Increased production of immature myeloid cells in cancer patients: a mechanism of immunosuppression in cancer

Innate immune cells in tumor microenvironment: A new frontier in cancer immunotherapy

Innate immune cells, crucial in resisting infections and initiating adaptive immunity, play diverse and significant roles in tumor development. These cells, including macrophages, granulocytes, dendritic cells (DCs), innate lymphoid cells, and innate-like T cells, are pivotal in the tumor microenvironment (TME). Innate immune cells are crucial components of the TME, based on which various immunotherapy strategies have been explored. Immunotherapy strategies, such as novel immune checkpoint inhibitors, STING/CD40 agonists, macrophage-based surface backpack anchoring, ex vivo polarization approaches, DC-based tumor vaccines, and CAR-engineered innate immune cells, aim to enhance their anti-tumor potential and counteract cancer-induced immunosuppression. The proximity of innate immune cells to tumor cells in the TME also makes them excellent drug carriers. In this review, we will first provide a systematic overview of innate immune cells within the TME and then discuss innate cell-based therapeutic strategies. Furthermore, the research obstacles and perspectives within the field will also be addressed.

Shifting phenotype and differentiation of CD11b+Gr.1+ immature heterogeneous myeloid derived adjuster cells support inflammation and induce regulators of IL17A in imiquimod induced psoriasis

OBJECTIVE AND DESIGN

The exact immunological mechanism of widespread chronic inflammatory skin disorder psoriasis has not been fully established. CD11b+Gr.1+ myeloid-derived cells are immature heterogeneous cells with T-cell suppressive property in neoplasia; however, influence of these cells on adaptive immunity is highly contextual; therefore, we dubbed these cells as myeloid-derived adjuster cells (MDAC). We studied imiquimod induced psoriasis in mouse model and evaluated for the first time the RORγt-NFAT1 axis in MDACs and the function, differentiation and interaction of these cells with T cells.

MATERIALS AND METHODS

The status of T cells and MDACs; their functionality and differentiation properties, and the roles of RORγt and NFAT1 in MDACs were evaluated using flow cytometry, qRT-PCR and confocal imaging.

RESULTS

We found gradual increase in T cells and MDACs and an increase in the number of IL17 -secreting MDACs and T cells in the skin of psoriatic animals. We also noted that MDAC differentiation is biased toward M1 macrophages and DCs which perpetuate inflammation. We found that psoriatic MDACs were unable to suppress T-cell proliferation or activation but seemingly helped these T cells produce more IL17. Inhibition of the RORγt/NFAT1 axis in MDACs increased the suppressive nature of MDACs, allowing these cells to suppress the activity of psoriatic T-cells.

CONCLUSION

Our results indicate that altered MDAC properties in psoriatic condition sustains pathological inflammation and RORγt and NFAT1 as promising intervention target for psoriasis management.

Combination of circulating tumor cells and 18F-FDG PET/CT for precision diagnosis in patients with non-small cell lung cancer

PURPOSE

To investigate the value of 2-deoxy-18f-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and circulating tumor cells (CTCs) for the differential diagnosis of patients with benign lung diseases and those with NSCLC. To explore the phenotypic heterogeneity of CTCs and their correlation with FDG uptake in patients with Stage I-IV NSCLC.

METHODS

Blood specimens from patients with benign lung diseases and patients with primary NSCLC were collected for the detection of CTCs and their subtypes (epithelial, mixed, and mesenchymal) and analyzed for 18F-FDG PET/CT tumor metabolic parameters, including the maximum standardized uptake value (SUVmax), standard uptake value (SUL), metabolic tumor volume of primary lesion (MTV), total lesion glycolysis of primary lesion (TLG). Clinical data including age, gender, smoking history, tumor size, TNM stage and pathology type were also collected. The value of the two method alone and in combination for the differential diagnosis of benign and malignant was comparatively analyzed. Finally, the differences in CTC and its subtypes in different stages of NSCLC were compared, and FDG metabolic parameters were correlated with CTC subtypes.

RESULTS

There were a total of 65 patients with pulmonary diseases, including 12 patients with benign pulmonary diseases and 53 patients with NSCLC. The mean age was 67 ± 10 (38-89 years), 27 were females and 38 were males. 31 (22 males and 9 females) had a long history of smoking. The mean size of the largest diameter of all single lesions was 36 ± 22 mm with a range of 10-108 mm. Seven out of 12 benign diseases were inflammatory granulomatous lesions and 5 were inflammatory pseudotumours. Twenty-four out of 53 NSCLC were adenocarcinomas and 29 were squamous carcinomas. Twelve out of 53 patients with NSCLC were in Stage I, 10 were in Stage II, 17 were in Stage III and 14 were in Stage IV. SUVmax, SUL, MTV, TLG, total CTCs, epithelial CTCs, and mixed CTCs were all valuable in the differential diagnosis of benign and malignant. TLG combined with mixed CTCs was statistically different from all other diagnostic methods (p < 0.05) and higher than any other diagnostic criteria. In the differential diagnosis of benign and Stage I NSCLC, only total CTC (Z = -2.188 p = 0.039) and mixed CTCs (Z = -3.020 p = 0.014) had certain diagnostic efficacy, and there was no statistical difference between them (p = 0.480). Only mesenchymal CTCs differed in Stage I-IV NSCLC, with a higher number of those who developed distant metastases than those who had non-distant metastases. Epithelial CTCs correlated with SUVmax (r = 0.333, p = 0.015) and SUL (r = 0.374, p = 0.006). Mmesenchymal CTCs correlated with MTV (r = 0.342, p = 0.018) and TLG (r = 0.319, p = 0.02). Further subgroup analyses revealed epithelial CTCs were correlated with SUVmax (r = 0.543, p = 0.009) and SUL (r = 0.552, p = 0.008), and the total CTCs was correlated with SUVmax (r = 0.622, p = 0.003), SUL (r = 0.652, p = 0.003), MTV (r = 0.460, p = 0.031), and TLG (r = 0.472, p = 0.027) in the early group (Stage I-II). Only mesenchymal CTCs was associated with MTV (r = 0.369, p = 0.041), and TLG (r = 0.415, p = 0.02) in the intermediate-late group (Stage III-IV).

CONCLUSION

Both FDG PET metabolic parameters and CTCs demonstrated diagnostic value for NSCLC, and combining TLG with mixed CTCs could enhance their diagnostic efficacy. The total CTCs and mixed CTCs showed greater diagnostic value than FDG PET in distinguishing benign lesions from Stage I NSCLC. In NSCLC patients, the epithelial CTCs exhibited a positive correlation with SUVmax and SUL, while mesenchymal CTCs correlated with MTV, and TLG. Besides, epithelial CTCs showed stronger correlations with SUVmax and SUL, and total CTCs showed stronger correlations with SUVmax, SUL, MTV, and TLG in Stage I-II NSCLC. Only mesenchymal CTCs in Stage III-IV NSCLC showed correlations with MTV and TLG. Stage IV NSCLC cases displayed a higher number of mesenchymal CTCs.

The Significance of Longitudinal Psoas Muscle Loss in Predicting the Maintenance Efficacy of Durvalumab Treatment Following Concurrent Chemoradiotherapy in Patients with Non-Small Cell Lung Cancer: A Retrospective Study

Sarcopenia assessed at a single time point is associated with the efficacy of immunotherapy, and we hypothesized that longitudinal changes in muscle mass may also be important. This retrospective study included patients with non-small cell lung cancer (NSCLC) who received durvalumab treatment after concurrent chemoradiotherapy (CCRT) between January 2017 and April 2023. Muscle loss and sarcopenia were assessed based on the lumbar skeletal muscle area. Patients with a decrease in muscle area of 10% or more during CCRT were categorized into the muscle loss group, while those with a decrease of less than 10% were categorized into the muscle maintenance group. We evaluated the relationship between muscle changes during CCRT and the efficacy of durvalumab treatment. Among the 98 patients, the muscle maintenance group had a significantly longer PFS of durvalumab treatment compared to the muscle loss group (29.2 months [95% confidence interval (CI): 17.2-not reached] versus 11.3 months [95% CI: 7.6-22.3]; p = 0.008). The multivariable analysis confirmed that muscle change was a significant predictor of a superior PFS (HR: 0.47 [95% CI: 0.25-0.90]; the p-value was less than 0.05). In contrast, the OS between the groups did not differ significantly (not reached [95% CI: 21.8 months-not reached] and 36.6 months [95% CI: 26.9-not reached]; p = 0.49). Longitudinal muscle changes during CCRT are a predictor of durvalumab's efficacy in patients with NSCLC after CCRT.

