Mechanisms Underlying the Role of Myeloid-Derived Suppressor Cells in Clinical Diseases: Good or Bad

Role of liposomes in chemoimmunotherapy of breast cancer

In the dynamic arena of cancer therapeutics, chemoimmunotherapy has shown tremendous promise, especially for aggressive forms of breast cancer like triple-negative breast cancer (TNBC). This review delves into the significant role of liposomes in enhancing the effectiveness of chemoimmunotherapy by leveraging breast cancer-specific mechanisms such as the induction of immunogenic cell death (ICD), reprogramming the tumour microenvironment (TME), and enabling sequential drug release. We examine innovative dual-targeting liposomes that capitalise on tumour heterogeneity, as well as pH-sensitive formulations that offer improved control over drug delivery. Unlike prior analyses, this review directly links advancements in preclinical research-such as PAMAM dendrimer-based nanoplatforms and RGD-decorated liposomes-to clinical trial results, highlighting their potential to revolutionise TNBC treatment strategies. Additionally, we address ongoing challenges related to scalability, toxicity, and regulatory compliance, and propose future directions for personalised, immune-focused nanomedicine. This work not only synthesises the latest research but also offers a framework for translating liposomal chemoimmunotherapy from laboratory research to clinical practice.

Insights of immune cell heterogeneity, tumor-initiated subtype transformation, drug resistance, treatment and detecting technologies in glioma microenvironment

BACKGROUND

With the gradual understanding of glioma development and the immune microenvironment, many immune cells have been discovered. Despite the growing comprehension of immune cell functions and the clinical application of immunotherapy, the precise roles and characteristics of immune cell subtypes, how glioma induces subtype transformation of immune cells and its impact on glioma progression have yet to be understood.

AIM OF THE REVIEW

In this review, we comprehensively center on the four major immune cells within the glioma microenvironment, particularly neutrophils, macrophages, lymphocytes, myeloid-derived suppressor cells (MDSCs), and other significant immune cells. We discuss (1) immune cell subtype markers, (2) glioma-induced immune cell subtype transformation, (3) the mechanisms of each subtype influencing chemotherapy resistance, (4) therapies targeting immune cells, and (5) immune cell-associated single-cell sequencing. Eventually, we identified the characteristics of immune cell subtypes in glioma, comprehensively summarized the exact mechanism of glioma-induced immune cell subtype transformation, and concluded the progress of single-cell sequencing in exploring immune cell subtypes in glioma.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In conclusion, we have analyzed the mechanism of chemotherapy resistance detailly, and have discovered prospective immunotherapy targets, excavating the potential of novel immunotherapies approach that synergistically combines radiotherapy, chemotherapy, and surgery, thereby paving the way for improved immunotherapeutic strategies against glioma and enhanced patient outcomes.

Reprogramming the breast tumor immune microenvironment: cold-to-hot transition for enhanced immunotherapy

This review discusses reprogramming the breast tumor immune microenvironment from an immunosuppressive cold state to an immunologically active hot state. A complex interplay is revealed, in which the accumulation of metabolic byproducts-such as lactate, reactive oxygen species (ROS), and ammonia-is shown to impair T-cell function and promote tumor immune escape. It is demonstrated that the tumor microenvironment (TME) is dominated by immunosuppressive cytokines, including interleukin-10 (IL-10), transforming growth factorβ (TGFβ), and IL-35. Notably, IL-35 is produced by regulatory T cells and breast cancer cells. The conversion of conventional T cells into IL-35-producing induced regulatory T cells, along with the inhibition of pro-inflammatory cytokine secretion, contributes to the suppression of anti-tumor immunity. It is further demonstrated that key immune checkpoint molecules-such as PD-1, PDL1, CTLA-4, TIM-3, LAG-3, and TIGIT-are upregulated within the TME, leading to Tcell exhaustion and diminished immune responses. The blockade of these checkpoints is shown to restore T-cell functionality and is proposed as a strategy to convert cold tumors into hot ones with robust effector cell infiltration. The therapeutic potential of chimeric antigen receptor (CAR)T cell therapy is also explored, and targeting specific tumor-associated antigens, such as glycoproteins and receptor tyrosine kinases, is highlighted. It is suggested that CART cell efficacy can be enhanced by combining these cells with immune checkpoint inhibitors and other immunomodulatory agents, thereby overcoming the barriers imposed by the immunosuppressive TME. Moreover, the role of the microbiome in regulating estrogen metabolism and systemic inflammation is reviewed. Alterations in the gut microbiota are shown to affect the TME, and microbiome-based interventions are proposed as an additional means to facilitate the cold-to-hot transition. It is concluded that by targeting the metabolic and immunological pathways that underpin immune suppression-through combination strategies involving checkpoint blockade, CART cell therapies, and microbiome modulation-the conversion of the breast TME from cold to hot can be achieved. This reprogramming is anticipated to enhance immune cell infiltration and function, thereby improving the overall efficacy of immunotherapies and leading to better clinical outcomes for breast cancer patients.

