Folate Receptor β (FRβ) Expression in Tissue-Resident and Tumor-Associated Macrophages Associates with and Depends on the Expression of PU.1

Folate Receptor β (FRβ) Expression on Myeloid Cells and the Impact of Reticuloendothelial System on Folate-Functionalized Nanoparticles' Biodistribution in Cancer

Folate uptake is largely mediated by folate receptor (FR)β, encoded by FOLR2 gene, in myeloid immune cells such as granulocytes, monocytes, and especially in macrophages that constitute the reticuloendothelial system (RES) and infiltrate the tumor microenvironment. Since the myeloid immune compartment dynamically changes during tumorigenesis, it is critical to assess the infiltration status of the tumors by FRβ-expressing myeloid cells to better define the targeting efficacy of folate-functionalized drug delivery systems. On the other hand, clearance by RES is a major limitation for the targeting efficacy of nanoparticles decorated with folate. Therefore, the aims of this study are (i) to determine the amount and subtypes of FRβ+ myeloid cells infiltrating the tumors at different stages, (ii) to compare the amount and subtype of FRβ+ myeloid cells in distinct organs of tumor-bearing and healthy animals, (iii) to test if the cancer-targeting efficacy and biodistribution of a prototypic folate-functionalized nanoparticle associates with the density of FRβ+ myeloid cells. Here, we report that myeloid cell infiltration was enhanced and FRβ was upregulated at distinct stages of tumorigenesis in a mouse breast cancer model. The CD206+ subset of macrophages highly expressed FRβ, prominently both in tumor-bearing and healthy mice. In tumor-bearing mice, the amount of all myeloid cells, but particularly granulocytes, was remarkably increased in the tumor, liver, lungs, spleen, kidneys, lymph nodes, peritoneal cavity, bone marrow, heart, and brain. Compared with macrophages, the level of FRβ was moderate in granulocytes and monocytes. The density of FRβ+ immune cells in the tumor microenvironment was not directly associated with the tumor-targeting efficacy of the folate-functionalized cyclodextrin nanoparticles. The lung was determined as a preferential site of accumulation for folate-functionalized nanoparticles, wherein FRβ+CD206+ macrophages significantly engulfed cyclodextrin nanoparticles. In conclusion, our results demonstrate that the tumor formation augments the FR levels and alters the infiltration and distribution of myeloid immune cells in all organs which should be considered as a major factor influencing the targeting efficacy of nanoparticles for drug delivery.

Unsupervised Analysis Reveals the Involvement of Key Immune Response Genes and the Matrisome in Resistance to BRAF and MEK Inhibitors in Melanoma

Melanoma tumors exhibit a wide range of heterogeneity in genomics even with shared mutations in the MAPK pathway, including BRAF mutations. Consistently, adaptive drug resistance to BRAF inhibitors and/or BRAF plus MEK inhibitors also exhibits a wide range of heterogeneous responses, which poses an obstacle for discovering common genes and pathways that can be used in clinic for overcoming drug resistance. This study objectively analyzed two sets of previously published tumor genomics data comparing pre-treated melanoma tumors and BRAFi- and/or MEKi-resistant tumors. Heterogeneity in response to BRAFi and BRAFi/MEKi was evident because the pre-treated tumors and resistant tumors did not exhibit a tendency of clustering together. Differentially expressed gene (DEG) analysis revealed eight genes and two related enriched signature gene sets (matrisome and matrisome-associated signature gene sets) shared by both sets of data. The matrisome was closely related to the tumor microenvironment and immune response, and five out of the eight shared genes were also related to immune response. The PLXNC1 gene links the shared gene set and the enriched signature gene sets as it presented in all analysis results. As the PLXNC1 gene was up-regulated in the resistant tumors, we validated the up-regulation of this gene in a laboratory using vemurafenib-resistant cell lines. Given its role in promoting inflammation, this study suggests that resistant tumors exhibit an inflammatory tumor microenvironment. The involvement of the matrisome and the specific set of immune genes identified in this study may provide new opportunities for developing future therapeutic methods.

Expression of the Folate Receptor Proteins FOLR1 and FOLR2 in Correlation With Clinicopathological Variables of Gastric Cancer

INTRODUCTION

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, owing to its aggressive nature and poor prognosis. The role of folate receptors, particularly folate receptor 1 (FOLR1) and folate receptor 2 (FOLR2), in cancer has been increasingly recognized due to their overexpression in various malignancies including gastric cancer, and its potential implications in cancer progression, treatment resistance and as therapeutic targets.

