Dectin-1 Activation by a Natural Product β-Glucan Converts Immunosuppressive Macrophages into an M1-like Phenotype

Yeast β-glucan-based nanoparticles loading methotrexate promotes osteogenesis of hDPSCs and periodontal bone regeneration under the inflammatory microenvironment

The regeneration of absorbed alveolar bone and reconstruction of periodontal support tissue are huge challenges in the clinical treatment of periodontitis due to the limited regenerative capacity of alveolar bone. It is essential to regulate inflammatory reaction and periodontal cell differentiation. Based on the anti-inflammatory effect of baker's yeast β-glucan (BYG) with biosafety by targeting macrophages, the BYG-based nanoparticles loading methotrexate (cBPM) were fabricated from polyethylene glycol-grafted BYG through chemical crosslinking for treatment of periodontitis. In our findings, cBPM promoted osteogenesis of human dental pulp stem cells (hDPSCs) under inflammatory microenvironment, characterized by the enhanced expression of osteogenesis-related Runx2 and activation of mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/Erk) pathway in vitro. Animal experiments further demonstrate that cBPM effectively promoted periodontal bone regeneration and achieved in a better effect of recovery indicated by 19.2 % increase in tissue volume, 7.1 % decrease in trabecular separation, and a significant increase in percent bone volume and trabecular thickness, compared with the model group. Additionally, cBPM inhibited inflammation and repaired alveolar bone by transforming macrophage phenotype from inflammatory M1 to anti-inflammatory M2. This work provides an alternative strategy for the clinical treatment of periodontitis through BYG-based delivery nanoplatform of anti-inflammatory drugs.

Distinct roles of TREM2 in central nervous system cancers and peripheral cancers

Glioblastomas (GBM) are incurable central nervous system (CNS) cancers characterized by substantial myeloid cell infiltration. Whether myeloid cell-directed therapeutic targets identified in peripheral non-CNS cancers are applicable to GBM requires further study. Here, we identify that the critical immunosuppressive target in peripheral cancers, triggering receptor expressed on myeloid cells-2 (TREM2), is immunoprotective in GBM. Genetic or pharmacological TREM2 deficiency promotes GBM progression in vivo. Single-cell and spatial sequencing reveals downregulated TREM2 in GBM-infiltrated myeloid cells. TREM2 negatively correlates with immunosuppressive myeloid and T cell exhaustion signatures in GBM. We further demonstrate that during GBM progression, CNS-enriched sphingolipids bind TREM2 on myeloid cells and elicit antitumor responses. Clinically, high TREM2 expression in myeloid cells correlates with better survival in GBM. Adeno-associated virus-mediated TREM2 overexpression impedes GBM progression and synergizes with anti-PD-1 therapy. Our results reveal distinct functions of TREM2 in CNS cancers and support organ-specific myeloid cell remodeling in cancer immunotherapy.

Ganoderma lucidum spores-derived particulate β-glucan treatment improves antitumor response by regulating myeloid-derived suppressor cells in triple-negative breast cancer

Granular β-1,3-glucan extracted from the wall of Ganoderma lucidum spores, named GPG, is a bioregulator. In this study, we investigated the structural, thermal, and other physical properties of GPG. We determined whether GPG ameliorated immunosuppression caused by Gemcitabine (GEM) chemotherapy. Triple-negative breast cancer mice with GPG combined with GEM treatment had reduced tumor burdens. In addition, GEM treatment alone altered the tumor microenvironment(TME), including a reduction in antitumor T cells and a rise in myeloid-derived suppressor cells (MDSC) and regulatory T cells (Tregs). However, combined GPG treatment reversed the tumor immunosuppressive microenvironment induced by GEM. GPG inhibited bone marrow (BM)-derived MDSC differentiation and reversed MDSC expansion induced by conditioned medium (CM) in GEM-treated E0771 cells through a Dectin-1 pathway. In addition, GPG downgraded PD-L1 and IDO1 expression on MDSC while boosting MHC-II, CD86, TNF-α, and IL-6 expression. In conclusion, this study demonstrated that GPG could alleviate the adverse effects induced by GEM chemotherapy by regulating TME.

Immunomodulatory activity of argentatins A and B isolated from guayule

Argentatins are secondary metabolites synthesized by guayule (Parthenium argentatum A. Gray) with numerous potential medical applications. In addition to inhibiting insect growth, they are endowed with several pharmacological properties including antimicrobial and antitumorigenic activity. However, their potential as immunomodulators remains unexplored. The aim of the present study was to investigate whether argentatins can modulate the function of the immune system. Human mesenchymal stem cells were treated with argentatins and the production of several anti- and proinflammatory cytokines was evaluated. The effect of argentatins on the polarization of CD4+ T-lymphocytes and macrophages was also assessed. Results demonstrated that argentatins can modulate the production of proinflammatory cytokines and the polarization of cellular phenotypes, including Th2 lymphocytes and M1 macrophages. These findings suggest that argentatins are promising therapeutic agents in autoimmune or allergic diseases, and open new perspectives for the investigation of argentatins in immune response and in the development of more targeted and effective immunomodulatory therapies.

Targeting Dectin-1 and or VISTA enhances anti-tumor immunity in melanoma but not colorectal cancer model

PURPOSE

Acquired resistance to immune checkpoint blockers (ICBs) is a major barrier in cancer treatment, emphasizing the need for innovative strategies. Dectin-1 (gene Clec7a) is a C-type lectin receptor best known for its ability to recognize β-glucan-rich structures in fungal cell walls. While Dectin-1 is expressed in myeloid cells and tumor cells, its significance in cancer remains the subject of controversy.

METHODS

Using Celc7a-/- mice and curdlan administration to stimulate Dectin-1 signaling, we explored its impact. VISTA KO mice were employed to assess VISTA's role, and bulk RNAseq analyzed curdlan effects on neutrophils.

RESULTS

Our findings reveal myeloid cells as primary Dectin-1 expressing cells in the tumor microenvironment (TME), displaying an activated phenotype. Strong Dectin-1 co-expression/co-localization with VISTA and PD-L1 in TME myeloid cells was observed. While Dectin-1 deletion lacked protective effects, curdlan stimulation significantly curtailed B16-F10 tumor progression. RNAseq and pathway analyses supported curdlan's role in triggering a cascade of events leading to increased production of pro-inflammatory mediators, potentially resulting in the recruitment and activation of immune cells. Moreover, we identified a heterogeneous subset of Dectin-1+ effector T cells in the TME. Similar to mice, human myeloid cells are the prominent cells expressing Dectin-1 in cancer patients.

CONCLUSION

Our study proposes Dectin-1 as a potential adjunctive target with ICBs, orchestrating a comprehensive engagement of innate and adaptive immune responses in melanoma. This innovative approach holds promise for overcoming acquired resistance to ICBs in cancer treatment, offering avenues for further exploration and development.

M1 macrophages polarized by crude polysaccharides isolated from Auricularia polytricha exhibit anti-tumor effect on human breast cancer cells

Breast cancer has been reported to correlate with the infiltration of tumor-associated macrophages (TAMs) or M2-like macrophages in tumor microenvironment (TME) that could promote breast cancer progression. In contrast, M1-like macrophages displayed anti-tumor activity toward cancer. This study was focused on Auricularia polytricha (AP), a cloud ear mushroom, which has been reported for anti-tumor activity and immunomodulation. AP extracts were screened on differentiated THP-1 macrophages (M0). Results demonstrated that water extract (APW) and crude polysaccharides (APW-CP) could upregulate M1-related genes and cytokines production (IL-6, IL-1 β and TNF-α) significantly. Moreover, APW and APW-CP showed a high expression of CD86 (M1 marker) compared to M0. The NF-κB signaling pathway is crucial for pro-inflammatory gene regulation. The APW and APW-CP treatment showed the induction of the NF-κB pathway in a dose-dependent manner, which related to the β-glucan content in the extracts. Furthermore, APW-CP polarized macrophages were investigated for anti-tumor activity on human breast cancer cells (MCF-7 and MDA-MB-231). Results showed that APW-CP could inhibit the invasion of breast cancer cells and induce apoptosis. Therefore, M1 macrophages polarized by APW-CP showed anti-tumor activity against the breast cancer cells and β-glucan may be the potential M1-phenotype inducer.

