Highly effective NK cells are associated with good prognosis in patients with metastatic prostate cancer

Natural killer cells in cancer immunotherapy

Natural killer (NK) cells, as innate lymphocytes, possess cytotoxic capabilities and engage target cells through a repertoire of activating and inhibitory receptors. Particularly, natural killer group 2, member D (NKG2D) receptor on NK cells recognizes stress-induced ligands-the MHC class I chain-related molecules A and B (MICA/B) presented on tumor cells and is key to trigger the cytolytic response of NK cells. However, tumors have developed sophisticated strategies to evade NK cell surveillance, which lead to failure of tumor immunotherapy. In this paper, we summarized these immune escaping strategies, including the downregulation of ligands for activating receptors, upregulation of ligands for inhibitory receptors, secretion of immunosuppressive compounds, and the development of apoptosis resistance. Then, we focus on recent advancements in NK cell immune therapies, which include engaging activating NK cell receptors, upregulating NKG2D ligand MICA/B expression, blocking inhibitory NK cell receptors, adoptive NK cell therapy, chimeric antigen receptor (CAR)-engineered NK cells (CAR-NK), and NKG2D CAR-T cells, especially several vaccines targeting MICA/B. This review will inspire the research in NK cell biology in tumor and provide significant hope for improving cancer treatment outcomes by harnessing the potent cytotoxic activity of NK cells.

Effects of opioid drugs on immune function in cancer patients

Opioid receptor agonists are often used when cancer patients undergo surgery or analgesic treatment. As analgesics in clinical care, opioids can provide intraoperative or to chronic cancer pain relief. Immune function plays an important role in anti-cancer therapy, with cellular immunity, comprised principally of T-lymphocytes and natural killer cells, representing the primary anti-cancer immune response. However, it remains unclear whether immune function is further affected with the use of opioids in already immunocompromised cancer patients. This article provides a review of the effects of commonly used clinical opioids, including morphine, oxycodone, fentanyl and tramadol, on immune function in cancer patients. It provides a summary of current evidence regarding the immunomodulatory effects of opioids in the cancer setting and mechanisms underlying these interactions.

Prognosis and diagnosis of prostate cancer based on hypergraph regularization sparse least partial squares regression algorithm

BACKGROUND

Prostate cancer (PCa) is a malignant tumor of the male reproductive system, and its incidence has increased significantly in recent years. This study aimed to further identify candidate biomarkers with prognostic and diagnostic significance by integrating gene expression and DNA methylation data from PCa patients through association analysis.

MATERIAL AND METHODS

To this end, this paper proposes a sparse partial least squares regression algorithm based on hypergraph regularization (HR-SPLS) by integrating and clustering two kinds of data. Next, module 2, with the most significant weight, was selected for further analysis according to the weight of each module related to DNA methylation and mRNAs. Based on the DNA methylation sites in module 2, this paper uses multiple machine learning methods to construct a PCa diagnosis-related model of 10-DNA methylation sites.

RESULTS

The results of Receiver Operating Characteristic (ROC) analysis showed that the DNA methylation-related diagnostic model we constructed could diagnose PCa patients with high accuracy. Subsequently, based on the mRNAs in module 2, we constructed a prognostic model for 7-mRNAs (MYH11, ACTG2, DDR2, CDC42EP3, MARCKSL1, LMOD1, and MYLK) using multivariate Cox regression analysis. The prognostic model could predict the disease free survival of PCa patients with moderate to high accuracy (area under the curve (AUC) =0.761). In addition, Gene Set EnrichmentAnalysis (GSEA) and immune analysis indicated that the prognosis of patients in the risk group might be related to immune cell infiltration.

CONCLUSIONS

Our findings may provide new methods and insights for identifying disease-related biomarkers by integrating DNA methylation and gene expression data.

Surgical stress induced tumor immune suppressive environment

Despite significant advances in cancer treatment over the decades, surgical resection remains a prominent management approach for solid neoplasms. Unfortunately, accumulating evidence suggests that surgical stress caused by tumor resection may potentially trigger postoperative metastatic niche formation. Surgical stress not only activates the sympathetic-adrenomedullary axis and hypothalamic-pituitary-adrenocortical axis but also induces hypoxia and hypercoagulable state. These adverse factors can negatively impact the immune system by downregulating immune effector cells and upregulating immune suppressor cells, which contribute to the colonization and progression of postoperative tumor metastatic niche. This review summarizes the effects of surgical stress on four types of immune effector cells (neutrophils, macrophages, natural killer cells and cytotoxic T lymphocytes) and two types of immunosuppressive cells (regulatory T cells and myeloid-derived suppressor cells), and discusses the immune mechanisms of postoperative tumor relapse and progression. Additionally, relevant therapeutic strategies to minimize the pro-tumorigenic effects of surgical stress are elucidated.

B cell responses and antibody-based therapeutic perspectives in human cancers

BACKGROUND

Immuno-oncology has been focused on T cell-centric approaches until the field recently started appreciating the importance of tumor-reactive antibody production by tumor-infiltrating plasma B cells, and the necessity of developing novel therapeutic antibodies for the treatment of different cancers.

RECENT FINDINGS

B lymphocytes often infiltrate solid tumors and the extent of B cell infiltration normally correlates with stronger T cell responses while generating humoral responses against malignant progression by producing tumor antigens-reactive antibodies that bind and coat the tumor cells and promote cytotoxic effector mechanisms, reiterating the fact that the adaptive immune system works by coordinated humoral and cellular immune responses. Isotypes, magnitude, and the effector functions of antibodies produced by the B cells within the tumor environment differ among cancer types. Interestingly, apart from binding with specific tumor antigens, antibodies produced by tumor-infiltrating B cells could bind to some non-specific receptors, peculiarly expressed by cancer cells. Antibody-based immunotherapies have revolutionized the modalities of cancer treatment across the world but are still limited against hematological malignancies and a few types of solid tumor cancers with a restricted number of targets, which necessitates the expansion of the field to have newer effective targeted antibody therapeutics.

CONCLUSION

Here, we discuss about recent understanding of the protective spontaneous antitumor humoral responses in human cancers, with an emphasis on the advancement and future perspectives of antibody-based immunotherapies in cancer.

Targeting the prostate tumor microenvironment by plant-derived natural products

Prostate cancer is among the most common malignancies for men, with limited therapy options for last stages of the tumor. There are some different options for treatment and control of prostate tumor growth. However, targeting some specific molecules and cells within tumors has been attracted interests in recent years. The tumor microenvironment (TME) has an important role in the initiation of various malignancies, which can also expand the progression of tumor and facilitate invasion of malignant cells. By regulating immune responses and distinct changes in the metabolism of cells in the tumor, TME has substantial effects in the resistance of cancer cells to therapy. TME in various solid cancers like prostate cancer includes various cells, including cancer cells, supportive stromal cells, immunosuppressive cells, and anticancer inflammatory cells. Natural products including herbal-derived agents and also other natural compounds have been well studied for their anti-tumor potentials. These compounds may modulate various signaling pathways involved in TME, such as immune responses, the metabolism of cells, epigenetics, angiogenesis, and extracellular matrix (ECM). This paper provides a review of the current knowledge of prostate TME and complex interactions in this environment. Additionally, the potential use of natural products and also nanoparticles loaded with natural products as therapeutic adjuvants on different cells and therapeutic targets within prostate TME will be discussed.

Phase 1/2 study of monalizumab plus durvalumab in patients with advanced solid tumors

BACKGROUND

The combination of monalizumab (anti-NKG2A/CD94) and durvalumab (anti-programmed death ligand-1) may promote antitumor immunity by targeting innate and adaptive immunity. This phase 1/2 study of monalizumab and durvalumab evaluated safety, antitumor activity, and pharmacodynamics in patients with advanced solid tumors.

MAIN BODY

Immunotherapy-naïve patients aged ≥18 years with advanced disease, Eastern Cooperative Oncology Group performance status of 0-1, and 1-3 prior lines of systemic therapy in the recurrent/metastatic setting were enrolled. In part 1 (dose escalation), patients received durvalumab 1500 mg every 4 weeks (Q4W) with increasing doses of monalizumab Q2W/Q4W (n=15). Dose expansion in part 1 included patients with cervical cancer (n=15; durvalumab 1500 mg Q4W and monalizumab 750 mg Q2W) or metastatic microsatellite stable (MSS)-colorectal cancer (CRC) (n=15; durvalumab 1500 mg Q4W and monalizumab 750 mg Q4W). In part 2 (dose expansion), patients with MSS-CRC (n=40), non-small cell lung cancer (NSCLC; n=20), MSS-endometrial cancer (n=40), or ovarian cancer (n=40) received durvalumab 1500 mg Q4W and monalizumab 750 mg Q2W. The primary endpoint was safety. Secondary endpoints included antitumor activity per Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1). Exploratory analyses included assessment of T-cell and natural killer (NK) cell activation and proliferation in peripheral blood and the tumor microenvironment (TME). The study enrolled 185 patients (part 1, 45; part 2, 140). No dose-limiting toxicities were observed and the maximum tolerated dose was not reached. In part 2, the most common treatment-related adverse events were fatigue (12.1%), asthenia (9.3%), diarrhea (9.3%), pruritus (7.9%), and pyrexia (7.1%). In the expansion cohorts, response rates were 0% (cervical), 7.7% (MSS-CRC), 10% (NSCLC), 5.4% (ovarian), and 0% (MSS-endometrial). Sustained NK cell activation, CD8+ T-cell proliferation, increased serum levels of CXCL10 (C-X-C motif chemokine ligand 10) and CXCL11, and increased tumor infiltration of CD8+ and granzyme B+ cells were observed.

