marker of macrophages, which promoted the stemness of pancreatic cancer cells. Furthermore, knockdown of CD51 in macrophages drove macrophages toward an M1-like phenotype. Mechanistically, macrophage-expressed CD51 contributed to the acquisition of stemness traits of pancreatic cancer cells by regulating the TGF-β1/smad2/3 pathway. Our data demonstrate the central role played by macrophage-expressed CD51 in the acquisition of stemness traits of pancreatic cancer cells through the paracrine induction of TGF-β1. We first show the connection between the CD51/TGF-β1/smad2/3 axis and PDAC cancer stem cell properties and then indicate that CD51-targeted therapy is a new therapeutic modality for PDAC., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In a previous study, we have identified MTBK&#95;24820, the complete protein form of PPE39 in the hypervirulent Mycobacterium tuberculosis (Mtb) strain Beijing/K by using comparative genomic analysis. PPE39 exhibited vaccine potential against Mtb challenge in a murine model. Thus, in this present study, we characterize PPE39-induced immunological features by investigating the interaction of PPE39 with dendritic cells (DCs). PPE39-treated DCs display reduced dextran uptake and enhanced MHC-I, MHC-II, CD80 and CD86 expression, indicating that this PPE protein induces phenotypic DC maturation. In addition, PPE39-treated DCs produce TNF-α, IL-6 and IL-12p70 to a similar and/or greater extent than lipopolysaccharide-treated DCs in a dose-dependent manner. The activating effect of PPE39 on DCs was mediated by TLR4 through downstream MAPK and NF-κB signaling pathways. Moreover, PPE39-treated DCs promoted naïve CD4 + T-cell proliferation accompanied by remarkable increases of IFN-γ and IL-2 secretion levels, and an increase in the Th1-related transcription factor T-bet but not in Th2-associated expression of GATA-3, suggesting that PPE39 induces Th1-type T-cell responses through DC activation. Collectively, the results indicate that the complete form of PPE39 is a so-far-unknown TLR4 agonist that induces Th1-cell biased immune responses by interacting with DCs.This article has an associated First Person interview with the first author of the paper., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2019. Published by The Company of Biologists Ltd.)

Background: Glioma is one of the most aggressive malignant brain tumors which is characterized with highly infiltrative growth and poor prognosis. NKAP (NF-κB activating protein) is a widely expressed 415-amino acid nuclear protein that is overexpressed by gliomas, but its function in glioma was still unknown., Methods: CCK8 and EDU assay was used to examine the cell viability in vitro, and the xenograft models in nude mice were established to explore the roles of NAKP in vivo. The expressions of NKAP, Notch1 and SDF-1 were analyzed by immunofluorescence analysis. The expression of NKAP and Notch1 in glioma and normal human brain samples were analyzed by immunohistochemical analysis. In addition, CHIP, Gene chip, western blot, flow cytometry, immunofluorescence, ELISA and luciferase assay were used to investigate the internal connection between NKAP and Notch1., Results: Here we showed that overexpression of NKAP in gliomas could promote tumor growth by contributing to a Notch1-dependent immune-suppressive tumor microenvironment. Downregulation of NKAP in gliomas had abrogated tumor growth and invasion in vitro and in vivo. Interestingly, compared to the control group, inhibiting NKAP set up obstacles to tumor-associated macrophage (TAM) polarization and recruitment by decreasing the secretion of SDF-1 and M-CSF. To identify the potential mechanisms involved, we performed RNA sequencing analysis and found that Notch1 appeared to positively correlate with the expression of NKAP. Furthermore, we proved that NKAP performed its function via directly binding to Notch1 promoter and trans-activating it. Notch1 inhibition could alleviate NKAP's gliomagenesis effects., Conclusion: these observations suggest that NKAP promotes glioma growth by TAM chemoattraction through upregulation of Notch1 and this finding introduces the potential utility of NKAP inhibitors for glioma therapy.

B lymphocytes capture antigens from the surface of presenting cells by forming an immune synapse. Local secretion of lysosomes, which are guided to the synaptic membrane by centrosome repositioning, can facilitate the extraction of immobilized antigens. However, the molecular basis underlying their delivery to precise domains of the plasma membrane remains elusive. Here we show that microtubule stabilization, triggered by engagement of the B cell receptor, acts as a cue to release centrosome-associated Exo70, which is redistributed to the immune synapse. This process is coupled to the recruitment and activation of GEF-H1, which is required for assembly of the exocyst complex, used to promote tethering and fusion of lysosomes at the immune synapse. B cells silenced for GEF-H1 or Exo70 display defective lysosome secretion, which results in impaired antigen extraction and presentation. Thus, centrosome repositioning coupled to changes in microtubule stability orchestrates the spatial-temporal distribution of the exocyst complex to promote polarized lysosome secretion at the immune synapse., (© 2019 Sáez et al.)

