AM-3K, an anti-macrophage antibody, recognizes CD163, a molecule associated with an anti-inflammatory macrophage phenotype

Role of pattern recognition receptors in sensing Mycobacterium tuberculosis

Mycobacterium tuberculosis is one of the major invasive intracellular pathogens causing most deaths by a single infectious agent. The interaction between host immune cells and this pathogen is the focal point of the disease, Tuberculosis. Host immune cells not only mount the protective action against this pathogen but also serve as the primary niche for growth. Thus, recognition of this pathogen by host immune cells and following signaling cascades are key dictators of the disease state. Immune cells, mainly belonging to myeloid cell lineage, recognize a wide variety of Mycobacterium tuberculosis ligands ranging from carbohydrate and lipids to proteins to nucleic acids by different membrane-bound and soluble pattern recognition receptors. Simultaneous interaction between different host receptors and pathogen ligands leads to immune-inflammatory response as well as contributes to virulence. This review summarizes the contribution of pattern recognition receptors of host immune cells in recognizing Mycobacterium tuberculosis and subsequent initiation of signaling pathways to provide the molecular insight of the specific Mtb ligands interacting with specific PRR, key adaptor molecules of the downstream signaling pathways and the resultant effector functions which will aid in identifying novel drug targets, and developing novel drugs and adjuvants.

Alterations in macrophage polarization in the craniofacial and extracranial skeleton after zoledronate application and surgical interventions - an in vivo experiment

Purpose

Medication-related osteonecrosis occurs exclusively in the jaw bones. However, the exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) and the unique predisposition of the jaw bones have not been elucidated, making its treatment a challenge. Recent evidence indicates that macrophages might play a pivotal role in MRONJ pathogenesis. The aim of the present study was to compare the macrophage populations between the craniofacial and extracranial skeleton and to investigate the changes induced by zoledronate (Zol) application and surgical interventions.

Materials and methods

An in vivo experiment was performed. 120 wistar rats were randomized to 4 groups (G1, G2, G3, G4). G1 served as an untreated control group. G2 and G4 received Zol injections for 8 weeks. Afterwards, the right lower molar of the animals from G3 and G4 was extracted and the right tibia osteotomized followed by osteosynthesis. Tissue samples were taken from the extraction socket and the tibia fracture at fixed time points. Immunohistochemistry was conducted to determine the labeling indexes of CD68+ and CD163+ macrophages.

Results

Comparing the mandible and the tibia, we observed a significantly higher number of macrophages and a heightened pro-inflammatory environment in the mandible compared to the tibia. Tooth extraction caused an increase of the overall number of macrophages and a shift toward a more pro-inflammatory microenvironment in the mandible. Zol application amplified this effect.

Conclusion

Our results indicate fundamental immunological differences between the jaw bone and the tibia, which might be a reason for the unique predisposition for MRONJ in the jaw bones. The more pro-inflammatory environment after Zol application and tooth extraction might contribute to the pathogenesis of MRONJ. Targeting macrophages might represent an attractive strategy to prevent MRONJ and improve therapy. In addition, our results support the hypothesis of an anti-tumoral and anti-metastatic effect induced by BPs. However, further studies are needed to delineate the mechanisms and specify the contributions of the various macrophage phenotypes.

Macrophage-Driven Inflammation in Metabolic Osteoarthritis: Implications for Biomarker and Therapy Development

Osteoarthritis (OA) is a common and debilitating joint disorder that leads to progressive joint breakdown and loss of articular cartilage. Accompanied by a state of low-grade inflammation, its etiology extends beyond that of a wear-and-tear disease, and the immune system might have a role in its initiation and progression. Obesity, which is directly associated with an increased incidence of OA, alters adipokine release, increases pro-inflammatory macrophage activity, and affects joint immune regulation. Studying inflammatory macrophage expression and strategies to inhibit inflammatory macrophage phenotype polarization might provide insights into disease pathogenesis and therapeutic applications. In pre-clinical studies, the detection of OA in its initial stages was shown to be possible using imaging techniques such as SPECT-CT, and advances are made to detect OA through blood-based biomarker analysis. In this review, obesity-induced osteoarthritis and its mechanisms in inducing joint degeneration are summarized, along with an analysis of the current developments in patient imaging and biomarker use for diagnostic and therapeutic strategies.

Heterogeneity of Phenotypic and Functional Changes to Porcine Monocyte-Derived Macrophages Triggered by Diverse Polarizing Factors In Vitro

Swine are attracting increasing attention as a biomedical model, due to many immunological similarities with humans. However, porcine macrophage polarization has not been extensively analyzed. Therefore, we investigated porcine monocyte-derived macrophages (moMΦ) triggered by either IFN-γ + LPS (classical activation) or by diverse "M2-related" polarizing factors: IL-4, IL-10, TGF-β, and dexamethasone. IFN-γ and LPS polarized moMΦ toward a proinflammatory phenotype, although a significant IL-1Ra response was observed. Exposure to IL-4, IL-10, TGF-β, and dexamethasone gave rise to four distinct phenotypes, all antithetic to IFN-γ and LPS. Some peculiarities were observed: IL-4 and IL-10 both enhanced expression of IL-18, and none of the "M2-related" stimuli induced IL-10 expression. Exposures to TGF-β and dexamethasone were characterized by enhanced levels of TGF-β2, whereas stimulation with dexamethasone, but not TGF-β2, triggered CD163 upregulation and induction of CCL23. Macrophages stimulated with IL-10, TGF-β, or dexamethasone presented decreased abilities to release proinflammatory cytokines in response to TLR2 or TLR3 ligands: IL-10 showed a powerful inhibitory activity for CXCL8 and TNF release, whereas TGF-β provided a strong inhibitory signal for IL-6 production. While our results emphasized porcine macrophage plasticity broadly comparable to human and murine macrophages, they also highlighted some peculiarities in this species.

Immunohistochemical Characterization of Immune System Cells in Lymphoid Organs from Roe and Fallow Deer

Simple Summary

Diseases emerging from wildlife represent a growing public health issue. Cervids share many pathogens with domestic species and humans, representing useful spontaneous models to evaluate host-pathogen balance. Histology and immunohistochemistry can help in fully understanding the pathogenesis of infection in these species, but few studies have been conducted to characterize immune cell markers. This study highlights that lymphocytes and macrophagic subsets in roe and fallow deer lymphoid tissue can be identified by a panel of commercial antibodies developed against humans. A description of the main immune cell distribution was provided. These results may support future investigations on immune cell response and pathogenesis in roe and fallow deer diseases.

Abstract

Roe and Fallow deer are common wild ruminants widely distributed in Italy. Infectious diseases of these species can potentially pose health risks to domestic animals and humans. However, few studies have been conducted in which immune system cells in these species were phenotyped. The aims of this study were to determine the cross-reactivity of a wide anti-human panel of commercial antibodies on formalin-fixed and paraffin-embedded (FFPE) samples and to describe the distribution of roe and fallow deer main immune cell subsets in the lymph nodes and spleen. Twenty retromandibular lymph nodes (RLNs) and spleen samples were collected from 10 roe deer and 10 fallow deer and were tested by a panel of 12 commercial anti-human antibodies. The CD79a, CD20, CD3, Iba-1, MAC387, and AM-3K antibodies were successfully labeled cells in cervine tissue, while the Foxp3 and the CD68 did not show suitable immunostaining. This study supplies the first immunohistochemical description of immune cell subpopulations in non-pathological spleen and RLNs from roe and fallow deer and provides an easily repeatable manual IHC protocol to immunolocalize cervine B-, T-cells, and macrophages subsets in FFPE tissue samples.

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 effect of CD163-positive M2 macrophages and Foxp3-positive Tregs in the progression of colorectal cancer and lymph node metastasis. It also investigated the correlation between 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. Immunohistochemical methods were used 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. The correlation between CD163 and Foxp3 in cancer tissues and lymph node tissues were analyzed, as well as the relationship between clinicopathological characteristics and preoperative tumor markers.

Results

M2 macrophages and Tregs were importantly 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. In addition, both CD163 and Foxp3 were upregulated with increasing tumor node metastasis stage, depth of infiltration, and lymphatic metastasis; and both were positively correlated with carcinoembryonic antigen.