Fungal polysaccharides from Inonotus obliquus are agonists for Toll-like receptors and induce macrophage anti-cancer activity

Fungal polysaccharides can exert immunomodulating activity by triggering pattern recognition receptors (PRRs) on innate immune cells such as macrophages. Here, we evaluate six polysaccharides isolated from the medicinal fungus Inonotus obliquus for their ability to activate mouse and human macrophages. We identify two water-soluble polysaccharides, AcF1 and AcF3, being able to trigger several critical antitumor functions of macrophages. AcF1 and AcF3 activate macrophages to secrete nitric oxide and the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Combined with interferon-γ, the fungal polysaccharides trigger high production of IL-12p70, a central cytokine for antitumor immunity, and induce macrophage-mediated inhibition of cancer cell growth in vitro and in vivo. AcF1 and AcF3 are strong agonists of the PRRs Toll-like receptor 2 (TLR2) and TLR4, and weak agonists of Dectin-1. In comparison, two prototypical particulate β-glucans, one isolated from I. obliquus and one from Saccharomyces cerevisiae (zymosan), are agonists for Dectin-1 but not TLR2 or TLR4, and are unable to trigger anti-cancer functions of macrophages. We conclude that the water-soluble polysaccharides AcF1 and AcF3 from I. obliquus have a strong potential for cancer immunotherapy by triggering multiple PRRs and by inducing potent anti-cancer activity of macrophages.

A novel polysaccharide isolated from Coriolus versicolor polarizes M2 macrophages into an M1 phenotype and reversesits immunosuppressive effect on tumor microenvironment

Converting M2 macrophages into an M1 phenotype in the tumor microenvironment, provides a new direction for tumor treatment. Here, we further report CVPW-1, a new polysaccharide of 1.03 × 106 Da that was isolated from Coriolus versicolor. Its monosaccharide was composed of mannose, glucose, and galactose at a ratio of 1.00:8.73:1.68. The backbone of CVPW-1 was composed of (1 → 3)-linked α-D-Glcp residues and (1 → 3,6)-linked α-D-Glcp residues that branched at O-6. The branch consisted of (1 → 6)-linked α-D-Glcp residues and (1 → 4)-linked α-D-Glap, and some branches were terminated with (1→)-linked β-D-Manp residues according to the results of HPLC, FT-IR, GC-MS, 1D and 2D NMR. Meanwhile, CVPW-1 could polarize M2 macrophages to M1 phenotypein vitro by binding to TLR4 and inducing the activation of Akt, JNK and NF-κB. This process involved reversing the functional inhibition of CD8+ T lymphocytes by inhibiting the expression of TREM2 in M2 macrophages. The in vivo experiments showed that oral administration of CVPW-1 could inhibit the growth of tumor in mice and polarize TAMs to M1 phenotype. Thus, the novel polysaccharide CVPW-1 from Coriolus versicolor might activate a variety of immune cells and then play an anti-tumor role. These results demonstrated that CVPW-1 could be developed as a potential immuno-oncology treatment reagent.

Yeast glucan particles: An express train for oral targeted drug delivery systems

As an emerging drug delivery vehicle, yeast glucan particles (YGPs) derived from yeast cells could be specifically taken up by macrophages. Therefore, these vehicles could rely on the recruitment of macrophages at the site of inflammation and tumors to enable targeted imaging and drug delivery. This review summarizes recent advances in the application of YGPs in oral targeted delivery systems, covering the basic structure of yeast cells, methods for pre-preparation, drug encapsulation and characterization. The mechanism and validation of the target recognition interaction of YGPs with macrophages are highlighted, and some inspiring cases are presented to show that yeast cells have promising applications. The future chances and difficulties that YGPs will confront are also emphasized throughout this essay. YGPs are not only the "armor" but also the "compass" of drugs in the process of targeted drug transport. This system is expected to provide a new idea about the oral targeted delivery of anti-inflammatory and anti-tumor drugs, and furthermore offer an effective delivery strategy for targeted therapy of other macrophage-related diseases.

Yeast β-glucan modulates macrophages and improves antitumor NK-cell responses in cancer

As the largest proportion of myeloid immune cells in tumors, macrophages play an important role in tumor growth and regression according to their different phenotypes, thus reprogramming macrophages has become a new research direction for cancer immunotherapy. Yeast-derived whole β-glucan particles (WGPs) can induce M0 macrophages to differentiate into M1 macrophages and convert M2 macrophages and tumor-associated macrophages (TAMs) into M1 macrophages. In vitro, studies have confirmed that WGP-treated macrophages increase the activating receptors in natural killer cells (NK cells) and enhance the cytotoxicity of NK cells. The extracellular regulated protein kinases (ERK) signaling pathway is involved in WGP-mediated regulation of the macrophage phenotype. Further in vivo studies show that oral WGP can significantly delay tumor growth, which is related to the increased proportion of macrophages and NK cells, the macrophage phenotype reversal, and the enhancement of NK cell immune function. NK-cell depletion reduces the therapeutic efficacy of WGP in tumor-bearing mice. These findings revealed that in addition to T cells, NK cells also participate in the antitumor process of WGP. It was confirmed that WGP regulates the macrophage phenotype to regulate NK-cell function.

Macrophage metabolism, phenotype, function, and therapy in hepatocellular carcinoma (HCC)

The pivotal role of the tumor microenvironment (TME) in the initiation and advancement of hepatocellular carcinoma (HCC) is widely acknowledged, as it fosters the proliferation and metastasis of HCC cells. Within the intricate TME of HCC, tumor-associated macrophages (TAMs) represent a significant constituent of non-malignant cells. TAMs engage in direct communication with cancer cells in HCC, while also exerting influence on other immune cells to adopt a tumor-supportive phenotype that facilitates tumor progression. Among the multifaceted mechanisms at play, the metabolic reprogramming of both tumor cells and macrophages leads to phenotypic alterations and functional modifications in macrophages. This comprehensive review elucidates the intricate interplay between cellular metabolism and macrophage phenotype/polarization, while also providing an overview of the associated signaling molecules and potential therapeutic strategies for HCC.

Targeting tumor-associated macrophage: an adjuvant strategy for lung cancer therapy

The emergence of immunotherapy has revolutionized the treatment landscape for various types of cancer. Nevertheless, lung cancer remains one of the leading causes of cancer-related mortality worldwide due to the development of resistance in most patients. As one of the most abundant groups of immune cells in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play crucial and complex roles in the development of lung cancer, including the regulation of immunosuppressive TME remodeling, metabolic reprogramming, neoangiogenesis, metastasis, and promotion of tumoral neurogenesis. Hence, relevant strategies for lung cancer therapy, such as inhibition of macrophage recruitment, TAM reprograming, depletion of TAMs, and engineering of TAMs for drug delivery, have been developed. Based on the satisfactory treatment effect of TAM-targeted therapy, recent studies also investigated its synergistic effect with current therapies for lung cancer, including immunotherapy, radiotherapy, chemotherapy, anti-epidermal growth factor receptor (anti-EGFR) treatment, or photodynamic therapy. Thus, in this article, we summarized the key mechanisms of TAMs contributing to lung cancer progression and elaborated on the novel therapeutic strategies against TAMs. We also discussed the therapeutic potential of TAM targeting as adjuvant therapy in the current treatment of lung cancer, particularly highlighting the TAM-centered strategies for improving the efficacy of anti-programmed cell death-1/programmed cell death-ligand 1 (anti-PD-1/PD-L1) treatment.

Bioinspired yeast-based β-glucan system for oral drug delivery

Oral drug delivery is the preferred route of drug administration for patients, especially those who need long-term medication. Recently, bioinspired drug delivery systems have emerged for the oral delivery of various therapeutics. Among them, the yeast-based β-glucan system is a novel and promising platform, for oral administration that can overcome the biological barriers of the harsh gastrointestinal environment. Remarkably, the yeast-based β-glucan system not only protects the drug through the harsh gastrointestinal environment but also achieves targeted therapeutic effects by specifically recognizing immune cells, especially macrophages. Otherwise, it exhibits immunomodulatory properties. Based on the pleasant characteristics of the yeast-based β-glucan system, they are widely used in various macrophage-related diseases for oral administration. In this review, we introduced the structure and function of yeast-based β-glucan. Subsequently, we further summarized the current preparation methods of yeast-based β-glucan carriers and the strategies for preparing yeast-based β-glucan drug delivery systems. In addition, we focus on discussing the applications of β-glucan drug delivery systems in various diseases. Finally, the current challenges and future perspectives of the β-glucan drug delivery system are introduced.