Diarrheal diseases are a major cause of morbidity and mortality worldwide. They are most prevalent in settings with inadequate sanitation, poor hygiene and contaminated water. An important diarrheal pathogen in such settings is Shigella . No commercially available vaccine exists against shigellosis and immunity to the pathogen is serotype-restricted. We have previously shown that a polypeptide fusion of the Type Three Secretion Apparatus (T3SA) proteins IpaB and IpaD (named DBF) was efficacious as a vaccine against Shigella . Vaccination using different administration routes indicated that protection conferred by DBF did not fully correlate with antibodies. To define the immune responses involved in protection, we studied cellular responses to intranasal immunization with the DBF and the adjuvant dmLT. We found dendritic cell (DC) activation at the nasal associated lymphoid tissue (NALT). Activation markers CD86 and MHCII significantly increase in cells from immunized mice. Antigen exposure in vitro further confirmed the upregulation of CD80 and CD40 in primary dendritic cells. Animals immunized with antigen-primed dendritic cells were protected against Shigella infection, at levels comparable to the efficacy of immunization with the protein vaccine formulation. Therefore, we show that antigen-primed DCs are enough to provide immunity, and propose a mechanism of protection against Shigella spp. based on DC-mediated antigen presentation to T cells.

Biological interactions between tumor-associated macrophages (TAMs), cancer cells and other cells within the tumor microenvironment contribute to tumorigenesis, tumor growth, metastasis and therapeutic resistance. TAMs can remodel the tumor microenvironment to reduce growth barriers such as the dense extracellular matrix and shift tumors towards an immunosuppressive microenvironment that protects cancer cells from targeted immune responses. Nanoparticles can interrupt these biological interactions within tumors by altering TAM phenotypes through a process called polarization. Macrophage polarization within tumors can shift TAMs from a growth-promoting phenotype towards a cancer cell-killing phenotype that predicts treatment efficacy. Because many types of nanoparticles have been shown to preferentially accumulate within macrophages following systemic administration, there is considerable interest in identifying nanoparticle effects on TAM polarization, evaluating nanoparticle-induced TAM polarization effects on cancer treatment using drug-loaded nanoparticles and identifying beneficial types of nanoparticles for effective cancer treatment. In this review, the macrophage polarization effects of nanoparticles will be described based on their primary chemical composition. Because of their strong macrophage-polarizing and antitumor effects compared to other types of nanoparticles, the effects of iron oxide nanoparticles on macrophages will be discussed in detail. By comparing the macrophage polarization effects of various nanoparticle treatments reported in the literature, this review aims to both elucidate nanoparticle material effects on macrophage polarization and to provide insight into engineering nanoparticles with more beneficial immunological responses for cancer treatment., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Mesangial cell (MC) activation and macrophage infiltration are 2 major events closely related with each other in mesangial proliferative glomerulonephritis. In the anti-Thy 1 nephritis model, macrophages mediate the damage and also the expansion of mesangium through secreting various inflammatory factors; however, in glomerular microenvironment how MCs affect macrophage activity in the presence of various stimuli have not yet been understood. In the present study, we found that resting human MCs (HMCs) constitutively expressed chemokine [C-C motif] ligand 2 (CCL-2) and interleukin (IL)-6 and induced M2 polarization of macrophages in the coculture system. HMC proliferation and migration and expression of IL-6, CCL-2, and macrophage colony-stimulating factor in HMCs were enhanced after platelet-derived growth factor (PDGF)-BB stimulation, among which CCL-2 was responsible for inducing the M2 polarization of macrophages. Furthermore, PDGF-BB-stimulated HMCs alleviated the classical activation of macrophages and drove more intensified M2 polarization of macrophages than resting HMCs did. However, lipopolysaccharide and interferon-γ (IFN-γ) stimulated HMCs maintained the M1 phenotype of cocultured macrophages. In conclusion, MCs actively participated in glomerular inflammation through influencing macrophage polarization. The interplay between MCs and infiltrated macrophages is finely modulated by secretory factors such as PDGF-BB and IFN-γ in response to the renal inflammatory microenvironment.

HIV-1 Nef is a multifunctional protein that optimizes virus spread and promotes immune evasion of infected cells to accelerate disease progression in AIDS patients. As one of its activities, Nef reduces the motility of infected CD4 + T lymphocytes in confined space. In vivo, Nef restricts T lymphocyte homing to lymph nodes as it reduces the ability for extravasation at the diapedesis step. Effects of Nef on T lymphocyte motility are typically mediated by its ability to reduce actin remodeling. However, interference with diapedesis does not depend on residues in Nef required for inhibition of host cell actin dynamics. In search for an alternative mechanism by which Nef could alter T lymphocyte extravasation, we noted that the viral protein interferes with the polarization of primary human CD4 + T lymphocytes upon infection with HIV-1. Expression of Nef alone is sufficient to disrupt T cell polarization, and this effect is conserved among lentiviral Nef proteins. Nef acts by arresting the oscillation of CD4 + T cells between polarized and nonpolarized morphologies. Mapping studies identified the binding site for the Nef-associated kinase complex (NAKC) as critical determinant of this Nef activity and a NAKC-binding-deficient Nef variant fails to impair CD4 + T lymphocyte extravasation and homing to lymph nodes. These results thus imply the disruption of T lymphocyte polarity via its NAKC binding site as a novel mechanism by which lentiviral Nef proteins alter T lymphocyte migration in vivo., (Copyright © 2018 by The American Association of Immunologists, Inc.)