The cross-talk between the macro and micro-environment in precursor lesions of pancreatic cancer leads to new and promising circulating biomarkers

Pancreatic cancer (PC) is a clinically challenging tumor to combat due to its advanced stage at diagnosis as well as its resistance to currently available therapies. The absence of early symptoms and known detectable biomarkers renders this disease incredibly difficult to detect/manage. Recent advances in the understanding of PC biology have highlighted the importance of cancer-immune cell interactions, not only in the tumor micro-environment but also in distant systemic sites, like the bone marrow, spleen and circulating immune cells, the so-called macro-environment. The response of the macro-environment is emerging as a determining factor in tumor development by contributing to the formation of an increasingly immunogenic micro-environment promoting tumor homeostasis and progression. We will summarize the key events associated with the feedback loop between the tumor immune micro-environment (TIME) and the tumor immune macroenvironment (TIMaE) in pancreatic precancerous lesions along with how it regulates disease development and progression. In addition, liquid biopsy biomarkers capable of diagnosing PC at an early stage of onset will also be discussed. A clearer understanding of the early crosstalk between micro-environment and macro-environment could contribute to identifying new molecular therapeutic targets and biomarkers, consequently improving early PC diagnosis and treatment.

Overcoming the challenges of primary resistance and relapse after CAR-T cell therapy

INTRODUCTION

While CAR T-cell therapy has led to remarkable responses in relapsed B-cell hematologic malignancies, only 50% of patients ultimately have a complete, sustained response. Understanding the mechanisms of resistance and relapse after CAR T-cell therapy is crucial to future development and improving outcomes.

AREAS COVERED

We review reasons for both primary resistance and relapse after CAR T-cell therapies. Reasons for primary failure include CAR T-cell manufacturing problems, suboptimal fitness of autologous T-cells themselves, and intrinsic features of the underlying cancer and tumor microenvironment. Relapse after initial response to CAR T-cell therapy may be antigen-positive, due to CAR T-cell exhaustion or limited persistence, or antigen-negative, due to antigen-modulation on the target cells. Finally, we discuss ongoing efforts to overcome resistance to CAR T-cell therapy with enhanced CAR constructs, manufacturing methods, alternate cell types, combinatorial strategies, and optimization of both pre-infusion conditioning regimens and post-infusion consolidative strategies.

EXPERT OPINION

There is a continued need for novel approaches to CAR T-cell therapy for both hematologic and solid malignancies to obtain sustained remissions. Opportunities for improvement include development of new targets, optimally combining existing CAR T-cell therapies, and defining the role for adjunctive immune modulators and stem cell transplant in enhancing long-term survival.

Pre-treatment peripheral blood immunophenotyping and response to neoadjuvant chemotherapy in operable breast cancer

BACKGROUND

Tumor immune infiltration and peripheral blood immune signatures have prognostic and predictive value in breast cancer. Whether distinct peripheral blood immune phenotypes are associated with response to neoadjuvant chemotherapy (NAC) remains understudied.

METHODS

Peripheral blood mononuclear cells from 126 breast cancer patients enrolled in a prospective clinical trial (NCT02022202) were analyzed using Cytometry by time-of-flight with a panel of 29 immune cell surface protein markers. Kruskal-Wallis tests or Wilcoxon rank-sum tests were used to evaluate differences in immune cell subpopulations according to breast cancer subtype and response to NAC.

RESULTS

There were 122 evaluable samples: 47 (38.5%) from patients with hormone receptor-positive, 39 (32%) triple-negative (TNBC), and 36 (29.5%) HER2-positive breast cancer. The relative abundances of pre-treatment peripheral blood T, B, myeloid, NK, and unclassified cells did not differ according to breast cancer subtype. In TNBC, higher pre-treatment myeloid cells were associated with lower pathologic complete response (pCR) rates. In hormone receptor-positive breast cancer, lower pre-treatment CD8 + naïve and CD4 + effector memory cells re-expressing CD45RA (TEMRA) T cells were associated with more extensive residual disease after NAC. In HER2 + breast cancer, the peripheral blood immune phenotype did not differ according to NAC response.

CONCLUSIONS

Pre-treatment peripheral blood immune cell populations (myeloid in TNBC; CD8 + naïve T cells and CD4 + TEMRA cells in luminal breast cancer) were associated with response to NAC in early-stage TNBC and hormone receptor-positive breast cancers, but not in HER2 + breast cancer.

TRIAL REGISTRATION

NCT02022202 . Registered 20 December 2013.

Exploring the Potential of Glycolytic Modulation in Myeloid-Derived Suppressor Cells for Immunotherapy and Disease Management

Recent advancements in various technologies have shed light on the critical role of metabolism in immune cells, paving the way for innovative disease treatment strategies through immunometabolism modulation. This review emphasizes the glucose metabolism of myeloid-derived suppressor cells (MDSCs), an emerging pivotal immunosuppressive factor especially within the tumor microenvironment. MDSCs, an immature and heterogeneous myeloid cell population, act as a double-edged sword by exacerbating tumors or mitigating inflammatory diseases through their immune-suppressive functions. Numerous recent studies have centered on glycolysis of MDSC, investigating the regulation of altered glycolytic pathways to manage diseases. However, the specific changes in MDSC glycolysis and their exact functions continue to be areas of ongoing discussion yet. In this paper, we review a range of current findings, including the latest research on the alteration of glycolysis in MDSCs, the consequential functional alterations in these cells, and the outcomes of attempts to modulate MDSC functions by regulating glycolysis. Ultimately, we will provide insights into whether these research efforts could be translated into clinical applications.

Immunomodulatory Precision: A Narrative Review Exploring the Critical Role of Immune Checkpoint Inhibitors in Cancer Treatment

An immune checkpoint is a signaling pathway that regulates the recognition of antigens by T-cell receptors (TCRs) during an immune response. These checkpoints play a pivotal role in suppressing excessive immune responses and maintaining immune homeostasis against viral or microbial infections. There are several FDA-approved immune checkpoint inhibitors (ICIs), including ipilimumab, pembrolizumab, and avelumab. These ICIs target cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed death ligand 1 (PD-L1). Furthermore, ongoing efforts are focused on developing new ICIs with emerging potential. In comparison to conventional treatments, ICIs offer the advantages of reduced side effects and durable responses. There is growing interest in the potential of combining different ICIs with chemotherapy, radiation therapy, or targeted therapies. This article comprehensively reviews the classification, mechanism of action, application, and combination strategies of ICIs in various cancers and discusses their current limitations. Our objective is to contribute to the future development of more effective anticancer drugs targeting immune checkpoints.

Profiling of Tumor-Infiltrating Immune Cells and Their Impact on Survival in Glioblastoma Patients Undergoing Immunotherapy with Dendritic Cells

Glioblastomas (GBM) are the most common primary malignant brain tumors, comprising 2% of all cancers in adults. Their location and cellular and molecular heterogeneity, along with their highly infiltrative nature, make their treatment challenging. Recently, our research group reported promising results from a prospective phase II clinical trial involving allogeneic vaccination with dendritic cells (DCs). To date, six out of the thirty-seven reported cases remain alive without tumor recurrence. In this study, we focused on the characterization of infiltrating immune cells observed at the time of surgical resection. An analytical model employing a neural network-based predictive algorithm was used to ascertain the potential prognostic implications of immunological variables on patients' overall survival. Counterintuitively, immune phenotyping of tumor-associated macrophages (TAMs) has revealed the extracellular marker PD-L1 to be a positive predictor of overall survival. In contrast, the elevated expression of CD86 within this cellular subset emerged as a negative prognostic indicator. Fundamentally, the neural network algorithm outlined here allows a prediction of the responsiveness of patients undergoing dendritic cell vaccination in terms of overall survival based on clinical parameters and the profile of infiltrated TAMs observed at the time of tumor excision.

Understanding the immunosuppressive microenvironment of glioma: mechanistic insights and clinical perspectives

Glioblastoma (GBM), the predominant and primary malignant intracranial tumor, poses a formidable challenge due to its immunosuppressive microenvironment, thereby confounding conventional therapeutic interventions. Despite the established treatment regimen comprising surgical intervention, radiotherapy, temozolomide administration, and the exploration of emerging modalities such as immunotherapy and integration of medicine and engineering technology therapy, the efficacy of these approaches remains constrained, resulting in suboptimal prognostic outcomes. In recent years, intensive scrutiny of the inhibitory and immunosuppressive milieu within GBM has underscored the significance of cellular constituents of the GBM microenvironment and their interactions with malignant cells and neurons. Novel immune and targeted therapy strategies have emerged, offering promising avenues for advancing GBM treatment. One pivotal mechanism orchestrating immunosuppression in GBM involves the aggregation of myeloid-derived suppressor cells (MDSCs), glioma-associated macrophage/microglia (GAM), and regulatory T cells (Tregs). Among these, MDSCs, though constituting a minority (4-8%) of CD45+ cells in GBM, play a central component in fostering immune evasion and propelling tumor progression, angiogenesis, invasion, and metastasis. MDSCs deploy intricate immunosuppressive mechanisms that adapt to the dynamic tumor microenvironment (TME). Understanding the interplay between GBM and MDSCs provides a compelling basis for therapeutic interventions. This review seeks to elucidate the immune regulatory mechanisms inherent in the GBM microenvironment, explore existing therapeutic targets, and consolidate recent insights into MDSC induction and their contribution to GBM immunosuppression. Additionally, the review comprehensively surveys ongoing clinical trials and potential treatment strategies, envisioning a future where targeting MDSCs could reshape the immune landscape of GBM. Through the synergistic integration of immunotherapy with other therapeutic modalities, this approach can establish a multidisciplinary, multi-target paradigm, ultimately improving the prognosis and quality of life in patients with GBM.