Glucocorticoid Receptor-Targeted Nanoliposome for STAT3 Inhibition-Led Myeloid-Derived Suppressor Cell Modulation and Efficient Colon Cancer Treatment

STAT3 is an important protein responsible for cellular proliferation, motility, and immune tolerance and is hyperactive in colorectal cancer, instigating metastasis, cellular proliferation, migration, as well as inhibition. It helps in proliferation of myeloid-derived suppressor cells (MDSCs), which within the tumor microenvironment (TME) suppress T cells to encourage tumor growth, metastasis, and resistance to immunotherapy, besides playing dynamic role in regulating macrophages within the tumor. Thus, MDSC is a potential target to augment immune surveillance within the TME. Herein, we report targeting both colorectal cancer and MDSCs using a glucocorticoid receptor (GR)-targeted nanoliposomal formulation carrying GR-ligand, dexamethasone (Dex), and a STAT3 inhibitor, niclosamide (N). Our main objective was to selectively inhibit STAT3, the key immunomodulatory factor in most TME-associated cells including MDSCs, and also repurpose the use of this antihelminthic, low-cost drug N for cancer treatment. The resultant formulation D1XN exhibited better tumor regression and survivability compared to GR nontargeted formulation. Further, bone marrow cell-derived MDSCs were engineered by D1XN treatment ex vivo and were inoculated back to tumor-bearing mice. Significant tumor growth inhibition with enhanced antiproliferative immune cell signatures, such as T cell infiltration, decrease in Treg cells, and increased M1/M2 macrophage ratio within the TME were observed. This reveals the effectiveness of engineered MDSCs to modulate tumor surveillance besides reversing the aggressiveness of the tumor. Therefore, D1XN and D1XN-mediated engineered MDSCs alone or in combination can be considered as potent selective chemo-immunotherapeutic nanoliposomal agent(s) against colorectal cancer.

Tumor Microenvironment: A Complex Landscape of Cancer Development and Drug Resistance

Cancer is responsible for nearly one in six global fatalities, making it a major health issue worldwide. Despite advancements in early detection, surgery, and targeted therapies, effective treatment remains challenging due to the complexity and heterogeneity of the disease. A key factor in cancer progression and resistance to treatment is the tumor microenvironment (TME). It is a complex ecosystem comprising cancer cells, stromal cells, immune cells, extracellular matrix (ECM), and soluble factors like cytokines and chemokines. These components interact dynamically to influence tumor growth, metastasis, immune evasion, and treatment resistance. Cancer cells drive the formation of the TME by releasing signaling molecules, while stromal cells, such as fibroblasts and endothelial cells, support tumor metabolism, angiogenesis, and invasion. Immune cells within the TME can either suppress or promote tumor progression, depending on their activation state. Additionally, the TME can promote the growth of immunosuppressive cells that aid cancer cells in evading immune surveillance, such as regulatory T-cells and myeloid-derived suppressor cells. The TME also impedes drug delivery by creating defective blood vessels, contributing to drug resistance. Recent technological advancements have deepened our understanding of the TME, revealing its role in immune modulation, metabolism, and extracellular matrix remodeling. As a result, targeting the TME has become a promising strategy to overcome treatment resistance and improve cancer therapy outcomes.

