RESUMEN

BACKGROUND: Acute myeloid leukemia (AML) is an immunosuppressive hematologic malignancy with a poor prognosis. An immunosuppressive microenvironment blunts AML therapy. However, the prognostic and therapeutic roles of the factors that mediate immunosuppression in AML remain elusive. METHODS: S100 calcium-binding protein A4 (S100A4) was identified as an immunosuppression-mediating factor by analyzing The Cancer Genome Atlas AML project (TCGA-LAML) transcriptome data and data from AML-bearing mice and AML patients. The S100A4-mediated signaling pathway in myeloid-derived suppressor cells (MDSCs) was evaluated. RESULTS: Elevated S100A4 expression was positively associated with worse survival of AML patients, MDSCs, macrophages and immune checkpoints. S100A4 silencing downregulated the expression levels of MDSC-associated CD14, CCR2 and CCL2, reduced MDSC expansion and impaired MDSC-mediated inhibition of T cell activation and proliferation. S100A4-based prognostic signature (SPS) was an independent risk factor for AML patients. The high-risk group based on SPS was not only associated with adverse survival, MDSCs and macrophages and immune checkpoints but also insensitive to 25 chemotherapy drugs. It was also found that CCAAT enhancer binding protein beta (CEBPB) mediated S100A4 transcription. CEBPB silencing downregulated the expression levels of MDSC-associated CD14, CCR2 and CCL2. Mechanistically, S100A4 activated GP130/JAK2/STAT3 signaling in MDSCs by interacting with the cytokine-binding domain of GP130. Moreover, S100A4 mediated MDSC expansion through JAK2/STAT3 signaling. CONCLUSION: This study uncovers the critical role of S100A4 in MDSC accumulation, and S100A4-based prognostic signature may guide chemotherapy sensitivity in patients with AML.

RESUMEN

BACKGROUND: Immunotherapies for malignant melanoma are challenged by the resistance developed in a significant proportion of patients. Myeloid-derived suppressor cells (MDSC), with their ability to inhibit antitumor T-cell responses, are a major contributor to immunosuppression and resistance to immune checkpoint therapies in melanoma. Damage-associated molecular patterns S100A8, S100A9, and HMGB1, acting as toll like receptor 4 (TLR4) and receptor for advanced glycation endproducts (RAGE) ligands, are highly expressed in the tumor microenvironment and drive MDSC activation. However, the role of TLR4 and RAGE signaling in the acquisition of MDSC immunosuppressive properties remains to be better defined. Our study investigates how the signaling via TLR4 and RAGE as well as their ligands S100A9 and HMGB1, shape MDSC-mediated immunosuppression in melanoma. METHODS: MDSC were isolated from the peripheral blood of patients with advanced melanoma or generated in vitro from healthy donor-derived monocytes. Monocytes were treated with S100A9 or HMGB1 for 72 hours. The immunosuppressive capacity of treated monocytes was assessed in the inhibition of T-cell proliferation assay in the presence or absence of TLR4 and RAGE inhibitors. Plasma levels of S100A8/9 and HMGB1 were quantified by ELISA. Single-cell RNA sequencing (scRNA-seq) was performed on monocytes from patients with melanoma and healthy donors. RESULTS: We showed that exposure to S100A9 and HMGB1 converted healthy donor-derived monocytes into MDSC through TLR4 signaling. Our scRNA-seq data revealed in patient monocytes enriched inflammatory genes, including S100 and those involved in NF-κB and TLR4 signaling, and a reduced major histocompatibility complex II gene expression. Furthermore, elevated plasma S100A8/9 levels correlated with shorter progression-free survival in patients with melanoma. CONCLUSIONS: These findings highlight the critical role of TLR4 and, to a lesser extent, RAGE signaling in the conversion of monocytes into MDSC-like cells, underscore the potential of targeting S100A9 to prevent this conversion, and highlight the prognostic value of S100A8/9 as a plasma biomarker in melanoma.

Asunto(s)

Calgranulina B , Proteína HMGB1 , Melanoma , Células Supresoras de Origen Mieloide , Transducción de Señal , Receptor Toll-Like 4 , Humanos , Calgranulina B/metabolismo , Receptor Toll-Like 4/metabolismo , Proteína HMGB1/metabolismo , Melanoma/inmunología , Melanoma/metabolismo , Melanoma/tratamiento farmacológico , Células Supresoras de Origen Mieloide/metabolismo , Células Supresoras de Origen Mieloide/inmunología , Masculino , Femenino , Microambiente Tumoral/inmunología , Persona de Mediana Edad , Tolerancia Inmunológica