The Role of Myeloid-Derived Suppressor Cells in Multiple Sclerosis and Its Animal Model

Myeloid-derived suppressor cells (MDSCs), a heterogeneous cell population that consists of mostly immature myeloid cells, are immunoregulatory cells mainly characterized by their suppressive functions. Emerging findings have revealed the involvement of MDSCs in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). MS is an autoimmune and degenerative disease of the central nervous system characterized by demyelination, axon loss, and inflammation. Studies have reported accumulation of MDSCs in inflamed tissues and lymphoid organs of MS patients and EAE mice, and these cells display dual functions in EAE. However, the contribution of MDSCs to MS/EAE pathogenesis remains unclear. This review aims to summarize our current understanding of MDSC subsets and their possible roles in MS/EAE pathogenesis. We also discuss the potential utility and associated obstacles in employing MDSCs as biomarkers and cell-based therapies for MS.

Local administration of myeloid-derived suppressor cells prevents progression of immune-mediated dry eye disease

Myeloid derived suppressor cells (MDSCs) are a heterogenous population of immature hematopoietic precursors with known immunoregulatory functions. The immunosuppressive role of MDSCs has been highlighted in several inflammatory ophthalmic disorders; however, their therapeutic application in suppressing the immune-mediated changes in dry eye disease (DED) has not been studied. We observed significant reduction in antigen presenting cell (APC) frequencies and their maturation in the presence of MDSCs. Moreover, co-culturing MDSCs with T helper 17 cells (Th17) resulted in reduced Th17 frequencies and their IL-17 expression. On the contrary, MDSCs maintained regulatory T cell frequencies and enhanced their function in-vitro. Furthermore, we delineated the role of interleukin-10 (IL-10) secreted by MDSCs in their immunoregulatory functions. We confirmed these results by flow cytometry analysis and observed that treatment with MDSCs in DED mice effectively suppressed the maturation of APCs, pathogenic Th17 response, and maintained Treg function and significantly ameliorated the disease. The results in this study highlight the potential therapeutic application of MDSCs in treating refractory DED.

Co-delivery of doxorubicin and STING agonist cGAMP for enhanced antitumor immunity

Many chemotherapeutic agents can induce immunogenic cell death (ICD), which leads to the release of danger-associated molecular patterns (DAMPs) and tumor-associated antigens. This process promotes dendritic cells (DCs) maturation and cytotoxic T lymphocyte (CTL) infiltration. However, cancer cells can employ diverse mechanisms to evade the host immune system. Recent studies have shown that stimulator of interferon genes (STING) agonists, such as cGAMP, can amplify ICD-triggered immune responses and enhance the infiltration of immune cells into the tumor microenvironment (TME). Building upon these findings, we constructed a doxorubicin (DOX) and cGAMP co-delivery system (DOX/cGAMP@NPs) for melanoma and triple-negative breast cancer (TNBC) therapy. The results demonstrated that DOX could effectively destroy tumors and induce the release of DAMPs by ICD. Furthermore, in orthotopic 4T1 tumors mice model and subcutaneous B16 tumor mice model, cGAMP could promote the maturation of DCs and CD8+ T cell activation and infiltration by inducing the secretion of type I interferons and pro-inflammation cytokine, which amplified the antitumor immune response induced by DOX. This strategy also promoted the depletion of immunosuppressive cells, potentially alleviating the immunosuppressive TME. In conclusion, our study highlights the combination of DOX-induced ICD and the immune-enhancing properties of cGAMP holds significant implications for future research and clinical applications.

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.

Engineering immune response to regulate cardiovascular disease and cancer

Cardiovascular disease (CVD) and cancer are major contributors to global morbidity and mortality. This book chapter delves into the intricate relationship between the immune system and the pathogenesis of both cardiovascular and cancer diseases, exploring the roles of innate and adaptive immunities, immune regulation, and immunotherapy in these complex conditions. The innate immune system acts as the first line of defense against tissue damage and infection, with a significant impact on the initiation and progression of CVD and cancer. Endothelial dysfunction, a hallmark in CVD, shares commonalities with the tumor microenvironment in cancer, emphasizing the parallel involvement of the immune system in both conditions. The adaptive immune system, particularly T cells, contributes to prolonged inflammation in both CVD and cancer. Regulatory T cells and the intricate balance between different T cell subtypes influence disease progression, wound healing, and the outcomes of ischemic injury and cancer immunosurveillance. Dysregulation of immune homeostasis can lead to chronic inflammation, contributing to the development and progression of both CVD and cancer. Thus, immunotherapy emerged as a promising avenue for preventing and managing these diseases, with strategies targeting immune cell modulation, cytokine manipulation, immune checkpoint blockade, and tolerance induction. The impact of gut microbiota on CVD and cancer too is explored in this chapter, highlighting the role of gut leakiness, microbial metabolites, and the potential for microbiome-based interventions in cardiovascular and cancer immunotherapies. In conclusion, immunomodulatory strategies and immunotherapy hold promise in reshaping the landscape of cardiovascular and cancer health. Additionally, harnessing the gut microbiota for immune modulation presents a novel approach to prevent and manage these complex diseases, emphasizing the importance of personalized and precision medicine in healthcare. Ongoing research and clinical trials are expected to further elucidate the complex immunological underpinnings of CVD and cancer thereby refining these innovative approaches.

The breast cancer tumor microenvironment and precision medicine: immunogenicity and conditions favoring response to immunotherapy

Some main recent researches that have dissected tumor microenvironment (TME) by imaging mass cytometry (IMC) in different subtypes of primary breast cancer samples were considered. The many phenotypic variants, clusters of epithelial tumor and immune cells, their structural features as well as the main genetic aberrations, sub-clonal heterogeneity and their systematic classification also have been examined. Mutational evolution has been assessed in primary and metastatic breast cancer samples. Overall, based on these findings the current concept of precision medicine is questioned and challenged by alternative therapeutic strategies. In the last two decades, immunotherapy as a powerful and harmless tool to fight cancer has received huge attention. Thus, the tumor immune microenvironment (TIME) composition, its prognostic role for clinical course as well as a novel definition of immunogenicity in breast cancer are proposed. Investigational clinical trials carried out by us and other findings suggest that G0-G1 state induced in endocrine-dependent metastatic breast cancer is more suitable for successful immune manipulation. Residual micro-metastatic disease seems to be another specific condition that can significantly favor the immune response in breast and other solid tumors.

Pancreatic cancer tumor microenvironment is a major therapeutic barrier and target

Pancreatic Ductal Adenocarcinoma (PDAC) is projected to become the 2nd leading cause of cancer-related deaths in the United States. Limitations in early detection and treatment barriers contribute to the lack of substantial success in the treatment of this challenging-to-treat malignancy. Desmoplasia is the hallmark of PDAC microenvironment that creates a physical and immunologic barrier. Stromal support cells and immunomodulatory cells face aberrant signaling by pancreatic cancer cells that shifts the complex balance of proper repair mechanisms into a state of dysregulation. The product of this dysregulation is the desmoplastic environment that encases the malignant cells leading to a dense, hypoxic environment that promotes further tumorigenesis, provides innate systemic resistance, and suppresses anti-tumor immune invasion. This desmoplastic environment combined with the immunoregulatory events that allow it to persist serve as the primary focus of this review. The physical barrier and immune counterbalance in the tumor microenvironment (TME) make PDAC an immunologically cold tumor. To convert PDAC into an immunologically hot tumor, tumor microenvironment could be considered alongside the tumor cells. We discuss the complex network of microenvironment molecular and cellular composition and explore how they can be targeted to overcome immuno-therapeutic challenges.

Minimizing false positives for CTC identification

BACKGROUND

Cancer is a leading cause of death worldwide, with metastasis playing a significant role. Circulating Tumour Cells (CTCs) can provide important real-time insights into tumour heterogeneity and clonal evolution, making them an important tool for early diagnosis and patient monitoring. Isolated CTCs are typically identified by immunocytochemistry using positive biomarkers (cytokeratin) and exclusion biomarkers (CD45). However, some white blood cell (WBC) populations can express low levels of CD45 and stain non-specifically for cytokeratin, increasing their risk of misclassification as CTCs. There is a clear need to improve CTC detection and enumeration criteria to unequivocally eliminate interfering WBC populations.