Monocyte-macrophage dynamics as key in disparate lung and peripheral immune responses in severe anti-melanoma differentiation-associated gene 5-positive dermatomyositis-related interstitial lung disease

BACKGROUND

Anti-melanoma differentiation-associated gene 5-positive dermatomyositis (anti-MDA5+ DM) is a rare inflammatory autoimmune disorder often complicated by life-threatening rapidly progressive interstitial lung disease (RP-ILD). The underlying mechanisms driving immune dysfunction and lung injury, however, remain poorly understood. The study aims to gain insights into the disrupted immune landscape in peripheral and pulmonary compartments of severe anti-MDA5+ DM and explore potential therapeutic targets.

METHODS

We employed single-cell RNA sequencing to examine cellular constituents within five patients' bronchoalveolar lavage fluid and paired peripheral blood mononuclear cells. Luminex assay and flow cytometry were further applied to validate the results.

RESULTS

Our analysis revealed starkly contrasting immune landscapes between the periphery and lungs, with peripheral immune suppression juxtaposed against pulmonary immune hyperactivation. Central to this dysregulation was the monocyte-macrophage lineage. Circulating monocytes exhibited an immunosuppressive phenotype, characterised by diminished cytokine production, reduced MHC II expression, and features resembling myeloid-derived suppressor cells. These monocytes were recruited to the lungs, where they differentiated into monocyte-derived alveolar macrophages (Mo-AMs) with robust proinflammatory and profibrotic activities. Mo-AMs drove cytokine storms and produced chemokines that amplified inflammatory cell recruitment and lung tissue remodelling. Additionally, peripheral T and NK cells exhibited increased cell death and active migration into the lungs, which may be the cause of lymphopenia.

CONCLUSIONS

Our study underscores the pivotal role of monocyte-macrophage dynamics in the immunopathogenesis of anti-MDA5+-associated RP-ILD, offering critical insights into compartment-specific immune dysregulation. These findings suggest potential therapeutic strategies targeting monocyte recruitment and macrophage activation to mitigate disease progression.

KEY POINTS

Peripheral immune suppression and pulmonary immune hyperactivation characterise the distinct immune landscapes in anti-MDA5+DM with RP-ILD. Circulating monocytes transition from an immunosuppressive phenotype in the periphery to proinflammatory and profibrotic Mo-AMs in the lungs. Chemokines produced by Mo-AMs drive monocyte and other immune cell recruitment to the lungs, amplifying pulmonary inflammation.

Chemotherapy-mediated lncRNA-induced immune cell plasticity in cancer immunopathogenesis

Tumor cells engage with the immune system in a complex manner, utilizing evasion and adaptability mechanisms. The development of cancer and resistance to treatment relies on the ability of immune cells to adjust their phenotype and function in response to cues from the tumor microenvironment, known as immunological cell plasticity. This study delves into the role of long non-coding RNAs (lncRNAs) in enhancing immune cell flexibility in cancer, focusing on their regulatory actions in the tumor microenvironment and potential therapeutic implications. Through a comprehensive review of existing literature, the study analyzes the impact of lncRNAs on macrophages, T-cells, and MDSCs, as well as the influence of cytokines and growth factors like TNF, IL-6, HGF, and TGFβ on immunological cell plasticity and tumor immunoediting. LncRNAs exert a strong influence on immune cell plasticity through mechanisms such as transcriptional regulation, post-transcriptional modifications, and chromatin remodeling. These RNA molecules intricately modulate gene expression networks, acting as scaffolding, decoys, guides, and sponges. Moreover, both direct cell-cell interactions and soluble chemicals in the tumor microenvironment contribute to enhancing immune cell activation and survival. Understanding the influence of lncRNAs on immune cell flexibility sheds light on the biological pathways of immune evasion and cancer progression. Targeting long non-coding RNAs holds promise for amplifying anti-tumor immunity and overcoming drug resistance in cancer treatment. However, further research is necessary to determine the therapeutic potential of manipulating lncRNAs in the tumor microenvironment.