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Photothermal therapy is an alternative cancer therapy that uses a photothermal agent with light irradiation to induce fatal hyperthermia in cancer cells. In a previous study, we found that ex vivo photothermal (PT) treatment induced expression of heat shock proteins (HSPs), such as HSP70, HSP27, and HSP90, in cancer cells; moreover, immunization with lysates from PT-treated tumor cells resulted in significant tumor growth inhibition in tumor-bearing mice. In this study, we hypothesized that sublethal PT treatment of antigen-presenting cells regulates their immunogenicity. We observed the upregulation of expression of intracellular HSP70 and surface activation markers, such as CD40, CD80, CD86, and MHC class II, in sublethal PT-treated cells. The protumoral activity of myeloid-derived suppressor cells (MDSCs) was reduced by sublethal hyperthermia. Furthermore, poorly immunogenic MDSCs were converted into immunogenic antigen-presenting cells by PT treatment. The differences in immunogenicity between MDSCs untreated or treated with the PT technique were evaluated using the Student's t-test or Mann-Whitney rank sum test. Collectively, direct hyperthermic treatment resulted in phenotypic changes and the functional regulation of immune cells.

Asunto(s)

Respuesta al Choque Térmico , Células Supresoras de Origen Mieloide , Terapia Fototérmica , Células Supresoras de Origen Mieloide/metabolismo , Células Supresoras de Origen Mieloide/inmunología , Animales , Ratones , Terapia Fototérmica/métodos , Línea Celular Tumoral , Células Presentadoras de Antígenos/inmunología , Células Presentadoras de Antígenos/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Hipertermia Inducida/métodos , Ratones Endogámicos C57BL , Femenino , Humanos

RESUMEN

The combination of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) with endocrine therapy (ET) is the standard-of-care for estrogen receptor (ER)-positive, HER2-negative (ER+/HER2- advanced/metastatic breast cancer (mBC). However, the impact of CDK4/6i on circulating immune cells and circulating tumor cells (CTCs) in patients receiving CDK4/6i and ET (CDK4/6i+ET) remains poorly understood. This was a prospective cohort study including 44 patients with ER+/HER2- mBC treated with CDK4/6i+ET in either first or second line. Peripheral blood samples were collected before (baseline) and 3 months (t2) after therapy. Immune cell's subsets were quantified by flow cytometry, and microfluidic-captured CTCs were counted and classified according to the expression of cytokeratin and/or vimentin. Patients were categorized according to response as responders (progression-free survival [PFS] ≥ 6.0 months; 79.1%) and non-responders (PFS < 6.0 months; 20.9%). CDK4/6i+ET resulted in significant changes in the hematological parameters, including decreased hemoglobin levels and increased mean corpuscular volume, as well as reductions in neutrophil, eosinophil, and basophil counts. Specific immune cell subsets, such as early-stage myeloid-derived suppressor cells, central memory CD4+ T cells, and Vδ2+ T cells expressing NKG2D, decreased 3 months after CDK4/6i+ET. Additionally, correlations between the presence of CTCs and immune cell populations were observed, highlighting the interplay between immune dysfunction and tumor dissemination. This study provides insights into the immunomodulatory effects of CDK4/6i+ET, underscoring the importance of considering immune dynamics in the management of ER+/HER2- mBC.

Asunto(s)

Neoplasias de la Mama , Quinasa 4 Dependiente de la Ciclina , Quinasa 6 Dependiente de la Ciclina , Células Neoplásicas Circulantes , Inhibidores de Proteínas Quinasas , Humanos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/sangre , Femenino , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 4 Dependiente de la Ciclina/metabolismo , Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 6 Dependiente de la Ciclina/metabolismo , Células Neoplásicas Circulantes/patología , Células Neoplásicas Circulantes/efectos de los fármacos , Células Neoplásicas Circulantes/metabolismo , Persona de Mediana Edad , Inhibidores de Proteínas Quinasas/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Anciano , Metástasis de la Neoplasia , Adulto , Estudios Prospectivos

RESUMEN

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.