CONCLUSIONS

Although efficacy was modest, monalizumab plus durvalumab was well tolerated and encouraging immune activation was observed in the peripheral blood and TME.

TRIAL REGISTRATION NUMBER

NCT02671435.

Effector and cytolytic function of natural killer cells in anticancer immunity

Adaptive immune cells play an important role in mounting antigen-specific antitumor immunity. The contribution of innate immune cells such as monocytes, macrophages, natural killer (NK) cells, dendritic cells, and gamma-delta T cells is well studied in cancer immunology. NK cells are innate lymphoid cells that show effector and regulatory function in a contact-dependent and contact-independent manner. The cytotoxic function of NK cells plays an important role in killing the infected and transformed host cells and controlling infection and tumor growth. However, several studies have also ascribed the role of NK cells in inducing pathophysiology in autoimmune diseases, promoting immune tolerance in the uterus, and antitumor function in the tumor microenvironment. We discuss the fundamentals of NK cell biology, its distribution in different organs, cellular and molecular interactions, and its cytotoxic and noncytotoxic functions in cancer biology. We also highlight the use of NK cell-based adoptive cellular therapy in cancer.

Pathological complete response to neoadjuvant therapy with serplulimab and chemotherapy in stage IIIB small cell lung cancer: a case report and literature review

Chemotherapy combined with immunotherapy has significantly improved survival in patients with extensive-stage small cell lung cancer (ES-SCLC), and neoadjuvant immunotherapy combined with chemotherapy has emerged as the standard treatment for those with resectable non-small cell lung cancer (NSCLC). However, the potential benefits of surgery following neoadjuvant immunotherapy combined with chemotherapy in locally advanced SCLC remain unclear. Herein, we report a patient diagnosed with stage IIIB SCLC, who was administered five cycles of neoadjuvant serplulimab combined with chemotherapy followed by surgery, and subsequently achieved a pathologic complete response (pCR). Within a follow-up duration of six months, the patient displayed neither recurrence nor metastasis and experienced no treatment-related adverse reactions of any grade. Based on this case, for locally advanced SCLC, neoadjuvant serplulimab combined with chemotherapy followed by surgery may present an effective, safe, and potentially curative treatment strategy. Nonetheless, further prospective studies are needed to verify our findings.

Targeting tumor and bone microenvironment: Novel therapeutic opportunities for castration-resistant prostate cancer patients with bone metastasis

Despite standard hormonal therapy that targets the androgen receptor (AR) attenuates prostate cancer (PCa) effectively in the initial stage, the tumor ultimately converts to castration-resistant prostate cancer (CRPC), and the acquired resistance is still a great challenge for the management of advanced prostate cancer patients. The tumor microenvironment (TME) consists of multiple cellular and noncellular agents is well known as a vital role during the development and progression of CRPC by establishing communication between TME and tumor cells. Additionally, as primary prostate cancer progresses towards metastasis, and CRPC always experiences bone metastasis, the TME is conducive to the spread of tumors to the distant sits, particularly in bone. In addition, the bone microenvironment (BME) is also closely related to the survival, growth and colonization of metastatic tumor cells. The present review summarized the recent studies which mainly focused on the role of TME or BME in the CRPC patients with bone metastasis, and discussed the underlying mechanisms, as well as the potential therapeutic values of targeting TME and BME in the management of metastatic CRPC patients.

Inhibitory receptors and checkpoints on NK cells: Implications for cancer immunotherapy

With the success of immunosuppressive checkpoint in tumor therapy, the corresponding adverse response and drug resistance defects have been exposed. T cells and NK cells are the body's immune system of the two substantial main forces. in recent years, study of T cell checkpoints appeared a certain block, such as PD-1 the effect not benign, on the distribution of NK cell surface excitatory and inhibitory receptors under normal conditions to maintain steady, could be targeted in the tumor treatment blockade have therapeutic effect. This paper reviews the function of NK cells and the effects of corresponding receptors in various types of tumors, providing a direction for the selection of appropriate gate control sites for future treatment.

TRAIL-conjugated liposomes that bind natural killer cells to induce colorectal cancer cell apoptosis

Natural killer (NK) cell functionality is a strong indicator of favorable prognosis in cancer patients, making NK cells an appealing therapeutic target to prevent lymph node dissemination. We engineered liposomes that are conjugated with anti-CD335 antibodies for NK cell targeting, and the apoptotic ligand TRAIL to kill cancer cells. Liposomes were made using a thin film hydration method followed by extrusion to approximately 100 nm in diameter and conjugation of proteins via thiol-maleimide click chemistry. TRAIL/anti-CD335 liposomes successfully bound to isolated NK cells. Once piggybacked to the surface of NK cells, these "Super Natural Killer Cells" were able to more effectively kill oxaliplatin-resistant SW620 cells and metastatic COLO205 colorectal cancer cells via TRAIL-mediated apoptosis compared to NK cells alone. Importantly, Super NK cells were more effective under physiological levels of fluid shear stress found in the lymphatics. Liposome biodistribution after intravenous administration confirmed the sustained presence of liposomes within the spleen and tumor draining mesenteric lymph nodes for at least 4 days. These results demonstrate the enhanced apoptotic effects of NK cells armored with liposomal TRAIL against clinically relevant colorectal cancer cells, providing the groundwork for in vivo treatment studies in mouse models of colorectal cancer metastasis.

Cancer Immunotherapy with Lipid Nanoparticles Loaded with a Stimulator of Interferon Genes Agonist against Renal Tumor Lung Metastasis

Metastatic renal cell carcinoma (RCC) has a poor prognosis, and the major organ of metastasis is the lung. Immunotherapy with immune checkpoint inhibitors (ICIs) is the first-line therapy, but the response rates are low. Thus, the development of a more effective immunotherapy against metastatic RCC would be highly desirable. We previously demonstrated how a stimulator of an interferon gene (STING) agonist-loaded lipid nanoparticles (STING-LNPs) significantly activates natural killer (NK) cells and induces an antitumor effect against cases of melanoma lung metastasis that have shown ICI resistance. In this study, we evaluated the potential of using STING-LNPs in the treatment of lung metastatic RCC (Renca). An intravenous injection of STING-LNPs drastically decreased the amount of Renca tumor colonies. In contrast, monotherapies using ICIs showed no antitumor effect, and even a combination of ICI and STING-LNP therapies failed to enhance the antitumor effects. The main effector cells would be NK cells, and the activation of NK cells by the STING-LNPs may avoid the increased expression of immune checkpoint molecules. These findings provide useful insights into the development of an effective immunotherapy against metastatic RCC.

Enhanced expression of natural cytotoxicity receptors on cytokine-induced memory-like natural killer cells correlates with effector function

Introduction

Natural killer (NK) cells are a key component of the innate immune system, involved in defending the host against virus-infected cells and tumor immunosurveillance. Under in vitro culture conditions, IL-12/15/18 can induce a memory-like phenotype in NK cells. These cytokine-induced memory-like (CIML) NK cells possess desirable characteristics for immunotherapies, including a longer lifespan and increased cytotoxicity.

Methods

In this study, NK cells were isolated from peripheral blood of healthy donors and stimulated with IL-12/15/18 to induce a memory-like phenotype or with IL-15 alone as a control. After seven days of culture, multiparametric flow cytometry analysis was performed to evaluate the phenotypic and functional profiles of CIML and control NK cells.

Results

Our results showed a significantly higher expression of CD25, CD69, NKG2D, NKp30, NKp44, NKp46, TACTILE, and Granzyme B in CIML NK cells compared to control NK cells. In contrast, KIR2D expression was significantly lower in CIML NK cells than in control NK cells. Moreover, functional experiments demonstrated that CIML NK cells displayed enhanced degranulation capacity and increased intracellular IFN-γ production against the target cell line K562. Interestingly, the degranulation capacity of CIML NK cells was positively correlated with the expression of the activating receptors NKp46 and NKp30, as well as with the inhibitory receptor TACTILE.

Discussion

In conclusion, this study provides a deep phenotypic characterization of in vitro-expanded CIML NK cells. Moreover, the correlations found between NK cell receptors and degranulation capacity of CIML NK cells allowed the identification of several biomarkers that could be useful in clinical settings.