OBJECTIVE

To evaluate the expression patterns of FOLR1 and FOLR2 in GC patients' tissue and blood specimens and to correlate these patterns with clinicopathological variables.

METHODS

A total of 58 gastric cancer patients were enrolled at the Regional Cancer Centre (RCC) from March 2017 to March 2020. Immunohistochemical analysis was performed to examine the expression of FOLR1 and FOLR2 in formalin-fixed paraffin-embedded (FFPE) tissue samples. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to analyze FOLR1 and FOLR2 expression in blood samples. Statistical analyses were conducted using chi-square tests, independent T-tests, and Kaplan-Meier survival analysis.

RESULTS

FOLR1 and FOLR2 were overexpressed in 82.76% and 70.69% of gastric cancer tissues, respectively. High expression levels of FOLR1 were significantly associated with the diffuse type of gastric cancer (p<0.005). qRT-PCR showed significant overexpression of FOLR1 in gastric cancer blood samples compared to control samples, with a median fold change of approximately 14.18 times. Conversely, FOLR2 was significantly underexpressed in gastric cancer samples, with a fold change of 0.30. However, no significant correlation was found between FOLR2 expression and the clinicopathological features. The overall survival analysis did not show a significant difference in survival rates based on the expression levels of FOLR1 and FOLR2.

CONCLUSIONS

This study highlights the differential expression patterns of FOLR1 and FOLR2 in gastric cancer and underscores the complexity of their roles in cancer biology. While FOLR1 shows potential as a biomarker for gastric cancer due to its overexpression, further studies are needed to fully elucidate the therapeutic and prognostic implications of folate receptors in gastric cancer.

Tumor-specific activation of folate receptor beta enables reprogramming of immune cells in the tumor microenvironment

Folate receptors can perform folate transport, cell adhesion, and/or transcription factor functions. The beta isoform of the folate receptor (FRβ) has attracted considerable attention as a biomarker for immunosuppressive macrophages and myeloid-derived suppressor cells, however, its role in immunosuppression remains uncharacterized. We demonstrate here that FRβ cannot bind folate on healthy tissue macrophages, but does bind folate after macrophage incubation in anti-inflammatory cytokines or cancer cell-conditioned media. We further show that FRβ becomes functionally active following macrophage infiltration into solid tumors, and we exploit this tumor-induced activation to target a toll-like receptor 7 agonist specifically to immunosuppressive myeloid cells in solid tumors without altering myeloid cells in healthy tissues. We then use single-cell RNA-seq to characterize the changes in gene expression induced by the targeted repolarization of tumor-associated macrophages and finally show that their repolarization not only changes their own phenotype, but also induces a proinflammatory shift in all other immune cells of the same tumor mass, leading to potent suppression of tumor growth. Because this selective reprogramming of tumor myeloid cells is accompanied by no systemic toxicity, we propose that it should constitute a safe method to reprogram the tumor microenvironment.

The intricate cellular ecosystem of human peripheral veins as revealed by single-cell transcriptomic analysis

The venous system has been historically understudied despite its critical roles in blood distribution, heart function, and systemic immunity. This study dissects the microanatomy of upper arm veins at the single cell level, and how it relates to wall structure, remodeling processes, and inflammatory responses to injury. We applied single-cell RNA sequencing to 4 non-diseased human veins (3 basilic, 1 cephalic) obtained from organ donors, followed by bioinformatic and histological analyses. Unsupervised clustering of 20,006 cells revealed a complex ecosystem of endothelial cell (EC) types, smooth muscle cell (SMCs) and pericytes, various types of fibroblasts, and immune cell populations. The venous endothelium showed significant upregulation of cell adhesion genes, with arteriovenous zonation EC phenotypes highlighting the heterogeneity of vasa vasorum (VV) microvessels. Venous SMCs had atypical contractile phenotypes and showed widespread localization in the intima and media. MYH11+DESlo SMCs were transcriptionally associated with negative regulation of contraction and pro-inflammatory gene expression. MYH11+DEShi SMCs showed significant upregulation of extracellular matrix genes and pro-migratory mediators. Venous fibroblasts ranging from secretory to myofibroblastic phenotypes were 4X more abundant than SMCs and widely distributed throughout the wall. Fibroblast-derived angiopoietin-like factors were identified as versatile signaling hubs to regulate angiogenesis and SMC proliferation. An abundant monocyte/macrophage population was detected and confirmed by histology, including pro-inflammatory and homeostatic phenotypes, with cell counts positively correlated with age. Ligand-receptor interactome networks identified the venous endothelium in the main lumen and the VV as a niche for monocyte recruitment and infiltration. This study underscores the transcriptional uniqueness of venous cells and their relevance for vascular inflammation and remodeling processes. Findings from this study may be relevant for molecular investigations of upper arm veins used for vascular access creation, where single-cell analyses of cell composition and phenotypes are currently lacking.