Targeted modulation of myeloid-derived suppressor cells in the tumor microenvironment: Implications for cancer therapy

Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of immature myeloid cells originating from the bone marrow, known for their potent immunosuppressive functions that contribute to tumor immune evasion and progression. This paper provides a comprehensive analysis of the multifaceted interactions between MDSCs and tumors, exploring their distinct phenotypes and immunosuppressive mechanisms. Key roles of MDSCs in tumor biology are discussed, including their involvement in the formation of the pre-metastatic niche, facilitation of angiogenesis, enhancement of vascular permeability, suppression of tumor cell apoptosis, and promotion of resistance to cancer therapies. Additionally, the review highlights recent advances in the development of MDSC-targeting therapies, with a focus on their potential to enhance anti-tumor immunity. The therapeutic potential of Traditional Chinese Medicine (TCM) in modulating MDSC quantity and function is also explored, suggesting a novel approach to cancer treatment by integrating traditional and modern therapeutic strategies.

The Prognostic Role of the Neutrophil-to-Lymphocytes Ratio in the Most Frequent Cardiovascular Diseases: An Update

Given the continuous changes in the world, with an increasing trend of unhealthy lifestyles, metabolic comorbidities, and increased susceptibility to cardiovascular diseases (CVDs), researchers change their attention to improve not only the therapeutic platform but also current CVD predictive and prognostic tools to improve disease outcomes. As CVD is characterized by an inflammatory paradigm involving, to some degree, the innate and adaptative immune systems, the neutrophil-to-lymphocyte ratio (NLR) emerged as a potential low-cost, rapidly available, and reliable inflammatory marker, with substantial recent evidence showing its potential utility in clinical practice. Thus, in this literature review, we will present an up-to-date discussion of the prognostic role of NLR in the most frequent CVDs, such as acute and chronic coronary disease, atherosclerotic disease, heart failure, cardiac valvopathies, and cardiac arrhythmias with predilection to atrial fibrillation.

Immune landscape of hepatocellular carcinoma: From dysregulation of the immune responses to the potential immunotherapies

Hepatocellular carcinoma (HCC) presents a considerable global health burden due to its late diagnosis and high morbidity. The liver's specific anatomical and physiological features expose it to various antigens, requiring precise immune regulation. To the best of our knowledge, this is the first time that a comprehensive overview of the interactions between the immune system and gut microbiota in the development of HCC, as well as the relevant therapeutic approaches are discussed. Dysregulation of immune compartments within the liver microenvironment drives HCC pathogenesis, characterized by elevated regulatory cells such as regulatory T cells (Tregs), myeloid-derived suppressor cells, and M2 macrophages as well as suppressive molecules, alongside reduced number of effector cells like T cells, natural killer cells, and M1 macrophages. Dysbiosis of gut microbiota also contributes to HCC by disrupting intestinal barrier integrity and triggering overactivated immune responses. Immunotherapy approaches, particularly immune checkpoint inhibitors, have exhibited promise in HCC management, yet adoptive cell therapy and cancer vaccination research are in the early steps with relatively less favorable outcomes. Further understanding of immune dysregulation, gut microbiota involvement, and therapeutic combination strategies are essential for advancing precision immunotherapy in HCC.