RESULTS

This study showed that, indeed, some granulocyte subpopulations expressed low levels of CD45 and stained non-specifically for cytokeratin, misidentifying them as CTCs. These same cells, however, strongly expressed CD15, allowing them to be identified as WBCs and excluded from CTC classification. Flow cytometry confirmed the specificity of the CD15 antibody for the granulocyte subpopulation. False positives were considerably reduced from 25 % to 0.2 % by double exclusion, combining a CD15 antibody with a highly specific CD45 antibody. Furthermore, complete elimination of potential false positives was achieved using double exclusion in combination with improved selection of cytokeratin antibody. The study emphasises the importance of a robust exclusion criteria and high antibody specificity in CTC immuno-assays for accurate identification of CTC candidates and thorough exclusion of interfering WBC subpopulations.

SIGNIFICANCE

This study demonstrated how misidentifying a granulocyte subpopulation can lead to inaccurate CTC evaluation. However, sensitivity and specificity of CTC identification may be improved by using high-performing antibodies and by including a second exclusion biomarker, in turn, allowing for a more comprehensive clinical application of CTCs.

Role of myeloid-derived suppressor cells in chronic brucellosis

Introduction

Human brucellosis, a Brucella infection caused most common zoonosis in the world, remains a serious public health burden in China. Brucella chronic infection always causes immunosuppressive status and results in severe organ or tissue damages. The aim of this work was to study the role of the myeloid-derived suppressor cells (MDSCs) in human chronic brucellosis.

Methods

Fifty cases of chronic brucellosis and 40 healthy individual controls were enrolled in this study. We analyzed the frequency and subsets of MDSCs in PBMC between the chronic brucellosis and healthy control groups by flow cytometry. Furthermore, we also measured the inflammatory-related cytokines in serum samples and the MDSCs inhibition ability to the proliferation of T cells in vitro.

Results

We found that the frequency of MDSCs in peripheral blood and the level of IL-6 and IL-10 Th2 cytokines and Arginase-1 were significantly increased in chronic brucellosis patients. In addition, we also found that the T cell function was suppressed in vitro by co-culturing with MDSCs from brucellosis patients.

Conclusion

Our study described an increase of immunosuppressive MDSCs in peripheral blood of chronic brucellosis patients. These results contribute to the understanding of Brucella persistent infection, which may provide an insight for effective treatment of chronic brucellosis patients in clinical practice.

Epigenetic modulation of antitumor immunity and immunotherapy response in breast cancer: biological mechanisms and clinical implications

Breast cancer (BC) is the most common non-skin cancer and the second leading cause of cancer death in American women. The initiation and progression of BC can proceed through the accumulation of genetic and epigenetic changes that allow transformed cells to escape the normal cell cycle checkpoint control. Unlike nucleotide mutations, epigenetic changes such as DNA methylation, histone posttranslational modifications (PTMs), nucleosome remodeling and non-coding RNAs are generally reversible and therefore potentially responsive to pharmacological intervention. Epigenetic dysregulations are critical mechanisms for impaired antitumor immunity, evasion of immune surveillance, and resistance to immunotherapy. Compared to highly immunogenic tumor types, such as melanoma or lung cancer, breast cancer has been viewed as an immunologically quiescent tumor which displays a relatively low population of tumor-infiltrating lymphocytes (TIL), low tumor mutational burden (TMB) and modest response rates to immune checkpoint inhibitors (ICI). Emerging evidence suggests that agents targeting aberrant epigenetic modifiers may augment host antitumor immunity in BC via several interrelated mechanisms such as enhancing tumor antigen presentation, activation of cytotoxic T cells, inhibition of immunosuppressive cells, boosting response to ICI, and induction of immunogenic cell death (ICD). These discoveries have established a highly promising basis for using combinatorial approaches of epigenetic drugs with immunotherapy as an innovative paradigm to improve outcomes of BC patients. In this review, we summarize the current understanding of how epigenetic processes regulate immune cell function and antitumor immunogenicity in the context of the breast tumor microenvironment. Moreover, we discuss the therapeutic potential and latest clinical trials of the combination of immune checkpoint blockers with epigenetic agents in breast cancer.

Circulating immunophenotypes are potentially prognostic in follicular cell-derived thyroid cancer

Background

Exploring the immune interface of follicular cell-derived thyroid cancer has prognostic and therapeutic potential. The available literature is lacking for comprehensive immunophenotyping in relation to clinical outcomes. In this study, we identify circulating immunophenotypes associated with thyroid cancer prognosis.

Methods

We conducted a pilot observational study of adults with follicular cell-derived thyroid cancer who underwent surgery at our tertiary care referral center and had consented for flow cytometry on peripheral blood collected at the time of thyroidectomy.

Results

Of the 32 included subjects, 20 (62%) had well differentiated, 5 (16%) had poorly differentiated, and 7 (22%) had anaplastic thyroid cancer. The most frequent AJCC stage was 4 (59%) and the ATA risk of recurrence category was high (56%). Patients with AJCC stage 3/4 demonstrated fewer circulating mononuclear cells (CD45+), more monocytes (CD14+), fewer total lymphocytes (CD14-), fewer T cells (CD3+), fewer CD4+ T cells, fewer gamma-delta T cells, fewer natural killer (NK) T-like cells, more myeloid-derived suppressor cells (MDSCs; Lin-CD33+HLADR-), and more effector memory T cells but similar CD8+ T cells compared to stage1/2. Immunophenotype comparisons by ATA risk stratification and course of thyroid cancer were comparable to those observed for stage, except for significant differences in memory T cell subtypes. The median follow-up was 58 months.

Conclusions

Aggressive follicular cell-derived thyroid cancer either at presentation or during follow-up is associated with down-regulation of the T cell populations specifically CD4+ T cells, gamma-delta T cells, and NK T-like cells but up-regulation of MDSCs and altered memory T cells. These immunophenotypes are potential prognostic biomarkers supporting future investigation for developing targeted immunotherapies against advanced thyroid cancer.

Modulatory effects of supplementation of Lentinula edodes mycelia extract and l-arginine on the therapeutic efficacy of immunogenic chemotherapy in colon cancer-bearing mice

Some chemotherapeutic drugs can induce cancer cell death and enhance antitumor T-cell immunity in cancer-bearing hosts. Immunomodulatory reagents could augment such chemotherapy-induced effects. We previously reported that oral digestion of Lentinula edodes mycelia (L.E.M.) extract or  l-arginine supplementation can augment antitumor T-cell responses in cancer-bearing mice. In this study, the effects of L.E.M. extract with or without  l-arginine on the therapeutic efficacy of immunogenic chemotherapy by 5-fluorouracil (5-FU)/oxaliplatin (L-OHP) and/or cyclophosphamide (CP) are examined using two mouse colon cancer models. In MC38 and CT26 cancer models, therapy with 5-FU/L-OHP/CP significantly suppressed tumor growth, and supplementation with L.E.M. extract halved the tumor volumes. However, the modulatory effect of L.E.M. extract was not significant. In the CT26 cancer model, supplementation with L.E.M. extract and  l-arginine had no clear effect on tumor growth. In contrast, their addition to chemotherapy halved the tumor volumes, although the effect was not significant. There was no difference in the cytotoxicity of tumor-specific cytotoxic T cells generated from CT26-cured mice treated by chemotherapy alone versus chemotherapy combined with L.E.M. extract/ l-arginine. These results indicate that the antitumor effects of immunogenic chemotherapy were too strong to ascertain the effects of supplementation of L.E.M. extract and  l-arginine, but these reagents nonetheless have immunomodulatory effects on the therapeutic efficacy of immunogenic chemotherapy in colon cancer-bearing mice.

Tumor Immune Microenvironment as a New Therapeutic Target for Hepatocellular Carcinoma Development

Development of hepatocellular carcinoma (HCC) is driven by a multistep and long-term process. Because current therapeutic strategies are limited for HCC patients, there are increasing demands for understanding of immunotherapy, which has made technological and conceptual innovations in the treatment of cancer. Here, I discuss HCC immunotherapy in the view of interaction between liver resident cells and immune cells.

Myeloid-derived suppressor cells as a potential biomarker for recurrent pregnancy loss and recurrent implantation failure: Increased levels of MDSCs in recurrent reproductive failure

PROBLEM

Recurrent pregnancy loss (RPL) and recurrent implantation failure (RIF) represent distinct clinical conditions with established definitions, both of which have been linked to an underlying pro-inflammatory state. This study aimed to explore the levels of monocytic-myeloid-derived suppressor cells (M-MDSCs) and regulatory T cells (TReg ) in a cohort of RPL and RIF women and their potential contribution to RPL and RIF.

METHOD OF STUDY

One hundred and eight non-pregnant women were evaluated: 40 RPL, 41 RIF, and 27 fertile healthy controls (HC). A multiparametric flow cytometry approach was utilized to measure and quantify the frequency of M-MDSCs and TReg cells. Cytokine levels in plasma samples were evaluated through a multiplex assay. M-MDSCs levels were significantly higher in RPL and RIF patients compared to HC.