Conclusion

CD163 may be a good predictor of pre-metastatic status of colorectal cancer lymph nodes. carcinoembryonic antigen affects the distribution of M2 macrophages and Tregs in colorectal cancer. There is a certain correlation between the two types of cells. It is possible that M2 macrophages, together with suppressor Tregs cells, promote an immunosuppressive environment.

TREM2 Is Associated with Advanced Stages and Inferior Prognosis in Oral Squamous Cell Carcinoma

Triggering receptor expressed on myeloid cells 2 (TREM2) is suggested to hamper antitumor immune response in multiple cancers. However, the role of TREM2 in oral squamous cell carcinoma (OSCC) and its expression in tumor-associated macrophages (TAMs) are unknown. In this study, TREM2 expression was analyzed in the primary tumors and corresponding lymph-node metastases of OSCC patients via immunohistochemistry on tissue microarrays. Human peripheral blood mononuclear cells (PBMCs) and single-cell suspensions of tumor and healthy adjacent tissues were analyzed for the presence of TREM2+ macrophages and TAMs using flow cytometry. The serum levels of soluble TREM2 (sTREM2) were quantified using an enzyme-linked immunosorbent assay. High TREM2 expression was associated with advanced UICC stages (Spearman’s rank correlation (SRC), p = 0.04) and significantly reduced survival rates in primary tumors (multivariate Cox regression, progression-free survival: hazard ratio (HR) of 2.548, 95% confidence interval (CI) of 1.089−5.964, p = 0.028; overall survival: HR of 2.17, 95% CI of 1.021−4.613, p = 0.044). TREM2 expression was significantly increased in the PBMCs of OSCC patients in UICC stage IV compared with healthy controls (ANOVA, p < 0.05). The serum levels of sTREM2 were higher in advanced UICC stages, but they narrowly missed significance (SRC, p = 0.059). We demonstrated that TREM2 was multi-factorially associated with advanced stages and inferior prognosis in OSCC patients and that it could serve as a prognostic biomarker in OSCC patients. Targeting TREM2 has the potential to reshape the local and systemic immune landscape for the potential enhancement of patients’ prognosis.

A Quantitative Digital Analysis of Tissue Immune Components Reveals an Immunosuppressive and Anergic Immune Response with Relevant Prognostic Significance in Glioblastoma

Objectives: Immunostimulatory therapies using immune checkpoint blockers show clinical activity in a subset of glioblastoma (GBM) patients. Several inhibitory mechanisms play a relevant role in the immune response to GBM. With the objective of analyzing the tumor immune microenvironment and its clinical significance, we quantified several relevant immune biomarkers. Design: We studied 76 primary (non-recurrent) GBMs with sufficient clinical follow-up, including a subgroup of patients treated with a dendritic cell vaccine. The IDH-mutation, EGFR-amplification, and MGMT methylation statuses were determined. Several relevant immune biomarkers, including CD163, CD8, PD1, and PDL1, were quantified in representative selected areas by digital image analysis and semiquantitative evaluation. The percentage of each immune expression was calculated with respect to the total number of tumor cells. Results: All GBMs were wild-type IDH, with a subgroup of classical GBMs according to the EGFR amplification (44%). Morphologically, CD163 immunostained microglia and intratumor clusters of macrophages were observed. A significant direct correlation was found between the expression of CD8 and the mechanisms of lymphocyte immunosuppression, in such a way that higher values of CD8 were directly associated with higher values of CD163 (p < 0.001), PDL1 (0.026), and PD1 (0.007). In a multivariate analysis, high expressions of CD8+ (HR = 2.05, 95%CI (1.02−4.13), p = 0.034) and CD163+ cells (HR 2.50, 95%CI (1.29−4.85), p = 0.007), were associated with shorter survival durations. The expression of immune biomarkers was higher in the non-classical (non-EGFR amplified tumors) GBMs. Other relevant prognostic factors were age, receipt of the dendritic cell vaccine, and MGMT methylation status. Conclusions: In accordance with the inverse correlation between CD8 and survival and the direct correlation between effector cells and CD163 macrophages and immune-checkpoint expression, we postulate that CD8 infiltration could be placed in a state of anergy or lymphocytic inefficient activity. Furthermore, the significant inverse correlation between CD163 tissue concentration and survival explains the relevance of this type of immune cell when creating a strong immunosuppressive environment. This information may potentially be used to support the selection of patients for immunotherapy.

Effect of exercise from a very early stage after intracerebral hemorrhage on microglial and macrophage reactivity states in rats

OBJECTIVE

This study investigated the effects of exercise, starting very early after intracerebral hemorrhage (ICH), on microglia and macrophages in a rat model. Collagenase solution was injected into the left striatum to induce ICH.

METHODS

Rats were randomly assigned to receive placebo surgery without exercise (sham surgery), ICH without exercise (ICH), or ICH with very early exercise (ICH + VET). The ICH + VET group was subjected to treadmill running 6 h, 24 h, and days 2-6 after ICH. Motor function assessment was performed using the ladder test and rotarod test 3 h, 25 h, and 7 days after ICH. Postexercise brain tissue was collected on day 8 after surgery to investigate the lesion volume. Very early exercise temporarily worsened motor dysfunction. The protein expression levels of the macrophage and microglial markers CD80, CD163, and TMEM119 were analyzed 6 h, 24 h, and 8 days after ICH. Protein analysis of NeuN, GFAP, and PSD95 was also performed on day 8 after ICH.

RESULTS

There was no significant difference in lesion volume between the ICH and ICH + VET groups on day 8 after ICH. Exercise from very early stage prevented elevated CD163 protein expression.

CONCLUSION

Very early exercise may inhibit the activation of anti-inflammatory-associated macrophages/microglia.

Skin Manifestation Associated With Multicentric Reticulohistiocytosis

ABSTRACT

Multicentric reticulohistiocytosis (MRH) is a rare multisystem disorder, primarily affecting the skin and joints. As severe joint damage is a possible symptom, early diagnosis and therapeutic intervention are required. Cutaneous lesions present with characteristic features such as discrete reddish nodules, especially on acral locations. Additionally, the face, scalp, trunk and extremities are also affected. Xanthomatous plaques are also seen on the face. The cutaneous manifestations of MRH are various, which therefore should be differentiated from several diseases. In particular, MRH has been reported to assume clinical appearances resembling Gottron papules, periungual erythema, V-neck erythema, shawl sign, and poikiloderma associated with dermatomyositis. Histopathologic features show proliferation of multinucleated giant cells with abundant eosinophilic granular ground glass-like cytoplasm in the dermis. Multicentric reticulohistiocytosis is occasionally paraneoplastic and is associated with internal malignancies. The appropriate therapies are still challenging, and oral prednisolone, immunosuppressants, and recent biologics are used. In this article, cutaneous lesions, histopathology, and pathogenesis of MRH are mainly discussed from a dermatological perspective. It is important, not only for dermatologists but also for rheumatologists and orthopedists, to be able to distinguish between the various types of skin lesions brought on by MRH. Cutaneous signs are important diagnostic clues and assessment tools for therapeutic efficacy.

Cyclic sulfur compounds targeting macrophage polarization into M2/protumor phenotype and their anti-tumor effects

Tumor-associated macrophages (TAMs), especially the M2-like phenotype, promote tumor progression, making them candidate targets for anti-tumor therapy. We previously discovered a cyclic sulfur compound, Onionin A (ONA), which suppresses tumor progression by inhibiting the M2-polarization of TAMs. In the present study, we sought to find new candidate compounds possessing a stronger effect compared to ONA by exploring compounds with structures similar to those of ONA among several cyclic sulfur compounds. A total of 81 cyclic sulfur compounds were screened, and their effects on macrophage polarization toward an M2-like phenotype were tested using human monocyte-derived macrophages (HMDMs). The anti-tumor effects of the identified candidate compounds were examined in a tumor-bearing mouse model. Three candidate compounds inhibited both IL-10- and tumor culture supernatant (TCS)-induced M2-polarization of HMDMs. These compounds also suppressed STAT3 activation in HMDMs stimulated by IL-10 and TCS, whereas these compounds had no effect on STAT3 activation in tumor cells. Furthermore, these compounds inhibited tumor cell proliferation under co-culture conditions with HMDMs, indicating that the three candidate compounds suppress tumor proliferation by regulating cell-cell interactions between tumor cells and macrophages. In addition, two of these candidate compounds had inhibitory effects on tumor growth and lung metastasis in the LM8 tumor-bearing mouse model. Our study identified new candidate cyclic sulfur compounds for anti-tumor therapy targeting the M2-polarization of TAMs.