Folate Receptor Beta Signaling in the Regulation of Macrophage Antimicrobial Immune Response: A Scoping Review

Introduction

Folate, vitamin B9, is a water-soluble vitamin that is essential to cellular proliferation and division. In addition to the reduced folate carrier, eukaryotic cells take up folate through endocytosis mediated by one of two GPI-anchored folate receptors (FRs), FRα or FRβ. Two other isoforms of FR exist, FRγ and FRδ, neither of which support endocytic activities of FR signaling. FRβ is expressed primarily by monocytes and macrophages and highly expressed on activated macrophages. Macrophage expression of FRβ suggests a role for this receptor in modulating function of these immune sentinels, particularly as they engage in inflammatory processes. Despite several studies suggesting that folates can suppress inflammatory responses of macrophages to proinflammatory stimuli, there appears to be a lack of basic research examining the role of FRβ in modulating macrophage responses to microbial sensing. We therefore conducted a scoping review to assess evidence within the published literature addressing the question, "what is known about the extent to which FRβ regulates macrophage responses to sensing, and responding to, microorganisms?".

Methods

As a strategy for the study selection, we queried articles indexed in the research database PubMed and the search engine Google Scholar (up until August 12, 2023), including combinations of the research words: macrophage, folate receptor beta, FOLR2.

Results

We identified 2 relevant articles out of 153 that are worth discussing here, none of which directly addressed our research question.

Conclusion

There is an unmet need to better define the contribution of FRβ to regulating the macrophage response to microbes.

Cerebrospinal fluid exploratory proteomics and ketamine metabolite pharmacokinetics in human volunteers after ketamine infusion

Ketamine is a treatment for both refractory depression and chronic pain syndromes. In order to explore ketamine's potential mechanism of action and whether ketamine or its metabolites cross the blood brain barrier, we examined the pharmacokinetics of ketamine and its metabolites-norketamine (NK), dehydronorketamine (DHNK), and hydroxynorketamines (HNKs)-in cerebrospinal fluid (CSF) and plasma, as well as in an exploratory proteomic analysis in the CSF of nine healthy volunteers who received ketamine intravenously (0.5 mg/kg IV). We found that ketamine, NK, and (2R,6R;2S,6S)-HNK readily crossed the blood brain barrier. Additionally, 354 proteins were altered in the CSF in at least two consecutive timepoints (p < 0.01). Proteins in the classes of tyrosine kinases, cellular adhesion molecules, and growth factors, including insulin, were most affected, suggesting an interplay of altered neurotransmission, neuroplasticity, neurogenesis, synaptogenesis, and neural network functions following ketamine administration.

Recent Advances in Folates and Autoantibodies against Folate Receptors in Early Pregnancy and Miscarriage

Though firstly identified in cerebral folate deficiency, autoantibodies against folate receptors (FRAbs) have been implicated in pregnancy complications such as miscarriage; however, the underlying mechanism needs to be further elaborated. FRAbs can be produced via sensitization mediated by folate-binding protein as well as gene mutation, aberrant modulation, or degradation of folate receptors (FRs). FRAbs may interfere with folate internalization and metabolism through blocking or binding with FRs. Interestingly, different types of FRs are expressed on trophoblast cells, decidual epithelium or stroma, and macrophages at the maternal-fetal interface, implying FRAbs may be involved in the critical events necessary for a successful pregnancy. Thus, we propose that FRAbs may disturb pregnancy establishment and maintenance by modulating trophoblastic biofunctions, placental development, decidualization, and decidua homeostasis as well as the functions of FOLR2+ macrophages. In light of these findings, FRAbs may be a critical factor in pathological pregnancy, and deserve careful consideration in therapies involving folic acid supplementation for pregnancy complications.

