Blood natural killer cells during treatment in recurrent ovarian cancer

The emerging role of glycolysis and immune evasion in ovarian cancer

Ovarian cancer (OC) is one of the three most common malignant tumors of the female reproductive system, with the highest mortality rate among gynecologic malignancies. Like other tumors, OC cells undergo metabolic reprogramming phenomenon and convert glucose metabolism into "aerobic glycolysis" and generate a high concentration of lactate, i.e., the "Warburg effect", which provides a large amount of energy and corresponding intermediary metabolites for their survival, reproduction and metastasis. Numerous studies have shown that targeted inhibition of aerobic glycolysis and lactate metabolism is a promising strategy to enhance the sensitivity of cancer cells to immunotherapy. Therefore, this review summarizes the metabolic features of glycolysis in OC cells and highlights how abnormal lactate concentration affects the differentiation, metabolism, and function of infiltrating immune cells, which contributes to immunosuppression, and how targeted inhibition of this phenomenon may be a potential strategy to enhance the therapeutic efficacy of OC.

The emergence of DNAM-1 as the facilitator of NK cell-mediated killing in ovarian cancer

Introduction

Ovarian cancer (OC) is the sixth most common malignancy in women and the poor 5-year survival emphasises the need for novel therapies. NK cells play an important role in the control of malignant disease but the nature of tumour-infiltrating and peripheral NK cells in OC remains unclear.

Methods

Using flow cytometric analysis, we studied the phenotype and function of NK cells in blood, primary tumour and metastatic tissue in 80 women with OC. The cell type contexture of metastatic OC tissue was explored utilising scRNAseq analysis, with a focus on portraying an immunogenic tumour microenvironment and determining the characteristics of a dysfunctional NK cell population.

Results

The proportion of peripheral NK cells was markedly elevated with a highly activated profile and increased cytotoxicity. In contrast, NK cell numbers in primary tumour and metastasis were substantially reduced, with downregulation of activatory receptors together with elevated PD-1 expression. scRNA-Seq identified 5 NK cell subpopulations along with increased exhausted and immature NK cells within tumour tissue compared to normal tissue. These features were attenuated following chemotherapy where higher levels of activated and cytotoxic NK cells associated with improved disease-free survival. Correlation of NK cell phenotype with clinical outcomes revealed high levels of DNAM-1 expression on tissue-localised and peripheral NK cells to be associated with reduced survival. Expression of PVR, the DNAM-1 ligand, was significantly increased on tumours and DNAM-1 mediated NK cell lysis of primary tumour tissue was observed in vitro.

Discussion

These findings reveal profound modulation of the tumour tissue and systemic profile of NK cells which likely contributes to the high rates of local progression and metastasis seen with OC. Immunotherapeutic approaches that overcome local immune suppression and enhance DNAM-1-targeted lysis of OC offer the potential to improve disease control.

Commentary: Ovarian Cancer: Path to Effective Treatments

Despite advancements in cancer therapeutics such as checkpoint inhibitors and some targeted therapies, we have not achieved success in effectively treating ovarian cancer, since these therapeutics only benefit a subset of patients, and also provide short-term protection. The use of chemotherapy and radiation therapy can cause depletion and/or lack of immune cells' function. Chimeric antigen receptor T (CAR-T) cell therapy is found to be effective against several blood-based cancers, but limited success was seen against solid tumors. Targeting fewer antigens and significant side effects of therapy decreases the efficacy of CAR-T cells as immunotherapeutic in solid tumors, even though there is a great drive and significant effort to establish these therapies around the world. Bispecific and tri-specific antibodies have recently been advocated as effective cancer therapeutics. However, at present, these also suffer the fate of CAR-Ts since the loss of antigen on tumor cells will render these therapeutics ineffective. At present, we should design therapeutics that may have synergistic effects on killing/treating tumors. The only way we can establish that will be by learning the mechanisms of actions of immune therapeutics. Thus, advancement in the knowledge and effective strategies are required to develop cancer immuno-therapeutics. We have dedicated our efforts to understand the immunobiology of natural killer (NK) cells. One of our most important discoveries was demonstration of targeting of cancer stem-like cells (CSCs)/poorly differentiated tumors exhibiting lower major histocompability complex class I expression by the NK cells. In addition, we showed that supercharged NK (sNK) cells had great ability to target both CSCs/poorly differentiated and well differentiated ovarian tumors, whereas activated primary NK cells only targeted CSCs/poorly differentiated tumors. Therefore, the use of sNK cells in immunotherapy should result in effective elimination of heterogeneous populations of ovarian tumors.