RESUMEN

BACKGROUND: Toll-like receptor 9 (TLR9) agonists induce inflammatory responses that promote the killing of infectious micro-organisms, cancer cells and develop adaptive immune responses. Their ability as immunomodulators to enhance the activity of checkpoint inhibitors (CPI) in treating liver tumors is limited in part by the distinctive biology of intrahepatic myeloid-derived suppressor cells (MDSC) and challenges with tumor-specific therapeutic delivery. We have shown that the regional delivery of type C TLR9 agonist via pressure-enabled drug delivery (PEDD) system improves delivery to the tumor, enhances depletion of MDSCs and overall, stimulates the immune system in combination with or without CPI. Currently, CPIs are delivered intravenously, although there is a growing interest in its subcutaneous (SQ) administration. We compared nelitolimod formerly known as SD-101 administered using PEDD in combination with systemic (Sys) or SQ CPI in murine liver metastases (LM). METHODS: The LM model was developed by injecting MC38-Luc cells via the spleen of 8-12 week old male C57/BL6 mice followed by splenectomy. After a week, fluorescently labeled nelitolimod (10 µg/mouse) was delivered via PEDD and co-administered anti-programmed cell death-1 (α-PD-1) either via Sys or SQ. Tumor burden was monitored by in vivo imaging system. Serum cytokine levels were analyzed by Luminex. Tissues were harvested on Day 3 (D3) or Day 10 (D10) post-PEDD to enrich CD45+ cells and were analyzed via NanoString targeted transcriptomics (D3) or flow cytometry (FC, D10) to interrogate immune cell populations (D10). For NanoString analysis, the innate immune panels were selected, and for FC, MDSCs (CD11b+Gr1+), B cells (B220+), dendritic cells (DC, CD11c+), T (CD3+) cells, and M1-like macrophages (F4/80+CD38+Egr2-) were quantified. RESULTS: Nelitolimod delivered via PEDD resulted in changes in innate and adaptive immune cells within LM, including depletion of liver MDSC and increased M1-like macrophages in the liver, which are supportive of antitumor immunity. While CPI monotherapy failed to control tumor progression, nelitolimod and CPI combination improved LM control, survival and antitumor immunity beyond the nelitolimod monotherapy effect, irrespective of CPI delivery route. CONCLUSION: The SQ route of CPI delivery was equivalent to Sys in combination with nelitolimod, suggesting SQ-CPI may be a rational choice in combination with PEDD of nelitolimod for liver tumor treatment.

Asunto(s)

Inhibidores de Puntos de Control Inmunológico , Neoplasias Hepáticas , Células Supresoras de Origen Mieloide , Animales , Ratones , Células Supresoras de Origen Mieloide/efectos de los fármacos , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/secundario , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Humanos , Sistemas de Liberación de Medicamentos , Ratones Endogámicos C57BL , Línea Celular Tumoral

RESUMEN

Introduction: Myeloid-derived suppressor cell (MDSC) exhibits immunosuppressive functions and affects cancer progression, but its relationship with prostate cancer remains unclear. We elucidated the association of polymorphonuclear MDSC (PMN-MDSC) and monocytic MDSC (M-MDSC) levels of the total peripheral blood mononuclear cells (PBMCs) with prostate cancer progression and evaluated their roles as prognostic indicators. Methods: We enrolled 115 patients with non-metastatic hormone-sensitive prostate cancer (nmHSPC, n = 62), metastatic hormone-sensitive prostate cancer (mHSPC, n = 23), and metastatic castration-resistant prostate cancer (mCRPC, n = 30). Subsequently, the proportions of MDSCs in each disease progression were compared. Log-rank tests and multivariate Cox regression analyses were performed to ascertain the associations of overall survival. Results: The patients with mCRPC had significantly higher PMN-MDSC percentage than those with nmHSPC and mHSPC (P = 7.73 × 10-5 and 0.0014). Significantly elevated M-MDSC levels were observed in mCRPC patients aged <70 years (P = 0.016) and with a body mass index (BMI) <25 kg/m2 (P = 0.043). The high PMN-MDSC group had notably shorter median survival duration (159 days) than the low PMN-MDSC group (768 days, log-rank P = 0.018). In the multivariate analysis including age, BMI, and MDSC subset, PMN-MDSC was significantly associated with prognosis (hazard ratios, 3.48; 95% confidence interval: 1.05-11.56, P = 0.042). Discussion: PMN-MDSC levels are significantly associated with mCRPC prognosis. Additionally, we highlight the remarkable associations of age and BMI with M-MDSC levels in mCRPC, offering novel insights into MDSC dynamics in prostate cancer progression.

Asunto(s)

Células Supresoras de Origen Mieloide , Neoplasias de la Próstata Resistentes a la Castración , Humanos , Masculino , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Neoplasias de la Próstata Resistentes a la Castración/inmunología , Neoplasias de la Próstata Resistentes a la Castración/patología , Neoplasias de la Próstata Resistentes a la Castración/mortalidad , Neoplasias de la Próstata Resistentes a la Castración/sangre , Anciano , Pronóstico , Persona de Mediana Edad , Neutrófilos/inmunología , Progresión de la Enfermedad , Anciano de 80 o más Años , Metástasis de la Neoplasia