RESULTS

M-MDSCs levels were significantly higher in RPL (9.4% [7-11.6]) and RIF (8.1% [5.9-11.6]) patients compared to HC (6% [4.2-7.6]). An optimal cut-off of 6.1% for M-MDSCs disclosed a sensitivity of 75.6% and 89.7% and a specificity of 57.7% and 57.7% in RIF and RPL groups, respectively. A significant negative correlation was observed between M-MDSCs and TReg (p = .002, r = -.51).

CONCLUSIONS

Our preliminary data allowed us to build a predictive model that may aid as a potential diagnostic tool in the clinic. These findings could provide a better understanding of these pathologies and a better definition of patients that could benefit from personalized treatments to promote pregnancy. Additional exploration and confirmation in distinct study groups are needed to fully assess the diagnostic capabilities of this biomarker.

Hope and Challenges: Immunotherapy in EGFR-Mutant NSCLC Patients

EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for non-small cell lung cancer (NSCLC) patients harboring sensitive EGFR mutations. Sadly, remission is transient, and no approved effective treatment options are available for EGFR-TKI-advanced EGFR-mutant NSCLCs. Although immunotherapy with immune checkpoint inhibitors (ICIs) induces sustained cancer remission in a subset of NSCLCs, ICI therapy exhibits limited activity in most EGFR-mutant NSCLCs. Mechanistically, the strong oncogenic EGFR signaling in EGFR-mutant NSCLCs contributes to a non-inflamed tumor immune microenvironment (TIME), characterized by a limited number of CD8+ T cell infiltration, a high number of regulatory CD4+ T cells, and an increased number of inactivated infiltrated T cells. Additionally, EGFR-mutant NSCLC patients are generally non-smokers with low levels of PD-L1 expression and tumor mutation burden. Promisingly, a small population of EGFR-mutant NSCLCs still durably respond to ICI therapy. The hope of ICI therapy from pre-clinical studies and clinical trials is reviewed in EGFR-mutant NSCLCs. The challenges of application ICI therapy in EGFR-mutant NSCLCs are also reviewed.

Comparison of peripheral leukocyte parameters in patients receiving conventionally and hypofractionated radiotherapy schemes for the treatment of newly diagnosed glioblastoma

Introduction

Treatment for glioblastomas, aggressive and nearly uniformly fatal brain tumors, provide limited long-term success. Immunosuppression by myeloid cells in both the tumor microenvironment and systemic circulation are believed to contribute to this treatment resistance. Standard multi-modality therapy includes conventionally fractionated radiotherapy over 6 weeks; however, hypofractionated radiotherapy over 3 weeks or less may be appropriate for older patients or populations with poor performance status. Lymphocyte concentration changes have been reported in patients with glioblastoma; however, monocytes are likely a key cell type contributing to immunosuppression in glioblastoma. Peripheral monocyte concentration changes in patients receiving commonly employed radiation fractionation schemes are unknown.

Methods

To determine the effect of conventionally fractionated and hypofractionated radiotherapy on complete blood cell leukocyte parameters, retrospective longitudinal concentrations were compared prior to, during, and following standard chemoradiation treatment.

Results

This study is the first to report increased monocyte concentrations and decreased lymphocyte concentrations in patients treated with conventionally fractionated radiotherapy compared to hypofractionated radiotherapy.

Discussion

Understanding the impact of fractionation on peripheral blood leukocytes is important to inform selection of dose fractionation schemes for patients receiving radiotherapy.

Crosstalk between gut microbiota and metastasis in colorectal cancer: implication of neutrophil extracellular traps

Primary colorectal cancer (CRC) often leads to liver metastasis, possibly due to the formation of pre-metastatic niche (PMN) in liver. Thus, unravelling the key modulator in metastasis is important for the development of clinical therapies. Gut microbiota dysregulation is a key event during CRC progression and metastasis. Numerous studies have elucidated the correlation between specific gut bacteria strains (e.g., pks + E. coli and Bacteroides fragilis) and CRC initiation, and gut bacteria translocation is commonly witnessed during CRC progression. Gut microbiota shapes tumor microenvironment (TME) through direct contact with immune cells or through its functional metabolites. However, how gut microbiota facilitates CRC metastasis remains controversial. Meanwhile, recent studies identify the dissemination of bacteria from gut lumen to liver, suggesting the role of gut microbiota in shaping tumor PMN. A pro-tumoral PMN is characterized by the infiltration of immunosuppressive cells and increased pro-inflammatory immune responses. Notably, neutrophils form web-like structures known as neutrophil extracellular traps (NETs) both in primary TME and metastatic sites, NETs are involved in cancer progression and metastasis. In this review, we focus on the role of gut microbiota in CRC progression and metastasis, highlight the multiple functions of different immune cell types in TME, especially neutrophils and NETs, discuss the possible mechanisms of gut microbiota in shaping PMN formation, and provide therapeutical indications in clinic.

In vitro osteoclastogenesis assessment using murine myeloid-derived suppressor cells

The study of myeloid-derived suppressor cells (MDSCs) has been commonly reported in the context of cancer immunology. MDSCs play a key role in cancer growth and progression by inhibiting both innate and adaptive immunity. In addition to the immunosuppressive function of MDSCs in cancer, a novel function of MDSCs as osteoclast precursors has recently been attracting attention. Because monocytic-MDSCs (M-MDSCs) are derived from the same myeloid lineage as macrophages, which are osteoclast progenitors, M-MDSCs can undergo differentiation into osteoclasts, contributing to bone destruction not only in the cancer microenvironment but also in inflammatory conditions including obesity and osteoarthritis. Herein, we present details of the technique to evaluate osteoclasts in vitro, as well as specific techniques to isolate M-MDSCs and identify them. This protocol can be easily adapted to isolate M-MDSCs from most pathologic conditions for easy evaluation.

Assessment of myeloid-derived suppressor cell differentiation ex vivo

Myeloid-derived suppressor cells (MDSCs) are major promoters of progression and metastasis in cancer. MDSCs inhibit the anti-tumor immune response through multiple mechanisms. The main MDSC functions in cancer are related to the inactivation of T cells and the establishment of an immunosuppressive tumor microenvironment (TME) through the production of pro-inflammatory cytokines, among other mechanisms. MDSCs are phenotypically similar to conventional myeloid cells, so their identification is challenging. Moreover, they infiltrate the tumors in limited numbers, and their purification from within the tumors is technically difficult and makes their study a challenge. Therefore, several ex vivo differentiation methods have been established. Our differentiation method leads to MDSCs that closely model tumor-infiltrating counterparts. In this protocol, MDSCs are differentiated from bone marrow precursors by incubation in differentiation medium produced by murine tumor cell lines engineered to constitutively express granulocyte-monocyte colony stimulating factor (GM-CSF). These ex vivo-generated MDSC subsets show high fidelity compared to their natural tumor-infiltrated counterparts. Moreover, the high yields of purification from these ex vivo differentiated MDSC enable their use for validation of new treatments in high-throughput assays. In this chapter we describe the engineering of a stable cell line overexpressing GM-CSF, followed by production and collection of conditioned media supporting MDSC differentiation. Finally, we detail the isolation procedure of bone marrow cells and the specific MDSC differentiation protocol.

Detection of myeloid-derived suppressor cells by flow cytometry

Recently discovered heterogeneous myeloid-derived suppressor cells (MDSCs) are some of the most discussed immunosuppressive cells in contemporary immunology, especially in the tumor microenvironment, and are defined primarily by their T cell immunosuppressive function. The importance of these cells extend to other chronic pathological conditions as well, including chronic infection, inflammation, and tissue remodeling. In many of these conditions, their accumulation/expansion correlates with disease progression, poor prognosis, and reduced survival, which highlights the potential of how these cells may be used in a clinical setting as both prognostic factor and therapeutic target. In healthy individuals, these cells are usually not present in the circulation. Therefore, monitoring this cell population is of potential clinical significance, and utility in basic research. However, these cells have a complex phenotype without one single marker of sufficient specificity for their identification. Flow cytometry is a powerful tool allowing multi-parameter analysis of heterogeneous cell populations, which makes it ideally suitable for the complex phenotypic analysis essential for identification and enumeration of circulating MDSCs. This approach has the potential to provide a novel clinically useful tool for assessment of prognosis and treatment outcomes. The protocol in this chapter describes a flow cytometric analysis to identify and quantify MDSCs from human or mouse whole blood leukocytes and peripheral blood mononuclear cells, as well as a single cell suspension from solid tissue, by using multicolor fluorescence-conjugated antibodies against their surface markers.