Decreased circulating myeloid-derived suppressor cell count at the engraftment is one of the risk factors for multiple myeloma relapse after autologous hematopoietic stem cell transplantation

Recent studies demonstrated that myeloid-derived suppressor cells (MDSCs) are involved in the pathogenesis and progression of multiple myeloma (MM). Nevertheless, data on the quantitative and functional changes in MDSCs during standard MM treatment remain poorly understood. Here, we determined that monocytic MDSCs (M-MDSC; CD14+HLA-DRlow/-) and granulocytic MDSCs (PMN-MDSC; Lin-HLA-DR-CD33+CD66b+) in MM patients in remission following induction therapy (IT) were significantly increased, while early MDSCs (E-MDSCs; Lin-HLA-DR-CD33+CD66b-) were decreased compared to the donor group. In progression, MM patients had the most pronounced decrease in E-MDSCs and enhanced levels of PMN-MDSCs. IT was accompanied with a decrease in the expression of arginase-1 (Arg-1). In MM patients with relapse or resistance to IT, Arg-1+ cell frequency in M-MDSCs and E-MDSCs, as well as PD-L1+ M-MDSCs, was increased, which may facilitate tumor immunosuppression. G-CSF administration led to a significant increment in the MDSC subsets. At the engraftment, circulating M-MDSC and PMN-MDSCs were temporarily increased, with a gradual decline to the pre-transplant levels in 12 months. The percentage of E-MDSCs was decreased at the leukocyte recovery. Patients with a higher (>Me) M-MDSC count at the engraftment had a shorter post-transplant leukopenia duration (Me 11 vs. 13 days; pU = 0.0086). The advanced MM stage, depth of response, and lower relative count of circulating E-MDSCs at the engraftment were independent risk factors associated with a lower progression-free survival. The obtained data allow us to hypothesize that MDSCs may play a positive role at the stage of leukocyte recovery by ameliorating the long-term anti-tumor response in MM.

Local Myeloid-Derived Suppressor Cells Impair Progression of Experimental Autoimmune Uveitis by Alleviating Oxidative Stress and Inflammation

Purpose

To evaluate the immune regulatory effect of human cord blood myeloid-derived suppressor cells (MDSCs) in experimental autoimmune uveitis (EAU) models.

Methods

MDSCs (1 × 106) or PBS were injected into established C57BL/6 EAU mice via the subconjunctival route on days 0 and 7. The severity of intraocular inflammation was evaluated for up to 3 weeks. Tissue injury and inflammation were analyzed using immunolabelled staining, real-time PCR, and ELISA. In addition, immune cells in draining lymph nodes (LNs) were quantified using flow cytometry.

Results

After 21 days, the clinical scores and histopathological grades of EAU were lower in the MDSCs group compared with the PBS group. Local administration of MDSCs suppressed the oxidative stress and the expression of TNF-α and IL-1β in the retinal tissues. In addition, it inhibited the activation of pathogenic T helper 1 (Th1) and Th17 cells in draining LNs. MDSCs increased the frequency of CD25+ Foxp3+ regulatory T cells and the mRNA expression of IL-10, as an immune modulator.

Conclusions

MDSCs suppressed inflammation and oxidative stress in the retina and inhibited pathogenic T cells in the LNs in EAU. Therefore, ocular administration of MDSCs has therapeutic potential for uveitis.

Bioinformatics and experimental analyses of glutamate receptor and its targets genes in myocardial and cerebral ischemia

BACKGROUND

There is a mutual hemodynamic and pathophysiological basis between the heart and brain. Glutamate (GLU) signaling plays an important role in the process of myocardial ischemia (MI) and ischemic stroke (IS). To further explore the common protective mechanism after cardiac and cerebral ischemic injuries, the relationship between GLU receptor-related genes and MI and IS were analyzed.