Immunological Markers, Prognostic Factors and Challenges Following Curative Treatments for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortalities worldwide. Patients with early-stage HCC are eligible for curative treatments, such as surgical resection, liver transplantation (LT) and percutaneous ablation. Although curative treatments provide excellent long-term survival, almost 70–80% of patients experience HCC recurrence after curative treatments. Tumor-related factors, including tumor size, number and differentiation, and underlying liver disease, are well-known risk factors for recurrence following curative therapies. Moreover, the tumor microenvironment (TME) also plays a key role in the recurrence of HCC. Many immunosuppressive mechanisms, such as an increase in regulatory T cells and myeloid-derived suppressor cells with a decrease in cytotoxic T cells, are implicated in HCC recurrence. These suppressive TMEs are also modulated by several factors and pathways, including mammalian target of rapamycin signaling, vascular endothelial growth factor, programmed cell death protein 1 and its ligand 1. Based on these mechanisms and the promising results of immune checkpoint blockers (ICBs) in advanced HCC, there have been several ongoing adjuvant studies using a single or combination of ICB following curative treatments in HCC. In this review, we strive to provide biologic and immunological markers, prognostic factors, and challenges associated with clinical outcomes after curative treatments, including resection, LT and ablation.

High Numbers of CD163-Positive Macrophages in the Fibrotic Region of Exuberant Granulation Tissue in Horses

Exuberant granulation tissue (EGT) is a frequently encountered complication during second intention healing in equine distal limb wounds. Although it is still unknown what exactly triggers the formation of this tissue, previous research has revealed a persistent inflammatory response in these wounds. In this preliminary study we examined this inflammatory response in EGT-developing wounds as well as in experimental induced wounds. Immunohistological stainings were performed to detect primary inflammatory immune cells (MAC387 staining) as well as pro-resolution immune cells (CD163 staining). Our results show a significantly higher amount of MAC387+ and CD163+ cells in the fibrotic regions of EGT compared with the 19-day-old experimental wounds. This persistent high amount of fibrosis-promoting CD163+ cells in EGT suggests that the wound healing processes in EGT-developing wounds are arrested at the level of the proliferation phase.

CD163-positive cancer cells are a predictor of a worse clinical course in lung adenocarcinoma

CD163 is one of the scavenger receptors expressed on macrophages. However, several immunohistochemical studies have demonstrated that CD163 is also detected on cancer cells, and is associated with a poor prognosis. In the present study, we detected CD163 staining on cancer cells in lung adenocarcinoma and squamous cell carcinoma (SCC), and investigated the relationship between CD163 on cancer cells and the clinical prognosis. CD163 staining was seen in 128 of 342 adenocarcinoma cases and 35 of 103 SCC cases. Among the lung adenocarcinoma cases, the progression-free survival and overall survival were significantly shorter in the CD163 high group than the CD163 low group. A similar trend was observed among the SCC cases, but the difference was not statistically significant. Additionally, a higher number of macrophages was detected in areas with CD163-positive cancer cells when compared to areas with CD163-negative cancer cells. In summary, we found that CD163-positive cancer cells are a predictor of a worse clinical course in lung adenocarcinoma and SCC.

Monocyte-macrophage polarization and recruitment pathways in the tumour microenvironment of B-cell acute lymphoblastic leukaemia

B-cell acute lymphoblastic leukaemia (B-ALL) reprograms the surrounding bone marrow (BM) stroma to create a leukaemia-supportive niche. To elucidate the contribution of immune cells to the leukaemic microenvironment, we investigated the involvement of monocyte/macrophage compartments, as well as several recruitment pathways in B-ALL development. Immunohistochemistry analyses showed that CD68-expressing macrophages were increased in leukaemic BM biopsies, compared to controls and predominantly expressed the M2-like markers CD163 and CD206. Furthermore, the "non-classical" CD14⁺ CD16⁺⁺ monocyte subset, expressing high CX3CR1 levels, was significantly increased in B-ALL patients' peripheral blood. CX3CL1 was shown to be significantly upregulated in leukaemic BM plasma, thus providing an altered migratory pathway possibly guiding NC monocyte recruitment into the BM. Additionally, the monocyte/macrophage chemoattractant chemokine ligand 2 (CCL2) strongly increased in leukaemic BM plasma, possibly because of the interaction of leukaemic cells with mesenchymal stromal cells and vascular cells and due to a stimulatory effect of leukaemia-related inflammatory mediators. C5a, a macrophage chemoattractant and M2-polarizing factor, further appeared to be upregulated in the leukaemic BM, possibly as an effect of PTX3 decrease, that could unleash complement cascade activation. Overall, deregulated monocyte/macrophage compartments are part of the extensive BM microenvironment remodelling at B-ALL diagnosis and could represent valuable targets for novel treatments to be coupled with classical chemotherapy.

Soluble Receptors Affecting Stroke Outcomes: Potential Biomarkers and Therapeutic Tools

Soluble receptors are widely understood to be freestanding moieties formed via cleavage from their membrane-bound counterparts. They have unique structures, are found among various receptor families, and have intriguing mechanisms of generation and release. Soluble receptors’ ability to exhibit pleiotropic action by receptor modulation or by exhibiting a dual role in cytoprotection and neuroinflammation is concentration dependent and has continually mystified researchers. Here, we have compiled findings from preclinical and clinical studies to provide insights into the role of soluble/decoy receptors, focusing on the soluble cluster of differentiation 36, the soluble cluster of differentiation 163, and soluble lipoprotein-related protein 1 (sCD36, sCD163, and sLRP1, respectively) and the functions they could likely serve in the management of stroke, as they would notably regulate the bioavailability of the hemoglobin and heme after red blood cell lysis. The key roles that these soluble receptors play in inflammation, oxidative stress, and the related pharmacotherapeutic potential in improving stroke outcomes are described. The precise pleiotropic physiological functions of soluble receptors remain unclear, and further scientific investigation/validation is required to establish their respective role in diagnosis and therapy.

Clinical, histopathological, and immunohistochemical studies of histiocytic sarcoma in four-toed hedgehogs (Atelerix albiventris): A retrospective study

Histiocytic sarcoma was investigated histopathologically and immunohistochemically in 17 four-toed hedgehogs (Atelerix albiventris), along with a review of their clinical data. Cases were histopathologically classified into two types: round-polygonal cell type (6 cases) and spindle cell type (11 cases). Round-polygonal cell type was found in visceral organs such as the spleen, lymph nodes, and more, and most cases of this type were consistent with disseminated histiocytic sarcoma. On the other hand, spindle cell type occurred mainly in skin, and almost all cases were consistent with localized histiocytic sarcoma. The prognosis of patients with round-polygonal cell type appeared worse than that of spindle cell type. Immunohistochemically, neoplastic cells of spindle cell type showed stronger reactivity against human leukocyte antigen-DR than round-polygonal cell type. Neoplastic cells of all cases showed strong reactivity against ionized calcium-binding adapter molecule-1 (Iba-1) and various reactivities against cluster of differentiation (CD) 204. Regardless of morphological classification, most tumor cells were negative for CD163, suggesting that this marker is less effective for the diagnosis of histiocytic sarcoma. The results of this study suggest that Iba-1 is the most effective marker for histiocytic sarcoma.