Patients with metastatic renal cell carcinoma who receive immune-targeted therapy may derive survival benefit from nephrectomy

BACKGROUND

Nephrectomy, whether in the era of cytokine therapy or targeted therapy, has an important role in the treatment of metastatic renal cell carcinoma. With the advent of immunotherapy, immunotherapy combined with targeted therapy has become the mainstream of systemic therapy, but the role of nephrectomy in metastatic renal cell carcinoma is unclear. In this study, we retrospectively analyzed the impact of nephrectomy on survival in patients with metastatic renal cell carcinoma who received immune-targeted therapy.

METHODS

Patients with metastatic renal cell carcinoma who received immune-targeted therapy at three centers between May 17, 2019 and August 1, 2022 were collected, who were divided into two groups based on whether nephrectomy was performed or not. Survival, response rate and adverse event were compared between the two groups. The primary end point was progression free survival, Subgroup analysis and univariate and multivariable prognostic analyses were also assessed.

RESULTS

With a median follow-up time of 29.3 months (95% CI 28.5-30.2), 165 patients were recruited and divided into two groups based on whether they underwent nephrectomy or not. There were 68 patients in the non-nephrectomy group, 97 in the nephrectomy group. Compared to patients treated with immune-targeted therapy, patients treated with immune-targeted therapy plus nephrectomy were able to achieve survival benefits, with a median PFS of 10.8 months (95% CI 8.3-13.3) and 14.4 months (95% CI 12.6-16.2), respectively, as well as an HR of 0.476 (95% CI 0.323-0.701, p = 0.0002). The 12-month and 18-month PFS rates were 30.9% versus 60.8% and 7.4% versus 25.8%, respectively. The objective response rate (ORR) was 52.9% and 60.8%, respectively, in the non-nephrectomy and nephrectomy groups (p = 0.313), and the disease control rate (DCR) was 75% and 83.5%, respectively (p = 0.179). The most common adverse events related to treatment were hypothyroidism, immune-related pneumonitis and rash. Multivariate analysis showed that primary tumor nephrectomy prior to immune-targeted therapy, clear cell renal carcinoma and oligo metastasis were independent prognostic factors.

CONCLUSIONS

Nephrectomy may provide PFS benefit with tolerable safety for patients with metastatic renal cell carcinoma who receive immune-targeted therapy. In multivariate analysis, nephrectomy, clear cell carcinoma, and oligo-organ metastasis were found to be favorable independent prognostic factors.

The Possible Role of Anti- and Protumor-Infiltrating Lymphocytes in Pathologic Complete Response in Early Breast Cancer Patients Treated with Neoadjuvant Systemic Therapy

The tumor microenvironment, composed of pro- and antitumor immune cells, affects cancer cell behavior. We aimed to evaluate whether tumor-infiltrating lymphocyte (TIL) density and TIL subtypes in core biopsies at the diagnosis of breast cancer patients could predict a pathologic complete response (pCR; ypT0/is ypN0) from neoadjuvant systemic therapy (NST). The TIL subtypes were determined based on the proportions of presumably antitumor (CD8+, CXCL13+) and protumor (PD-1+, FOXP3+) immune cells. A prospective, noninterventional study, including 171 participants undergoing NST, was performed. The median TIL density for the entire cohort was 10% (IQR: 3.5-23.8), and 59 (35%) patients achieved pCR. TIL density was positively associated with pCR (univariately and multivariably). In the multivariable logistic regression model, TIL density was an independent predictor of pCR (p = 0.012, OR 1.27; 95% CI 1.05-1.54) when controlled for age (p = 0.232), Ki-67 (p = 0.001), node-negative status (p = 0.024), and HER2+/triple negative vs. luminal B-like subtype (p < 0.001). In our sample, higher proportions of PD-1+ TILs and FOXP3+ TILs were associated with a higher probability of pCR but the association was not statistically significant and we could not make any conclusions on the direction of associations in the model with all four biomarkers. In the exploratory multivariable analysis, we showed that only higher CD8+ TILs were associated with pCR. In conclusion, TIL density and its subtypes are associated with pCR.

Myeloid-derived suppressor cells: Key immunosuppressive regulators and therapeutic targets in cancer

Myeloid-derived suppressor cell (MDSC) mainly exists in tumor microenvironment (TME) and interferes with normal immune response of the body. These immature differentiated cells cooperate with tumor cells for immune escape and proliferation. The subtypes of MDSC are different in different organisms, and STAT become a high priority for the signaling pathway mediating the regulation of MDSC. The surface of MDSC cell population contains a variety of signal molecular receptors, and its differentiation degree is toilless to be chemotaxis by different factors. The role of MDSC in silencing T cells and promoting regulatory T cells (Treg) is particularly significant. This review mainly contains the origin of MDSC, the characteristics of subgroups, the focus of the study on MDSC heat molecules and signaling pathways, the relationship between MDSC and carcinoma, prognosis and hope to propose an overview of current MDSCs- targeting therapies so as to provide new ideas for cancer treatment.

Low Motor Dexterity and Significant Behaviors Following Hospitalized Isolation in Children

The main objective of this study was to describe the cortical patterns of brain activity during a gross dexterity task and develop a behavioral profile of children experiencing isolation. A cross-sectional assessment was conducted during one visit. Sample: Four pediatric patients who had undergone isolation within a hospital comprised the full data collection. During the collection, participants completed the Box and Blocks Test of gross manual dexterity while undergoing imaging of the motor cortex using functional near-infrared spectroscopy. Participants also completed a Behavioral Assessment System for Children, Third Edition (BASC-3) self-report, which was analyzed along with a parent report to quantify their emotional and social behaviors. All participants displayed lower gross dexterity levels than normative data. Furthermore, three out of the four participants displayed ipsilateral dominance of the motor cortex during the dexterity task. Three of the participants displayed behavioral measures reported within clinically significant or at-risk scores. Clinically significant behavioral scores coupled with lower than expected manual dexterity values and ipsilateral hemispheric dominance indicate that neuroplastic changes can occur in populations undergoing hospitalized isolation. While the impacts of the treatments and isolation in this case cannot be separated, further studies should be conducted to understand these impacts of isolation.

TLR Agonist Therapy of Metastatic Breast Cancer in Mice

Toll-like receptor (TLR) 7/8 and 9 agonists stimulate an innate immune response that supports the development of tumor-specific immunity. Previous studies showed that either agonist individually could cure mice of small tumors and that when used in combination, they could prevent the progression of larger tumors (>300 mm 3 ). To examine whether these agents combined could control metastatic disease, syngeneic mice were challenged with the highly aggressive 66cl4 triple-negative breast tumor cell line. Treatment was not initiated until pulmonary metastases were established, as verified by bioluminescent imaging of luciferase-tagged tumor cells. Results show that combined therapy with TLR7/8 and TLR9 agonists delivered to both primary and metastatic tumor sites significantly reduced tumor burden and extended survival. The inclusion of cyclophosphamide and anti-PD-L1 resulted in optimal tumor control, characterized by a 5-fold increase in the average duration of survival.

Cytokine-Induced Myeloid-Derived Suppressor Cells Demonstrate Their Immunoregulatory Functions to Prolong the Survival of Diabetic Mice

Type 1 diabetes is an inflammatory state. Myeloid-derived suppressive cells (MDSCs) originate from immature myeloid cells and quickly expand to control host immunity during infection, inflammation, trauma, and cancer. This study presents an ex vivo procedure to develop MDSCs from bone marrow cells propagated from granulocyte-macrophage-colony-stimulating factor (GM-CSF), interleukin (IL)-6, and IL-1β cytokines expressing immature morphology and high immunosuppression of T-cell proliferation. The adoptive transfer of cytokine-induced MDSCs (cMDSCs) improved the hyperglycemic state and prolonged the diabetes-free survival of nonobese diabetic (NOD) mice with severe combined immune deficiency (SCID) induced by reactive splenic T cells harvested from NOD mice. In addition, the application of cMDSCs reduced fibronectin production in the renal glomeruli and improved renal function and proteinuria in diabetic mice. Moreover, cMDSCs use mitigated pancreatic insulitis to restore insulin production and reduce the levels of HbA1c. In conclusion, administering cMDSCs propagated from GM-CSF, IL-6, and IL-1β cytokines provides an alternative immunotherapy protocol for treating diabetic pancreatic insulitis and renal nephropathy.