A Comparison of Cellular Immune Response and Immunological Biomarkers in Laparoscopic Surgery for Colorectal Cancer and Benign Disorders

BACKGROUND

Surgical trauma causes immune impairment, but it is largely unknown whether surgery for cancer and benign diseases instigate comparable levels of immune inhibition. Here, we compared the impact of laparoscopic surgery on immunological biomarkers in patients with colorectal cancer (CRC) and ventral hernia (VH).

METHODS

Natural Killer cell activity (NKA), leukocyte subsets, and soluble programmed death ligand 1 (sPD-L1) were measured in blood samples collected from CRC (n = 29) and VH (n = 9) patients preoperatively (PREOP) and on postoperative day (POD) 1, 3-6, 2 weeks and 3 months. NKA was evaluated by the NK Vue assay that uses the level of IFNγ as a surrogate marker of NKA. Normal NKA was defined as IFNγ > 250 pg/mL and low NKA was defined as IFNγ < 250 pg/mL.

RESULTS

The CRC cohort was classified into either PREOPLOW having preoperative low NKA or PREOPHIGH having preoperative normal NKA. The median NKA of the PREOPLOW subset was only in the normal range in the POD3 months sample, whereas median NKA of the PREOPHIGH subset and the VH cohort were only low in the POD1 sample. While PREOPLOW differed from VH in the PREOP-, POD1-, and POD3-6 samples (P =.0006, P = .0181, and P = .0021), NKA in PREOPHIGH and VH differed in the POD1 samples (P = .0226). There were no apparent differences in the distribution of leukocyte subsets in the perioperative period between the cohorts.

CONCLUSION

CRC patients with preoperative normal NKA and VH patients showed the same pattern of recovery in NKA, while the CRC subset with preoperative low NKA seemed to experience prolonged NK cell impairment. As low NKA is associated with recurrence, preoperative level of NKA may identify patients who will benefit from immune-enhancing therapy in the perioperative period.

Immune cell status, cardiorespiratory fitness and body composition among breast cancer survivors and healthy women: a cross sectional study

Methods: We examined whether immune cell profiles differ between healthy women (n = 38) and breast cancer survivors (n = 27) within 2 years of treatment, and whether any group-differences were influenced by age, cytomegalovirus infection, cardiorespiratory fitness and body composition. Using flow cytometry, CD4+ and CD8+ T cell subsets, including naïve (NA), central memory (CM) and effector cells (EM and EMRA) were identified using CD27/CD45RA. Activation was measured by HLA-DR expression. Stem cell-like memory T cells (TSCMs) were identified using CD95/CD127. B cells, including plasmablasts, memory, immature and naïve cells were identified using CD19/CD27/CD38/CD10. Effector and regulatory Natural Killer cells were identified using CD56/CD16. Results: Compared to healthy women, CD4+ CM were +Δ21% higher among survivors (p = 0.028) and CD8+ NA were -Δ25% lower (p = 0.034). Across CD4+ and CD8+ subsets, the proportion of activated (HLA-DR+) cells was +Δ31% higher among survivors: CD4+ CM (+Δ25%), CD4+ EM (+Δ32%) and CD4+ EMRA (+Δ43%), total CD8⁺ (+Δ30%), CD8+ EM (+Δ30%) and CD8+ EMRA (+Δ25%) (p < 0.046). The counts of immature B cells, NK cells and CD16+ NK effector cells were higher among survivors (+Δ100%, +Δ108% and +Δ143% respectively, p < 0.04). Subsequent analyses examined whether statistically significant differences in participant characteristics, influenced immunological differences between groups. Compared to healthy women, survivors were older (56 ± 6 y vs. 45 ± 11 y), had lower cardiorespiratory fitness (V˙O2max mL kg^-1 min^-1: 28.8 ± 5.0 vs. 36.2 ± 8.5), lower lean mass (42.3 ± 5.0 kg vs. 48.4 ± 15.8 kg), higher body fat (36.3% ± 5.3% vs. 32.7% ± 6.4%) and higher fat mass index (FMI kg/m²: 9.5 ± 2.2 vs. 8.1 ± 2.7) (all p < 0.033). Analysis of covariance revealed divergent moderating effects of age, CMV serostatus, cardiorespiratory fitness and body composition on the differences in immune cell profiles between groups, depending on the cell type examined. Moreover, across all participants, fat mass index was positively associated with the proportion of HLA-DR+ CD4+ EMRA and CD8+ EM/EMRA T cells (Pearson correlation: r > 0.305, p < 0.019). The association between fat mass index and HLA-DR+ CD8+ EMRA T cells withstood statistical adjustment for all variables, including age, CMV serostatus, lean mass and cardiorespiratory fitness, potentially implicating these cells as contributors to inflammatory/immune-dysfunction in overweight/obesity.