Macrophage-Hitchhiked Orally Administered β-Glucans-Functionalized Nanoparticles as "Precision-Guided Stealth Missiles" for Targeted Pancreatic Cancer Therapy

The prognosis in cases of pancreatic ductal adenocarcinoma (PDAC) with current treatment modalities is poor owing to the highly desmoplastic tumor microenvironment (TME). Herein, a β-glucans-functionalized zinc-doxorubicin nanoparticle system (βGlus-ZnD NPs) that can be orally administered, is developed for targeted PDAC therapy. Following oral administration in PDAC-bearing mice, βGlus-ZnD NPs actively target/transpass microfold cells, overcome the intestinal epithelial barrier, and then undergo subsequent phagocytosis by endogenous macrophages (βGlus-ZnD@Mϕ). As hitchhiking cellular vehicles, βGlus-ZnD@Mϕ transits through the intestinal lymphatic system and enters systemic circulation, ultimately accumulating in the tumor tissue as a result of the tumor-homing and "stealth" properties that are conferred by endogenous Mϕ. Meanwhile, the Mϕ that hitchhikes βGlus-ZnD NPs is activated to produce matrix metalloproteinases, destroying the desmoplastic stromal barrier, and differentiates toward the M1 -like phenotype, modulating the TME and recruiting effector T cells, ultimately inducing apoptosis of the tumor cells. The combination of βGlus-ZnD@Mϕ and immune checkpoint blockade effectively inhibits the growth of the primary tumor and suppresses the development of metastasis. It thus represents an appealing approach to targeted PDAC therapy.

Advancing Immunotherapies for HPV-Related Cancers: Exploring Novel Vaccine Strategies and the Influence of Tumor Microenvironment

The understanding of the relationship between immunological responses and cancers, especially those related to HPV, has allowed for the study and development of therapeutic vaccines against these neoplasias. There is a growing number of studies about the composition and influence of the tumor microenvironment (TME) in the progression or establishment of the most varied types of cancer. Hence, it has been possible to structure immunotherapy approaches based on therapeutic vaccines that are even more specific and directed to components of TME and the immune response associated with tumors. Among these components are dendritic cells (DCs), which are the main professional antigen-presenting cells (APCs) already studied in therapy strategies for HPV-related cancers. On the other hand, tumor-associated macrophages are also potential targets since the profile present in tumor infiltrates, M1 or M2, influences the prognosis of some types of cancer. These two cell types can be targets for therapy or immunomodulation. In this context, our review aims to provide an overview of immunotherapy strategies for HPV-positive tumors, such as cervical and head and neck cancers, pointing to TME immune cells as promising targets for these approaches. This review also explores the potential of immunotherapy in cancer treatment, including checkpoint inhibitors, cytokine immunotherapies, immunotherapy vaccines, and cell therapies. Furthermore, it highlights the importance of understanding the TME and its effect on the design and achievement of immunotherapeutic methods.

Functional immune boosters; the herb or its dead microbiome? Antigenic TLR4 agonist MAMPs found in 65 medicinal roots and algae's

Background

Humans have been consuming medicinal plants (as herbs/ spices) to combat illness for centuries while ascribing beneficial effects predominantly to the plant/phytochemical constituents, without recognizing the power of obligatory resident microorganism' communities (MOCs) (live/dead bacteria, fungus, yeast, molds etc.) which remain after industrial microbial reduction methods. Very little is known about the taxonomic identity of residual antigenic microbial associated molecular patterns (MAMPs) debris in our botanical over the counter (OTC) products, which if present would be recognized as foreign (non-self) antigenic matter by host pattern recognition receptors (PRRs) provoking a host immune response; this the basis of vaccine adjuvants. As of today, only few research groups have removed the herbal MAMP biomass from herbs, all suggesting that immune activation may not be from the plant but rather its microbial biomass; a hypothesis we corroborate.

Purpose

The purpose of this work was to conduct a high through put screening (HTPS) of over 2500 natural plants, OTC botanical supplements and phytochemicals to elucidate those with pro-inflammatory; toll like receptor 4 (TLR4) activating properties in macrophages.

Study Design

The HTPS was conducted on RAW 264.7 cells vs. lipopolysaccharide (LPS) E. coli 0111:B4, testing iNOS / nitric oxide production ( NO 2 - ) as a perimeter endpoint. The data show not a single drug/chemical/ phytochemical and approximately 98 % of botanicals to be immune idle (not effective) with only 65 pro-inflammatory (hits) in a potency range of LPS. Method validation studies eliminated the possibility of false artifact or contamination, and results were cross verified through multiple vendors/ manufacturers/lot numbers by botanical species. Lead botanicals were evaluated for plant concentration of LPS, 1,3:1,6-β-glucan, 1,3:1,4-β-D-glucan and α-glucans; where the former paralleled strength in vitro. LPS was then removed from plants using high-capacity endotoxin poly lysine columns, where bioactivity of LPS null "plant" extracts were lost. The stability of E.Coli 0111:B4 in an acid stomach mimetic model was confirmed. Last, we conducted a reverse culture on aerobic plate counts (APCs) from select hits, with subsequent isolation of gram-negative bacteria (MacConkey agar). Cultures were 1) heat destroyed (retested/ confirming bioactivity) and 2) subject to taxonomical identification by genetic sequencing 18S, ITS1, 5.8 s, ITS2 28S, and 16S.

Conclusion

The data show significant gram negative MAMP biomass dominance in A) roots (e.g. echinacea, yucca, burdock, stinging nettle, sarsaparilla, hydrangea, poke, madder, calamus, rhaponticum, pleurisy, aconite etc.) and B) oceanic plants / algae's (e.g. bladderwrack, chlorella, spirulina, kelp, and "OTC Seamoss-blends" (irish moss, bladderwrack, burdock root etc), as well as other random herbs (eg. corn silk, cleavers, watercress, cardamom seed, tribulus, duckweed, puffball, hordeum and pollen). The results show a dominance of gram negative microbes (e.g. Klebsilla aerogenes, Pantoae agglomerans, Cronobacter sakazakii), fungus (Glomeracaea, Ascomycota, Irpex lacteus, Aureobasidium pullulans, Fibroporia albicans, Chlorociboria clavula, Aspergillus_sp JUC-2), with black walnut hull, echinacea and burdock root also containing gram positive microbial strains (Fontibacillus, Paenibacillus, Enterococcus gallinarum, Bromate-reducing bacterium B6 and various strains of Clostridium).

Conclusion

This work brings attention to the existence of a functional immune bioactive herbal microbiome, independent from the plant. There is need to further this avenue of research, which should be carried out with consideration as to both positive or negative consequences arising from daily consumption of botanicals highly laden with bioactive MAMPS.

Plants against cancer: the immune-boosting herbal microbiome: not of the plant, but in the plant. Basic concepts, introduction, and future resource for vaccine adjuvant discovery

The presence of microorganism communities (MOCs) comprised of bacteria, fungi, archaea, algae, protozoa, viruses, and the like, are ubiquitous in all living tissue, including plant and animal. MOCs play a significant role in establishing innate and acquired immunity, thereby influencing susceptibility and resistance to disease. This understanding has fostered substantial advancements in several fields such as agriculture, food science/safety, and the development of vaccines/adjuvants, which rely on administering inactivated-attenuated MOC pathogens. Historical evidence dating back to the 1800s, including reports by Drs Busch, Coley, and Fehleisen, suggested that acute febrile infection in response to "specific microbes" could trigger spontaneous tumor remission in humans. This discovery led to the purposeful administration of the same attenuated strains, known as "Coley's toxin," marking the onset of the first microbial (pathogen) associated molecular pattern (MAMPs or PAMPs)-based tumor immunotherapy, used clinically for over four decades. Today, these same MAMPS are consumed orally by billions of consumers around the globe, through "specific" mediums (immune boosting "herbal supplements") as carriers of highly concentrated MOCs accrued in roots, barks, hulls, sea algae, and seeds. The American Herbal Products Association (AHPA) mandates microbial reduction in botanical product processing but does not necessitate the removal of dead MAMP laden microbial debris, which we ingest. Moreover, while existing research has focused on the immune-modulating role of plant phytochemicals, the actual immune-boosting properties might instead reside solely in the plant's MOC MAMP laden biomass. This assertion is logical, considering that antigenic immune-provoking epitopes, not phytochemicals, are known to stimulate immune response. This review explores a neglected area of research regarding the immune-boosting effects of the herbal microbiome - a presence which is indirectly corroborated by various peripheral fields of study and poses a fundamental question: Given that food safety focuses on the elimination of harmful pathogens and crop science acknowledges the existence of plant microbiomes, what precisely are the immune effects of ingesting MAMPs of diverse structural composition and concentration, and where are these distributed in our botanicals? We will discuss the topic of concentrated edible MAMPs as acid and thermally stable motifs found in specific herbs and how these would activate cognate pattern recognition receptors (PPRs) in the upper gut-associated lymphoid tissue (GALT), including Peyer's patches and the lamina propria, to boost antibody titers, CD8+ and CD4+ T cells, NK activity, hematopoiesis, and facilitating M2 to M1 macrophage phenotype transition in a similar manner as vaccines. This new knowledge could pave the way for developing bioreactor-grown/heat-inactivated MOC therapies to boost human immunity against infections and improve tumor surveillance.