Abnormal Expression of Indoleamine 2, 3-Dioxygenase in Human Recurrent Miscarriage

Indoleamine 2, 3-dioxygenase (IDO), an immunosuppressive enzyme that mediates the conversion of tryptophan to kynurenine, was shown to play a key role in placental development during normal pregnancy. However, little is known about the pattern of IDO expression in the endometrium and its attendant functional significance in pregnancies complicated with recurrent miscarriage (RM). Immunohistochemical studies of IDO, Foxp3, CD56, and CD163 expression were performed in endometrial samples from women with RM and healthy fertile controls. Our study found that IDO was localized in glandular epithelial cells, surface epithelial cells, and a small number of cells within the stromal compartment (including stromal cells and leukocytes) in endometrium. Indoleamine 2, 3-dioxygenase expression in the RM group was significantly lower than control group. The Foxp3 and CD56 expression were significantly increased with the elevated IDO expression in controls but not in RM. The percentage of Foxp3 + Tregs was significantly correlated with the level of IDO expression in the control group. Comparatively, no correlation was found between the percentage of CD56 + cells, CD163 + cells, and the level of IDO expression, no matter in controls and RM patients. This study demonstrated that the downregulation of IDO expression and noncoordinated association between IDO and other endometrial immune cells were associated with RM. Our findings provide insights into the contribution of IDO in immune regulation to maintain normal pregnancy, which could be used to develop potential therapeutic methods for RM.

The prognostic and predictive value of tumor infiltrating Macrophage and Neutrophil in patient with clear cell renal cell carcinoma: Tumor infiltrating lymphocytes in renal cell carcinoma

Renal cell carcinoma (RCC) is the leading cancer affecting humans; however, the relationship between tumour-infiltrating lymphocytes (TILs) and patient prognosis in RCC is relatively unreported. This study aimed to investigate the relationships among factors (TIL, clinicopathological characteristics, and patient prognosis in RCC).This retrospective study evaluated 533 patients with clear cell renal cell carcinoma (ccRCC) deposited in the the Cancer Genome Atlas between 2004 and 2015. We downloaded immune cell type absolute fraction data for ccRCC patients from the Cancer Immunome Atlas database. The CIBERSORT method was used to transform RNA-sequencing data into microarray data for the cancer genome atlas -ccRCC samples for which microarray and RNA-sequencing data were available on the the Cancer Immunome Atlas website.The overall survival (OS) and disease free survival (DFS) analyses of ccRCC patients showed that M1 macrophages (OS, P = .00000134; DFS, P = .00958) and neutrophils (OS, P = .00000723; DFS, P = .0255) were significant. Age at diagnosis (P < .0001, c-index = 0.59), tumour stage (P < .0001, c-index = 0.667), stage (P < .0001, c-index = 0.729), neoplasm histological grade (P < .0001, c-index = 0.624), and haemoglobin level (P < .0001, c-index = 0.583) were independent predictors of OS. Similarly, the stage, haemoglobin level, and serum calcium level were independent predictors of DFS. There were significant correlations between the M1 macrophage fraction and tumour stage, stage, and neoplasm histological grade. Stage and neoplasm histological grade showed associations with the neutrophil fraction.The correlations between TILs and prognosis and clinicopathological characteristics in ccRCC were demonstrated. The prognosis of ccRCC patients may differ according to the TIL fractions.

A blocking antibody against canine CSF-1R maturated by limited CDR mutagenesis

CSF-1R is a receptor mostly associated with the mononuclear phagocytic system. However, its expression within tumors has been linked with poor prognosis in both humans and dogs. Accordingly, several reports have demonstrated the beneficial effects of blocking CSF-1R in model systems of cancer. In this study, we generated a monoclonal antibody that could block CSF-1R in dogs as the first step to develop an anticancer drug for this species. Initially, an antibody was raised by the hybridoma methodology against the fragment responsible for receptor dimerization. mAb3.1, one of the resulting hybridoma clones, was able to bind macrophages in fixed tissues and was shown to inhibit cells of the mononuclear phagocytic line. Nevertheless, mAb 3.1 could not bind to some glycoforms of the receptor in its native form, while also demonstrating cross-reactivity with other proteins. To enhance binding properties of the mAb, five amino acids of the complementarity-determining region 2 of the variable heavy chain of mAb3.1 were mutated by PCR, and the variant scFv clones were screened by phage display. The selected scFv clones demonstrated improved binding to the native receptor as well as increased anti-macrophage activity. The resulting scFv antibody fragment presented here has the potential for use in cancer patients and in inflammatory diseases. Furthermore, this work provides insights into the use of such restricted mutations in antibody engineering.

Decaturenol A and known oxalicine related meroterpenoids isolated from Penicillium decaturense RO050, and their new biological activities

Decaturenol A (1), a new oxalicine related meroterpenoid, has been isolated from Penicillium decaturense RO050 along with seven known compounds (2-8). The structure of 1 was elucidated by spectroscopic data. The effects of isolated compounds (1-8) on endoplasmic reticulum (ER) stress-induced cell death in HT22 hippocampal nerve cells and on the interleukin 10 (IL-10)-induced expression of CD163, a M2 phenotype marker, in human monocyte-derived macrophages were evaluated. While decaturenol A (1) exhibited a protective effect on ER stress-induced cell death in HT22 cells at 10 µM, on the other hand oxalicine A (7) showed cytotoxic activity (IC₅₀ = 5.9 µM). Additionally, decaturenol A (1), decaturins D (2), E (3), and B (4) inhibited the IL-10-induced expression of CD163 each at a concentration of 20 µg/mL.

The endometrial immune environment of women with endometriosis

BACKGROUND

Endometriosis, a common oestrogen-dependent inflammatory disorder in women of reproductive age, is characterized by endometrial-like tissue outside its normal location in the uterus, which causes pelvic scarring, pain and infertility. While its pathogenesis is poorly understood, the immune system (systemically and locally in endometrium, pelvic endometriotic lesions and peritoneal fluid) is believed to play a central role in its aetiology, pathophysiology and associated morbidities of pain, infertility and poor pregnancy outcomes. However, immune cell populations within the endometrium of women with the disease have had incomplete phenotyping, thereby limiting insight into their roles in this disorder.

OBJECTIVE AND RATIONALE

The objective herein was to determine reproducible and consistent findings regarding specific immune cell populations and their abundance, steroid hormone responsiveness, functionality, activation states, and markers, locally and systemically in women with and without endometriosis.

SEARCH METHODS

A comprehensive English language PubMed, Medline and Google Scholar search was conducted with key search terms that included endometriosis, inflammation, human eutopic/ectopic endometrium, immune cells, immune population, immune system, macrophages, dendritic cells (DC), natural killer cells, mast cells, eosinophils, neutrophils, B cells and T cells.

OUTCOMES

In women with endometriosis compared to those without endometriosis, some endometrial immune cells display similar cycle-phase variation, whereas macrophages (Mø), immature DC and regulatory T cells behave differently. A pro-inflammatory Mø1 phenotype versus anti-inflammatory Mø2 phenotype predominates and natural killer cells display abnormal activity in endometrium of women with the disease. Conflicting data largely derive from small studies, variably defined hormonal milieu and different experimental approaches and technologies.

WIDER IMPLICATIONS

Phenotyping immune cell subtypes is essential to determine the role of the endometrial immune niche in pregnancy and endometrial homeostasis normally and in women with poor reproductive history and can facilitate development of innovative diagnostics and therapeutics for associated symptoms and compromised reproductive outcomes.

Increased Vascular Adhesion Protein 1 (VAP-1) Levels are Associated with Alternative M2 Macrophage Activation and Poor Prognosis for Human Gliomas

Glioma is characterized by a high heterogeneity in the brain tumor. Abundant tumor-associated macrophages (TAMs) exist as neoplastic tissues, implicating tumor plasticity and thus leading to therapeutic challenges. Vascular adhesion protein (VAP-1) potentially serves as a mediator for TAM immunity in tumor milieu. We previously demonstrated that VAP-1 could contribute to tumor malignancy, but its characteristics in TAM immunity of glioma progression are still unclear. This study explored the association of VAP-1 expression with TAM distribution as well as the resulting clinical significance and prognostic value in human gliomas. An in-depth analysis of AOC3 (VAP-1) gene expression was performed using 695 glioma samples derived from the cancer genome atlas (TCGA)-lower grade glioma and glioblastoma (GBMLGG) cohort. Bioinformatic analysis confirmed that VAP-1 expression is associated with poor prognosis of glioma patients (p = 0.0283). VAP-1 and TAM biomarkers (CD68, iNOS, and CD163) were evaluated by immunohistochemistry in 108 gliomas from Kaohsiung Medical University Hospital. VAP-1+ was expressed in 56 (51.85%) cases and this phenotype revealed a significant association with overall survival in Kaplan–Meier analysis (p < 0.0001). Immunohistochemical double staining showed that VAP-1 immunoreactivity was present around CD163+ M2 infiltration location, including aggressive lesions and neighboring neovasculature. We demonstrated that high VAP-1 expression levels positively correlated with CD163+ M2 activation and coexpression of these two proteins was associated with worse survival in gliomas (p < 0.0001). Multivariate analysis indicated that VAP-1 alone and co-expressed with CD163 were the significantly independent indicators (both p < 0.0001). Furthermore, VAP-1/CD163 coexpression exhibited excellent diagnostic accuracy in gliomas (AUC = 0.8008). In conclusion, VAP-1 and TAM CD163 M2 coexpression was found in glioma tissues belonging to a highly malignant subgroup that was associated with poor prognosis. These results implied VAP-1 abundance is closely linked to alternative M2 activation during glioma progression. From the aforementioned data, a reasonable inference is that VAP-1 combined with targeting M2 immunity might be an effective therapeutic target for human gliomas.