Crosstalk of Immune Cells and Platelets in an Ovarian Cancer Microenvironment and Their Prognostic Significance

Ovarian cancer (OC) is one of the deadliest gynecological cancers, largely due to the fast development of metastasis and drug resistance. The immune system is a critical component of the OC tumor microenvironment (TME) and immune cells such as T cells, NK cells, and dendritic cells (DC) play a key role in anti-tumor immunity. However, OC tumor cells are well known for evading immune surveillance by modulating the immune response through various mechanisms. Recruiting immune-suppressive cells such as regulatory T cells (Treg cells), macrophages, or myeloid-derived suppressor cells (MDSC) inhibit the anti-tumor immune response and promote the development and progression of OC. Platelets are also involved in immune evasion by interaction with tumor cells or through the secretion of a variety of growth factors and cytokines to promote tumor growth and angiogenesis. In this review, we discuss the role and contribution of immune cells and platelets in TME. Furthermore, we discuss their potential prognostic significance to help in the early detection of OC and to predict disease outcome.

PP4 inhibition sensitizes ovarian cancer to NK cell-mediated cytotoxicity via STAT1 activation and inflammatory signaling

BACKGROUND

Increased infiltration of T cells into ovarian tumors has been repeatedly shown to be predictive of enhanced patient survival. However, despite the evidence of an active immune response in ovarian cancer (OC), the frequency of responses to immune checkpoint blockade (ICB) therapy in OC is much lower than other cancer types. Recent studies have highlighted that deficiencies in the DNA damage response (DDR) can drive increased genomic instability and tumor immunogenicity, which leads to enhanced responses to ICB. Protein phosphatase 4 (PP4) is a critical regulator of the DDR; however, its potential role in antitumor immunity is currently unknown.

RESULTS

Our results show that the PP4 inhibitor, fostriecin, combined with carboplatin leads to increased carboplatin sensitivity, DNA damage, and micronuclei formation. Using multiple OC cell lines, we show that PP4 inhibition or PPP4C knockdown combined with carboplatin triggers inflammatory signaling via Nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 1 (STAT1) activation. This resulted in increased expression of the pro-inflammatory cytokines and chemokines: CCL5, CXCL10, and IL-6. In addition, IFNB1 expression was increased suggesting activation of the type I interferon response. Conditioned media from OC cells treated with the combination of PP4 inhibitor and carboplatin significantly increased migration of both CD8 T cell and natural killer (NK) cells over carboplatin treatment alone. Knockdown of stimulator of interferon genes (STING) in OC cells significantly abrogated the increase in CD8 T-cell migration induced by PP4 inhibition. Co-culture of NK-92 cells and OC cells with PPP4C or PPP4R3B knockdown resulted in strong induction of NK cell interferon-γ, increased degranulation, and increased NK cell-mediated cytotoxicity against OC cells. Stable knockdown of PP4C in a syngeneic, immunocompetent mouse model of OC resulted in significantly reduced tumor growth in vivo. Tumors with PP4C knockdown had increased infiltration of NK cells, NK T cells, and CD4⁺ T cells. Addition of low dose carboplatin treatment led to increased CD8⁺ T-cell infiltration in PP4C knockdown tumors as compared with the untreated PP4C knockdown tumors.

CONCLUSIONS

Our work has identified a role for PP4 inhibition in promoting inflammatory signaling and enhanced immune cell effector function. These findings support the further investigation of PP4 inhibitors to enhance chemo-immunotherapy for OC treatment.