Targeting extracellular matrix through phytochemicals: a promising approach of multi-step actions on the treatment and prevention of cancer

Extracellular matrix (ECM) plays a pivotal and dynamic role in the construction of tumor microenvironment (TME), becoming the focus in cancer research and treatment. Multiple cell signaling in ECM remodeling contribute to uncontrolled proliferation, metastasis, immune evasion and drug resistance of cancer. Targeting trilogy of ECM remodeling could be a new strategy during the early-, middle-, advanced-stages of cancer and overcoming drug resistance. Currently nearly 60% of the alternative anticancer drugs are derived from natural products or active ingredients or structural analogs isolated from plants. According to the characteristics of ECM, this manuscript proposes three phases of whole-process management of cancer, including prevention of cancer development in the early stage of cancer (Phase I); prevent the metastasis of tumor in the middle stage of cancer (Phase II); provide a novel method in the use of immunotherapy for advanced cancer (Phase III), and present novel insights on the contribution of natural products use as innovative strategies to exert anticancer effects by targeting components in ECM. Herein, we focus on trilogy of ECM remodeling and the interaction among ECM, cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), and sort out the intervention effects of natural products on the ECM and related targets in the tumor progression, provide a reference for the development of new drugs against tumor metastasis and recurrence.

Crude polysaccharide from Danggui Buxue decoction enhanced the anti-tumor effect of gemcitabine by remodeling tumor-associated macrophages

Tumor-associated macrophages (TAMs) with an M2-phenotype mediate gemcitabine resistance to cancer by influencing the metabolic enzymes of gemcitabine and releasing competitive deoxycytidine (dC). Our previous studies showed that Danggui Buxue Decoction (DBD), a traditional Chinese medicinal recipe, enhances the anti-tumor activity of gemcitabine in vivo and alleviates gemcitabine-induced myelosuppression. However, the material basis and exact mechanism underlying its enhanced effects remain unclear. In this study, a bioactive polysaccharide consisting of arabinose, mannose, ribose, and glucose was isolated from DBD. In vivo results demonstrated that DBD crude polysaccharide (DBDP) ameliorated gemcitabine-induced immune system disorders. Moreover, DBDP improved the sensitivity of Lewis lung carcinoma-bearing mice to gemcitabine by reshaping the tumor-promoting M2-like macrophages into tumor-inhibiting M1-phenotypes. Furthermore, in vitro results further revealed that DBDP blocked the protective effects of TAMs and M2-macrophages against gemcitabine by inhibiting the excessive secretion of dC and decreasing the high expression of cytidine deaminase. In conclusion, our results demonstrated that DBDP, as the pharmacodynamic material basis of DBD, enhanced the anti-tumor activity of gemcitabine against lung cancer in vitro and in vivo, which was associated with remodeling of the M2-phenotype.

Mycochemicals against Cancer Stem Cells

Since ancient times, mushrooms have been considered valuable allies of human well-being both from a dietary and medicinal point of view. Their essential role in several traditional medicines is explained today by the discovery of the plethora of biomolecules that have shown proven efficacy for treating various diseases, including cancer. Numerous studies have already been conducted to explore the antitumoural properties of mushroom extracts against cancer. Still, very few have reported the anticancer properties of mushroom polysaccharides and mycochemicals against the specific population of cancer stem cells (CSCs). In this context, β-glucans are relevant in modulating immunological surveillance against this subpopulation of cancer cells within tumours. Small molecules, less studied despite their spread and assortment, could exhibit the same importance. In this review, we discuss several pieces of evidence of the association between β-glucans and small mycochemicals in modulating biological mechanisms which are proven to be involved with CSCs development. Experimental evidence and an in silico approach are evaluated with the hope of contributing to future strategies aimed at the direct study of the action of these mycochemicals on this subpopulation of cancer cells.

Beta glucan as an immune stimulant in tumor microenvironment - Insight into lessons and promises from past decade

Cancer is characterized by a perturbed immune landscape. Inside tumor microenvironment, immune system is reprogrammed to facilitate tumor growth and survival rather than eliminating it. This immune evasive mechanism needs to be reversed to normal for effective anticancer therapeutic strategy. Immunotherapy has emerged as a novel strategy for redeployment of immune cells against cancer. However, they suffer in their efficacy, response rate and side effects. This necessitated us to turn toward natural repertoires which can act as a substitute to conventional immunotherapeutics. Beta glucan, a polysaccharide derived from mushroom, serves the role of immunomodulator inside tumor microenvironment. It acts as pathogen associated molecular pattern and bind to various pattern recognition receptors expressed on surface of immune cells thereby facilitating their activation and crosstalk. This result in resurgence of suppressed immune surveillance in the tumor milieu. In this review, we highlight in brief the advances and limitation of cancer immunotherapy. Alongside, we have discussed the detailed mechanistic principle and recent advances underlying restoration of immune functionality by beta glucan.

Beyond Bacteria: Fungi in the Tumor Microbiome

The microbiota is widely recognized to influence diverse biological processes, including metabolism, neurological and cardiovascular functions, the inflammatory response and immunity [...].

Fungal melanin-induced metabolic reprogramming in macrophages is crucial for inflammation

The overuse of antifungal and immunosuppressant drugs and the higher frequency of organ transplantation has resulted in mycosis being increasingly intractable, and there is a great need for the development of new therapies. Melanin is an important virulence factor that can inhibit the inflammatory response in the host and facilitate fungal survival by several methods. However, a recent study showed that the Akt/mTOR/HIF1α axis in macrophages was activated after melanin-binding proteins recognised the DHN melanin of Aspergillus fumigatus, with a resulting metabolic shift towards glycolysis (i.e., metabolic reprogramming). As a result, antimicrobial compounds (e.g., inflammatory mediators and reactive oxygen species) were increased to fight the fungal invasion. Actually, DHN melanin from other fungi and DOPA melanin can induce inflammation and stimulate the production of melanin-binding antibodies. In addition, DOPA melanin contains conserved repeating units that are similar to those of DHN melanin. Therefore, we evaluated the associated evidence to propose an interesting and reasonable hypothesis that melanin promotes inflammation by metabolic reprogramming, which could provide a research direction for antifungal therapy. It suggests that regulating the metabolism of immune cells can guide the inflammatory response against fungi, despite the presence of immunosuppressant melanin. Since the biochemical molecules of glycolysis are clearly described, regulating glycolysis in macrophages may be easier than inventing new antifungal drugs. Further clarification of our hypothesis may strengthen the candidacy of melanin for future antifungal vaccines.