Flavonoid Compounds Contained in Epimedii Herba Inhibit Tumor Progression by Suppressing STAT3 Activation in the Tumor Microenvironment

M2-like tumor-associated macrophages (TAMs) in the tumor tissues promote tumor progression by various mechanisms and represent possible targets of antitumor therapy. In the present study, we tested whether compounds from Epimedii Herba inhibit macrophage polarization to the M2/protumorigenic phenotype and prevent tumor progression, using human monocyte-derived macrophages (HMDMs) and an animal sarcoma model. Four Epimedii Herba-derived flavonoid compounds, namely, limonianin, epimedokoreanin B, icaritin, and desmethylicaritin, inhibited CD163 expression and interleukin (IL)-10 production, which are known M2 markers, suggesting that these compounds inhibit M2 polarization. Among these compounds, epimedokoreanin B and limonianin suppressed STAT3 activation in HMDMs. Notably, epimedokoreanin B also suppressed cell proliferation by blocking STAT3 activation in Saos-2 human sarcoma and LM8 mouse sarcoma cell lines. Furthermore, oral administration of epimedokoreanin B inhibited tumor growth in an LM8 tumor-bearing murine model. These results indicate that Epimedii Herba and Epimedii Herba-derived compounds, such as epimedokoreanin B, may be potentially new agents that can be used for the treatment and prevention of various malignant tumors. They may also be promising compounds for targeting the tumor microenvironment by inhibiting M2 polarization of the TAMs.

Standardized protocols for differentiation of THP-1 cells to macrophages with distinct M(IFNγ+LPS), M(IL-4) and M(IL-10) phenotypes

In vitro models of differing macrophage functions are useful since human monocyte-derived macrophages are short-lived, finite and vary from donor to donor. Published protocols using the promonocytic cell line THP-1 have tended to result in cells that closely resemble classically-activated macrophages, differentiated in IFNγ and LPS. However, no protocol, to date, has fully recapitulated polarization of THP-1 to the M(IL-4) or M(IL-10) macrophage phenotypes seen when human monocyte-derived macrophages are exposed to each cytokine. Here we present protocols that can be used to prepare M(IL-4) polarized THP-1 that transcribe CCL17, CCL26, CD200R and MRC1 and M(IL-10) cells which transcribe CD163, C1QA and SEPP1. We show that the inhibitory Fcγ Receptor IIb is preferentially expressed on the surface of M(IL-4) cells, altering the balance of activating to inhibitory Fcγ Receptors. Adoption of standardized experimental conditions for macrophage polarization will make it easier to compare downstream effector functions of different macrophage polarization states, where the impact of PMA exposure is minimized and rest periods and cytokine exposure have been optimized.

Pushing the Envelope: Advancement of ADCs Outside of Oncology

The majority of ADCs in preclinical and clinical development are for oncology indications where cytotoxic payloads are targeted to antigen-expressing cancer cells. However, the modulation of pathogenic cellular activity via ADC-mediated delivery of bioactive small molecules is also an attractive concept for non-oncology indications leading to an expanded application of the technology. Here we summarize those ADCs that have been described so far for non-oncology applications and which cover a variety of payload mechanisms beyond cell killing, from early in vitro proof-of-concept experiments to clinical trials. As our understanding of ADC technology continues to grow, it is anticipated that the development of ADCs as therapeutics for disease areas outside of oncology will also increase.

Intratendon delivery of leukocyte-rich platelet-rich plasma at early stage promotes tendon repair in a rabbit Achilles tendinopathy model

Tendinopathy is a great obstacle in clinical practice due to its poor regenerative capacity. The influence of different stages of tendinopathy on effects of leukocyte-rich platelet-rich plasma (Lr-PRP) has not been elucidated. The aim of this study is to investigate the optimal time point for delivery of Lr-PRP on tendinopathy. A tendinopathy model was established by local collagenase injection on the rabbit Achilles tendon. Then after collagenase induction, following treatments were applied randomly on the lesion: (a) 200 μl of Lr-PRP at 1 week (PRP-1 group), (b) 200 μl of saline at 1 week (Saline-1 group), (c) 200 μl of Lr-PRP at 4 weeks (PRP-2 group), and (d) 200 μl of saline at 4 weeks (Saline-2 group). Six weeks after collagenase induction, outcomes were assessed by magnetic resonance imaging, cytokine quantification, gene expression, histology, and transmission electron microscopy. Our results demonstrated that PRP-1 group had the least cross-sectional area and lesion percent of the involved tendon, as well as the lowest signal intensity in magnetic resonance imaging among all groups. However, the PRP-2 group showed larger cross-sectional area than saline groups. Enzyme-linked immunosorbent assay indicated that PRP-1 group had a higher level of interleukin-10 but lower level of interleukin-6 when compared with PRP-2 and saline groups. Meanwhile, the highest expression of collagen (Col) 1 in PRP-1 and Col 3, matrix metalloproteinase (MMP)-1, and MMP-3 in PRP-2 was found. Histologically, the PRP-1 showed better general scores than PRP-2, and no significant difference was found between the PRP-2 and saline groups. For transmission electron microscopy, PRP-1 had the largest mean collagen fibril diameter, and the PRP-2 group showed even smaller mean collagen fibril diameter than saline groups. In conclusion, intratendon delivery of Lr-PRP at early stage showed beneficial effect for repair of tendinopathy but not at late stage. For translation of our results to clinical circumstances, further studies are still needed.

The differential statin effect on cytokine production of monocytes or macrophages is mediated by differential geranylgeranylation-dependent Rac1 activation

Monocytes and macrophages contribute to pathogenesis of various inflammatory diseases, including auto-inflammatory diseases, cancer, sepsis, or atherosclerosis. They do so by production of cytokines, the central regulators of inflammation. Isoprenylation of small G-proteins is involved in regulation of production of some cytokines. Statins possibly affect isoprenylation-dependent cytokine production of monocytes and macrophages differentially. Thus, we compared statin-dependent cytokine production of lipopolysaccharide (LPS)-stimulated freshly isolated human monocytes and macrophages derived from monocytes by overnight differentiation. Stimulated monocytes readily produced tumor necrosis factor-α, interleukin-6, and interleukin-1β. Statins did not alter cytokine production of LPS-stimulated monocytes. In contrast, monocyte-derived macrophages prepared in the absence of statin lost the capacity to produce cytokines, whereas macrophages prepared in the presence of statin still produced cytokines. The cells expressed indistinguishable nuclear factor-kB activity, suggesting involvement of separate, statin-dependent regulation pathways. The presence of statin was necessary during the differentiation phase of the macrophages, indicating that retainment-of-function rather than costimulation was involved. Reconstitution with mevalonic acid, farnesyl pyrophosphate, or geranylgeranyl pyrophosphate blocked the retainment effect, whereas reconstitution of cholesterol synthesis by squalene did not. Inhibition of geranylgeranylation by GGTI-298, but not inhibition of farnesylation or cholesterol synthesis, mimicked the retainment effect of the statin. Inhibition of Rac1 activation by the Rac1/TIAM1-inhibitor NSC23766 or by Rac1-siRNA (small interfering RNA) blocked the retainment effect. Consistent with this finding, macrophages differentiated in the presence of statin expressed enhanced Rac1-GTP-levels. In line with the above hypothesis that monocytes and macrophages are differentially regulated by statins, the CD14/CD16-, merTK-, CX₃CR1-, or CD163-expression (M2-macrophage-related) correlated inversely to the cytokine production. Thus, monocytes and macrophages display differential Rac1-geranylgeranylation-dependent functional capacities, that is, statins sway monocytes and macrophages differentially.