RESULTS

A total of 25 crosstalk genes were identified, which were mainly enriched in the Toll-like receptor signaling pathway, Th17 cell differentiation, and other signaling pathways. Protein-protein interaction analysis suggested that the top six genes with the most interactions with shared genes were IL6, TLR4, IL1B, SRC, TLR2, and CCL2. Immune infiltration analysis suggested that immune cells such as myeloid-derived suppressor cells and monocytes were highly expressed in the MI and IS data. Memory B cells and Th17 cells were expressed at low levels in the MI and IS data; molecular interaction network construction suggested that genes such as JUN, FOS, and PPARA were shared genes and transcription factors; FCGR2A was a shared gene of MI and IS as well as an immune gene. Least absolute shrinkage and selection operator logistic regression analysis identified nine hub genes: IL1B, FOS, JUN, FCGR2A, IL6, AKT1, DRD4, GLUD2, and SRC. Receiver operating characteristic analysis revealed that the area under the curve of these hub genes was > 65% in MI and IS for all seven genes except IL6 and DRD4. Furthermore, clinical blood samples and cellular models showed that the expression of relevant hub genes was consistent with the bioinformatics analysis.

CONCLUSIONS

In this study, we found that the GLU receptor-related genes IL1B, FOS, JUN, FCGR2A, and SRC were expressed in MI and IS with the same trend, which can be used to predict the occurrence of cardiac and cerebral ischemic diseases and provide reliable biomarkers to further explore the co-protective mechanism after cardiac and cerebral ischemic injury.

Advances in the study of myeloid-derived suppressor cells in infectious lung diseases

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells capable of inhibiting T-cell responses. MDSCs have a crucial role in the regulation of the immune response of the body to pathogens, especially in inflammatory response and pathogenesis during anti-infection. Pathogens such as bacteria and viruses use MDSCs as their infectious targets, and even some pathogens may exploit the inhibitory activity of MDSCs to enhance pathogen persistence and chronic infection of the host. Recent researches have revealed the pathogenic significance of MDSCs in pathogens such as bacteria and viruses, despite the fact that the majority of studies on MDSCs have focused on tumor immune evasion. With the increased prevalence of viral respiratory infections, the resurgence of classical tuberculosis, and the advent of medication resistance in common bacterial pneumonia, research on MDSCs in these illnesses is intensifying. The purpose of this work is to provide new avenues for treatment approaches to pulmonary infectious disorders by outlining the mechanism of action of MDSCs as a biomarker and therapeutic target in pulmonary infectious diseases.

Blocking the A2B adenosine receptor alleviates myocardial damage by inhibiting spleen-derived MDSC mobilisation after acute myocardial infarction

BACKGROUND

Myeloid-derived suppressor cell (MDSC) mobilisation is an important immune event in acute myocardial infarction (AMI). The A_2B adenosine receptor (A_2BAR) plays key role in regulating MDSC function, but its specific involvement in MDSC mobilisation in AMI remains unclear.

METHODS

In AMI patients, the circulating MDSC ratio and A_2BAR mRNA expression were measured. A mouse AMI model was established by left anterior descending coronary artery (LADCA) ligation. MDSCs were analysed by FACS and immunofluorescence staining (of heart tissue). A_2BAR mRNA expression was assessed by qRT-PCR. Myocardial injury was detected by HE staining. Myocardial cell apoptosis was analysed by immunohistochemistry. Cardiac systolic function was evaluated by transthoracic echocardiography.

RESULTS

In AMI patients, the circulating MDSC ratio was increased and positively correlated with A_2BAR mRNA expression (r = 0.86, p < 0.01). In AMI model mice, the percentage of MDSCs was increased in the circulation and infarcted heart and decreased in the spleen. MRS-1754-mediated A_2BAR inhibition decreased the MDSC ratio in the circulation and infarcted heart and prevented the decrease in MDSC number in the spleens of mice with AMI. A_2BAR blockade inhibited myocardial cell apoptosis, alleviated myocardial inflammatory injury, and improved myocardial systolic function in the AMI mouse model. Similar results were found in mice after splenectomy. Additionally, spleen-derived MDSC injection increased the MDSC ratio in the infarcted heart, increased myocardial cell apoptosis, aggravated myocardial injury, and decreased cardiac systolic function in mice with AMI.