Reanalysis of single-cell data reveals macrophage subsets associated with the immunotherapy response and prognosis of patients with endometrial cancer

Endometrial cancer (EC) is an aggressive gynecological malignancy with an increased incidence rate. The immune landscape crucially affects immunotherapy efficacy and prognosis in EC patients. Here, we characterized the distinct tumor microenvironment signatures of EC tumors by analyzing single-cell RNA sequencing data from Gene Expression Omnibus and bulk RNA sequencing data from The Cancer Genome Atlas, which were compared with normal endometrium. Three macrophage subsets were identified, and two of them showed tissue-specific distribution. One of the macrophage subsets was dominant in macrophages derived from EC and exhibited characteristic behaviors such as promoting tumor growth and metastasis. One of the other macrophage subsets was mainly found in normal endometrium and served functions related to antigen presentation. We also identified a macrophage subset that was found in both EC and normal endometrial tissue. However, the pathway and cellular cross-talk of this subset were completely different based on the respective origin, suggesting a tumor-related differentiation mechanism of macrophages. Additionally, the tumor-enriched macrophage subset was found to predict immunotherapy responses in EC. Notably, we selected six genes from macrophage subset markers that could predict the survival of EC patients, SCL8A1, TXN, ANXA5, CST3, CD74 and NANS, and constructed a prognostic signature. To verify the signature, we identified immunohistochemistry for the tumor samples of 83 EC patients based on the selected genes and further followed up with the survival of the patients. Our results provide strong evidence that the signature can effectively predict the prognosis of EC patients.

The NR_109/FUBP1/c-Myc axis regulates TAM polarization and remodels the tumor microenvironment to promote cancer development

BACKGROUND

Tumor-associated macrophages (TAMs) are a major component of the tumor microenvironment (TME) and exert an important role in tumor progression. Due to the heterogeneity and plasticity of TAMs, modulating the polarization states of TAMs is considered as a potential therapeutic strategy for tumors. Long noncoding RNAs (lncRNAs) have been implicated in various physiological and pathological processes, yet the underlying mechanism on how lncRNAs manipulate the polarization states of TAMs is still unclear and remains to be further investigated.

METHODS

Microarray analyses were employed to characterize the lncRNA profile involved in THP-1-induced M0, M1 and M2-like macrophage. Among those differentially expressed lncRNAs, NR_109 was further studied, for its function in M2-like macrophage polarization and the effects of the condition medium or macrophages mediated by NR_109 on tumor proliferation, metastasis and TME remodeling both in vitro and in vivo. Moreover, we revealed how NR_109 interacted with far upstream element-binding protein 1 (FUBP1) to regulate the protein stability through hindering ubiquitination modification by competitively binding with JVT-1. Finally, we examined sections of tumor patients to probe the correlation among the expression of NR_109 and related proteins, showing the clinical significance of NR_109.

RESULTS

We found that lncRNA NR_109 was highly expressed in M2-like macrophages. Knockdown NR_109 impeded IL-4 induced M2-like macrophage polarization and significantly reduced the activity of M2-like macrophages to support the proliferation and metastasis of tumor cells in vitro and in vivo. Mechanistically, NR_109 competed with JVT-1 to bind FUBP1 at its C-terminus domain, impeded the ubiquitin-mediated degradation of FUBP1, activated c-Myc transcription and thus promoted M2-like macrophages polarization. Meanwhile, as a transcription factor, c-Myc could bind to the promoter of NR_109 and enhance the transcription of NR_109. Clinically, high NR_109 expression was found in CD163⁺ TAMs from tumor tissues and was positively correlated with poor clinical stages of patients with gastric cancer and breast cancer.

CONCLUSIONS

Our work revealed for the first time that NR_109 exerted a crucial role in regulating the phenotype-remodeling and function of M2-like macrophages via a NR_109/FUBP1/c-Myc positive feedback loop. Thus, NR_109 has great translational potentials in the diagnosis, prognosis and immunotherapy of cancer.