CD83 expressed by macrophages is an important immune checkpoint molecule for the resolution of inflammation

Excessive macrophage (Mφ) activation results in chronic inflammatory responses or autoimmune diseases. Therefore, identification of novel immune checkpoints on Mφ, which contribute to resolution of inflammation, is crucial for the development of new therapeutic agents. Herein, we identify CD83 as a marker for IL-4 stimulated pro-resolving alternatively activated Mφ (AAM). Using a conditional KO mouse (cKO), we show that CD83 is important for the phenotype and function of pro-resolving Mφ. CD83-deletion in IL-4 stimulated Mφ results in decreased levels of inhibitory receptors, such as CD200R and MSR-1, which correlates with a reduced phagocytic capacity. In addition, CD83-deficient Mφ upon IL-4 stimulation, show an altered STAT-6 phosphorylation pattern, which is characterized by reduced pSTAT-6 levels and expression of the target gene Gata3. Concomitantly, functional studies in IL-4 stimulated CD83 KO Mφ reveal an increased production of pro-inflammatory mediators, such as TNF-α, IL-6, CXCL1 and G-CSF. Furthermore, we show that CD83-deficient Mφ have enhanced capacities to stimulate the proliferation of allo-reactive T cells, which was accompanied by reduced frequencies of Tregs. In addition, we show that CD83 expressed by Mφ is important to limit the inflammatory phase using a full-thickness excision wound healing model, since inflammatory transcripts (e.g. Cxcl1, Il6) were increased, whilst resolving transcripts (e.g. Ym1, Cd200r, Msr-1) were decreased in wounds at day 3 after wound infliction, which reflects the CD83 resolving function on Mφ also in vivo. Consequently, this enhanced inflammatory milieu led to an altered tissue reconstitution after wound infliction. Thus, our data provide evidence that CD83 acts as a gatekeeper for the phenotype and function of pro-resolving Mφ.

The mechanisms and cross-protection of trained innate immunity

In recent years, the traditional cognition of immunological memory being specific to adaptive immunity has been challenged. Innate immunity can mount enhanced responsiveness upon secondary stimulation, and a phenomenon is termed trained innate immunity. Trained innate immunity is orchestrated by distinct metabolic and epigenetic reprogramming in both circulating myeloid cells and myeloid progenitor cells in bone marrow, leading to long-term resistance to related and non-related pathogens infections. The induction of trained innate immunity can also polarize innate immune cells towards a hyperresponsive phenotype in the tumor microenvironment to exert antitumor effects. This review will discuss the current understanding of innate immune memory and the mechanisms during the induction of innate immunity, including signaling pathways, metabolic changes, and epigenetic rewriting. We also provide an overview of cross-protection against infectious diseases and cancers based on trained innate immunity.

Immunotherapeutic effects of intratumorally injected Zymosan-Adenovirus conjugates encoding constant active IRF3 in a melanoma mouse model

M2-like tumor-associated macrophages (TAMs) play a significant role in immunosuppressive conditions in the tumor microenvironment (TME). TAM reprogramming, a dual-pronged therapy, reduces immunosuppression and induces immune favorable conditions in the TME. In this study, recombinant adenoviruses encoding active forms of interferon regulatory factor 3 (IRF3) were conjugated to zymosan particles to target phagocytic cells to create a pro-inflammatory immunomodulatory therapy. We determined TAM reprogramming by upregulation and downregulation of M1- and M2-associated genes, respectively, as well as cytokine and transcription factor expression in vitro. The overall shift to immune favorable conditions in the TME was suggested by metabolic, cytokine, and immune cell gene expression. Our data indicated that the zymosan:adenovirus (Zym:Ad) particle itself induced a shift from M2-like to M1-like TAMs, a shift in immune status of the TME, and systemic tumor immunity as determined using a double tumor melanoma mouse model and splenocyte functional assay. Notably, direct intratumoral injection of Zym:Ad IRF3 reduced tumor growth more significantly than Zym:Ad GFP, indicating additional therapeutic benefits due to incorporation of constant active IRF3.

Polarization and β-Glucan Reprogram Immunomodulatory Metabolism in Human Macrophages and Ex Vivo in Human Lung Cancer Tissues

Immunomodulatory (IM) metabolic reprogramming in macrophages (Mϕs) is fundamental to immune function. However, limited information is available for human Mϕs, particularly in response plasticity, which is critical to understanding the variable efficacy of immunotherapies in cancer patients. We carried out an in-depth analysis by combining multiplex stable isotope-resolved metabolomics with reversed phase protein array to map the dynamic changes of the IM metabolic network and key protein regulators in four human donors' Mϕs in response to differential polarization and M1 repolarizer β-glucan (whole glucan particles [WGPs]). These responses were compared with those of WGP-treated ex vivo organotypic tissue cultures (OTCs) of human non-small cell lung cancer. We found consistently enhanced tryptophan catabolism with blocked NAD+ and UTP synthesis in M1-type Mϕs (M1-Mϕs), which was associated with immune activation evidenced by increased release of IL-1β/CXCL10/IFN-γ/TNF-α and reduced phagocytosis. In M2a-Mϕs, WGP treatment of M2a-Mϕs robustly increased glucose utilization via the glycolysis/oxidative branch of the pentose phosphate pathway while enhancing UDP-N-acetyl-glucosamine turnover and glutamine-fueled gluconeogenesis, which was accompanied by the release of proinflammatory IL-1β/TNF-α to above M1-Mϕ's levels, anti-inflammatory IL-10 to above M2a-Mϕ's levels, and attenuated phagocytosis. These IM metabolic responses could underlie the opposing effects of WGP, i.e., reverting M2- to M1-type immune functions but also boosting anti-inflammation. Variable reprogrammed Krebs cycle and glutamine-fueled synthesis of UTP in WGP-treated OTCs of human non-small cell lung cancer were observed, reflecting variable M1 repolarization of tumor-associated Mϕs. This was supported by correlation with IL-1β/TNF-α release and compromised tumor status, making patient-derived OTCs unique models for studying variable immunotherapeutic efficacy in cancer patients.

Chinese Cordyceps: Bioactive Components, Antitumor Effects and Underlying Mechanism-A Review

Chinese Cordyceps is a valuable source of natural products with various therapeutic effects. It is rich in various active components, of which adenosine, cordycepin and polysaccharides have been confirmed with significant immunomodulatory and antitumor functions. However, the underlying antitumor mechanism remains poorly understood. In this review, we summarized and analyzed the chemical characteristics of the main components and their pharmacological effects and mechanism on immunomodulatory and antitumor functions. The analysis revealed that Chinese Cordyceps promotes immune cells' antitumor function by via upregulating immune responses and downregulating immunosuppression in the tumor microenvironment and resetting the immune cells' phenotype. Moreover, Chinese Cordyceps can inhibit the growth and metastasis of tumor cells by death (including apoptosis and autophagy) induction, cell-cycle arrest, and angiogenesis inhibition. Recent evidence has revealed that the signal pathways of mitogen-activated protein kinases (MAPKs), nuclear factor kappaB (NF-κB), cysteine-aspartic proteases (caspases) and serine/threonine kinase Akt were involved in the antitumor mechanisms. In conclusion, Chinese Cordyceps, one type of magic mushroom, can be potentially developed as immunomodulator and anticancer therapeutic agents.

Beta-Glucan from S. cerevisiae Protected AOM-Induced Colon Cancer in cGAS-Deficient Mice Partly through Dectin-1-Manipulated Macrophage Cell Energy

Although the impacts of Saccharomyces cerevisiae on cancers are mentioned, data on its use in mice with cyclic GMP-AMP synthase deficiency (cGAS-/-) are even rarer. Here, 12 weeks of oral administration of S. cerevisiae protected cGAS-/- mice from azoxymethane (AOM)-induced colon cancers, partly through dysbiosis attenuation (fecal microbiome analysis). In parallel, a daily intralesional injection of a whole glucan particle (WGP; the beta-glucan extracted from S. cerevisiae) attenuated the growth of subcutaneous tumor using MC38 (murine colon cancer cell line) in cGAS-/- mice. Interestingly, the incubation of fluorescent-stained MC38 with several subtypes of macrophages, including M1 (using Lipopolysaccharide; LPS), M2 (IL-4), and tumor-associated macrophages (TAM; using MC38 supernatant activation), could not further reduce the tumor burdens (fluorescent intensity) compared with M0 (control culture media). However, WGP enhanced tumoricidal activities (fluorescent intensity), the genes of M1 pro-inflammatory macrophage polarization (IL-1β and iNOS), and Dectin-1 expression and increased cell energy status (extracellular flux analysis) in M0, M2, and TAM. In M1, WGP could not increase tumoricidal activities, Dectin-1, and glycolysis activity, despite the upregulated IL-1β. In conclusion, S. cerevisiae inhibited the growth of colon cancers through dysbiosis attenuation and macrophage energy activation, partly through Dectin-1 stimulation. Our data support the use of S. cerevisiae for colon cancer protection.