Natural killer cell activity in metastatic castration resistant prostate cancer patients treated with enzalutamide

Metastatic castration resistant prostate cancer (mCRPC) is still the lethal stage for the whole spectrum of prostate cancer disease. Even though different treatment options have been introduced in the last decade with a significant survival improvement for this population, a lack of more reliable prognostic and predictive markers is still one of the main clinical challenges in management of mCRPC. The aim of this study was to investigate the correlation between Natural Killer cell activity (NKA) and both treatment effect and outcomes in patients with mCRPC treated with enzalutamide. A total of 87 patients with mCRPC treated with enzalutamide as the first line treatment were enrolled. NKA was estimated at baseline and prior to each treatment cycle. Endpoints included both treatment effect with biochemical response (BR), biochemical progression (BP) and radiological progression (RP), as well as outcome data with overall survival (OS), radiologic progression free survival (rPFS), and time to next treatment (TTT). At the time of BR, interferon-gamma (IFNγ) decreased significantly compared to levels detected at baseline (z-score = 2.33, p = 0.019). Regarding outcome data, the whole cohort was divided into four groups according to the change of IFNγ level during the first 3 cycles of enzalutamide treatment. In group 1 (n = 42) the IFNγ level remained within a normal range (≥ 250 pg/mL),while in group 2 (n = 7) it increased from an abnormal (< 250 pg/mL) to a normal level. In group 3 (n = 13) it dropped to an abnormal level, and it remained at an abnormal level during treatment in group 4 (n = 17). Patients in group 2 showed the worst prognosis with shorter both rPFS and TTT (HR 4.30, p = 0.037; and HR 6.82, p = 0.011, respectively). In this study inverse correlations between NKA and both treatment response and outcomes was observed in mCRPC patients receiving enzalutamide, suggesting an unfavourable role of NK cells in the late stage of PCa.

Advances in natural killer cell therapies for breast cancer

Breast cancer (BC) is the most common cause of cancer death in women. According to the American Cancer Society's yearly cancer statistics, BC constituted almost 15% of all the newly diagnosed cancer cases in 2022 for both sexes. Metastatic disease occurs in 30% of patients with BC. The currently available treatments fail to cure metastatic BC, and the average survival time for patients with metastatic BC is approximately 2 years. Developing a treatment method that terminates cancer stem cells without harming healthy cells is the primary objective of novel therapeutics. Adoptive cell therapy is a branch of cancer immunotherapy that utilizes the immune cells to attack cancer cells. Natural killer (NK) cells are an essential component of innate immunity and are critical in destroying tumor cells without prior stimulation with antigens. With the advent of chimeric antigen receptors (CARs), the autologous or allogeneic use of NK/CAR-NK cell therapy has raised new hopes for treating patients with cancer. Here, we describe recent developments in NK and CAR-NK cell immunotherapy, including the biology and function of NK cells, clinical trials, different sources of NK cells and their future perspectives on BC.

Fulvestrant increases the susceptibility of enzalutamide-resistant prostate cancer cells to NK-mediated lysis

BACKGROUND

Enzalutamide, a next-generation antiandrogen agent, is approved for the treatment of metastatic castration-resistant prostate cancer (CRPC). While enzalutamide has been shown to improve time to progression and extend overall survival in men with CRPC, the majority of patients ultimately develop resistance to treatment. Immunotherapy approaches have shown limited clinical benefit in this patient population; understanding resistance mechanisms could help develop novel and more effective treatments for CRPC. One of the mechanisms involved in tumor resistance to various therapeutics is tumor phenotypic plasticity, whereby carcinoma cells acquire mesenchymal features with or without the loss of classical epithelial characteristics. This work investigated a potential link between enzalutamide resistance, tumor phenotypic plasticity, and resistance to immune-mediated lysis in prostate cancer.

METHODS

Models of prostate cancer resistant to enzalutamide were established by long-term exposure of human prostate cancer cell lines to the drug in culture. Tumor cells were evaluated for phenotypic features in vitro and in vivo, as well as for sensitivity to immune effector cell-mediated cytotoxicity.

RESULTS

Resistance to enzalutamide was associated with gain of mesenchymal tumor features, upregulation of estrogen receptor expression, and significantly reduced tumor susceptibility to natural killer (NK)-mediated lysis, an effect that was associated with decreased tumor/NK cell conjugate formation with enzalutamide-resistant cells. Fulvestrant, a selective estrogen receptor degrader, restored the formation of target/NK cell conjugates and increased susceptibility to NK cell lysis in vitro. In vivo, fulvestrant demonstrated antitumor activity against enzalutamide-resistant cells, an effect that was associated with activation of NK cells.

CONCLUSION

NK cells are emerging as a promising therapeutic approach in prostate cancer. Modifying tumor plasticity via blockade of estrogen receptor with fulvestrant may offer an opportunity for immune intervention via NK cell-based approaches in enzalutamide-resistant CRPC.

Immunologic Assessment of Tumors from a Race-matched Military Cohort Identifies Mast Cell Depletion as a Marker of Prostate Cancer Progression

Elucidating the cellular immune components underlying aggressive prostate cancer, especially among African American (AA) men who are disproportionately affected by this disease compared with Caucasian American (CA) men, will support more inclusive precision medicine treatment strategies. We aimed to evaluate which immune-related genes and cell types are differentially expressed in AA tumors and how immunobiology impacts prostate cancer progression. We purified nucleic acid from tumor biopsies, obtained following radical prostatectomy, from 51 patients (AA = 26, CA = 25). Gene expression was measured using the NanoString platform from which we estimated immune cell abundances and assessed differences between groups based on clinicopathologic data. Product-limit estimates determined associations with biochemical recurrence (BCR)-free and metastasis-free survival. DVL2 and KLRC2 were significantly upregulated in CA tumors and were also associated with worse disease progression. No significant differences in immune cell abundances by race were observed. Highly significant reductions in abundances of mast cells versus tumor-infiltrating lymphocytes (TIL) were found in men with high-grade pathologies and in men who later developed metastases. Low ratios of mast cells versus TILs were associated with worse BCR-free survival and metastasis-free survival. Although estimated immune cell abundances were not different by race, we identified genes involved in metabolism and natural killer cell functions that were differentially expressed between AA and CA tumors. Among the entire cohort, depletion of mast cells within prostatectomy tumors was characteristic of advanced disease and susceptibility to disease progression.

Significance

Our findings demonstrate that there are immune-related genes and pathways that differ by race. Impaired intratumoral cellular immune composition, especially for TIL-normalized mast cells, may be vital in predicting and contributing to prostate cancer disease progression.

Immature and activated phenotype of blood NK cells is associated with acute rejection in adult liver transplant

Natural killer (NK) cells contribute to liver transplant (LTx) rejection. However, the blood-circulating NK-cell dynamics of patients who experience acute rejection (AR) are unclear. Herein, we longitudinally profiled the total NK cells and their subsets, along with the expression of activating and inhibitory receptors in sequential peripheral blood mononuclear cell samples, spanning from before LTx to the first year after LTx of 32 patients with AR and 30 patients under a steady immune status. Before transplantation, patients with AR (rejectors) contained a significantly higher proportion of the immature CD56 bright CD16 - subset and a lower cytolytic CD56 dim CD16 + in the total blood-circulating NK cells than patients with steady immunity. Both subsets contained a high NKp30-positive population, and CD56 dim CD16 + additionally exhibited a high NKp46-positive ratio. The NKp30-positive ratio in CD56 dim CD16 + subset showed the most prominent AR predictive ability before LTx and was an independent risk factor of LTx AR. After transplantation, the blood-circulating NK cells in rejectors maintained a higher CD56 bright CD16 - and lower CD56 dim CD16 + composition than the controls throughout the first year after LTx. Moreover, both subsets maintained a high NKp30-positive ratio, and CD56 dim CD16 + retained a high NKp46-positive ratio. The blood-circulating NK cell subset composition was consistent during AR, while the expressions of NKp30 and NKp46 were augmented. Collectively, a more immature CD56 bright CD16 - subset composition and an activated phenotype of high NKp30 expression were the general properties of blood-circulating NK cells in rejected LTx recipients, and the NKp30-positive ratio in CD56 dim CD16 + NK subset before LTx possessed AR predictive potential.

Clinical significance of regulatory T cells and T lymphocyte subsets in peripheral blood in neoadjuvant chemotherapy for breast cancer

The impact of the immune response on the therapeutical efficacy of neoadjuvant chemotherapy for breast cancer remains largely unknown. To characterize the role of regulatory T cells (CD4+CD25+CD127lowTreg), T lymphocyte subsets (CD3+, CD4+, CD4+/CD8+) and NK cells in neoadjuvant chemotherapy, we investigated the correlation patterns of these immune cell subsets with the progression of breast cancer. A total of 120 breast cancer patients receiving neoadjuvant chemotherapy in Nanjing Maternal and Child Health Hospital from May 2019 to November 2021 were retrospectively collected as the breast cancer group, and 46 healthy women were selected as the control group. The number of regulatory T cells, T lymphocyte subsets and NK cells in the peripheral blood were analyzed by flow cytometry. Compared with the control group, CD3+, CD4+, CD4+/CD8+ ratio and NK cells were significantly decreased in patients with breast cancer (P < 0.05), while the levels of Treg and CD8+ cells were significantly increased (P < 0.05). In addition, the status of the immune response among breast cancer patients at different clinical stages was obviously different. In higher tumor stages, the level of CD3+, CD4+, CD4+/CD8+ ratio and NK cell were reduced, while the level of Treg and CD8+ T cells gradually increased. Furthermore, we found a lower percentage of CD3+, CD4+, CD4+/CD8+ and NK cells in association with lymph node metastasis, accompanied by a higher number of CD8+ T cells. Interestingly, after treatment with neoadjuvant chemotherapy, the levels of Tregs, CD3+, CD4+ and CD4+/CD8+ ratio of patients were all upregulated compared with the levels before treatment, indicating the recovery of cytotoxic lymphocytes and a consolidation of the immunosuppressive microenvironment at the same time (P < 0.05). Immune dysfunction is commonly observed in breast cancer patients, which is closely associated with tumor progression and lymph node metastasis. Neoadjuvant chemotherapy was found to highly influence the number of T lymphocytes and improve the immune function of T lymphocyte subsets in breast cancer patients. At the same time, as immunosuppressive cells, the proportion of Tregs (CD4+CD25+CD127lowTreg) also increased after treatment with neoadjuvant chemotherapy. Our results provide guidance for the development of new combination strategies during neoadjuvant chemotherapy to reverse the immunosuppressive microenvironment and achieve better clinical outcomes.