Inhibition of LXR controls the polarization of human inflammatory macrophages through upregulation of MAFB

Monocyte-derived macrophages contribute to pathogenesis in inflammatory diseases and their effector functions greatly depend on the prevailing extracellular milieu. Whereas M-CSF primes macrophages for acquisition of an anti-inflammatory profile, GM-CSF drives the generation of T cell-stimulatory and pro-inflammatory macrophages. Liver X Receptors (LXRα and LXRβ) are nuclear receptors that control cholesterol metabolism and regulate differentiation of tissue-resident macrophages. Macrophages from rheumatoid arthritis and other inflammatory pathologies exhibit an enriched LXR pathway, and recent reports have shown that LXR activation raises pro-inflammatory effects and impairs the acquisition of the anti-Inflammatory profile of M-CSF-dependent monocyte-derived macrophages (M-MØ). We now report that LXR inhibition prompts the acquisition of an anti-inflammatory gene and functional profile of macrophages generated within a pathological environment (synovial fluid from Rheumatoid Arthritis patients) as well as during the GM-CSF-dependent differentiation of human monocyte-derived macrophages (GM-MØ). Mechanistically, inhibition of LXR results in macrophages with higher expression of the v-Maf Avian Musculoaponeurotic Fibrosarcoma Oncogene Homolog B (MAFB) transcription factor, which governs the macrophage anti-inflammatory profile, as well as over-expression of MAFB-regulated genes. Indeed, gene silencing experiments on human macrophages evidenced that MAFB is required for the LXR inhibitor to enhance the anti-inflammatory nature of human macrophages. As a whole, our results demonstrate that LXR inhibition prompts the acquisition of an anti-inflammatory transcriptional and functional profile of human macrophages in a MAFB-dependent manner, and propose the use of LXR antagonists as potential therapeutic alternatives in macrophage re-programming strategies during inflammatory responses.

Niclosamide targets the dynamic progression of macrophages for the resolution of endometriosis in a mouse model

Due to the vital roles of macrophages in the pathogenesis of endometriosis, targeting macrophages could be a promising therapeutic direction. Here, we investigated the efficacy of niclosamide for the resolution of a perturbed microenvironment caused by dysregulated macrophages in a mouse model of endometriosis. Single-cell transcriptomic analysis revealed the heterogeneity of macrophages including three intermediate subtypes with sharing characteristics of traditional “small” or “large” peritoneal macrophages (SPMs and LPMs) in the peritoneal cavity. Endometriosis-like lesions (ELL) enhanced the differentiation of recruited macrophages, promoted the replenishment of resident LPMs, and increased the ablation of embryo-derived LPMs, which were stepwise suppressed by niclosamide. In addition, niclosamide restored intercellular communications between macrophages and B cells. Therefore, niclosamide rescued the perturbed microenvironment in endometriosis through its fine regulations on the dynamic progression of macrophages. Validation of similar macrophage pathogenesis in patients will further promote the clinical usage of niclosamide for endometriosis treatment.

Single-cell analysis of endometriosis reveals a coordinated transcriptional programme driving immunotolerance and angiogenesis across eutopic and ectopic tissues

Endometriosis is characterized by the growth of endometrial-like tissue outside the uterus. It affects many women during their reproductive age, causing years of pelvic pain and potential infertility. Its pathophysiology remains largely unknown, which limits early diagnosis and treatment. We characterized peritoneal and ovarian lesions at single-cell transcriptome resolution and compared them to matched eutopic endometrium, unaffected endometrium and organoids derived from these tissues, generating data on over 122,000 cells across 14 individuals. We spatially localized many of the cell types using imaging mass cytometry. We identify a perivascular mural cell specific to the peritoneal lesions, with dual roles in angiogenesis promotion and immune cell trafficking. We define an immunotolerant peritoneal niche, fundamental differences in eutopic endometrium and between lesion microenvironments and an unreported progenitor-like epithelial cell subpopulation. Altogether, this study provides a holistic view of the endometriosis microenvironment that represents a comprehensive cell atlas of the disease in individuals undergoing hormonal treatment, providing essential information for future therapeutics and diagnostics.

Synovial Macrophages: Past Life, Current Situation, and Application in Inflammatory Arthritis

Inflammatory arthritis is an inflammatory disease that involves the joints and surrounding tissues. Synovial hyperplasia often presents when joints become inflamed due to immune cell infiltration. Synovial membrane is an important as well as a highly specific component of the joint, and its lesions can lead to degeneration of the joint surface, causing pain and joint disability or affecting the patients’ quality of life in severe cases. Synovial macrophages (SMs) are one of the cellular components of the synovial membrane, which not only retain the function of macrophages to engulf foreign bodies in the joint cavity, but also interact with synovial fibroblasts (SFs), T cells, B cells, and other inflammatory cells to promote the production of a variety of pro-inflammatory cytokines and chemokines, such as TNF-α, IL-1β, IL-8, and IL-6, which are involved in the pathogenic process of inflammatory arthritis. SMs from different tissue sources have differently differentiated potentials and functional expressions. This article provides a summary on studies pertaining to SMs in inflammatory arthritis, and explores their role in its treatment, in order to highlight novel treatment modalities for the disease.