Resolution of inflammation during multiple sclerosis

Multiple sclerosis (MS) is a frequent autoimmune demyelinating disease of the central nervous system (CNS). There are three clinical forms described: relapsing-remitting multiple sclerosis (RRMS), the most common initial presentation (85%) among which, if not treated, about half will transform, into the secondary progressive multiple sclerosis (SPMS) and the primary progressive MS (PPMS) (15%) that is directly progressive without superimposed clinical relapses. Inflammation is present in all subsets of MS. The relapsing/remitting form could represent itself a particular interest for the study of inflammation resolution even though it remains incomplete in MS. Successful resolution of acute inflammation is a highly regulated process and dependent on mechanisms engaged early in the inflammatory response that are scarcely studied in MS. Moreover, recent classes of disease-modifying treatment (DMTs) that are effective against RRMS act by re-establishing the inflammatory imbalance, taking advantage of the pre-existing endogenous suppressor. In this review, we will discuss the active role of regulatory immune cells in inflammation resolution as well as the role of tissue and non-hematopoietic cells as contributors to inflammation resolution. Finally, we will explore how DMTs, more specifically induction therapies, impact the resolution of inflammation during MS.

Transcriptional Response of Ovine Lung to Infection with Jaagsiekte Sheep Retrovirus

Jaagsiekte sheep retrovirus (JSRV) is the etiologic agent of ovine pulmonary adenocarcinoma (OPA), a neoplastic lung disease of sheep. OPA is an important economic and welfare issue for sheep farmers and a valuable naturally occurring animal model for human lung adenocarcinoma. Here, we used RNA sequencing to study the transcriptional response of ovine lung tissue to infection by JSRV. We identified 1,971 ovine genes differentially expressed in JSRV-infected lung compared to noninfected lung, including many genes with roles in carcinogenesis and immunomodulation. The differential expression of selected genes was confirmed using immunohistochemistry and reverse transcription-quantitative PCR. A key finding was the activation of anterior gradient 2, yes-associated protein 1, and amphiregulin in OPA tumor cells, indicating a role for this oncogenic pathway in OPA. In addition, there was differential expression of genes related to innate immunity, including genes encoding cytokines, chemokines, and complement system proteins. In contrast, there was little evidence for the upregulation of genes involved in T-cell immunity. Many genes related to macrophage function were also differentially expressed, reflecting the increased abundance of these cells in OPA-affected lung tissue. Comparison of the genes differentially regulated in OPA with the transcriptional changes occurring in human lung cancer revealed important similarities and differences between OPA and human lung adenocarcinoma. This study provides valuable new information on the pathogenesis of OPA and strengthens the use of this naturally occurring animal model for human lung adenocarcinoma.IMPORTANCE Ovine pulmonary adenocarcinoma is a chronic respiratory disease of sheep caused by jaagsiekte sheep retrovirus (JSRV). OPA is a significant economic problem for sheep farmers in many countries and is a valuable animal model for some forms of human lung cancer. Here, we examined the changes in host gene expression that occur in the lung in response to JSRV infection. We identified a large number of genes with altered expression in infected lung, including factors with roles in cancer and immune system function. We also compared the data from OPA to previously published data from human lung adenocarcinoma and found a large degree of overlap in the genes that were dysregulated. The results of this study provide exciting new avenues for future studies of OPA and may have comparative relevance for understanding human lung cancer.

CD206+ tumor-associated macrophages promote proliferation and invasion in oral squamous cell carcinoma via EGF production

Tumor-associated macrophages (TAMs) promote tumor progression and inhibit anti-tumor immune response by producing various mediators and preferentially express CD163, CD204, and CD206. However, the role of these TAM subsets in oral squamous cell carcinoma (OSCC) remains unclear. Here we investigated the expression and function of TAM subsets in OSCC, especially in cancer cell proliferation. Biopsy sample from 44 patients with OSCC were examined for the expression of TAM markers and EGF by immunohistochemistry. EGF production of TAM subsets isolated from OSCC patients was assessed by flow cytometry. We also examined the effect of conditioned medium from TAM subsets on the proliferation of OSCC cells. CD163⁺ cells were detected diffusely all over the tumor and connective tissue area, while CD204⁺ and CD206⁺ cells were mainly detected in/around the tumors. Flow cytometric analysis found that CD206⁺ TAMs strongly produced EGF compared with CD163⁺ and CD204⁺ TAMs. Cell proliferation and invasion of OSCC cells cultured with conditioned medium of CD206⁺ TAMs were strongly enhanced and inhibited by anti-EGFR. The number of CD206⁺ TAMs positively correlated with worse clinical prognosis. Our results revealed differences in localization and EGF production among these TAM subsets. CD206⁺ TAMs might play a critical role in the proliferation of OSCC via EGF production.

Prognostic significance of neutrophil-lymphocyte ratio in resectable pancreatic neuroendocrine tumors with special reference to tumor-associated macrophages

BACKGROUND

Recent studies have shown that the systemic inflammatory response induced by cancer leads to cancer progression. Neutrophil-to-lymphocyte ratio (NLR) is the most reliable marker to detect systemic inflammation. In this study, we investigated the significance of NLR in patients with well-differentiated pancreatic neuroendocrine tumors (PanNETs) according to the World Health Organization 2017 classification.

METHODS

We retrospectively collected data for patients with PanNET who underwent pancreatic resection with curative intent between January 2008 and December 2017 at six institutions. Clinicopathological factors, recurrence, and immunohistochemical staining of tumor-associated macrophages (TAMs) were analyzed in a total of 55 patients in this study.

RESULTS

High NLR (>3.41) in patients was significantly associated with higher white blood cell count, higher Ki-67 index, higher mitotic count, higher grade, higher incidence of lymph node metastasis, higher incidence of lymphatic and neural invasion, massive blood loss, and a large number of CD163-expressing TAMs. Recurrence-free survival of patients with high NLR was significantly poorer than that of patients with low NLR. Multivariate analysis identified high NLR, NET Grade 2 (G2) or Grade 3 (G3), and synchronous hepatic resection as independent risk factors for recurrence after curative resection.

CONCLUSIONS

NLR is a promising predictor of recurrence after pancreatectomy that needs to be further investigated and that accumulation of TAMs in the tumor could be one of the causes of NLR elevation.

The Role of Tumor-Associated Macrophages in Leukemia

In addition to intrinsic factors, leukemia cell growth is influenced by the surrounding nonhematopoietic cells in the leukemic microenvironment, including fibroblasts, mesenchymal stem cells, vascular cells, and various immune cells. Despite the fact that macrophages are an important component of human innate immunity, tumor-associated macrophages (TAMs) have long been considered as an accomplice promoting tumor growth and metastasis. TAMs are activated by an abnormal malignant microenvironment, polarizing into a specific phenotype and participating in tumor progression. TAMs that exist in the microenvironment of different types of leukemia are called leukemia-associated macrophages (LAMs), which are reported to be associated with the progression of leukemia. This review describes the role of LAMs in different leukemia subtypes.

Saphenous vein histopathology 5.5 years after cyanoacrylate closure

VenaSeal (Medtronic, Minneapolis, Minn) is a cyanoacrylate polymer adhesive for the treatment of patients with chronic venous insufficiency. As an implanted device, questions remain about how long cyanoacrylate persists after closure. In this report, a 65-year-old man was examined 5.5 years after cyanoacrylate closure, and a segment of great saphenous vein was excised for histopathologic analysis. Findings were typical of a foreign body reaction. The vessel was occluded with collagenized mature fibrous tissue and polymer remnants, which were encapsulated by multinucleated giant cells. Focal areas of granulomatous inflammation were present in the vein wall extending to the adventitia.