The effects of allogeneic and autologous blood transfusion on immune function in patients receiving total hip replacement

OBJECTIVE

To evaluate the effects of allogeneic and autologous blood transfusion on immune function and postoperative inflammation in patients after total hip replacement.

METHODS

In this retrospective study, the clinical data of 60 patients undergoing total hip arthroplasty through a posterolateral approach were analyzed. The patients were grouped into an autologous blood transfusion group (allo group) (n = 30) and an autologous blood transfusion group (auto-group) (n = 30) according to the treatment they received. All patients did not receive preoperative and intraoperative blood transfusion. The blood collected in the operation area was transfused to the patients in the auto-group with the autotransfusion device and the allogeneic blood was transfused to the patients in the allo-group after the operation. The average amount of blood transfusion was 400 ml. The immune function after blood transfusion was mainly evaluated by natural killer cell cytotoxicity (NKCC) and interleukin-2 (IL-2) using ELISA kits, meanwhile the changes of cellular immune factor levels (differentiation cluster of differentiation, CD) (CD3+, CD4+) and humoral immune factor levels (Immunoglobulin E, IgE) after blood transfusion were determined by flow cytometry. The secondary outcome was postoperative inflammatory response measured by white blood cell (WBC) count, neutrophil percentage (NP) and C-reactive protein (CRP).

RESULTS

The parameters of both groups of patients were comparable. The auto-group significantly outperformed the Allo-group in the following laboratory parameters: NKCC (%, E:T = 10:1) at day 2 [26.1 (Auto) vs 19.3 (Allo); P = 0.0025], NKCC (%, E:T = 5:1) at day 2 [20.0 (Auto) vs 17.3 (Allo); P = 0.0094], CD3+ (%) at day 2 [50.5 (Auto) vs 40.8 (Allo); P = 0.0233], CD4+ (%) at day 2 [41.2 (Auto) vs 26.3 (Allo); P = 0.0122], IgE (U/mL) at day 2 [157.8 (Auto) vs 319.8 (Allo); P = 0.0064].

CONCLUSION

Autotransfusion can safely replace allogeneic blood transfusion and reduce the damage of postoperative immune function after total hip arthroplasty.

The therapeutic age of the neonatal Fc receptor

IgGs are essential soluble components of the adaptive immune response that evolved to protect the body from infection. Compared with other immunoglobulins, the role of IgGs is distinguished and enhanced by their high circulating levels, long half-life and ability to transfer from mother to offspring, properties that are conferred by interactions with neonatal Fc receptor (FcRn). FcRn binds to the Fc portion of IgGs in a pH-dependent manner and protects them from intracellular degradation. It also allows their transport across polarized cells that separate tissue compartments, such as the endothelium and epithelium. Further, it is becoming apparent that FcRn functions to potentiate cellular immune responses when IgGs, bound to their antigens, form IgG immune complexes. Besides the protective role of IgG, IgG autoantibodies are associated with numerous pathological conditions. As such, FcRn blockade is a novel and effective strategy to reduce circulating levels of pathogenic IgG autoantibodies and curtail IgG-mediated diseases, with several FcRn-blocking strategies on the path to therapeutic use. Here, we describe the current state of knowledge of FcRn-IgG immunobiology, with an emphasis on the functional and pathological aspects, and an overview of FcRn-targeted therapy development.

AATF/Che-1 RNA polymerase II binding protein overexpression reduces the anti-tumor NK-cell cytotoxicity through activating receptors modulation

Introduction

AATF/Che-1 over-expression in different tumors is well known and its effect on tumorigenicity is mainly due to its central role demonstrated in the oncogenic pathways of solid tumors, where it controls proliferation and viability. The effect exerted by tumors overexpressing Che-1 on the immune response has not yet been investigated.

Methods

Starting from ChIP-sequencing data we confirmed Che-1 enrichment on Nectin-1 promoter. Several co-cultures experiments between NK-cells and tumor cells transduced by lentiviral vectors carrying Che-1-interfering sequence, analyzed by flow-cytometry have allowed a detailed characterization of NK receptors and tumor ligands expression.

Results

Here, we show that Che-1 is able to modulate the expression of Nectin-1 ligand at the transcriptional level, leading to the impairment of killing activity of NK-cells. Nectin-1 down-modulation induces a modification in NK-cell ligands expression able to interact with activating receptors and to stimulate NK-cell function. In addition, NK-cells from Che-1 transgenic mice, confirming a reduced expression of activating receptors, exhibit impaired activation and a preferential immature status.

Discussion

The critical equilibrium between NK-cell ligand expression on tumor cells and the interaction with NK cell receptors is affected by Che-1 over-expression and partially restored by Che-1 interference. The evidence of a new role for Che-1 as regulator of anti-tumor immunity supports the necessity to develop approaches able to target this molecule which shows a dual tumorigenic function as cancer promoter and immune response modulator.

New insights and options into the mechanisms and effects of combined targeted therapy and immunotherapy in prostate cancer

Chronic inflammation is believed to drive prostate carcinogenesis by producing reactive oxygen species or reactive nitrogen species to induce DNA damage. This effect might subsequently cause epigenetic and genomic alterations, leading to malignant transformation. Although established therapeutic advances have extended overall survival, tumors in patients with advanced prostate cancer are prone to metastasis, transformation into metastatic castration-resistant prostate cancer, and therapeutic resistance. The tumor microenvironment (TME) of prostate cancer is involved in carcinogenesis, invasion and drug resistance. A plethora of preclinical studies have focused on immune-based therapies. Understanding the intricate TME system in prostate cancer may hold much promise for developing novel therapies, designing combinational therapeutic strategies, and further overcoming resistance to established treatments to improve the lives of prostate cancer patients. In this review, we discuss nonimmune components and various immune cells within the TME and their putative roles during prostate cancer initiation, progression, and metastasis. We also outline the updated fundamental research focusing on therapeutic advances of targeted therapy as well as combinational options for prostate cancer.

Immunotherapy in Prostate Cancer: State of Art and New Therapeutic Perspectives

Prostate cancer (PC) is the most common type of tumor in men. In the early stage of the disease, it is sensitive to androgen deprivation therapy. In patients with metastatic castration-sensitive prostate cancer (mHSPC), chemotherapy and second-generation androgen receptor therapy have led to increased survival. However, despite advances in the management of mHSPC, castration resistance is unavoidable and many patients develop metastatic castration-resistant disease (mCRPC). In the past few decades, immunotherapy has dramatically changed the oncology landscape and has increased the survival rate of many types of cancer. However, immunotherapy in prostate cancer has not yet given the revolutionary results it has in other types of tumors. Research into new treatments is very important for patients with mCRPC because of its poor prognosis. In this review, we focus on the reasons for the apparent intrinsic resistance of prostate cancer to immunotherapy, the possibilities for overcoming this resistance, and the clinical evidence and new therapeutic perspectives regarding immunotherapy in prostate cancer with a look toward the future.

A Blinded Investigation: Accentuated NK Lymphocyte CD335 (NKp46) Expression Predicts Pregnancy Failures

AIM

NKp46 is an NK cell receptor uniquely expressed by NK cells and a small subset of innate lymphoid cells. In our previous studies, we suggested a tight connection between the activity of NK cells and the expression of NKp46 and supported the clinical significance of NKp46 expression in NK cells in women with reproductive failures. In this study, we investigated the expression of NKp46 in NK cells in the peripheral blood of women in early pregnancy and analyzed its association with pregnancy loss.

METHODS

In a blinded study, we examined blood samples and analyzed the subsequent pregnancy outcomes from 98 early pregnant women (5th-7th week of gestation-w.g.) and 66 women in the 11th-13th week of pregnancy who served as controls. We studied the expression of NKp46 and the levels of anti-cardiolipin antibodies (aCL). The results of aCL were shared with the clinic, while the expression of NKp46 was blinded and not analyzed until the end of the study.