RESUMEN

TPO receptor agonists (TPO-RAs) are a class of clinical second-line regimens for the treatment of primary immune thrombocytopenia (ITP). It can promote megakaryocyte maturation and increase platelet production, but its effect on immunosuppressive cells in patients with ITP has not been explored. Sixty-two ITP patients and 34 healthy controls (HCs) were included in this study. The proportion and functions of myeloid-derived immunosuppressive cells (MDSCs) in ITP patients and HCs were investigated. We found that the proportion and function of MDSCs in ITP patients treated with TPO-RAs were significantly higher than those treated with glucocorticoids (GCs), which was correlated with the clinical efficacy. The proportion and function of cytotoxic Th1 cells and CD8+T cells decreased, while the proportion and immunosuppressive function of Treg cells increased in ITP patients treated with TPO-RAs. We further proved, through MDSC depletion tests, that the inhibitory effect of MDSCs on Th1 cells and the promotion of Treg cells in the original immune micro-environment of GCs-treated ITP patients were impaired; however, these MDSCs' functions were improved in TPO-RAs-treated patients. Finally, we found that the KLF9 gene in MDSCs cells of ITP patients treated with TPO-RAs was down-regulated, which contribute to the higher mRNA expression of GADD34 gene and improved function of MDSCs. These results demonstrate a novel mechanism of TPO-RAs for the treatment of ITP through the assessment of MDSCs and their subsequent impact on T cells, which provides a new basis for TPO-RAs as first-line treatment approach to the treatment of ITP.

Asunto(s)

Células Supresoras de Origen Mieloide , Púrpura Trombocitopénica Idiopática , Receptores de Trombopoyetina , Humanos , Células Supresoras de Origen Mieloide/efectos de los fármacos , Células Supresoras de Origen Mieloide/inmunología , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Púrpura Trombocitopénica Idiopática/inmunología , Femenino , Masculino , Receptores de Trombopoyetina/agonistas , Adulto , Persona de Mediana Edad , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología , Anciano , Adulto Joven , Células TH1/inmunología , Células TH1/efectos de los fármacos , Inmunomodulación/efectos de los fármacos , Trombopoyetina/uso terapéutico , Trombopoyetina/farmacología

RESUMEN

Immune cell migration is required for the development of an effective and robust immune response. This elegant process is regulated by both cellular and environmental factors, with variables such as immune cell state, anatomical location, and disease state that govern differences in migration patterns. In all cases, a major factor is the expression of cell surface receptors and their cognate ligands. Rapid adaptation to environmental conditions partly depends on intrinsic cellular immune factors that affect a cell's ability to adjust to new environment. In this review, we discuss both myeloid and lymphoid cells and outline key determinants that govern immune cell migration, including molecules required for immune cell adhesion, modes of migration, chemotaxis, and specific chemokine signaling. Furthermore, we summarize tumor-specific elements that contribute to immune cell trafficking to cancer, while also exploring microenvironment factors that can alter these cellular dynamics within the tumor in both a pro and antitumor fashion. Specifically, we highlight the importance of the secretome in these later aspects. This review considers a myriad of factors that impact immune cell trajectory in cancer. We aim to highlight the immunotherapeutic targets that can be harnessed to achieve controlled immune trafficking to and within tumors.

Asunto(s)

Movimiento Celular , Neoplasias , Microambiente Tumoral , Humanos , Neoplasias/inmunología , Neoplasias/patología , Microambiente Tumoral/inmunología , Animales , Linfocitos/inmunología , Linfocitos/metabolismo , Transducción de Señal

RESUMEN

Myeloid-derived suppressor cells (MDSCs) play an essential role in suppressing the antitumor activity of T lymphocytes in solid tumors, thus representing an attractive therapeutic target to enhance the efficacy of immunotherapy. However, the differences in protein expression between MDSCs and their physiological counterparts, particularly polymorphonuclear neutrophils (PMNs), remain inadequately characterized, making the specific identification and targeting of MDSCs difficult. PMNs and PMN-MDSCs share markers such as CD11b+CD14-CD15+/CD66b+, and some MDSC-enriched markers are emerging, such as LOX-1 and CD84. More proteomics studies are needed to identify the signature and markers for MDSCs. Recently, we reported the induced differentiation of isogenic PMNs or MDSCs (referred to as iPMNs and iMDSCs, respectively) from the human promyelocytic cell line HL60. Here, we profiled the global proteomics and membrane proteomics of these cells with quantitative mass spectrometry, which identified a 41-protein signature ("cluster 6") that was upregulated in iMDSCs compared with HL60 and iPMN. We further integrated our cell line-based proteomics data with a published proteomics dataset of normal human primary monocytes and monocyte-derived MDSCs induced by cancer-associated fibroblasts. The analysis identified a 38-protein signature that exhibits an upregulated expression pattern in MDSCs compared with normal monocytes or PMNs. These signatures may provide a hypothesis-generating platform to identify protein biomarkers that phenotypically distinguish MDSCs from their healthy counterparts, as well as potential therapeutic targets that impair MDSCs without harming normal myeloid cells.