Quantification of Macrophages and Mycobacterium avium Subsp. paratuberculosis in Bovine Intestinal Tissue During Different Stages of Johne's Disease

Johne's disease is an enteric disease caused by the intracellular pathogen Mycobacterium avium subsp. paratuberculosis (MAP). Upon ingestion of MAP, it is translocated across the intestinal epithelium and may be killed by intestinal macrophages, or depending on the bacterial burden and immunological status of the animal, MAP may thwart innate defense mechanisms and persist within the macrophage. This study aimed to determine the numbers of macrophages and MAP present in bovine midileal tissue during different stages of infection. Immunofluorescent (IF) labeling was performed on frozen bovine midileal intestinal tissue collected from 28 Holstein dairy cows. The number of macrophages in midileal tissue sections was higher for clinically affected cows, followed by subclinically affected cows and then uninfected control cows. Macrophages were present throughout the tissue sections in clinical cows, including the tunica muscularis, submucosa, and the lamina propria around the crypts and in the villous tips, with progressively fewer macrophages in subclinically affected and control cows. Clinically affected cows also demonstrated significantly higher numbers of MAP and higher numbers of macrophages with intracellular MAP compared to subclinically affected cows. MAP IF labeling was present within the submucosa and lamina propria around the crypts, progressing into the villous tips in some clinically affected cows. Our findings indicate that number of macrophages increases with progression of infection, but a significant number of the macrophages present in the midileum are not associated with MAP.

Insights Into Dolphins' Immunology: Immuno-Phenotypic Study on Mediterranean and Atlantic Stranded Cetaceans

Immunology of marine mammals is a relatively understudied field and its monitoring plays an important role in the individual and group management of these animals, along with an increasing value as an environmental health indicator. This study was aimed at implementing the knowledge on the immune response in cetaceans stranded along the Italian coastline to provide a baseline useful for assessing the immune status of bottlenose (Tursiops truncatus) and striped (Stenella coeruleoalba) dolphins. In particular, since the Mediterranean Sea is considered a heavily polluted basin, a comparison with animals living in open waters such as the Atlantic Ocean was made. Formalin-fixed, paraffin-embedded spleen, thymus, and lymph node tissues from 16 animals stranded along Italian and 11 cetaceans from the Canary Island shores were sampled within 48 h from death. Information regarding stranding sites, gender, and age as well as virologic, microbiological, and parasitological investigations, and the cause and/or the death mechanism were also collected in order to carry out statistical analyses. Selected tissues were routinely stained with hematoxylin-eosin (H&E) and with immunohistochemical techniques (IHC). For IHC analysis, anti-human CD5 monoclonal mouse antibody to identify T lymphocytes, CD20 monoclonal mouse antibody for the identification of mature B lymphocytes and HLA-DR antigen (alpha-chain) monoclonal mouse antibody for the identification of the major histocompatibility complex type II were previously validated for both species by Western-blotting technique. T-test method applied to quantitative evaluation of IHC positive cells showed a significant relationship between the number of (expression) of CD20 stained lymphocytes and normal and hypoplastic lymph nodes, respectively. No other significant correlations were noticed. Analyses for organochlorines (OC) compounds were performed in animals (n°5) having frozen blubber tissue available. A simple linear regression was calculated to predict if the amount of OCs could influence the number of inflammatory cell subpopulations and a moderate negative correlation was found between the presence of high quantity of contaminants and the number of T lymphocytes. Future analysis should be aimed to understand the effect of the major immunomodulatory pathogens on sub-populations of B and T cells.

Molecular and clinical characterization of CD163 expression via large-scale analysis in glioma

The expression and function of CD163 in glioma are not fully understood. In this report, we collected totally 1323 glioma samples from the Chinese Glioma Genome Atlas (CGGA) dataset, including 325 RNA-seq data and 301 mRNA microarray data, and 697 glioma samples from The Cancer Genome Atlas (TCGA) dataset to characterize the molecular and clinical features of CD163 in glioma by conducting a large-scale study. We found that CD163 expression was positively associated with the grade of malignancy of glioma. CD163 expression was up-regulated in IDH wild-type glioma and mesenchymal subtype. Gene ontology analysis suggested that CD163-related genes were more involved in immune response and angiogenesis in glioma. Moreover, CD163 showed a positive relationship with stromal and immune cell populations. Kaplan-Meier curves analysis revealed that higher CD163 expression indicated significantly poor survival in glioma and glioblastoma multiforme (GBM). Pearson correlation analysis revealed that CD163 was robustly associated with the immune checkpoints and other macrophage markers. These results demonstrated that CD163 predicts poor prognosis in glioma patients. Additionally, combination of CD163 and immune checkpoints may impair angiogenesis and reverse dysfunctional phenotypes of T cells, which suggest that CD163 may be a promising biomarker and target for immunotherapeutic strategies. Abbreviations: CGGA: Chinese Glioma Genome Atlas; TCGA: The Cancer Genome Atlas; TAMs: Tumor associated macrophages; IDH: isocitrate dehydrogenase; GBM: glioblastoma.

Abnormal Expression of Indoleamine 2, 3-Dioxygenase in Human Recurrent Miscarriage

Indoleamine 2, 3-dioxygenase (IDO), an immunosuppressive enzyme that mediates the conversion of tryptophan to kynurenine, was shown to play a key role in placental development during normal pregnancy. However, little is known about the pattern of IDO expression in the endometrium and its attendant functional significance in pregnancies complicated with recurrent miscarriage (RM). Immunohistochemical studies of IDO, Foxp3, CD56, and CD163 expression were performed in endometrial samples from women with RM and healthy fertile controls. Our study found that IDO was localized in glandular epithelial cells, surface epithelial cells, and a small number of cells within the stromal compartment (including stromal cells and leukocytes) in endometrium. Indoleamine 2, 3-dioxygenase expression in the RM group was significantly lower than control group. The Foxp3 and CD56 expression were significantly increased with the elevated IDO expression in controls but not in RM. The percentage of Foxp3+ Tregs was significantly correlated with the level of IDO expression in the control group. Comparatively, no correlation was found between the percentage of CD56+ cells, CD163+ cells, and the level of IDO expression, no matter in controls and RM patients. This study demonstrated that the downregulation of IDO expression and noncoordinated association between IDO and other endometrial immune cells were associated with RM. Our findings provide insights into the contribution of IDO in immune regulation to maintain normal pregnancy, which could be used to develop potential therapeutic methods for RM.

M2 macrophages and regulatory T cells in lethal prostate cancer

BACKGROUND

Prostate cancer (PCa) is one of the most frequently diagnosed cancers in the world. Emerging evidence suggests that inflammatory cells such as M2 macrophages and regulatory T cells (T_regs ) can contribute to cancer progression by suppressing the anti-tumor immune response. This study investigated the number of CD163-positive M2 macrophages in PCa tissue. It also investigated the correlation and interaction of M2 macrophages and T_regs .

METHODS

This nested case-control study included subjects from a cohort of men diagnosed with PCa as an incidental finding during transurethral resection of the prostate. The cases were 225 men who died from PCa, and the controls were 367 men who survived more than 10 years after PCa diagnosis without disease progression. Infiltrating CD163-positive M2 macrophages and FOXP3/CD4-positive T_regs in PCa tissue were identified using immunohistochemistry. The correlation and interaction of M2 macrophages and T_regs were assessed using Spearman's rank-order correlation and a likelihood test, respectively. Logistic regression was used to estimate odds ratios (ORs) for lethal PCa and macrophage counts.

RESULTS

The number of M2 macrophages and T_regs showed a significant correlation (P < 0.001) but no interactions. The OR for lethal PCa was 1.93 (95%CI: 1.23-3.03) for men with high numbers of M2 macrophages. Also for cases with uncertain outcome (GS categories 3 + 4 and 4 + 3) high numbers of M2 macrophages does predict a poorer prognosis.

CONCLUSIONS

Our data showed that men with high numbers of M2 macrophages in the prostate tumor environment had increased odds of dying of PCa. It is possible that M2 macrophages, together with other suppressor cells such as T_regs , promote an immunosuppressive environment.