CONCLUSION

Blocking A_2BAR alleviates myocardial damage and improves myocardial systolic function through inhibition of spleen-derived MDSC mobilisation after AMI. Key MessagesSpleen-derived MDSC mobilisation aggravates myocardial inflammatory injury within 24 h of AMI.A_2BAR promotes spleen-derived MDSC mobilisation within 24 h of AMI.Blocking A_2BAR improves myocardial systolic function through inhibition of spleen-derived MDSC mobilisation.

Expression of Inhibitory Molecules (Arginase-1, IDO, and PD-L1) by Myeloid-Derived Suppressor Cells in Multiple Myeloma Patients in Remission

We studied suppressor potential of myeloid-derived suppressor cells (MDSC) in multiple myeloma patients, including before and after mobilization of hematopoietic stem cells (HSC), by evaluating the expression of arginase-1 (Arg1), indolamine-2,3-dioxygenase (IDO), and PD-L1 in MDSC subsets. The study included 20 multiple myeloma patients in remission, 5 patients with progression, as well as 10 sex-and age-matched healthy donors. The expression of Arg1, IDO, and PD-L1 in circulating granulocytic MDSC (G-MDSC, Lin^-HLA-DR^-CD33⁺CD66b⁺), monocytic MDSC (M-MDSC, CD14⁺HLA-DR^low/-), and early-stage MDSC (E-MDSC, Lin^-HLA-DR^-CD33⁺CD66b^-) was evaluated by flow cytometry. Multiple myeloma patients in remission were characterized by reduced expression of Arg1 in M-MDSC in comparison with donors. The expression of Arg1 in M-MDSC depended on the number of induction therapy lines performed and was significantly lower in patients who received ⩾2 lines and responded with remission. Patients with multiple myeloma progression (resistant to therapy) showed significantly increased expression of Arg1 and PD-L1 in M-MDSC, as well as increased expression of Arg1 in E-MDSC. After G-CSF-induced mobilization of HSC, the content of circulating Arg1-expressing M-MDSC increased significantly. Considering the presence of MDSC in apheresis products, MDSC suppressive activity is discussed as a factor affecting the outcomes of autologous HSC transplantation in multiple myeloma patients.

The Modulatory Effects and Targets Prediction of Herbal Medicines or Phytochemicals on Cancer Immunosurveillance

Cancer is a main life-threatening disease worldwide. Due to the adverse effects of conventional chemotherapies and radiotherapies, immunotherapy has emerged as a potent strategy to treat cancer. In cancer immunotherapy, cancer immune surveillance plays a crucial role in the cancer process, which contains various effector cells from innate and adaptive immunity. This review summarized the functions of innate and adaptive immune cells in cancer immunosurveillance and their main reported targets. Moreover, the potential targets about the modulatory effects of cancer immunosurveillance were predicted using network-based target analysis, with total predicted pathways not only reporting previously reported pathways, but also putative signaling pathways pending for investigation. In addition, the potential use of herbal medicines and their phytochemicals in the modulation of cancer immunosurveillance were also discussed. Taken together, this review paper aims to provide scientific insight into further drug development, particularly herbs, phytochemicals, and TCM formulae, in the modulatory effects of cancer immunosurveillance.

Myeloid-derived suppressor cells in COVID-19: A review

Coronavirus disease 2019 (COVID-19) is a potentially life-threatening infection characterized by excessive inflammation, coagulation disorders and organ damage. A dysregulated myeloid cell compartment is one of the most striking immunopathologic signatures of this newly emerged infection. A growing number of studies are reporting on the expansion of myeloid cells with immunoregulatory activities in the periphery and airways of COVID-19 patients. These cells share phenotypic and functional similarities with myeloid-derived suppressor cells (MDSCs), which were first described in cancer patients. MDSCs are a heterogeneous population of pathologically activated myeloid cells that exert immunosuppressive activities against mainly effector T cells. The increased frequency of these cells in COVID-19 patients suggests that they are involved in immune regulation during this infection. In this article, we review the current findings on MDSCs in COVID-19 and discuss the complex role of these cells in the immunopathology of COVID-19.