Temporal Control of Trained Immunity via Encapsulated Release of β-Glucan Improves Therapeutic Applications

Emerging diseases require generating new vaccines, which can often be time consuming. An alternate method to boost host defense is by inducing nonspecific innate immune memory, called trained immunity, to develop novel prophylactics. Many molecules, most notably β-glucan, induce trained immunity, but their effects are often short-lived and uncontrolled. This lack of temporal control limits both the therapeutic ability of training and provides fundamental questions about its nature. To achieve temporal control of trained immunity, controlled release nanoparticles encapsulating only 3.5% of the standard dose of β-glucan to attain sustained release over a month are engineered. Nanoparticle-trained mice exhibit prolonged training effects and improve resistance to a B16F10 tumor challenge compared to mice that receive an equivalent amount of free β-glucan. The duration of trained immunity is further fine tuned by synthesizing nanoparticles composed of different molecular weights to modulate the release kinetics. These results demonstrate that dosing and temporal control can substantially alter the trained response to unanticipated levels. As such, this approach using sustained release platforms might lead to a novel prophylactic strategy for improved disease resistance against a wide variety of diseases.

Antitumor effect of a polysaccharide from Pseudostellaria heterophylla through reversing tumor-associated macrophages phenotype

Tumor-associated macrophages (TAMs), which are predominant tumor-infiltrating immune cells in the tumor microenvironment, participate in promoting the occurrence and metastasis of tumor cells. Reprogramming TAMs has become a promising immunotherapeutic approach for novel cancer treatments. In this study, a homogeneous polysaccharide (PHP-1) was obtained from Pseudostellaria heterophylla, and its antitumor and immunological activities, as well as the underlying molecular mechanisms were explored. These findings suggested that PHP-1 can switch M2 macrophages to the M1 type, thereby promoting tumor cell apoptosis in vitro. In addition, PHP-1 can modulate the TAMs phenotype, maintain the CD4⁺/CD8⁺ lymphocyte balance, and exert antitumor effects in H22 tumor-bearing mice. Mechanistically, PHP-1 is recognized by the TLR4 receptor, promotes Ca²⁺ release, and activates the NF-κB and MAPK signaling pathways to reset the M2-type macrophages. These findings indicate that PHP-1 from P. heterophylla can function as a tumor immunotherapeutic modulator.

Natural compounds: A new perspective on targeting polarization and infiltration of tumor-associated macrophages in lung cancer

With the development in tumor immunology, people are gradually understanding the complexity and diversity of the tumor microenvironment immune status and its important effect on tumors. Tumor-associated macrophages (TAMs), an important part of the tumor immune microenvironment, have a double effect on tumor growth and metastasis. Many studies have focused on lung cancer, especially non-small cell lung cancer and other "hot tumors" with typical inflammatory characteristics. The polarization and infiltration of TAMs is an important mechanism in the occurrence and development of malignant tumors, such as lung cancer, and in the tumor immune microenvironment. Therapeutic drugs designed for these reasons are key to targeting TAMs in the treatment of lung cancer. A large number of reports have suggested that natural compounds have a strong potential of affecting immunity by targeting the polarization and infiltration of TAMs to improve the immune microenvironment of lung cancer and exert a natural antitumor effect. This paper discusses the infiltration and polarization effects of natural compounds on lung cancer TAMs, provides a detailed classification and systematic review of natural compounds, and summarizes the bias of different kinds of natural compounds by affecting their antitumor mechanism of TAMs, with the aim of providing new perspectives and potential therapeutic drugs for targeted macrophages in the treatment of lung cancer.

Natural Products and their Derivatives as Immune Check Point Inhibitors: Targeting Cytokine/Chemokine Signalling in Cancer

Cancer immunotherapy is the new generation and widely accepted form of tumour treatment. It is, however, associated with exclusive challenges which include organ-specific inflammation, and single-target strategies. Therefore, approaches that can enhance the efficiency of existing immunotherapies and expand their indications are required for the further development of immunotherapy. Natural products and medicines are stated to have this desired effect on cancer immunotherapy (adoptive immune-cells therapy, cancer vaccines, and immune-check point inhibitors). They refurbish the immunosuppressed tumour microenvironment, which is the primary location of interaction of tumour cells with the host immune system. Various immune cell subsets, via interaction with cytokine/chemokine receptors, are recruited into this microenvironment, and these subsets have roles in tumour progression and treatment responsiveness. This review summarises cytokine/chemokine signalling, types of cancer immunotherapy and the herbal medicine-derived natural products targeting cytokine/chemokines and immune checkpoints. These natural compounds possess immunomodulatory activities and exert their anti-tumour effect by either blocking the interaction or modulating the expression of the proteins linked with immune checkpoint signaling pathways. Some compounds also show a synergistic effect in combination with existing monoclonal antibody drugs to reverse the tumour microenvironment. Additionally, we have also reported some studies about the derivatives and formulations used to overcome the limitations of natural forms. This review can provide important insights for directing future research.

Mushroom Carboxymethylated β-d-Glucan Functions as a Macrophage-Targeting Carrier for Iron Oxide Nanoparticles and an Inducer of Proinflammatory Macrophage Polarization for Immunotherapy

β-d-glucans have the potential of serving as both macrophage-targeted carriers and immune stimulators via inducing trained immunity in macrophages. In this study, a carboxymethylated β-glucan from mushroom sclerotium of Pleurotus tuber-regium (CMPTR) was combined with iron oxide nanoparticles (IONPs) to form nanocomplexes (CMPTR/IONPs) with particle size around 193 ± 7 nm, which could exert a concerted effect on inducing proinflammatory M1 phenotype macrophages for immunotherapy. This nanocomplex exhibited good stability and low cytotoxicity (over 80% cellular viability of RAW 264.7 and THP-1) and higher cellular uptake by murine macrophages compared with B16F10 cells (p < 0.05). CMPTR/IONPs could convert M2-like bone marrow-derived macrophages into M1 phenotypes with upregulated expression of pro-inflammatory cytokines (IL12 and TNF-α, p < 0.05) and reduced immune-suppressive cytokines (IL10 and TGF-β, p < 0.05). Such polarization was mediated by the combined signaling regulatory factors, including IONP-stimulated IRF5 and CMPTR-triggered TLRs-NF-κB pathways (p < 0.05). Accordingly, CMPTR could have a dual function as a macrophage-targeting carrier for IONPs and an immunostimulant to induce inflammatory M1 macrophage polarization for immunotherapy.

The Mycobiome: Cancer Pathogenesis, Diagnosis, and Therapy

Cancer is among the leading causes of death globally. Despite advances in cancer research, a full understanding of the exact cause has not been established. Recent data have shown that the microbiome has an important relationship with cancer on various levels, including cancer pathogenesis, diagnosis and prognosis, and treatment. Since most studies have focused only on the role of bacteria in this process, in this article we review the role of fungi-another important group of the microbiome, the totality of which is referred to as the "mycobiome"-in the development of cancer and how it can impact responses to anticancer medications. Furthermore, we provide recent evidence that shows how the different microbial communities interact and affect each other at gastrointestinal and non-gastrointestinal sites, including the skin, thereby emphasizing the importance of investigating the microbiome beyond bacteria.

β-Glucans from Yeast—Immunomodulators from Novel Waste Resources

β-glucans are a large class of complex polysaccharides with bioactive properties, including immune modulation. Natural sources of these compounds include yeast, oats, barley, mushrooms, and algae. Yeast is abundant in various processes, including fermentation, and they are often discarded as waste products. The production of biomolecules from waste resources is a growing trend worldwide with novel waste resources being constantly identified. Yeast-derived β-glucans may assist the host’s defence against infections by influencing neutrophil and macrophage inflammatory and antibacterial activities. β-glucans were long regarded as an essential anti-cancer therapy and were licensed in Japan as immune-adjuvant therapy for cancer in 1980 and new mechanisms of action of these molecules are constantly emerging. This paper outlines yeast β-glucans’ immune-modulatory and anti-cancer effects, production and extraction, and their availability in waste streams.

Yeast as carrier for drug delivery and vaccine construction

Yeast has been employed as an effective derived drug carrier as a unicellular microorganism. Many research works have been devoted to the encapsulation of nucleic acid compounds, insoluble small molecule drugs, small molecules, liposomes, polymers, and various nanoparticles in yeast for the treatment of disease. Recombinant yeast-based vaccine carriers (WYV) have played a major role in the development of vaccines. Herein, the latest reports on the application of yeast carriers and the development of related research are summarized, a conceptual description of gastrointestinal absorption of yeast carriers, as well as the various package forms of different drug molecules and nanoparticles in yeast carriers are introduced. In addition, the advantages and development of recombinant yeast vaccine carriers for the disease, veterinary and aquaculture applications are discussed. Moreover, the current challenges and future directions of yeast carriers are proposed.