RESULTS

A misbalance in the NKp46⁺NK cells subpopulations was associated with an unfavorable ongoing pregnancy. A decreased level of NKp46^high cells (<14%) was strongly associated with miscarriage. A decreased level of the double-bright subpopulation (NKp46^hightCD56⁺⁺) also was a negative prognostic factor for the pregnancy course, but its increased level (>4%) was strongly associated with a successful pregnancy course.

CONCLUSIONS

Our results showed that accentuated levels of NKp46⁺NK cells lead to a negative prognosis for early pregnancy courses in women.

Genome-Wide Integrative Transcriptional Profiling Identifies Age-Associated Signatures in Dogs

Mammals experience similar stages of embryonic development, birth, infancy, youth, adolescence, maturity, and senescence. While embryonic developmental processes have been extensively researched, many molecular mechanisms regulating the different life stages after birth, such as aging, remain unresolved. We investigated the conserved and global molecular transitions in transcriptional remodeling with age in dogs of 15 breeds, which revealed that genes underlying hormone level regulation and developmental programs were differentially regulated during aging. Subsequently, we show that the candidate genes associated with tumorigenesis also exhibit age-dependent DNA methylation patterns, which might have contributed to the tumor state through inhibiting the plasticity of cell differentiation processes during aging, and ultimately suggesting the molecular events that link the processes of aging and cancer. These results highlight that the rate of age-related transcriptional remodeling is influenced not only by the lifespan, but also by the timing of critical physiological milestones.

The Function of NK Cells in Tumor Metastasis and NK Cell-Based Immunotherapy

Metastatic tumors cause the most deaths in cancer patients. Treating metastasis remains the primary goal of current cancer research. Although the immune system prevents and kills the tumor cells, the function of the immune system in metastatic cancer has been unappreciated for decades because tumors are able to develop complex signaling pathways to suppress immune responses, leading them to escape detection and elimination. Studies showed NK cell-based therapies have many advantages and promise for fighting metastatic cancers. We here review the function of the immune system in tumor progression, specifically focusing on the ability of NK cells in antimetastasis, how metastatic tumors escape the NK cell attack, as well as the recent development of effective antimetastatic immunotherapies.

IFN-β activates cytotoxic function of human natural killer cells toward IL-27 and poly(I:C) stimulated PC3 and DU145 cells

Natural killer (NK) cell phenotype and function are altered in patients with prostate cancer, and increased NK cell activity is associated with a better prognosis in patients with disease. For patients with advanced stage prostate cancer, immunotherapies are a promising approach when standard treatment options have been exhausted. With the rapid emergence of NK cell-based therapies, it is important to understand the mechanisms by which NK cells can be triggered to kill cancer cells that have developed immune-evasive strategies. Altering the cytokine profiles of advanced prostate cancer cells may be an area to explore when considering ways in which NK cell activation can be modulated. We have previously demonstrated that combining the cytokine, IL-27, with TLR3 agonist, poly(I:C), changes cytokine secretion in the advanced prostate cancer models, PC3 and DU145 cells. Herein, we extend our previous work to study the effect of primary human NK cells on prostate cancer cell death in an in vitro co-culture model. Stimulating PC3 and DU145 cells with IL-27 and poly(I:C) induced IFN-β secretion, which was required for activation of primary human NK cells to kill these stimulated prostate cancer cells. PC3 cells were more sensitized to NK cell-mediated killing when compared to DU145 cells, which was attributed to differential levels of IFN-β produced in response to stimulation with IL-27 and poly(I:C). IFN-β increased granzyme B secretion and membrane-bound TRAIL expression by co-cultured NK cells. We further demonstrated that these NK cells killed PC3 cells in a partially TRAIL-dependent manner. This work provides mechanistic insight into how the cytotoxic function of NK cells can be improved to target cancer cells.

POLD1 as a Prognostic Biomarker Correlated with Cell Proliferation and Immune Infiltration in Clear Cell Renal Cell Carcinoma

DNA polymerase delta 1 catalytic subunit (POLD1) plays a vital role in genomic copy with high fidelity and DNA damage repair processes. However, the prognostic value of POLD1 and its relationship with tumor immunity in clear cell renal cell carcinoma (ccRCC) remains to be further explored. Transcriptional data sets and clinical information were obtained from the TCGA, ICGC, and GEO databases. Differentially expressed genes (DEGs) were derived from the comparison between the low and high POLD1 expression groups in the TCGA–KIRC cohort. KEGG and gene ontology (GO) analyses were performed for those DEGs to explore the potential influence of POLD1 on the biological behaviors of ccRCC. The prognostic clinical value and mutational characteristics of patients were described and analyzed according to the POLD1 expression levels. TIMER and TISIDB databases were utilized to comprehensively investigate the potential relevance between the POLD1 levels and the status of the immune cells, as well as the tumor infiltration of immune cells. In addition, RT-qPCR, Western blot, immunohistochemistry and several functional and animal experiments were performed for clinical, in vitro and in vivo validation. POLD1 was highly expressed in a variety of tumors including ccRCC, and further verified in a validation cohort of 60 ccRCC samples and in vitro cell line experiments. POLD1 expression levels in the ccRCC samples were associated with various clinical characteristics including pathologic tumor stage and histologic grade. ccRCC patients with high POLD1 expression have poor clinical outcomes and exhibit a higher rate of somatic mutations than those with low POLD1 expression. Cox regression analysis also showed that POLD1 could act as a potential independent prognostic biomarker. The DEGs associated with POLD1 were significantly enriched in the immunity-related pathways. Moreover, further immune infiltration analysis indicated that high POLD1 expression was associated with high NK CD56bright cells, Treg cells, and myeloid-derived suppressor cells’ (MDSCs) infiltration scores, as well as their marker gene sets of immune cell status. Meanwhile, POLD1 exhibited resistance to various drugs when highly expressed. Finally, the knockdown of POLD1 inhibited the proliferation and migration, and promoted the apoptosis of ccRCC cells in vitro and in vivo, as well as influenced the activation of oncogenic signaling. Our current study demonstrated that POLD1 is a potential prognostic biomarker for ccRCC patients. It might create a tumor immunosuppressive microenvironment and inhibit the susceptibility to ferroptosis leading to a poor prognosis.

Tumor immune contexture predicts recurrence after prostatectomy and efficacy of androgen deprivation and immunotherapy in prostate cancer

BACKGROUND

Prostate cancer is one of the most common cancers in men with notable interpatient heterogeneity. Implications of the immune microenvironment in predicting the biochemical recurrence-free survival (BCRFS) after radical prostatectomy and the efficacy of systemic therapies in prostate cancer remain ambiguous.

METHODS

The tumor immune contexture score (TICS) involving eight immune contexture-related signatures was developed using seven cohorts of 1120 patients treated with radical prostatectomy (training: GSE46602, GSE54460, GSE70769, and GSE94767; validation: GSE70768, DKFZ2018, and TCGA). The association between the TICS and treatment efficacy was investigated in GSE111177 (androgen deprivation therapy [ADT]) and EGAS00001004050 (ipilimumab).

RESULTS

A high TICS was associated with prolonged BCRFS after radical prostatectomy in the training (HR = 0.32, 95% CI 0.24-0.45, P < 0.001) and the validation cohorts (HR = 0.45, 95% CI 0.32-0.62, P < 0.001). The TICS showed stable prognostic power independent of tumor stage, surgical margin, pre-treatment prostatic specific antigen (PSA), and Gleason score (multivariable HR = 0.50, 95% CI 0.39-0.63, P < 0.001). Adding the TICS into the prognostic model constructed using clinicopathological features significantly improved its 1/2/3/4/5-year area under curve (P < 0.05). A low TICS was associated with high homologous recombination deficiency scores, abnormally activated pathways concerning DNA replication, cell cycle, steroid hormone biosynthesis, and drug metabolism, and fewer tumor-infiltrating immune cells (P < 0.05). The patients with a high TICS had favorable BCRFS with ADT (HR = 0.25, 95% CI 0.06-0.99, P = 0.034) or ipilimumab monotherapy (HR = 0.23, 95% CI 0.06-0.81, P = 0.012).

CONCLUSIONS

Our study delineates the associations of tumor immune contexture with molecular features, recurrence after radical prostatectomy, and the efficacy of ADT and immunotherapy. The TICS may improve the existing risk stratification systems and serve as a patient-selection tool for ADT and immunotherapy in prostate cancer.