Early variation of inflammatory indexes refines prognostic prediction in patients with hepatocellular carcinoma under systemic treatment

Prognostic markers in advanced hepatocellular carcinoma (HCC) are relevant for clinical decisions. Variations in inflammatory indexes, such as neutrophil-to-lymphocyte ratio (NLR) or platelet-to-lymphocyte ratio (PLR), may correlate with outcomes. In the present study, it was aimed to assess the prognostic role of inflammation indexes in patients with HCC and the evolutionary behavior of these variables within the first month of treatment in a cohort of patients treated with sorafenib from 2009-2021. Subgroups were divided based on the median of each variable ('low' or 'high)'. Survival was estimated using the Kaplan-Meier method. Hazard Ratio (HR) with 95% confidence interval (CI) were estimated using Cox regression models. A total of 373 patients were included, most Child-Pugh-A (83.1%) and BCLC-C (74%). Child-Pugh-A (P=0.011), performance status 0 (P<0.001), no ascites (P<0.001) and NLR<2.6 (P<0.001) were independently associated with improved survival. Baseline PLR was not correlated with survival (P=0.137). Patients who maintained low NLR at baseline and at 1 month (reference subgroup) had improved survival (18.6 months, 95% CI:15.4-22.0) compared with the subgroup that maintained high NLR at baseline and at 1 month (4.2 months, 95% CI:3.6-5.9), with HR: 3.80 (95% CI: 2.89-4.96). The subgroup with low NLR at baseline and high NLR at 1 month had a worse prognosis compared with the reference group (HR:1.4, 95% CI: 1.1-2.0), whereas the subgroup with high NLR at baseline and low at 1 month had similar outcome (HR:1.2, 95% CI: 0.8-1.6). It was concluded that evolutionary variation of NLR has a prognostic role in HCC patients under systemic therapy. This finding suggested that systemic inflammation and early modulation of the immune environment during treatment may correlate with outcomes.

Myeloid cells in the era of cancer immunotherapy: Top 3 unanswered questions

Myeloid cells are increasingly being recognized as central players orchestrating or suppressing antitumor immune responses. With the advent of high-resolution analytical methods such as single-cell technologies, we now appreciate the heterogeneity and complexity of the myeloid compartment in the context of cancer. Because of their highly plastic nature, targeting myeloid cells has shown promising results either as a monotherapy or in combination with immunotherapy in preclinical models and cancer patients. However, the complexity of myeloid cell cellular crosstalk and molecular networks contributes to our poor understanding of the different myeloid cell subsets in tumorigenesis, which makes targeting myeloid cells challenging. Here, we summarize varied myeloid cell subsets and their contribution to tumor progression with a main focus on mononuclear phagocytes. The top three unanswered questions challenging the field of myeloid cells and cancer in the era of cancer immunotherapy are addressed. Through these questions, we discuss how myeloid cell origin and identity influence their function and disease outcomes. Different therapeutic strategies used to target myeloid cells in cancer are also addressed. Finally, the durability of myeloid cell targeting is interrogated by examining the complexity of resultant compensatory cellular and molecular mechanisms.

Innate immune cellular therapeutics in transplantation

Successful organ transplantation provides an opportunity to extend the lives of patients with end-stage organ failure. Selectively suppressing the donor-specific alloimmune response, however, remains challenging without the continuous use of non-specific immunosuppressive medications, which have multiple adverse effects including elevated risks of infection, chronic kidney injury, cardiovascular disease, and cancer. Efforts to promote allograft tolerance have focused on manipulating the adaptive immune response, but long-term allograft survival rates remain disappointing. In recent years, the innate immune system has become an attractive therapeutic target for the prevention and treatment of transplant organ rejection. Indeed, contemporary studies demonstrate that innate immune cells participate in both the initial alloimmune response and chronic allograft rejection and undergo non-permanent functional reprogramming in a phenomenon termed "trained immunity." Several types of innate immune cells are currently under investigation as potential therapeutics in transplantation, including myeloid-derived suppressor cells, dendritic cells, regulatory macrophages, natural killer cells, and innate lymphoid cells. In this review, we discuss the features and functions of these cell types, with a focus on their role in the alloimmune response. We examine their potential application as therapeutics to prevent or treat allograft rejection, as well as challenges in their clinical translation and future directions for investigation.

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.

Tumour-derived small extracellular vesicles contribute to the tumour progression through reshaping the systemic immune macroenvironment

BACKGROUND

Tumour-derived small extracellular vesicles (sEVs) play a crucial role in cancer immunomodulation. In addition to tumour immune microenvironment, the peripheral immune system also contributes significantly to cancer progression and is essential for anticancer immunity. However, a comprehensive definition of which and how peripheral immune lineages are regulated by tumour-derived sEVs during cancer development remains incomplete.

METHODS

In this study, we used mass cytometry with extensive antibody panels to comprehensively construct the systemic immune landscape in response to tumour development and tumour-derived sEVs.

RESULTS

Systemic immunity was dramatically altered by tumour growth and tumour-derived sEVs. Tumour-derived sEVs significantly and extensively affected immune cell population composition as well as intracellular pathways, resulting in an immunosuppressive peripheral and tumour immune microenvironment, characterised by increased myeloid-derived suppressor cells and decreased Ly6C+CD8 T cells. These sEVs largely promoted hematopoietic recovery and accelerate the differentiation towards myeloid-derived suppressor cells. The knockdown of Rab27a reduced sEV secretion from tumour cells and delayed tumour growth and metastasis in vivo.

CONCLUSIONS

These results highlight that tumour-derived sEVs function as a bridge between peripheral immunity regulation and the tumour microenvironment, and contribute to cancer progression through altering the composition and function of the global immune macroenvironment.

The Characteristics of Tumor Microenvironment Predict Survival and Response to Immunotherapy in Adrenocortical Carcinomas

Increasing evidence confirms that tumor microenvironment (TME) can influence tumor progression and treatment, but TME is still understudied in adrenocortical carcinoma (ACC). In this study, we first scored TME using the xCell algorithm, then defined genes associated with TME, and then used consensus unsupervised clustering analysis to construct TME-related subtypes. Meanwhile, weighted gene co-expression network analysis was used to identify modules correlated with TME-related subtypes. Ultimately, the LASSO-Cox approach was used to establish a TME-related signature. The results showed that TME-related scores in ACC may not correlate with clinical features but do promote a better overall survival. Patients were classified into two TME-related subtypes. Subtype 2 had more immune signaling features, higher expression of immune checkpoints and MHC molecules, no CTNNB1 mutations, higher infiltration of macrophages and endothelial cells, lower tumor immune dysfunction and exclusion scores, and higher immunophenoscore, suggesting that subtype 2 may be more sensitive to immunotherapy. 231 modular genes highly relevant to TME-related subtypes were identified, and a 7-gene TME-related signature that independently predicted patient prognosis was established. Our study revealed an integrated role of TME in ACC and helped to identify those patients who really responded to immunotherapy, while providing new strategies on risk management and prognosis prediction.

Xuanhusuo powder has an anti-breast cancer effect by inhibiting myeloid-derived suppressor cell differentiation in the spleen of mice through down-regulating granulocyte colony stimulating factor

OBJECTIVES

To investigate the mechanism of Xuanhusuo powder (XHSP) inhibiting the differentiation of spleen myeloid-derived suppressor cells (MDSCs) in breast cancer mice.

METHODS

Forty-eight BALB/c female mice aged 4-5 weeks were selected, 6 of them were in normal control group, while others were in tumor-bearing models established by orthotopic injection of 4T1 cells into the subcutaneous fat pad of the second pair of left mammary glands. The tumor-bearing mice were divided into granulocyte colony stimulating factor (G-CSF) control group, G-CSF knock-down group, model control group, XHSP small dose group, XHSP medium dose group, XHSP high dose group, and cyclophosphamide (CTX) group, with 6 mice in each group. G-CSF control group and G-CSF knock-down group were constructed by stably transfecting 4T1 cells established by shRNA lentivirus combined with puromycin selection. 48 h after the model was established, XHSP small, medium, high dose group were given 2, 4, 8 g·kg－1·d－1 intragastric administration once a day, respectively. CTX was given 30 mg/kg by intraperitoneal injection, once every other day. The other groups were given an equal volume of 0.5% hydroxymethylcellulose sodium. The drugs in each group were continuously administered for 25 d. Histological changes in spleen were observed by HE staining, the proportion of MDSCs subsets in the spleen were detected by flow cytometry, the co-expression of CD11b and Ly6G in the spleen was detected by immunofluorescence, and the concentration of G-CSF in peripheral blood was detected by ELISA. The spleen of tumor-bearing mice was co-cultured with 4T1 stably transfected cell lines in vitro, treated with XHSP (30 μg/mL) for 24 h, and the co-expression of CD11b and Ly6G in the spleen was detected by immunofluorescence. 4T1 cells were treated by XHSP (10, 30, 100 μg/mL) for 12 h. The mRNA level of G-CSF was detected by realtime RT-PCR.

RESULTS

Compared with normal mice, the red pulp of the spleen in tumor-bearing mice was widened with megakaryocyte infiltration. The proportion of spleen polymorphonucleocyte-like MDSCs (PMN-MDSCs) was significantly increased (P<0.01) and the co-expression of CD11b and Ly6G was increased, and the concentration of G-CSF in peripheral blood was significantly increased (P<0.01). However, XHSP could significantly reduce the proportion of PMN-MDSCs (P<0.05) and the co-expression of CD11b and Ly6G in the spleen, down-regulate the mRNA level of G-CSF in 4T1 cells (P<0.01). The concentration of G-CSF in peripheral blood of tumor-bearing mice also decreased (P<0.05) and tumor volume was reduced and splenomegaly was improved (all P<0.05).