Advances in the Immunomodulatory Properties of Glycoantigens in Cancer

Simple Summary

This work reviews the role of aberrant glycosylation in cancer cells during tumour growth and spreading, as well as in immune evasion. The interaction of tumour-associated glycans with the immune system through C-type lectin receptors can favour immune escape but can also provide opportunities to develop novel tumour immunotherapy strategies. This work highlights the main findings in this area and spotlights the challenges that remain to be investigated.

Abstract

Aberrant glycosylation in tumour progression is currently a topic of main interest. Tumour-associated carbohydrate antigens (TACAs) are expressed in a wide variety of epithelial cancers, being both a diagnostic tool and a potential treatment target, as they have impact on patient outcome and disease progression. Glycans affect both tumour-cell biology properties as well as the antitumor immune response. It has been ascertained that TACAs affect cell migration, invasion and metastatic properties both when expressed by cancer cells or by their extracellular vesicles. On the other hand, tumour-associated glycans recognized by C-type lectin receptors in immune cells possess immunomodulatory properties which enable tumour growth and immune response evasion. Yet, much remains unknown, concerning mechanisms involved in deregulation of glycan synthesis and how this affects cell biology on a major level. This review summarises the main findings to date concerning how aberrant glycans influence tumour growth and immunity, their application in cancer treatment and spotlights of unanswered challenges remaining to be solved.

Yeast β-glucan increases etoposide sensitivity in lung cancer cell line A549 by suppressing Nrf2 via the non-canonical NF-κB pathway

Etoposide is regarded as one of the main standard cytotoxic drugs for lung cancer. However, mutations in Keap1, the main regulator of nuclear factor erythroid 2-related factor 2 (Nrf2), are often detected in lung cancer and lead to chemoresistance. Since the aberrant activation of Nrf2 enhances drug resistance, the suppression of the Nrf2 pathway is a promising therapeutic strategy for lung cancer. We herein used the human lung adenocarcinoma cell line A549 because it harbors a Keap1 loss-of-function mutation. A treatment with β-glucan, a major component of the fungal cell wall, reduced Nrf2 protein levels, down-regulated the expression of CYP3A5, UGT1A1, and MDR1, and increased etoposide sensitivity in A549 cells. Furthermore, the ephrin type-A receptor 2 (EphA2) receptor was important for the recognition and biological activity of β-glucan in A549 cells. EphA2 signaling includes nuclear factor kappa B (NF-κB), STAT3, and p38 mitogen-activated protein kinase (MAPK). However, treatment of cells with stattic (STAT3 inhibitor) or SB203580 (p38 MAPK inhibitor) did not diminish the effects of β-glucan. In contrast, knockdown of RelB abolished the effects of β-glucan, suggesting the involvement of the non-canonical NF-κB pathway. The β-glucan effects were also attenuated by the knockdown of WDR23. The β-glucan treatment and RelB overexpression induced the expression of CUL4A, which increased WDR23 ligase activity and promoted the subsequent depletion of Nrf2. These results revealed a novel property of β-glucan as a resistance-modifying agent in addition to its widely reported immunomodulatory effects for lung cancer therapy via the EphA2-RelB-CUL4A-Nrf2 axis. Significance Statement Chemotherapeutic resistance remains a major obstacle in cancer therapy despite extensive efforts to elucidate the underlying molecular mechanisms and overcome multidrug resistance. The present study revealed a novel resistance-modifying property of β-glucan, thereby expanding our knowledge on the beneficial roles of β-glucan and providing an alternative strategy to prevent drug resistance by cancer. The present results provide evidence for the involvement of a novel mode of NF-κB and Nrf2 crosstalk in the drug resistance phenotype.

Scavenger Receptors: Novel Roles in the Pathogenesis of Liver Inflammation and Cancer

The scavenger receptor superfamily represents a highly diverse collection of evolutionarily-conserved receptors which are known to play key roles in host homeostasis, the most prominent of which is the clearance of unwanted endogenous macromolecules, such as oxidized low-density lipoproteins, from the systemic circulation. Members of this family have also been well characterized in their binding and internalization of a vast range of exogenous antigens and, consequently, are generally considered to be pattern recognition receptors, thus contributing to innate immunity. Several studies have implicated scavenger receptors in the pathophysiology of several inflammatory diseases, such as Alzheimer's and atherosclerosis. Hepatic resident cellular populations express a diverse complement of scavenger receptors in keeping with the liver's homeostatic functions, but there is gathering interest in the contribution of these receptors to hepatic inflammation and its complications. Here, we review the expression of scavenger receptors in the liver, their functionality in liver homeostasis, and their role in inflammatory liver disease and cancer.

Immunomodulatory potential of natural products from herbal medicines as immune checkpoints inhibitors: Helping to fight against cancer via multiple targets

Immunotherapy sheds new light to cancer treatment and is satisfied by cancer patients. However, immunotoxicity, single‐source antibodies, and single‐targeting stratege are potential challenges to the success of cancer immunotherapy. A huge number of promising lead compounds for cancer treatment are of natural origin from herbal medicines. The application of natural products from herbal medicines that have immunomodulatory properties could alter the landscape of immunotherapy drastically. The present study summarizes current medication for cancer immunotherapy and discusses the potential chemicals from herbal medicines as immune checkpoint inhibitors that have a broad range of immunomodulatory effects. Therefore, this review provides valuable insights into the efficacy and mechanism of actions of cancer immunotherapies, including natural products and combined treatment with immune checkpoint inhibitors, which could confer an improved clinical outcome for cancer treatment.

Crosstalk between macrophages and natural killer cells in the tumor microenvironment

The tumor microenvironment (TME) is jointly constructed by a variety of cell types, including tumor cells, immune cells, fibroblasts, and epithelial cells, among others. The cells within the TME interact with each other and with tumor cells to influence tumor development and progression. As the most abundant immune cells in the TME, macrophages regulate the immune network by not only secreting a large amount of versatile cytokines but also expressing a series of ligands or receptors on the surface to interact with other cells directly. Due to their strong plasticity, they exert both immunostimulatory and immunosuppressive effects in the complex TME. The major effector cells of the immune system that directly target cancer cells include but are not limited to natural killer cells (NKs), dendritic cells (DCs), macrophages, polymorphonuclear leukocytes, mast cells, and cytotoxic T lymphocytes (CTLs). Among them, NK cells are the predominant innate lymphocyte subsets that mediate antitumor and antiviral responses. The activation and inhibition of NK cells are regulated by cytokines and the balance between activating and inhibitory receptors. There is an inextricable regulatory relationship between macrophages and NK cells. Herein, we systematically elaborate on the regulatory network between macrophages and NK cells through soluble mediator crosstalk and cell-to-cell interactions. We believe that a better understanding of the crosstalk between macrophages and NKs in the TME will benefit the development of novel macrophage- or NK cell-focused therapeutic strategies with superior efficacies in cancer therapy.

Amphiphilic galactomannan nanoparticles trigger the alternative activation of murine macrophages

Macrophages are highly plastic phagocytic cells that can exist in distinct phenotypes and play key roles in physiological and pathological pathways. They can be classically activated to the pro-inflammatory M1 phenotype or alternatively activated to an M2 anti-inflammatory one by various stimuli in the biological milieu. Different biomaterials polarize macrophages to M1 or M2 phenotypes and emerged as a very promising strategy to modulate their activation and performance. In this work, we investigate the ability of drug-free amphiphilic nanoparticles (hydrodynamic diameter of ~130 nm) produced by the self-assembly of a graft copolymer of hydrolyzed galactomannan, a natural polysaccharide of galactose and mannose, that was hydrophobized in the side-chain with poly(methyl methacrylate) blocks and that can encapsulate hydrophobic drugs, to trigger macrophage polarization. The compatibility and uptake of the nanoparticles are demonstrated in the murine macrophage cell line RAW264.7 by a metabolic assay, confocal laser scanning fluorescence microscopy (CLSFM) and imaging flow cytometry in the absence and the presence of endocytosis inhibitors. Results indicate that they are internalized by both clathrin- and caveolin-mediated endocytosis. The ability of these drug-free nanoparticles to polarize these cells to the M2-like phenotype and to switch an M1 to an M2 phenotype is confirmed by the downregulation of the M1 marker cluster of differentiation 80 (CD80), and upregulation of M2 markers CD163 and CD206, as measured by flow cytometry and CLSFM. In addition, we preliminarily assess the effect of the nanoparticles on wound healing by tracking the closure of an artificial wound of RAW264.7 macrophages in a scratch assay. Findings indicate a faster closure of the wound in the presence of the nanoparticles with respect to untreated cells. Finally, a migration assay utilizing a macrophage/fibroblast co-culture model in vitro demonstrates that M2 polarization increases fibroblast migration by 24-fold with respect to untreated cells. These findings demonstrate the ability of this nanotechnology platform to interfere and change the macrophages phenotype in vitro and represent robust evidence for the investigation of their therapeutic performance alone or in combination with an encapsulated hydrophobic drug in wound models in vivo.