The impact of killer cell immunoglobulin-like receptor (KIR) genes and human leukocyte antigen (HLA) class I ligands on predisposition or protection against prostate cancer

Natural killer (NK) cell development largely depends on killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands. In the current study, we investigated the role of KIR genes, HLA ligands, and KIR-HLA combinations in vulnerability or protection against prostate cancer (PC). To analyze the frequency of 16 KIR genes and 5 HLA ligands, polymerase chain reaction with sequence-specific primers (PCR-SSP) was conducted in 150 PC patients and 200 healthy controls (CNs). KIR2DL5 (p = 0.0346, OR = 0.606, CI = 0.3916-0.9336), KIR2DS5 (p = 0.0227, OR = 0.587, CI = 0.3793-0.9139), HLA-B Bw4^Thr80 (p = 0.0401, OR = 0.3552, CI = 0.1466-0.9059), HLA Bw4 (p = 0.0190, OR = 0.4744, CI = 0.2656-0.8521), and T4 gene cluster (including KIR2DS5-2DL5-3DS1-2DS1 genes) (p = 0.0194, OR = 0.5575, CI = 0.3449-0.8938) had a lower frequency in the PC patients compared to the control group. Moreover, a lower frequency of the genotypes contacting activating KIR (aKIR) > inhibitory KIR (iKIR) (p = 0.0298, OR = 0.5291, CI = 0.3056-0.9174) and iKIR + HLA < aKIR + HLA (p = 0.0183, OR = 0.2197, CI = 0.0672-0.7001) in PC patients compared to the CNs implies a protective role for aKIR genes. In the case of KIR-HLA interactions, we detected a significant association between KIR3DS1⁺ + HLA-A Bw4⁺ (p = 0.0113, OR = 0.5093, CI = 0.3124-0.8416) and KIR3DL1^- + HLA-A Bw4⁺ (p = 0.0306, OR = 0.1153, CI = 0.0106-0.6537) combinations and resistance to prostate cancer. In contrast, the presence of KIR3DL1 in the absence of HLA-A Bw4 (p = 0.0040, OR = 2.00, CI = 1.264-3.111), HLA Bw4 (p = 0.0296, OR = 2.066, CI = 1.094-3.906), and HLA-Bw4^Thr80 (p = 0.0071, OR = 2.505, CI = 1.319-4.703) genes probably predisposes to prostate cancer. Carrying the CxT4 genotype in PC patients was positively associated with lower tumor grades (Gleason score ≤ 6) (p = 0.0331, OR = 3.290, and CI = 1.181-8.395). Altogether, our data suggest a protective role for aKIRs, HLA-B Bw4^Thr80, and HLA Bw4 ligands as well as a predisposing role for certain KIR-HLA combinations in prostate cancer. The findings of this study offer new insight into the population's risk assessment for prostate cancer in men. Additionally, predicting immunotherapy response based on KIR-HLA combinations aids in implementing the most effective therapeutic approach in the early stages of the disease.

Autofluorescence lifetime imaging classifies human lymphocyte activation and subtype

New non-destructive tools are needed to reliably assess lymphocyte function for immune profiling and adoptive cell therapy. Optical metabolic imaging (OMI) is a label-free method that measures the autofluorescence intensity and lifetime of metabolic cofactors NAD(P)H and FAD to quantify metabolism at a single-cell level. Here, we investigate whether OMI can resolve metabolic changes between human quiescent versus IL4/CD40 activated B cells and IL12/IL15/IL18 activated memory-like NK cells. We found that quiescent B and NK cells were more oxidized compared to activated cells. Additionally, the NAD(P)H mean fluorescence lifetime decreased and the fraction of unbound NAD(P)H increased in the activated B and NK cells compared to quiescent cells. Machine learning classified B cells and NK cells according to activation state (CD69+) based on OMI parameters with up to 93.4% and 92.6% accuracy, respectively. Leveraging our previously published OMI data from activated and quiescent T cells, we found that the NAD(P)H mean fluorescence lifetime increased in NK cells compared to T cells, and further increased in B cells compared to NK cells. Random forest models based on OMI classified lymphocytes according to subtype (B, NK, T cell) with 97.8% accuracy, and according to activation state (quiescent or activated) and subtype (B, NK, T cell) with 90.0% accuracy. Our results show that autofluorescence lifetime imaging can accurately assess lymphocyte activation and subtype in a label-free, non-destructive manner.

Receptors of immune cells mediates recognition for tumors

Over the last few decades, the immune system has been steered toward eradication of cancer cells with the help of cancer immunotherapy. T cells, B cells, monocytes/macrophages, dendritic cells, T-reg cells, and natural killer (NK) cells are some of the numerous immune cell types that play a significant part in cancer cell detection and reduction of inflammation, and the antitumor response. Briefly stated, chimeric antigen receptors, adoptive transfer and immune checkpoint modulators are currently the subjects of research focus for successful immunotherapy-based treatments for a variety of cancers. This chapter discusses ongoing investigations on the mechanisms and recent developments by which receptors of immune cells especially that of lymphocytes and monocytes/macrophages regulate the detection of immune system leading to malignancies. We will also be looking into the treatment strategies based on these mechanisms.

Epigenetic modulation and prostate cancer: Paving the way for NK cell anti-tumor immunity

Immunoepigenetics is a growing field, as there is mounting evidence on the key role played by epigenetic mechanisms in the regulation of tumor immune cell recognition and control of immune cell anti-tumor responses. Moreover, it is increasingly acknowledgeable a tie between epigenetic regulation and prostate cancer (PCa) development and progression. PCa is intrinsically a cold tumor, with scarce immune cell infiltration and low inflammatory tumor microenvironment. However, Natural Killer (NK) cells, main anti-tumor effector immune cells, have been frequently linked to improved PCa prognosis. The role that epigenetic-related mechanisms might have in regulating both NK cell recognition of PCa tumor cells and NK cell functions in PCa is still mainly unknown. Epigenetic modulating drugs have been showing boundless therapeutic potential as anti-tumor agents, however their role in immune cell regulation and recognition is scarce. In this review, we focused on studies addressing modulation of epigenetic mechanisms involved in NK cell-mediated responses, including both the epigenetic modulation of tumor cell NK ligand expression and NK cell receptor expression and function in different tumor models, highlighting studies in PCa. The integrated knowledge from diverse epigenetic modulation mechanisms promoting NK cell-mediated immunity in various tumor models might open doors for the development of novel epigenetic-based therapeutic options for PCa management.

Effect of Peripheral Blood Lymphocytes on Prognosis of Multiple Cancers

BACKGROUND

In the era of immunotherapy, the immune function of patients with cancer has attracted increasingly more attention. The immune scoring system is an important supplement to the classical tumor staging and classification process. The immune system plays a controversial role in the development of cancer. Meanwhile, the prognostic significance of peripheral blood lymphocytes is still controversial. The present study aimed to assess the prognostic significance of peripheral blood lymphocytes in eight types of cancers.

METHODS

We performed a retrospective analysis of 32731 patients with cancer hospitalized in Shanxi Cancer Hospital from January 2012 to December 2016. The percentages of CD3+, CD4+, CD8+, CD19+, CD56+, and CD127+ lymphocytes in the peripheral blood of all patients were examined using flow cytometry. The immune cell subsets of patients with cancer were classified into three groups using the K-means clustering method via the R language software. Differences in the overall survival rate were analyzed using the Kaplan-Meier method. The Cox regression model was utilized for univariate and multivariate analysis.

RESULTS

The mean survival time of patients with liver cancer, rectal cancer, gastric cancer, breast cancer, esophageal cancer, colon cancer, ovarian cancer, and lymphoma was 30.25, 21.74, 37.67, 16.28, 21.62, 30.25, 31.43, and 34.27 months, respectively. The survival curves showed that the most prognostically beneficial immune state of the patients was when the expression of the immune cells in the peripheral blood was in equilibrium. Moreover, Cox proportional hazards regression model analysis revealed that the factors affecting the overall survival (OS) of patients with eight different kinds of cancer were not identical. However, CD19+ lymphocytes had the most significant impact on the prognosis of these patients.

CONCLUSIONS

Cancer occurrence and development were associated with the density of lymphocyte infiltration. Thus, immune homeostasis could be an effective indicator to evaluate prognosis and judge cancer treatment.

Harnessing NK Cells to Control Metastasis

In recent years, tumor immunotherapy has produced remarkable results in tumor treatment. Nevertheless, its effects are severely limited in patients with low or absent pre-existing T cell immunity. Accordingly, metastasis remains the major cause of tumor-associated death. On the other hand, natural killer (NK) cells have the unique ability to recognize and rapidly act against tumor cells and surveil tumor cell dissemination. The role of NK cells in metastasis prevention is undisputable as an increase in the number of these cells mostly leads to a favorable prognosis. Hence, it is reasonable to consider that successful metastasis involves evasion of NK-cell-mediated immunosurveillance. Therefore, harnessing NK cells to control metastasis is promising. Circulating tumor cells (CTCs) are the seeds for distant metastasis, and the number of CTCs detected in the blood of patients with tumor is associated with a worse prognosis, whereas NK cells can eliminate highly motile CTCs especially in the blood. Here, we review the role of NK cells during metastasis, particularly the specific interactions of NK cells with CTCs, which may provide essential clues on how to harness the power of NK cells against tumor metastasis. As a result, a new way to prevent or treat metastatic tumor may be developed.

Metformin increases natural killer cell functions in head and neck squamous cell carcinoma through CXCL1 inhibition

BACKGROUND

Metformin slows tumor growth and progression in vitro, and in combination with chemoradiotherapy, resulted in high overall survival in patients with head and neck cancer squamous cell carcinoma (HNSCC) in our phase 1 clinical trial (NCT02325401). Metformin is also postulated to activate an antitumor immune response. Here, we investigate immunologic effects of metformin on natural killer (NK) and natural killer T cells, including results from two phase I open-label studies in patients with HNSCC treated with metformin (NCT02325401, NCT02083692).