Asunto(s)

Diferenciación Celular , Células Supresoras de Origen Mieloide , Neutrófilos , Proteómica , Humanos , Células Supresoras de Origen Mieloide/metabolismo , Células Supresoras de Origen Mieloide/citología , Neutrófilos/metabolismo , Neutrófilos/citología , Proteómica/métodos , Células HL-60 , Línea Celular

Asunto(s)

Reprogramación Celular , Células Mieloides , Humanos , Células Mieloides/metabolismo , Células Mieloides/inmunología , Animales , Transducción de Señal

RESUMEN

RATIONALE: Androgen deprivation therapy (ADT) is the primary treatment for recurrent and metastatic prostate cancer. In addition to direct antitumor effects, ADT has immunomodulatory effects such as promoting T-cell infiltration and enhancing antigen processing/presentation. Previous studies in our laboratory have demonstrated that ADT also leads to increased expression of the androgen receptor (AR) and increased recognition of prostate tumor cells by AR-specific CD8+T cells. We have also demonstrated that ADT combined with a DNA vaccine encoding the AR significantly slowed tumor growth and improved the survival of prostate tumor-bearing mice. The current study aimed to investigate the impact of the timing and sequencing of ADT with vaccination on the tumor immune microenvironment in murine prostate cancer models to further increase the antitumor efficacy of vaccines. METHODS: Male FVB mice implanted with Myc-CaP tumor cells, or male C57BL/6 mice implanted with TRAMP-C1 prostate tumor cells, were treated with a DNA vaccine encoding AR (pTVG-AR) and ADT. The sequence of administration was evaluated for its effect on tumor growth, and tumor-infiltrating immune populations were characterized. RESULTS: Vaccination prior to ADT (pTVG-AR → ADT) significantly enhanced antitumor responses and survival. This was associated with increased tumor infiltration by CD4+ and CD8+ T cells, including AR-specific CD8+T cells. Depletion of CD8+T cells prior to ADT significantly worsened overall survival. Following ADT treatment, however, Gr1+ myeloid-derived suppressor cells (MDSCs) increased, and this was associated with fewer infiltrating T cells and reduced tumor growth. Inhibiting Gr1+MDSCs recruitment, either by using a CXCR2 antagonist or by cycling androgen deprivation with testosterone replacement, improved antitumor responses and overall survival. CONCLUSION: Vaccination prior to ADT significantly improved antitumor responses, mediated in part by increased infiltration of CD8+T cells following ADT. Targeting MDSC recruitment following ADT further enhanced antitumor responses. These findings suggest logical directions for future clinical trials to improve the efficacy of prostate cancer vaccines.

Asunto(s)

Vacunas contra el Cáncer , Neoplasias de la Próstata , Receptores Androgénicos , Masculino , Animales , Ratones , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/inmunología , Neoplasias de la Próstata/patología , Receptores Androgénicos/metabolismo , Vacunas contra el Cáncer/uso terapéutico , Vacunas contra el Cáncer/farmacología , Vacunas contra el Cáncer/inmunología , Vacunas de ADN/uso terapéutico , Vacunas de ADN/farmacología , Antagonistas de Andrógenos/uso terapéutico , Antagonistas de Andrógenos/farmacología , Línea Celular Tumoral , Ratones Endogámicos C57BL , Vacunación , Humanos , Microambiente Tumoral , Modelos Animales de Enfermedad , Linfocitos T CD8-positivos/inmunología

RESUMEN

Triple-negative breast cancer (TNBC) is an aggressive and highly metastatic type of tumor. TNBC is often enriched in tumor-infiltrating neutrophils (TINs), which support cancer growth in part by counteracting tumor-infiltrating lymphocytes (TILs). Prior studies identified the enhancer of zeste homolog 2 (EZH2) as a pro-tumor methyltransferase in primary and metastatic TNBCs. We hypothesized that EZH2 inhibition in TNBC cells per se would exert antitumor activity by altering the tumor immune microenvironment. To test this hypothesis, we used CRISPR to generate EZH2 gene knockout (KO) and overexpressing (OE) lines from parent (wild-type-WT) 4T1 cells, an established murine TNBC model, resulting in EZH2 protein KO and OE, respectively. In vitro, EZH2 KO and OE cells showed early, transient changes in replicative capacity and invasiveness, and marked changes in surface marker profile and cytokine/chemokine secretion compared to WT cells. In vivo, EZH2 KO cells showed significantly reduced primary tumor growth and a 10-fold decrease in lung metastasis compared to WT cells, while EZH2 OE cells were unchanged. Compared to WT tumors, TIN:TIL ratios were greatly reduced in EZH2 KO tumors but unchanged in EZH2 OE tumors. Thus, EZH2 is key to 4T1 aggressiveness as its tumor-intrinsic knockout alters their in vitro secretome and in vivo primary tumor growth, TIN/TIL poise, and metastasis.