Development of a novel beta-glucan supplemented hydrogel spray formulation and wound healing efficacy in a db/db diabetic mouse model

To relief the severe economic and social burdens and patient suffering caused by the increasing incidence of chronic wounds, more effective treatments are urgently needed. In this study, we focused on developing a novel sprayable wound dressing with the active ingredient β-1,3/1,6-glucan (βG). Since βG is already available as the active ingredient in a commercial wound healing product provided as a hydrogel in a tube (βG-Gel), the sprayable format should bring clinical benefit by being easily sprayed onto wounds; whilst retaining βG-Gel's physical stability, biological safety and wound healing efficacy. Potentially sprayable βG hydrogels were therefore formulated, based on an experimental design setup. One spray formulation, named βG-Spray, was selected for further investigation, as it showed favorable rheological and spraying properties. The βG-Spray was furthermore found to be stable at room temperature for more than a year, retaining its rheological properties and sprayability. The cytotoxicity of βG-Spray in keratinocytes in vitro, was shown to be promising even at the highest tested concentration of 100 μg/ml. The βG-Spray also displayed favorable fluid affinity characteristics, with a capacity to both donate and absorb close to 10% fluid relative to its own weight. Finally, the βG-Spray was proven comparably effective to the commercial product, βG-Gel, and superior to both the water and the carrier controls (NoβG-Spray), in terms of its ability to promote wound healing in healing-impaired animals. Contraction was found to be the main wound closure mechanism responsible for the improvement seen in the βG-treatment groups (βG-Spray and βG-Gel). In conclusion, the novel sprayable βG formulation, confirmed its potential to expand the clinical use of βG as wound dressing.

Regulation of myeloid-cell activation

Myeloid cells (macrophages, monocytes, dendritic cells, and granulocytes) survey the body for signs of infection and damage and regulate tissue homeostasis, organogenesis, and immunity. They express receptors that initiate the inflammatory response, send signals that alter the vascular and cytokine milieu, and oversee the recruitment, differentiation, and activation of other myeloid and adaptive immune cells. Their activation must therefore be tightly regulated, optimized for maximal innate-immune protection with a minimum of collateral tissue damage or disorganization. In this review we discuss what it means for myeloid cells to become activated, with emphasis on the receptors and signaling molecules important for the recognition of pathogen-associated and damage-associated molecular patterns. We also outline how these signals are regulated by the steric properties of proteins, by adhesive and cytoskeletal interactions, and by negative feedback to keep inflammation in check and support healthy tissue development and homeostasis. Throughout the text we highlight recent publications and reviews and direct readers therein for a comprehensive bibliography.

Emerging roles of Dectin-1 in noninfectious settings and in the CNS

Dectin-1 is a C-type lectin receptor (CLR) expressed on the surface of various mammalian myeloid cells. Dectin-1 recognizes β-glucans and elicits antifungal proinflammatory immune responses. Recent studies have begun to examine the biology of Dectin-1 in previously less explored settings, such as homeostasis, sterile inflammation, and in the central nervous system. Indeed, in certain contexts, Dectin-1 is now known to promote tolerance, and anti-inflammatory and neuroprotective responses. In this review, we provide an overview of the current understanding of the roles of Dectin-1 in immunology beyond the context of fungal infections, mainly focusing on in vivo neuroimmunology studies, which could reveal new therapeutic approaches to modify innate immune responses in neurologic disorders.

Identification of the Primary Structure of Selenium-Containing Polysaccharides Selectively Inhibiting T-Cell Proliferation

We previously described the biosynthesis, isolation, and immunosuppressive activity of the selenium-containing polysaccharide fraction isolated from the mycelial culture of Lentinula edodes. Structural studies have shown that the fraction was a protein-containing mixture of high molar mass polysaccharides α- and β-glucans. However, which of the components of the complex fraction is responsible for the immunosuppressive activity non-typical for polysaccharides of fungal origin has not been explained. In the current study, we defined four-polysaccharide components of the Se-containing polysaccharide fraction determined their primary structure and examined the effect on T- and B-cell proliferation. The isolated Se-polysaccharides, α-1,4-glucan (M_w 2.25 × 10⁶ g/mol), unbranched β-1,6-d-glucan, unbranched β-1,3-d-glucan and β-1,3-branched β-1,6-d-glucan (M_w 1.10 × 10⁵ g/mol), are not typical as components of the cell wall of L. edodes. All are biologically active, but the inhibitory effect of the isolated polysaccharides on lymphocyte proliferation was weaker, though more selective than that of the crude fraction.

Characterization of a neutral polysaccharide from pumpkin (Cucurbita moschata Duch) with potential immunomodulatory activity

A neutral polysaccharide designated as CMDP-1a (molecular mass 9.263 kDa) was isolated from Cucurbita moschata Duch through hot water extraction, ethanol precipitation, and column chromatography. On the basis of methylation, fourier-transform infrared, monosaccharide composition, and one- and two-dimensional nuclear magnetic resonance spectroscopy analyses, the structure of CMDP-1a was determined to be a backbone composed of α-1,4 linked glucopyranosyl residues with α-Glcp residue linkage at backbone C-6. Atomic force microscopy and scanning electron microscopy analyses revealed that CMDP-1a had a spherical conformation in solution. In immunostimulation assays, CMDP-1a promoted the proliferation of RAW 264.7 macrophages and significantly enhanced their pinocytic and phagocytic capacity. Furthermore, CMDP-1a induced the M1 polarization of original macrophages and the conversion of macrophages from M2 to M1, thereby modulating the balance of M1/M2 macrophages. These results indicated that CMDP-1a might be a potential immunomodulator for food purposes.

Cigarette smoke promotes oral leukoplakia via regulating glutamine metabolism and M2 polarization of macrophage

Oral immunosuppression caused by smoking creates a microenvironment to promote the occurrence and development of oral mucosa precancerous lesions. This study aimed to investigate the role of metabolism and macrophage polarization in cigarette-promoting oral leukoplakia. The effects of cigarette smoke extract (CSE) on macrophage polarization and metabolism were studied in vivo and in vitro. The polarity of macrophages was detected by flow cytometric analysis and qPCR. Liquid chromatography-mass spectrometry (LC-MS) was used to perform a metabolomic analysis of Raw cells stimulated with CSE. Immunofluorescence and flow cytometry were used to detect the polarity of macrophages in the condition of glutamine abundance and deficiency. Cell Counting Kit-8 (CCK-8), wound-healing assay, and Annexin V-FITC (fluorescein isothiocyanate)/PI (propidium iodide) double-staining flow cytometry were applied to detect the growth and transferability and apoptosis of Leuk-1 cells in the supernatant of Raw cells which were stimulated with CSE, glutamine abundance and deficiency. Hyperkeratosis and dysplasia of the epithelium were evident in smoking mice. M2 macrophages increased under CSE stimulation in vivo and in vitro. In total, 162 types of metabolites were detected in the CSE group. The metabolites of nicotine, glutamate, arachidic acid, and arginine changed significantly. The significant enrichment pathways were also selected, including nicotine addiction, glutamine and glutamate metabolism, and arginine biosynthesis. The results also showed that the supernatant of Raw cells stimulated by CSE could induce excessive proliferation of Leuk-1 and inhibit apoptosis. Glutamine abundance can facilitate this process. Cigarette smoke promotes oral leukoplakia via regulating glutamine metabolism and macrophage M2 polarization.