METHODS

Peripheral blood was collected before and after metformin treatment or from newly diagnosed patients with HNSCC. Peripheral immune cell phenotypes were evaluated using flow cytometry, cytokine expression by ELISA and/or IsoLight, and NK cell-mediated cytotoxicity was determined with a flow-based NK cell cytotoxicity assay (NKCA). Patient tumor immune infiltration before and after metformin treatment was analyzed with immunofluorescence. NK cells were treated with either vehicle or metformin and analyzed by RNA sequencing (RNA-seq). NK cells were then treated with inhibitors of significant pathways determined by RNA-seq and analyzed by NKCA, ELISA, and western blot analyses.

RESULTS

Increased peripheral NK cell activated populations were observed in patients treated with metformin. NK cell tumor infiltration was enhanced in patients with HNSCC treated with metformin preoperatively. Metformin increased antitumorigenic cytokines ex vivo, including significant increases in perforin. Metformin increased HNSCC NK cell cytotoxicity and inhibited the CXCL1 pathway while stimulating the STAT1 pathway within HNSCC NK cells. Exogenous CXCL1 prevented metformin-enhanced NK cell-mediated cytotoxicity. Metformin-mediated NK cell cytotoxicity was found to be AMP-activated protein kinase independent, but dependent on both mechanistic target of rapamycin and pSTAT1.

CONCLUSIONS

Our data identifies a new role for metformin-mediated immune antitumorigenic function through NK cell-mediated cytotoxicity and downregulation of CXCL1 in HNSCC. These findings will inform future immunomodulating therapies in HNSCC.

New Immuno-oncology Targets and Resistance Mechanisms

OPINION STATEMENT

Immune checkpoint inhibition (ICI) has revolutionized the field of non-small cell lung cancer (NSCLC); currently, most patients with advanced disease receive upfront ICI either alone or in combination with chemotherapy. These advances have recently extended into early-stage NSCLC, with ICI incorporation into neoadjuvant and adjuvant treatment regimens. However, despite these successes, immunotherapy (IO) resistance remains a fundamental challenge in NSCLC, introducing a central quandary of how to precisely select the appropriate IO therapy or IO combination therapy for each individual patient. To address this vital need in the field, there has been an explosion of research in immuno-oncology to identify mechanisms of resistance, ranging from genomic alterations in the tumor to immunosuppressive conditions in the tumor microenvironment (TME). There remain many questions about how this complex interplay between the tumor and the immune microenvironment translates into clinical phenotypes of primary and acquired resistance. In NSCLC, a number of novel therapeutics are being developed to prevent and overcome resistance to ICI. Particular promise has been shown with therapeutics targeting novel T cell immune checkpoint inhibitors and targeting innate immune cells in the TME, chief among these cells are natural killer cells, neutrophils, and macrophages. Further research into tissue-based and non-invasive biomarkers that can be prospectively integrated into therapeutic trial design will be critical to advance the field's understanding of individual resistance patterns and enable the ultimate goal of precision immuno-oncology.

Biodegradable nanoparticles induce cGAS/STING-dependent reprogramming of myeloid cells to promote tumor immunotherapy

Cancer treatment utilizing infusion therapies to enhance the patient's own immune response against the tumor have shown significant functionality in a small subpopulation of patients. Additionally, advances have been made in the utilization of nanotechnology for the treatment of disease. We have previously reported the potent effects of 3-4 daily intravenous infusions of immune modifying poly(lactic-co-glycolic acid) (PLGA) nanoparticles (IMPs; named ONP-302) for the amelioration of acute inflammatory diseases by targeting myeloid cells. The present studies describe a novel use for ONP-302, employing an altered dosing scheme to reprogram myeloid cells resulting in significant enhancement of tumor immunity. ONP-302 infusion decreased tumor growth via the activation of the cGAS/STING pathway within myeloid cells, and subsequently increased NK cell activation via an IL-15-dependent mechanism. Additionally, ONP-302 treatment increased PD-1/PD-L1 expression in the tumor microenvironment, thereby allowing for functionality of anti-PD-1 for treatment in the B16.F10 melanoma tumor model which is normally unresponsive to monotherapy with anti-PD-1. These findings indicate that ONP-302 allows for tumor control via reprogramming myeloid cells via activation of the STING/IL-15/NK cell mechanism, as well as increasing anti-PD-1 response rates.

Signaling new therapeutic opportunities: cytokines in prostate cancer

INTRODUCTION

Despite FDA approval of sipuleucel-T in 2010, endeavors to use immune checkpoint inhibitors in unselected prostate cancer patients have not improved clinical outcomes. These efforts include studies with anti-PD1/PD-L1 and anti-CTLA-4 alone and in combination with existing standards of care. These strategies are generally T-cell centric and disregard the broader complex and pleiotropic components of the prostate cancer tumor microenvironment such as natural killer cells, myeloid-derived suppressor cells and tumor associated macrophages.

AREAS COVERED

We performed an online literature search and undertook a review of existing pre-clinical and clinical literature for cytokine-based therapy relating to prostate cancer, specifically on interleukin (IL)-2, IL-15, IL-12, IL-23, IL-8 and transforming growth factor (TGF)-β.

EXPERT OPINION

Cytokine-based therapies present an alternative immune strategy to target the pleiotropic prostate cancer tumor microenvironment beyond T-cells. Future immunotherapy strategies in prostate cancer should address these immune cell populations which may play more important roles in the prostate cancer tumor microenvironment.

The Immunotherapy and Immunosuppressive Signaling in Therapy-Resistant Prostate Cancer

Prostate cancer is one of the most common malignant tumors in men. Initially, it is androgen-dependent, but it eventually develops into castration-resistant prostate cancer (CRPC), which is incurable with current androgen receptor signaling target therapy and chemotherapy. Immunotherapy, specifically with immune checkpoint inhibitors, has brought hope for the treatment of this type of prostate cancer. Approaches such as vaccines, adoptive chimeric antigen receptor-T (CAR-T) cells, and immune checkpoint inhibitors have been employed to activate innate and adaptive immune responses to treat prostate cancer, but with limited success. Only Sipuleucel-T and the immune checkpoint inhibitor pembrolizumab are approved by the US FDA for the treatment of limited prostate cancer patients. Prostate cancer has a complex tumor microenvironment (TME) in which various immunosuppressive molecules and mechanisms coexist and interact. Additionally, prostate cancer is considered a “cold” tumor with low levels of tumor mutational burden, low amounts of antigen-presenting and cytotoxic T-cell activation, and high levels of immunosuppressive molecules including cytokines/chemokines. Thus, understanding the mechanisms of immunosuppressive signaling activation and immune evasion will help develop more effective treatments for prostate cancer. The purpose of this review is to summarize emerging advances in prostate cancer immunotherapy, with a particular focus on the molecular mechanisms that lead to immune evasion in prostate cancer. At the same time, we also highlight some potential therapeutic targets to provide a theoretical basis for the treatment of prostate cancer.

Integrative Analysis of Bulk RNA-Seq and Single-Cell RNA-Seq Unveils the Characteristics of the Immune Microenvironment and Prognosis Signature in Prostate Cancer

The immune microenvironment is a culmination of the collaborative effort of immune cells and is important in cancer development. The underlying mechanisms of the tumor immune microenvironment in regulating prostate cancer (PRAD) are unclear. In the current study, 144 natural killer cell-related genes were identified using differential expression, single-sample gene set enrichment analysis, and weighted gene coexpression network analysis. Furthermore, VCL, ACTA2, MYL9, MYLK, MYH11, TPM1, ACTG2, TAGLN, and FLNC were selected as hub genes via the protein-protein interaction network. Based on the expression patterns of the hub genes, endothelial, epithelial, and tissue stem cells were identified as key cell subpopulations, which could regulate PRAD via immune response, extracellular signaling, and protein formation. Moreover, 27 genes were identified as prognostic signatures and used to construct the risk score model. Receiver operating characteristic curves revealed the good performance of the risk score model in both the training and testing datasets. Different chemotherapeutic responses were observed between the low- and high-risk groups. Additionally, a nomogram based on the risk score and other clinical features was established to predict the 1-, 3-, and 5-year progression-free interval of patients with PRAD. This study provides novel insights into the molecular mechanisms of the immune microenvironment and its role in the pathogenesis of PARD. The identification of key cell subpopulations has a potential therapeutic and prognostic use in PRAD.

Targeting CISH enhances natural cytotoxicity receptor signaling and reduces NK cell exhaustion to improve solid tumor immunity

Background

The success and limitations of current immunotherapies have pushed research toward the development of alternative approaches and the possibility to manipulate other cytotoxic immune cells such as natural killer (NK) cells. Here, we targeted an intracellular inhibiting protein ‘cytokine inducible SH2-containing protein’ (CISH) in NK cells to evaluate the impact on their functions and antitumor properties.

Methods

To further understand CISH functions in NK cells, we developed a conditional Cish-deficient mouse model in NK cells (Cish^fl/flNcr1^Ki/+). NK cells cytokine expression, signaling and cytotoxicity has been evaluated in vitro. Using intravenous injection of B16F10 melanoma cell line and EO711 triple negative breast cancer cell line, metastasis evaluation was performed. Then, orthotopic implantation of breast tumors was performed and tumor growth was followed using bioluminescence. Infiltration and phenotype of NK cells in the tumor was evaluated. Finally, we targeted CISH in human NK-92 or primary NK cells, using a technology combining the CRISPR(i)-dCas9 tool with a new lentiviral pseudotype. We then tested human NK cells functions.