Asunto(s)

Proteína Potenciadora del Homólogo Zeste 2 , Neoplasias Pulmonares , Linfocitos Infiltrantes de Tumor , Neoplasias de la Mama Triple Negativas , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/inmunología , Animales , Neoplasias Pulmonares/secundario , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/inmunología , Ratones , Femenino , Línea Celular Tumoral , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Microambiente Tumoral/inmunología , Proliferación Celular , Humanos , Ratones Endogámicos BALB C , Técnicas de Inactivación de Genes , Modelos Animales de Enfermedad , Regulación Neoplásica de la Expresión Génica

RESUMEN

Mesenchymal stem/stromal cells (MSCs) modulate the immune response through interactions with innate immune cells. We previously demonstrated that MSCs alleviate ocular autoimmune inflammation by directing bone marrow cell differentiation from pro-inflammatory CD11bhiLy6ChiLy6Glo cells into immunosuppressive CD11bmidLy6CmidLy6Glo cells. Herein, we analyzed MSC-induced CD11bmidLy6Cmid cells using single-cell RNA sequencing and compared them with CD11bhiLy6Chi cells. Our investigation revealed seven distinct immune cell types including myeloid-derived suppressor cells (MDSCs) in the CD11bmidLy6Cmid cells, while CD11bhiLy6Chi cells included mostly monocytes/macrophages with a small cluster of neutrophils. These MSC-induced MDSCs highly expressed Retnlg, Cxcl3, Cxcl2, Mmp8, Cd14, and Csf1r as well as Arg1. Comparative analyses of CSF-1RhiCD11bmidLy6Cmid and CSF-1RloCD11bmidLy6Cmid cells demonstrated that the former had a homogeneous monocyte morphology and produced elevated levels of interleukin-10. Functionally, these CSF-1RhiCD11bmidLy6Cmid cells, compared with the CSF-1RloCD11bmidLy6Cmid cells, inhibited CD4+ T cell proliferation and promoted CD4+CD25+Foxp3+ Treg expansion in culture and in a mouse model of experimental autoimmune uveoretinitis. Resistin-like molecule (RELM)-γ encoded by Retnlg, one of the highly upregulated genes in MSC-induced MDSCs, had no direct effects on T cell proliferation, Treg expansion, or splenocyte activation. Together, our study revealed a distinct transcriptional profile of MSC-induced MDSCs and identified CSF-1R as a key cell-surface marker for detection and therapeutic enrichment of MDSCs.

Asunto(s)

Células Madre Mesenquimatosas , Células Supresoras de Origen Mieloide , Análisis de la Célula Individual , Animales , Ratones , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/citología , Células Supresoras de Origen Mieloide/metabolismo , Células Supresoras de Origen Mieloide/inmunología , Análisis de la Célula Individual/métodos , Transcriptoma , Diferenciación Celular/genética , Perfilación de la Expresión Génica , Modelos Animales de Enfermedad , Uveítis/genética , Uveítis/inmunología , Uveítis/metabolismo , Humanos

RESUMEN

RATIONALE: Androgen deprivation therapy (ADT) is pivotal in treating recurrent prostate cancer and is often combined with external beam radiation therapy (EBRT) for localized disease. However, for metastatic castration-resistant prostate cancer, EBRT is typically only used in the palliative setting, because of the inability to radiate all sites of disease. Systemic radiation treatments that preferentially irradiate cancer cells, known as radiopharmaceutical therapy or targeted radionuclide therapy (TRT), have demonstrable benefits for treating metastatic prostate cancer. Here, we explored the use of a novel TRT, 90Y-NM600, specifically in combination with ADT, in murine prostate tumor models. METHODS: 6-week-old male FVB mice were implanted subcutaneously with Myc-CaP tumor cells and given a single intravenous injection of 90Y-NM600, in combination with ADT (degarelix). The combination and sequence of administration were evaluated for effect on tumor growth and infiltrating immune populations were analyzed by flow cytometry. Sera were assessed to determine treatment effects on cytokine profiles. RESULTS: ADT delivered prior to TRT (ADT→TRT) resulted in significantly greater antitumor response and overall survival than if delivered after TRT (TRT→ADT). Studies conducted in immunodeficient NRG mice failed to show a difference in treatment sequence, suggesting an immunological mechanism. Myeloid-derived suppressor cells (MDSCs) significantly accumulated in tumors following TRT→ADT treatment and retained immune suppressive function. However, CD4+ and CD8+ T cells with an activated and memory phenotype were more prevalent in the ADT→TRT group. Depletion of Gr1+MDSCs led to greater antitumor response following either treatment sequence. Chemotaxis assays suggested that tumor cells secreted chemokines that recruited MDSCs, notably CXCL1 and CXCL2. The use of a selective CXCR2 antagonist, reparixin, further improved antitumor responses and overall survival when used in tumor-bearing mice treated with TRT→ADT. CONCLUSION: The combination of ADT and TRT improved antitumor responses in murine models of prostate cancer, however, this was dependent on the order of administration. This was found to be associated with one treatment sequence leading to an increase in infiltrating MDSCs. Combining treatment with a CXCR2 antagonist improved the antitumor effect of this combination, suggesting a possible approach for treating advanced human prostate cancer.