PD-L1 expression enhancement by infiltrating macrophage-derived tumor necrosis factor-α leads to poor pancreatic cancer prognosis

Immunotherapy using anti‐PD‐1/PD‐L1 antibodies for several types of cancer has received considerable attention in recent decades. However, the molecular mechanism underlying PD‐L1 expression in pancreatic ductal adenocarcinoma (PDAC) cells has not been clearly elucidated. We investigated the clinical significance and regulatory mechanism of PD‐L1 expression in PDAC cells. Among the various cytokines tested, tumor necrosis factor (TNF)‐α upregulated PD‐L1 expression in PDAC cells through NF‐κB signaling. The induction of PD‐L1 expression was also caused by co‐culture with activated macrophages, and the upregulation was inhibited by neutralization with anti‐TNF‐α antibody after co‐culture with activated macrophages. PD‐L1 expression in PDAC cells was positively correlated with macrophage infiltration in tumor stroma of human PDAC tissues. In addition, survival analysis revealed that high PD‐L1 expression was significantly associated with poor prognosis in 235 PDAC patients and especially in patients harboring high CD8‐positive T‐cell infiltration. These findings indicate that tumor‐infiltrating macrophage‐derived TNF‐α could be a potential therapeutic target for PDAC.

Exosomes derived from hypoxic epithelial ovarian cancer cells deliver microRNAs to macrophages and elicit a tumor-promoted phenotype

Recently, cancer has been considered to be a complex system that includes the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most common immune-related stromal cells in the TME, and communication between cancer cells and TAMs is crucial for the progression of epithelial ovarian cancer (EOC). In this study, we revealed that exosomes derived from EOC cells remodel macrophages to a tumor-promoted phenotype, namely TAMs. In addition, hypoxic microenvironments have been postulated to facilitate this process in the TME, and hypoxia-inducible factors (HIFs) play an important role in this process. We found that TAMs educated by hypoxic exosomes derived from EOC cells promote tumor proliferation and migration in a feedback loop. Based on microarray analysis of normoxic and hypoxic exosomes, we discovered that a panel of miRNAs was enriched in hypoxic exosomes. And these three highly expressed miRNAs were induced by hypoxia via HIFs. In this study, we revealed that under hypoxic conditions, EOC cell-derived exosomes deliver miRNAs to induce M2 macrophage polarization, which promotes EOC cell proliferation and migration. This study suggests that these exosomes and associated miRNAs might serve as targets for novel treatments or diagnostic biomarkers for EOC.

Downregulation of 15-hydroxyprostaglandin dehydrogenase by interleukin-1β from activated macrophages leads to poor prognosis in pancreatic cancer

Chronic inflammation has a crucial role in cancer development and the progression of various tumors, including pancreatic ductal adenocarcinoma (PDAC). The arachidonate cascade is a major inflammatory pathway that produces several metabolites, such as prostaglandin E2. The enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH) degrades prostaglandin and is frequently decreased in several types of cancer; however, the molecular mechanisms of 15-PGDH suppression are unclear. The current study was carried out to elucidate the molecular mechanisms and clinical significance of 15-PGDH suppression in PDAC. Here, we showed that interleukin-1β (IL-1β), a pro-inflammatory cytokine, downregulates 15-PGDH expression in PDAC cells, and that IL-1β expression was inversely correlated with 15-PGDH levels in frozen PDAC tissues. We also found that activated macrophages produced IL-1β and reduced 15-PGDH expression in PDAC cells. Furthermore, the number of CD163-positive tumor-associated macrophages was shown to be inversely correlated with 15-PGDH levels in PDAC cells by immunohistochemical staining of 107 PDAC samples. Finally, we found that low 15-PGDH expression was significantly associated with advanced tumors, presence of lymph node metastasis and nerve invasion, and poor prognosis in PDAC patients. Our results indicate that IL-1β derived from TAMs suppresses 15-PGDH expression in PDAC cells, resulting in poor prognosis of PDAC patients.

Impaired lymphatic function accelerates cancer growth

Increased lymphangiogenesis is a common feature of cancer development and progression, yet the influence of impaired lymphangiogenesis on tumor growth is elusive. C3HBA breast cancer and KHT-1 sarcoma cell lines were implanted orthotopically in Chy mice, harboring a heterozygous inactivating mutation of vascular endothelial growth factor receptor-3, resulting in impaired dermal lymphangiogenesis. Accelerated tumor growth was observed in both cancer models in Chy mice, coinciding with reduced peritumoral lymphangiogenesis. An impaired lymphatic washout was observed from the peritumoral area in Chy mice with C3HBA tumors, and the number of macrophages was significantly reduced. While fewer macrophages were detected, the fraction of CD163+ M2 macrophages remained constant, causing a shift towards a higher M2/M1 ratio in Chy mice. No difference in adaptive immune cells was observed between wt and Chy mice. Interestingly, levels of pro- and anti-inflammatory macrophage-associated cytokines were reduced in C3HBA tumors, pointing to an impaired innate immune response. However, IL-6 was profoundly elevated in the C3HBA tumor interstitial fluid, and treatment with the anti-IL-6 receptor antibody tocilizumab inhibited breast cancer growth. Collectively, our data indicate that impaired lymphangiogenesis weakens anti-tumor immunity and favors tumor growth at an early stage of cancer development.

Clinicopathological correlation of tumor-associated macrophages in Ewing sarcoma

AIMS

Tumor-associated macrophages (TAMs) are known markers playing complex roles in tumorigenesis. However, the function of TAMs in a variety of malignancies is not yet fully understood. The aim of this pilot study was to quantify the density of TAMs in Ewing sarcoma and to determine the correlation between TAMs and clinicopathological parameters.

METHODS

Using immunohistochemistry, the expressions of CD68 and CD163 were examined in 24 tissue samples of Ewing sarcoma of bone. The density of CD68 and CD163-positive TAMs was analyzed quantitatively and semi-quantitatively and statistically correlated with clinical parameters.

RESULTS

CD163-positive TAMs outnumbered CD68-positive cells (median of 130 vs 96, respectively). No statistically significant relatio nship was found between density of CD68-positive cells, clinical parameters or prognosis. However, high levels of CD163-positive TAMs were associated with localized disease (P=0.008). In cases with a higher density of CD163-positive cells, a trend toward longer survival was revealed (P=0.063).

CONCLUSION

This is the first study that has quantified CD163 expression in TAMs in Ewing sarcoma and showed its possible prognostic value. CD163 was confirmed to be a more specific marker of macrophages than CD68. CD163 is not an exclusive hallmark of M2 macrophages.

Macrophage type 2 differentiation in a patient with laryngeal squamous cell carcinoma and metastatic prostate adenocarcinoma to the cervical lymph nodes

Background

The tumor microenvironment often polarizes infiltrating macrophages towards a type 2, or M2 phenotype, that is characterized by expression of various cysteine-rich, scavenger receptors, including CD163. The primary function of M2 macrophages is to facilitate wound healing. As such, they are capable of providing metabolic support to a growing tumor, neovascularization, as well as protection from cytotoxic T cells. The tumor microenvironment contains a milieu of secreted factors and vesicles, which in certain circumstances can gain access to lymphatic vessels that drain to local lymph nodes.

Case presentation

We report a 59-year-old male with recurrent T4 squamous cell carcinoma (SCC) of the larynx with synchronous prostate adenocarcinoma confined to the prostate and regional pelvic lymph nodes, without metastatic disease. The patient underwent salvage total laryngectomy and bilateral neck dissection with final pathology revealing a recurrent moderately differentiated SCC involving the larynx as well as prostate cancer in draining level 4 cervical lymph nodes bilaterally. CD163 staining was performed on the primary tumor, a negative draining lymph node, and a level four lymph node with a focus of metastatic prostate cancer and compared to benign controls. The negative draining lymph node demonstrated a large CD163 population of cells as did the interface of the focus of prostate cancer and surrounding lymph node. CD163 levels were markedly increased in this patient compared to benign lymph node controls. The macrophage differentiation at the primary tumor in the larynx was strongly CD163 positive supporting an immune permissive environment for tumor growth and metastasis.

Conclusion

We describe a unique case of solitary metastatic prostate cancer to cervical lymph nodes in the setting of a laryngeal cancer. These observations suggest that SCC-derived factors drive a tumor-supportive environment in draining lymph nodes dominated by an overwhelming number of CD163+, M2 macrophages. Lymph nodes that are ‘primed’ by SCC differentiation to M2 phenotype may be at higher risk of harboring metastases.