Journal of Leukocyte Biology

Relationship and prognostic significance of IL-33, PD-1/PD-L1, and tertiary lymphoid structures in cervical cancer

AbstractIL-33, an epithelial-derived cytokine, functions as an alarmin for the immune system in the tumor microenvironment (TME). However, the expression and role of IL-33 on cervical cancer remain unclear. The aim of this study was to investigate the expression of IL-33 and its relationship with clinicopathologic features, tertiary lymphoid structures (TLS), and programmed cell death 1 (PD-1)/programmed cell death 1 ligand (PD-L1) immune checkpoints by immunohistochemistry in 93 cervical cancer patient specimens. Down-regulation of IL-33 expression was observed in tumor tissues compared with adjacent tissues. More importantly, IL-33 was detected in the cytoplasm of tumor fraction. IL-33 expression in tumor cytoplasm was associated with tumor size and the invasive depth of tumors (p < 0.05). Meanwhile, IL-33 expression in tumor cytoplasm was positively correlated with infiltration of CD3+ T cells, CD8+ T cells, and PD-L1 expression in tumor tissues (p < 0.05). The number of TLS strongly correlated with the depth of tumor invasion, preoperative chemotherapy, human papillomavirus infection, and high level of PD-1 (p < 0.05). However, there was no significant relationship between IL-33 and TLS. Kaplan–Meier survival curves showed that the formation of TLS was associated with a better prognosis (p = 0.008). In multivariable Cox regression modeling, high expression of PD-L1 in tumor tissues was correlated with poor prognosis (HR = 0.128; 95% CI: 0.026–0.646; p = 0.013), whereas the high expression of IL-33 in tumor tissues was associated with better prognosis (HR = 5.097; 95% CI:1.050–24.755; p = 0.043). These results indicate that IL-33, TLS, and PD-L1 are potentially valuable prognostic predictor for cervical cancer. IL-33 has potential for combination with PD-L1-related antitumor therapy.

G-CSF induces neutrophil extracellular traps formation and promotes ovarian cancer peritoneal dissemination

Abstract Epithelial ovarian cancer is characterized by aggressive peritoneal dissemination. Neutrophils are mobilized to peritoneal cavity in some patients with ovarian cancer dissemination; however, its pathological significance remains unknown. This study aimed to investigate the role of neutrophil extracellular traps (NETs) in ovarian cancer dissemination. We conducted a retrospective analysis of clinical data and samples from 340 patients with ovarian cancer who underwent primary surgery between 2007 and 2016 at the Osaka University Hospital. In vitro, NETs formation was induced by stimulating human peripheral neutrophils. The human ovarian cancer cell line, OVCAR8, was cocultured with NETs. For an ovarian cancer dissemination mouse model, we performed an intraperitoneal injection of OVCAR8 cells into nude mice. The association between NETs and peritoneal dissemination was explored, and model mice were treated with the PAD4 inhibitor GSK484 to assess antitumor efficacy. Neutrophilia (neutrophil count >7000/mm3) correlated with shorter survival, advanced peritoneal dissemination, elevated granulocyte colony-stimulating factor (G-CSF) levels, increased neutrophil count in ascites, and augmented NETs foci in peritoneal dissemination sites. In vitro assays revealed that G-CSF stimulated neutrophils to form NETs, promoting cancer cell adhesion. In vivo investigations revealed that G-CSF–producing tumor-bearing mice had accelerated peritoneal dissemination and poor prognosis. NETs formation was pathologically observed at the peritoneal dissemination sites. Inhibition of NETs formation by GSK484 significantly delayed peritoneal dissemination in vivo. In conclusion, G-CSF was associated with intra-abdominal NETs formation and increased peritoneal dissemination. NETs represent potential therapeutic targets for ovarian cancer, particularly in patients with neutrophilia.

Adenosine drives suppression of CD16low NK cell responses against HGSC via NKG2A:hLA-E interactions

Abstract High-grade serous carcinoma (HGSC) of the ovary remains the deadliest gynecologic cancer, with 5-year survival rates of less than 50%. Remission is usually achieved by surgical debulking and chemotherapy, but most (∼70%) of patients ultimately develop treatment-resistant disease. Infiltration of immune cells into the HGSC microenvironment, including natural killer (NK) cells, is associated with lengthened overall and progression-free survival, suggesting that immunosurveillance contributes to HGSC control. The mechanisms permitting or prohibiting anticancer activity are unclear, but if understood, they might shed light on opportunities for immunotherapy or precision medicine. We investigated the interactions between NK cells and adenosine, an immunosuppressive metabolite that concentrates in HGSC. Exposure of HGSC to adenosine induces upregulation of ligands associated with NK cell inhibition, including HLA-E. On NK cells, adenosine induces upregulation of the cognate inhibitory receptor for HLA-E, natural killer group 2A (NKG2A). The CD16low NK cell subset was most responsive to the HGSC cell line, OVCAR4, but also more likely to upregulate NKG2A and become inhibited after adenosine treatment. A single nucleotide polymorphism (SNP) in the gene for NKG2A (V5: rs2734440 C) encodes for higher NKG2A surface expression and a stronger inhibitory response to HLA-E-expressing targets. Here, we demonstrate that NK cell suppression in the context of adenosine is most profound in NK cells homozygous for the V5 variant. Our results reveal a novel link between metabolism and immunologic inhibition and highlight the KLRC1-V5 variant as a putative biomarker for response to anti-NKG2A therapy and/or susceptibility to adenosine-driven immunosuppression.