Results

In Cish^fl/flNcr1^Ki/+ mice, we detected no developmental or homeostatic difference in NK cells. Global gene expression of Cish^fl/flNcr1^Ki/+ NK cells compared with Cish^+/+Ncr1^Ki/+ NK cells revealed upregulation of pathways and genes associated with NK cell cycling and activation. We show that CISH does not only regulate interleukin-15 (IL-15) signaling pathways but also natural cytotoxicity receptors (NCR) pathways, triggering CISH protein expression. Primed Cish^fl/flNcr1^Ki/+ NK cells display increased activation upon NCR stimulation. Cish^fl/flNcr1^Ki/+ NK cells display lower activation thresholds and Cish^fl/flNcr1^Ki/+ mice are more resistant to tumor metastasis and to primary breast cancer growth. CISH deletion favors NK cell accumulation to the primary tumor, optimizes NK cell killing properties and decreases TIGIT immune checkpoint receptor expression, limiting NK cell exhaustion. Finally, using CRISPRi, we then targeted CISH in human NK-92 or primary NK cells. In human NK cells, CISH deletion also favors NCR signaling and antitumor functions.

Conclusion

This study represents a crucial step in the mechanistic understanding and safety of Cish targeting to unleash NK cell antitumor function in solid tumors. Our results validate CISH as an emerging therapeutic target to enhance NK cell immunotherapy.

Combination Blockade of the IL6R/STAT-3 Axis with TIGIT and Its Impact on the Functional Activity of NK Cells against Prostate Cancer Cells

Background/Aims. Prostate cancer (PCa) is one of the neoplasms with the highest incidence and mortality rate in men worldwide. Advanced stages of the disease are usually very aggressive, and most are treated with chemotherapeutic drugs that generally cause side effects in these patients. However, additional therapeutic targets such as the IL6R/STAT-3 axis and TIGIT have been proposed, mainly due to their relevance in the development of PCa and regulation of NK cell-mediated cytotoxicity. Here, we evaluate the effect of inhibitors directed against these therapeutic targets primarily via an analysis of NK cell function versus prostate cancer cells. Methods. We analyzed the secretion of cytokines, chemokines, and growth factors in 22Rv1, LNCaP, and DU145 cells. In these cells, we also evaluated the expression of NK ligands, IL6R, STAT-3, and phosporylated STAT-3. In NK-92 cells, we evaluated the effects of Stattic (Stt) and tocilizumab (Tcz) on NK receptors. In addition, we assessed if the disruption of the IL6R/STAT-3 pathway and blockade of TIGIT potentiated the cytotoxicity of NK-92 cells versus DU145 cells. Results. DU145 abundantly secretes M-CSF, VEGF, IL-6, CXCL8, and TGF-β. Furthermore, the expression of CD155 was found to increase in accordance with aggressiveness and metastatic status in the prostate cancer cells. Stt and Tcz induce a decrease in STAT-3 phosphorylation in the DU145 cells and, in turn, induce an increase of NKp46 and a decrease of TIGIT expression in NK-92 cells. Finally, the disruption of the IL6R/STAT-3 axis in prostate cancer cells and the blocking of TIGIT on NK-92 were observed to increase the cytotoxicity of NK-92 cells against DU145 cells through an increase in sFasL, granzyme A, granzyme B, and granulysin. Conclusions. Our results reveal that the combined use of inhibitors directed against the IL6R/STAT-3 axis and TIGIT enhances the functional activity of NK cells against castration-resistant prostate cancer cells.

Tumor-Infiltrating Lymphocytes in Colorectal Cancer: The Fundamental Indication and Application on Immunotherapy

The clinical success of immunotherapy has revolutionized the treatment of cancer patients, bringing renewed attention to tumor-infiltrating lymphocytes (TILs) of various cancer types. Immune checkpoint blockade is effective in patients with mismatched repair defects and high microsatellite instability (dMMR-MSI-H) in metastatic colorectal cancer (CRC), leading the FDA to accelerate the approval of two programmed cell death 1 (PD-1) blocking antibodies, pembrolizumab and nivolumab, for treatment of dMMR-MSI-H cancers. In contrast, patients with proficient mismatch repair and low levels of microsatellite stability or microsatellite instability (pMMR-MSI-L/MSS) typically have low tumor-infiltrating lymphocytes and have shown unsatisfied responses to the immune checkpoint inhibitor. Different TILs environments reflect different responses to immunotherapy, highlighting the complexity of the underlying tumor-immune interaction. Profiling of TILs fundamental Indication would shed light on the mechanisms of cancer-immune evasion, thus providing opportunities for the development of novel therapeutic strategies. In this review, we summarize phenotypic diversities of TILs and their connections with prognosis in CRC and provide insights into the subsets-specific nature of TILs with different MSI status. We also discuss current clinical immunotherapy approaches based on TILs as well as promising directions for future expansion, and highlight existing clinical data supporting its use.

The evolving role of immune cells in prostate cancer

Prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer-related death among men in western countries. Androgen deprivation therapy (ADT) is considered the standard therapy for recurrent prostate cancer; however, this therapy may lead to ADT resistance and tumor progression, which seems to be regulated by epithelial-mesenchymal transition (EMT) and/or neuroendocrine differentiation (NED). In addition, recent data suggested the involvement of either adaptive or innate infiltrated immune cells in the initiation, progression, metastasis, and treatment of prostate cancer. In this review, we outlined the characteristics and roles of these immune cells in the initiation, progression, metastasis, and treatments of prostate cancer. We also summarized the current therapeutic strategies in targeting immune cells of the prostate tumor microenvironment.

Profiling of immune features to predict immunotherapy efficacy

Immune checkpoint blockade (ICB) therapies exhibit substantial clinical benefit in different cancers, but relatively low response rates in the majority of patients highlight the need to understand mutual relationships among immune features. Here, we reveal overall positive correlations among immune checkpoints and immune cell populations. Clinically, patients benefiting from ICB exhibited increases for both immune stimulatory and inhibitory features after initiation of therapy, suggesting that the activation of the immune microenvironment might serve as the biomarker to predict immune response. As proof-of-concept, we demonstrated that the immune activation score (IS_Δ) based on dynamic alteration of interleukins in patient plasma as early as two cycles (4–6 weeks) after starting immunotherapy can accurately predict immunotherapy efficacy. Our results reveal a systematic landscape of associations among immune features and provide a noninvasive, cost-effective, and time-efficient approach based on dynamic profiling of pre- and on-treatment plasma to predict immunotherapy efficacy.

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Reveal a systematic landscape of associations among immune features in primary, metastatic, and ICB-treated tumors

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The activation of the immune microenvironment might serve as the biomarker of immunotherapy

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Dynamic alteration of interleukins in patient plasma can accurately predict immunotherapy efficacy

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Provide a noninvasive, cost-effective, and time-efficient approach to predict immunotherapy efficacy

The tumor innate immune microenvironment in prostate cancer: an overview of soluble factors and cellular effectors

Prostate cancer (PCa) accounts as the most common non-cutaneous disease affecting males, and as the first cancer, for incidence, in male. With the introduction of the concept of immunoscore, PCa has been classified as a cold tumor, thus driving the attention in the development of strategies aimed at blocking the infiltration/activation of immunosuppressive cells, while favoring the infiltration/activation of anti-tumor immune cells. Even if immunotherapy has revolutionized the approaches to cancer therapy, there is still a window failure, due to the immune cell plasticity within PCa, that can acquire pro-tumor features, subsequent to the tumor microenvironment (TME) capability to polarize them. This review discussed selected relevant soluble factors [transforming growth factor-beta (TGFβ), interleukin-6 (IL-6), IL-10, IL-23] and cellular components of the innate immunity, as drivers of tumor progression, immunosuppression, and angiogenesis within the PCa-TME.

Challenges and Recent Advances in NK Cell-Targeted Immunotherapies in Solid Tumors

Natural killer (NK) cell is a powerful malignant cells killer, providing rapid immune responses via direct cytotoxicity without the need of antigen processing and presentation. It plays an essential role in preventing early tumor, metastasis and minimal residual disease. Although adoptive NK therapies achieved great success in clinical trials against hematologic malignancies, their accumulation, activation, cytotoxic and immunoregulatory functions are severely impaired in the immunosuppressive microenvironment of solid tumors. Now with better understandings of the tumor evasive mechanisms from NK-mediated immunosurveillance, immunotherapies targeting the key molecules for NK cell dysfunction and exhaustion have been developed and tested in both preclinical and clinical studies. In this review, we introduce the challenges that NK cells encountered in solid tumor microenvironment (TME) and the therapeutic approaches to overcome these limitations, followed by an outline of the recent preclinical advances and the latest clinical outcomes of NK-based immunotherapies, as well as promising strategies to optimize current NK-targeted immunotherapies for solid tumors.