Combined Photothermal and Photodynamic Therapy for Cancer Treatment Using a Multifunctional Graphene Oxide

Graphene oxide (GO) is one of the most studied nanomaterials in many fields, including the biomedical field. Most of the nanomaterials developed for drug delivery and phototherapies are based on noncovalent approaches that lead to an unspecific release of physisorbed molecules in complex biological environments. Therefore, preparing covalently functionalized GO using straightforward and versatile methods is highly valuable. Phototherapies, including photothermal therapy (PTT) and photodynamic therapy (PDT), have shown great potential as effective therapeutic approaches against cancer. To overcome the limits of a single method, the combination of PTT and PDT can lead to a combined effect with a higher therapeutic efficiency. In this work, we prepare a folic acid (FA) and chlorin e6 (Ce6) double-functionalized GO for combined targeted PTT/PDT. This conjugate can penetrate rapidly into cancer cells and macrophages. A combined effect of PTT and PDT is observed, leading to a higher killing efficiency toward different types of cells involved in cancer and other diseases. Our work provides a simple protocol to prepare multifunctional platforms for the treatment of various diseases.

Folate Receptor Beta for Macrophage Imaging in Rheumatoid Arthritis

Non-invasive imaging modalities constitute an increasingly important tool in diagnostic and therapy response monitoring of patients with autoimmune diseases, including rheumatoid arthritis (RA). In particular, macrophage imaging with positron emission tomography (PET) using novel radiotracers based on differential expression of plasma membrane proteins and functioning of cellular processes may be suited for this. Over the past decade, selective expression of folate receptor β (FRβ), a glycosylphosphatidylinositol-anchored plasma membrane protein, on myeloid cells has emerged as an attractive target for macrophage imaging by exploiting the high binding affinity of folate-based PET tracers. This work discusses molecular, biochemical and functional properties of FRβ, describes the preclinical development of a folate-PET tracer and the evaluation of this tracer in a translational model of arthritis for diagnostics and therapy-response monitoring, and finally the first clinical application of the folate-PET tracer in RA patients with active disease. Consequently, folate-based PET tracers hold great promise for macrophage imaging in a variety of (chronic) inflammatory (autoimmune) diseases beyond RA.

Targeting folate receptor beta on monocytes/macrophages renders rapid inflammation resolution independent of root causes

Provoked by sterile/nonsterile insults, prolonged monocyte mobilization and uncontrolled monocyte/macrophage activation can pose imminent or impending harm to the affected organs. Curiously, folate receptor beta (FRβ), with subnanomolar affinity for the vitamin folic acid (FA), is upregulated during immune activation in hematopoietic cells of the myeloid lineage. This phenomenon has inspired a strong interest in exploring FRβ-directed diagnostics/therapeutics. Previously, we have reported that FA-targeted aminopterin (AMT) therapy can modulate macrophage function and effectively treat animal models of inflammation. Our current investigation of a lead compound (EC2319) leads to discovery of a highly FR-specific mechanism of action independent of the root causes against inflammatory monocytes. We further show that EC2319 suppresses interleukin-6/interleukin-1β release by FRβ⁺ monocytes in a triple co-culture leukemic model of cytokine release syndrome with anti-CD19 chimeric antigen receptor T cells. Because of its chemical stability and metabolically activated linker, EC2319 demonstrates favorable pharmacokinetic characteristics and cross-species translatability to support future pre-clinical and clinical development.

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Functional folate receptor beta is transiently expressed on inflammatory monocytes

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EC2319 is an enhancement of traditional dihydrofolate reductase inhibitors

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EC2319 anti-monocyte activity correlates with local/systemic therapeutic benefit

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EC2319 inhibition of cytokine release suggests emergency use for hyperinflammation

Molecular and Cellular Basis of Autoimmune Diseases

The defense organization of our organism is found in the immune system, which has two important components, the innate and the adaptive immunity, where different molecules, cells, and organs are involved and coordinated to protect us from external and internal damage [...].