CONCLUSIONS

XHSP may play an anti-breast cancer role by down-regulating G-CSF, negatively regulating the differentiation of MDSCs, and reconstruct the spleen myeloid microenvironment.

Correlation between hypoxia and HGF/c-MET expression in the management of pancreatic cancer

Pancreatic cancer (PC) is very deadly and difficult to treat. The presence of hypoxia has been shown to increase the probability of cancer developing and spreading. Pancreatic ductal adenocarcinoma (PDAC/PC) has traditionally viewed a highly lethal form of cancer due to its high occurrence of early metastases. Desmoplasia/stroma is often thick and collagenous, with pancreatic stellate cells as the primary source (PSCs). Cancer cells and other stromal cells interact with PSCs, promoting disease development. The hepatocyte growth factor (HGF)/c-MET pathway have been proposed as a growth factor mechanism mediating this interaction. Human growth factor (HGF) is secreted by pancreatic stellate cells (PSCs), and its receptor, c-MET, is generated by pancreatic cancer cells and endothelial cells. Hypoxia is frequent in malignant tumors, particularly pancreatic (PC). Hypoxia results from limitless tumor development and promotes survival, progression, and invasion. Hypoxic is becoming a critical driver and therapeutic target of pancreatic cancer as its hypoxia microenvironment is defined. Recent breakthroughs in cancer biology show that hypoxia promotes tumor proliferation, aggressiveness, and therapeutic resistance. Hypoxia-inducible factors (HIFs) stabilize hypoxia signaling. Hypoxia cMet is a key component of pancreatic tumor microenvironments, which also have a fibrotic response, that hypoxia, promotes and modulates. c-Met is a tyrosine-protein kinase. As describe it simply, the MET gene in humans' codes for a protein called hepatocyte growth factor receptor (HGFR). Most cancerous tumors and pancreatic cancer in particular, suffer from a lack of oxygen (PC). Due to unrestrained tumor development, hypoxia develops, actively contributing to tumor survival, progression, and invasion. As the processes by which hypoxia signaling promotes invasion and metastasis become clear, c-MET has emerged as an important determinant of pancreatic cancer malignancy and a potential pharmacological target. This manuscript provides the most current findings on the role of hypoxia and HGF/c-MET expression in the treatment of pancreatic cancer.

CAR T-cells to treat brain tumors

Tremendous success using CAR T therapy in hematological malignancies has garnered significant interest in developing such treatments for solid tumors, including brain tumors. This success, however, has yet to be mirrored in solid organ neoplasms. CAR T function has shown limited efficacy against brain tumors due to several factors including the immunosuppressive tumor microenvironment, blood-brain barrier, and tumor-antigen heterogeneity. Despite these considerations, CAR T-cell therapy has the potential to be implemented as a treatment modality for brain tumors. Here, we review adult and pediatric brain tumors, including glioblastoma, diffuse midline gliomas, and medulloblastomas that continue to portend a grim prognosis. We describe insights gained from different preclinical models using CAR T therapy against various brain tumors and results gathered from ongoing clinical trials. Furthermore, we outline the challenges limiting CAR T therapy success against brain tumors and summarize advancements made to overcome these obstacles.

Effect of Cancer-Related Cachexia and Associated Changes in Nutritional Status, Inflammatory Status, and Muscle Mass on Immunotherapy Efficacy and Survival in Patients with Advanced Non-Small Cell Lung Cancer

Immune checkpoint inhibitor (ICI)-based immunotherapy has significantly improved the survival of patients with advanced non-small cell lung cancer (NSCLC); however, a significant percentage of patients do not benefit from this approach, and predictive biomarkers are needed. Increasing evidence demonstrates that cachexia, a complex syndrome driven by cancer-related chronic inflammation often encountered in patients with NSCLC, may impair the immune response and ICI efficacy. Herein, we carried out a prospective study aimed at evaluating the prognostic and predictive role of cachexia with the related changes in nutritional, metabolic, and inflammatory parameters (assessed by the multidimensional miniCASCO tool) on the survival and clinical response (i.e., disease control rate) to ICI-based immunotherapy in patients with advanced NSCLC. We included 74 consecutive patients. Upon multivariate regression analysis, we found a negative association between IL-6 levels (odds ratio (OR) = 0.9036; 95%CI = 0.8408-0.9711; p = 0.0025) and the miniCASCO score (OR = 0.9768; 95%CI = 0.9102-0.9999; p = 0.0310) with the clinical response. As for survival outcomes, multivariate COX regression analysis found that IL-6 levels and miniCASCO-based cachexia severity significantly affected PFS (hazard ratio (HR) = 1.0388; 95%CI = 1.0230-1.0548; p < 0.001 and HR = 1.2587; 95%CI = 1.0850-1.4602; p = 0.0024, respectively) and OS (HR = 1.0404; 95%CI = 1.0221-1.0589; p < 0.0001 and HR = 2.3834; 95%CI = 1.1504-4.9378; p = 0.0194, respectively). A comparison of the survival curves by Kaplan-Meier analysis showed a significantly lower OS in patients with cachexia versus those without cachexia (p = 0.0323), as well as higher miniCASCO-based cachexia severity (p = 0.0428), an mGPS of 2 versus those with a lower mGPS (p = 0.0074), and higher IL-6 levels (>6 ng/mL) versus those with lower IL-6 levels (≤6 ng/mL) (p = 0.0120). In conclusion, our study supports the evidence that cachexia, with its related changes in inflammatory, body composition, and nutritional parameters, is a key prognostic and predictive factor for ICIs. Further larger studies are needed to confirm these findings and to explore the potential benefit of counteracting cachexia to improve immunotherapy efficacy.

Epigenetically programmed resistance to chemo- and immuno-therapies

Resistance to cancer treatments remains a major barrier in developing cancer cures. While promising combination chemotherapy treatments and novel immunotherapies have improved patient outcomes, resistance to these treatments remains poorly understood. New insights into the dysregulation of the epigenome show how it promotes tumor growth and resistance to therapy. By altering control of gene expression, tumor cells can evade immune cell recognition, ignore apoptotic cues, and reverse DNA damage induced by chemotherapies. In this chapter, we summarize the data on epigenetic remodeling during cancer progression and treatment that enable cancer cell survival and describe how these epigenetic changes are being targeted clinically to overcome resistance.

Contribution of skeletal muscle to cancer immunotherapy: A focus on muscle function, inflammation, and microbiota

Sarcopenia, characterized by degenerative and systemic loss of skeletal muscle mass and function, is a multifactorial syndrome commonly observed in individuals with cancer. Additionally, it represents a poor nutritional status and indicates possible presence of cancer cachexia. Recently, with the extensive application of cancer immunotherapy, the effects of sarcopenia/cachexia on cancer immunotherapy, have gained attention. The aim of this review was to summarize the influence of low muscle mass (sarcopenia/cachexia) on the response and immune-related adverse events to immunotherapy from the latest literature. It was revealed that low muscle mass (sarcopenia/cachexia) has detrimental effects on cancer immunotherapy in most cases, although there were results that were not consistent with this finding. This review also discussed potential causes of the paradox, such as different measure methods, research types, muscle indicators, time point, and cancer type. Mechanically, chronic inflammation, immune cells, and microbiota may be critically involved in regulating the efficacy of immunotherapy under the condition of low muscle mass (sarcopenia/cachexia). Thus, nutritional interventions will likely be promising ways for individuals with cancer to increase the efficacy of immunotherapy in the future, for low muscle mass (sarcopenia/cachexia) is an important prognostic factor for cancer immunotherapy.

Myeloid-derived suppressor cells: A new emerging player in endometriosis

Endometriosis is a common gynecological disorder defined by the presence of endometrial tissue outside the uterus. This is commonly associated with chronic pelvic pain, infertility, and dysmenorrhea, which occurs in approximately 10% of women of reproductive age. Although the exact mechanism remains uncertain, it has been widely accepted to be an estrogen-dependent and inflammatory disease. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of immune cells with immunosuppressive capacity and non-immunological functions. They have been found to be aggressively involved in the pathologies of various disorders. In regards to tumors, the functions of MDSCs have been profoundly shown to inhibit tumor immune response and to promote angiogenesis, tumor metastasis, fibrosis, and epithelial-mesenchymal transition (EMT). In recent years, the elevation of MDSCs in endometriosis was reported by several studies that provoke the assumption that MDSCs might exert similar roles to promote the development of endometriosis. Such that, precision treatments targeting MDSCs might be a promising direction for future study. Herein, we will review the research progress of MDSCs in endometriosis and its potential relevance to the pathogenesis, progression, and therapeutics strategy of endometriosis.