Asunto(s)

Células Supresoras de Origen Mieloide , Neoplasias de la Próstata , Animales , Masculino , Células Supresoras de Origen Mieloide/efectos de los fármacos , Células Supresoras de Origen Mieloide/metabolismo , Células Supresoras de Origen Mieloide/inmunología , Ratones , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/radioterapia , Radiofármacos/uso terapéutico , Radiofármacos/farmacología , Humanos , Línea Celular Tumoral , Radioisótopos de Itrio/uso terapéutico , Radioisótopos de Itrio/farmacología , Modelos Animales de Enfermedad , Antagonistas de Andrógenos/uso terapéutico , Antagonistas de Andrógenos/farmacología , Terapia Combinada

RESUMEN

BACKGROUND: Leukocyte telomere length (LTL) and myeloid-derived suppressor cells (MDSC) are associated with aging and the development and progression of cancer. However, the exact nature of this relationship remains unclear. Our study aimed to investigate the potential of LTL and MDSC as diagnostic biomarkers for prostate cancer while also seeking to deepen our understanding of the relationship of these potential biomarkers to each other. METHODS: Our study involved patients undergoing a prostate biopsy. We analyzed the relative LTL in genomic DNA obtained from peripheral blood leukocytes as well as the percentage of MDSC and their subtypes in peripheral blood mononuclear cells (PBMC). Our evaluation focused on examining the relationship between LTL and MDSC and pathological diagnoses as well as investigating the correlation between LTL and MDSC levels. RESULTS: In our study of 102 participants, 56 were pathologically diagnosed with localized prostate cancer (cancer group), while 46 tested negative (control group). The cancer group exhibited significantly shorter LTL in comparison to the control group (p = 0.024). Additionally, the cancer group showed a tendency towards a higher percentage of monocytic MDSC (M-MDSC), although this difference did not reach statistical significance (p = 0.056). Our multivariate logistic regression analysis revealed that patients with shorter LTL and higher percentages of M-MDSC had a 2.98-fold (95% CI = 1.001-8.869, p = 0.049) and 3.03-fold (95% CI = 1.152-7.977, p = 0.025) increased risk of prostate cancer diagnosis, respectively. There was also a significant negative correlation between LTL and M-MDSC. (r = -0.347, p < 0.001). CONCLUSIONS: Our research has established a correlation between LTL and MDSC in patients undergoing biopsy for prostate cancer. Notably, we observed that individuals with localized prostate cancer tend to have shorter LTL and a higher percentage of M-MDSC prior to their diagnosis. These findings suggest that LTL and M-MDSC could potentially serve as adjunctive biomarkers for the early diagnosis of prostate cancer.

RESUMEN

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous family of myeloid cells that suppress T cell immunity in tumor-bearing hosts. The present study aimed to examine roles of T and MDSC subsets in lung malignancy. The study analyzed 102 cases with lung malignancy and 34 healthy individuals. Flow cytometry was performed for identification of T cell and MDSC subsets and their phenotypic characteristics in peripheral blood. The lung malignancy cases exhibited lower frequencies of granulocyte-like MDSCs (G-MDSCs) expressing PD-L2 and PD-L1 than healthy controls (P=0.013 and P<0.001, respectively). Additionally, there was a higher frequency of monocyte-like MDSCs (M-MDSCs) expressing PD-L1 in the peripheral blood of patients with lung malignancy than healthy controls (P<0.001). The frequencies of G-MDSCs and M-MDSCs were positively correlated with proportions of PD-1+ and CTLA-4+ regulatory T cells (Tregs). In vitro co-culture assay demonstrated M-MDSCs of lung malignancy enhanced naive T cell apoptosis and promoted Treg subset differentiation compared with M-MDSCs of healthy controls. The findings suggested accumulation of MDSC subsets in lung malignancy and MDSCs expressing PD-L2 and PD-L1 induced Treg expansion by binding to PD-1 on the surface of Tregs.