Ovarian cancer drives TLR5-dependent expansion of myeloid progenitors through systemic ligand dissemination

Abstract Ovarian cancer remains the most lethal gynecologic malignancy, due in part to the establishment of a profoundly immunosuppressive tumor microenvironment (TME). While toll-like receptor 5 (TLR5) signaling has previously been implicated in promoting myeloid cell recruitment to the ovarian TME, source(s) of ligand and systemic effects on hematopoiesis remain poorly understood. Here, we demonstrate that ovarian cancer disrupts gut barrier integrity, leading to systemic translocation of TLR5 ligands into the peritoneum, blood, and bone marrow. This translocation correlates with enhanced expansion of myeloid progenitors in the bone marrow of wild-type (WT) but not TLR5-deficient (TLR5 KO) mice, leading to enhanced accumulation of monocytes and macrophages into the TME. In the bone marrow, direct TLR5 signaling induced expansion of TLR5-expressing granulocyte-monocyte progenitors, a phenotype recapitulated both using an in vitro colony-forming assay and in a mixed bone marrow chimera model. Acute pharmacologic blockade of TLR5 in tumor-bearing mice altered the composition of tumor-associated myeloid populations, reducing the frequency of monocytes and CCR2-expressing macrophages accumulating within the TME of WT mice. These data reveal that chronic TLR5 signaling, driven by tumor-induced loss of gut barrier integrity, promotes expansion of myeloid cells within the bone marrow and is a host-intrinsic mechanism driving accumulation of immature monocytes and macrophages into the TME.

Bispecific antibodies enhance tumor-infiltrating T cell cytotoxicity against autologous HER-2-expressing high-grade ovarian tumors

Abstract Epithelial ovarian cancer displays the highest mortality of all gynecological tumors. A relapse of the disease even after successful surgical treatment is a significant problem. Resistance against the current platinum-based chemotherapeutic standard regime requires a detailed ex vivo immune profiling of tumor-infiltrating cells and the development of new therapeutic strategies. In this study, we phenotypically and functionally characterize tumor cells and autologous tumor-derived αβ and γδ T lymphocyte subsets. Tumor-infiltrating (TIL) and tumor-ascites lymphocytes (TAL) were ex vivo isolated out of tumor tissue and ascites, respectively, from high-grade ovarian carcinoma patients (FIGO-stage IIIa-IV). We observed an increased γδ T cell percentage in ascites compared to tumor-tissue and blood of these patients, whereas CD8+ αβ T cells were increased within TAL and TIL. The number of Vδ1 and non-Vδ1/Vδ2-expressing γδ T cells was increased in the ascites and in the tumor tissue compared to the blood of the same donors. Commonly in PBL, the Vγ9 chain of the γδ T cell receptor is usually associated exclusively with the Vδ2 chain. Interestingly, we detected Vδ1 and non-Vδ1/Vδ2 T cells co-expressing Vγ9, which is so far not described for TAL and TIL. Importantly, our data demonstrated an expression of human epidermal growth factor receptor (HER)-2 on high-grade ovarian tumors, which can serve as an efficient tumor antigen to target CD3 TIL or selectively Vγ9-expressing γδ T cells by bispecific antibodies (bsAbs) to ovarian cancer cells. Our bsAbs efficiently enhance cytotoxicity of TIL and TAL against autologous HER-2-expressing ovarian cells.

Natural killer cell impairment in ovarian clear cell carcinoma

Abstract In the present study, we report the analysis of NK cells derived from patients suffering from a rare ovarian cancer histotype of clear cell carcinoma (OCCC) resistant to conventional chemotherapies. We analyzed the phenotype of NK cells derived from peripheral blood (PB) and peritoneal fluid (PF) and evaluated cytotoxic interactions between NK cells and autologous tumor cells (ATC) derived from patients. We provided evidence of impaired degranulation capacity of NK cells derived from patients’ PF in the presence of ATC. Analyzing tumor cell ligands recognized by NK cell receptors, we found that ATC are characterized by an HLA class I+ phenotype (although the level of HLA-I expression varies among all patients) and by a heterogeneous expression of ligands for activating NK receptors (from normal to decreased expression of some markers). Furthermore, we observed a down-regulation of crucial NK cell activating receptors, primarily DNAX Accessory Molecule-1 (DNAM-1), on tumor-associated NK cells. Based on these results, we propose that this severe lysis defect may be due to both negative interactions between HLA-I-specific inhibitory NK cell receptors/HLA-I molecules and to defective interactions between activating NK receptors and cognate ligands. In conclusion, for the first time, the phenotypic and functional properties of tumor-associated NK cells and their ATC derived from PF of patients with advanced stage of OCCC were characterized. Taken together results indicate altered interactions between NK cells and ATC and shed light on the aggressive mechanisms of this cancer histotype. Further studies on this rare tumor will be helpful to improve and define more effective therapies.

Impact of age-, cancer-, and treatment-driven inflammation on T cell function and immunotherapy

Abstract Many cancers are predominantly diagnosed in older individuals and chronic inflammation has a major impact on the overall health and immune function of older cancer patients. Chronic inflammation is a feature of aging, it can accelerate disease in many cancers and it is often exacerbated during conventional treatments for cancer. This review will provide an overview of the factors that lead to increased inflammation in older individuals and/or individuals with cancer, as well as those that result from conventional treatments for cancer, using ovarian cancer (OC) and multiple myeloma (MM) as key examples. We will also consider the impact of chronic inflammation on immune function, with a particular focus on T cells as they are key targets for novel cancer immunotherapies. Overall, this review aims to highlight specific pathways for potential interventions that may be able to mitigate the impact of chronic inflammation in older cancer patients.