Integration of local and systemic immunity in ovarian cancer: Implications for immunotherapy

Cancer is a disease that induces many local and systemic changes in immunity. The difficult nature of ovarian cancer stems from the lack of characteristic symptoms that contributes to a delayed diagnosis and treatment. Despite the enormous progress in immunotherapy, its efficacy remains limited. The heterogeneity of tumors, lack of diagnostic biomarkers, and complex immune landscape are the main challenges in the treatment of ovarian cancer. Integrative approaches that combine the tumor microenvironment - local immunity - together with periphery - systemic immunity - are urgently needed to improve the understanding of the disease and the efficacy of treatment. In fact, multiparametric analyses are poised to improve our understanding of ovarian tumor immunology. We outline an integrative approach including local and systemic immunity in ovarian cancer. Understanding the nature of both localized and systemic immune responses will be crucial to boosting the efficacy of immunotherapies in ovarian cancer patients.

Cell-based immunotherapies in gynecologic cancers

PURPOSE OF REVIEW

This review provides an update on recent developments in cell-based immunotherapy in gynecologic cancers.

RECENT FINDINGS

Chimeric antigen receptor (CAR) technology has made significant progress allowing now for not only expressing CARs on T-cells, but also on other immune effector cells, such as natural killer cells and macrophages. Cell-based vaccines have started to show promising results in clinical trials.

SUMMARY

Cell-based immunotherapies in gynecologic cancers continue to evolve with promising clinical efficacy in select patients.

High Density of CD16+ Tumor-Infiltrating Immune Cells in Recurrent Ovarian Cancer Is Associated with Enhanced Responsiveness to Chemotherapy and Prolonged Overall Survival

Simple Summary

The late—and in most cases at an advanced stage—diagnosis of patients with ovarian cancer (OC) and the high recurrence rate make this malignant disease the most lethal among gynecological cancers. With a mortality-to-incidence ratio of 0.74, OC is a tumor with the fifth most frequent progression after esophageal cancer, liver cancer, pancreatic cancer, and brain tumors. The updated FIGO staging system is the gold standard in the clinic and includes surgical, radiologic, and pathologic elements to describe the extent of OC. This system is used to describe tumor extent, plan further therapy, and predict prognosis. However, it is consistently observed that patients with identical stages and treatments have a completely different outcome in terms of survival and recurrence. This fact indicates that this classification alone is not sufficient for the prognosis of OC in the vast majority of cases. Over the last two decades, many studies have demonstrated the critical role of the tumor microenvironment in tumorigenesis, progression, prognosis, and response to chemotherapy. In the current study, we investigate the role of CD16 expression in OC.

Abstract

Background: Ovarian cancer (OC) is the most aggressive and fatal malignancy of the female reproductive system. Debulking surgery with adjuvant chemotherapy represents the standard treatment, but recurrence rates are particularly high. Over the past decades, the association between the immune system and cancer progression has been extensively investigated. However, the interaction between chemotherapy and cancer immune infiltration is still unclear. In this study, we examined the prognostic role of CD16 expression in OC, as related to the effectiveness of standard adjuvant chemotherapy treatment. Methods: We analyzed the infiltration by immune cells expressing CD16, a well-characterized natural killer (NK) and myeloid cell marker, in a tissue microarray (TMA) of 47 patient specimens of primary OCs and their matching recurrences by immunohistochemistry (IHC). We analyzed our data first in the whole cohort, then in the primary tumors, and finally in recurrences. We focused on recurrence-free survival (RFS), overall survival (OS), and chemosensitivity. Chemosensitivity was defined as RFS of more than 6 months. Results: There was no significant correlation between CD16 expression and prognosis in primary carcinomas. However, interestingly, a high density of CD16-expressing tumor-infiltrating immune cells (TICs) in recurrent carcinoma was associated with better RFS (p = 0.008) and OS (p = 0.029). Moreover, high CD16 cell density in recurrent ovarian carcinoma showed a significant association with chemosensitivity (p = 0.034). Univariate Cox regression analysis revealed that the high expression of CD16+ TIC in recurrent cancer biopsies is significantly associated with an increased RFS (HR = 0.49; 95% CI 0.24–0.99; p = 0.047) and OS (HR = 0.28; 95% CI 0.10–0.77; p = 0.013). However, this was not independent of known prognostic factors such as age, FIGO stage, resection status, and the number of chemotherapy cycles. Conclusions: The high density of CD16-expressing TICs in recurrent ovarian cancer is associated with a better RFS and OS, thereby suggesting a previously unsuspected interaction between standard OC chemotherapy and immune cell infiltration.