RESUMEN

Endometriosis is a chronic, painful disease whose etiology remains unknown. The development of novel therapies and diagnostic tools for endometriosis has been limited due in part to challenges in studying the disease. Recently, a few reports have shown that immunosuppressive cells, such as myeloid-derived suppressor cell (MDSC), may promote the progression of endometriosis. MDSCs are a heterogeneous group of myeloid cells with potent immunosuppressive and angiogenic properties. Here, in this chapter, we provide a detailed protocol to phenotype MDSC as well as to isolate and assess the functionality from the peritoneal cavity of a mouse model of surgically induced endometriosis. Importantly, the current mouse model has been widely used to study how the immune system, hormones, and environmental factors affect endometriosis as well as the effects of endometriosis on fertility and pain.

Asunto(s)

Endometriosis , Células Supresoras de Origen Mieloide , Humanos , Ratones , Femenino , Animales , Fenotipo

RESUMEN

Cancer is the leading cause of death globally superseded only by cardiovascular diseases, and novel strategies to overcome therapeutic resistance against existing cancer treatments are urgently required. Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells with potent immunosuppressive capacity against well-established anti-tumour effectors such as natural killer cells (NK cells) and T cells thereby promoting cancer initiation and progression. Critically, MDSCs are readily identified in almost all tumour types and human cancer patients, and numerous studies in the past decade have recognised their role in contributing to therapeutic resistance against all four pillars of modern cancer treatment, namely surgery, chemotherapy, radiotherapy and immunotherapy. MDSCs suppress anti-tumour immunity through a plethora of mechanisms including the well-characterised arginase 1 (Arg1), inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS)-mediated pathways, along with several other more recently discovered. MDSCs are largely absent in healthy homeostatic states and predominantly exist in pathological conditions, making them attractive therapeutic targets. However, the lack of specific markers identified for MDSCs to date greatly hindered therapeutic development, and currently there are no clinically approved drugs that specifically target MDSCs. Methods to deplete MDSCs clinically and inhibit their immunosuppressive function will be crucial in advancing cancer treatment and to overcome treatment resistance. This review provides a detailed overview of the current understandings behind the mechanisms of MDSC-mediated suppression of anti-tumour immunity, and discusses potential strategies to target MDSC immunosuppressive mechanisms to overcome therapeutic resistance.

RESUMEN

BACKGROUND: Gastric cancer is primarily treated by surgery; however, little is known about the changes in the intraperitoneal immune environment and the prognostic impact of surgery. Surgical stress and cancer-associated inflammation cause immune cells to mobilize into the abdominal cavity via numerous cytokines. One such cytokine, CX3CR1, has various immune-related functions that remain to be fully explained. We characterized the intraperitoneal immune environment by investigating CX3CR1+ cells in intraperitoneal lavage fluid during gastric cancer surgery. METHODS: Lavage fluid samples were obtained from a total of 41 patients who underwent gastrectomy. The relative expression of various genes was analyzed using quantitative real-time PCR. The association of each gene expression with clinicopathological features and surgical outcomes was examined. The fraction of CX3CR1+ cells was analyzed by flow cytometry. Cytokine profiles in lavage fluid samples were investigated using a cytometric beads array. RESULTS: CX3CR1high patients exhibited higher levels of perioperative inflammation in blood tests and more recurrences than CX3CR1low patients. CX3CR1high patients tended to exhibit higher pathological T and N stage than CX3CR1low patients. CX3CR1 was primarily expressed on myeloid-derived suppressor cells and tumor-associated macrophages. In particular, polymorphonuclear myeloid-derived suppressor cells were associated with perioperative inflammation, pathological N, and recurrences. These immunosuppressive cells were associated with a trend toward unfavorable prognosis. Moreover, CX3CR1 expression was correlated with programmed death-1 expression. CONCLUSIONS: Our results suggest that CX3CR1+ cells are associated with an acute inflammatory response, tumor-promotion, and recurrence. CX3CR1 expression could be taken advantage of as a beneficial therapeutic target for improving immunosuppressive state in the future. In addition, analysis of intra-abdominal CX3CR1+ cells could be useful for characterizing the immune environment after gastric cancer surgery.

Asunto(s)

Cavidad Abdominal , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirugía , Gastrectomía , Citocinas , Inmunosupresores , Inflamación , Receptor 1 de Quimiocinas CX3C