Effect of tacrolimus on soluble costimulatory molecules in patients with refractory myasthenia gravis.

OBJECTIVES: To investigate the expression and possible role of soluble costimulatory molecules in the treatment of refractory myasthenia gravis. METHODS: Thirty-two patients with refractory myasthenia gravis were enrolled into this study and given tacrolimus 3 mg/day. At the beginning of treatment and 12 months follow-up period, clinical data were collected and recorded. The clinical classification of myasthenia gravis Foundation (MGFA) was performed. The MGFA-quantitative myasthenia gravis score (MGFA-QMGS), manual muscle test (MMT), MG activity of daily living (MG-ADL) and the activity of daily living (MG-ADL), the 15-item myasthenia gravis quality of life (MG QOL-15) and the dose change of prednisone were used to evaluate the efficacy. The expression levels of soluble costimulatory molecules and their ligands (sPD-1/sPD-L1, sICOS/sICOSL, sCD40/sCD40L), soluble CD25 and IL-2 in serum were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: We observed that oral administration of 3 mg tacrolimus daily for 1 year can significantly improve the clinical symptoms of patients with refractory myasthenia gravis, which is characterized by a significant reduction in clinical scores, such as QMG, MMT, ADL, MGQOL-15, and a reduction daily oral prednisolone (PSL) dose (P < 0.0001).We also found that the levels of plasma sPD-1, sCD40, IL-2 in refractory MG patients increased significantly, and those decreased significantly 12 months after tacrolimus treatment (P < 0.05). The level of sCD25 was negatively correlated with clinical severity scores (P < 0.05). After tacrolimus treatment, the level of sPD-L1 increased although there was no significant difference. CONCLUSION: Tacrolimus could relieve the symptoms of refractory MG and significantly decrease the levels of plasma sPD-1, sICOSL, sCD40, sCD25 and IL-2. Soluble costimulatory molecules might be potential biomarkers for MG and tacrolimus treatment.

PD-1 blockade combined with IL-33 enhances the antitumor immune response in a type-1 lymphocyte-mediated manner.

PD-1 immune checkpoint blockade and cytokine IL-33 have shown significant therapeutic effects in tumor immunotherapy. These therapies promote CD8+ T cell activation, proliferation, and effector functions. However, there were few research about the combined therapy efficacy. In this study, we established B16-empty vector and B16-IL33 melanoma mouse models and treated with PD-1 monoclonal antibody. We reported that PD-1 blockade combined with cytokine IL-33 further inhibited tumor progression and prolonged the survival of tumor-bearing mice. Mechanistically, the combination therapy was found to further facilitate CD4+ and CD8+ T lymphocytes accumulation, and enhance the antitumor effects of CD4+or CD8+tumor-infiltrating lymphocytes by promoting type-1 immune response within the tumor microenvironment using flow cytometry and quantitative real time polymerase chain reaction. Thus, PD-1 blockade combined with IL-33 has application potential in tumor immunotherapy. Further, this study provides a new promising strategy and theoretical basis for tumor combination immunotherapy.

Eomes Impedes Durable Response to Tumor Immunotherapy by Inhibiting Stemness, Tissue Residency, and Promoting the Dysfunctional State of Intratumoral CD8+ T Cells.

Sustaining efficacious T cell-mediated antitumor immune responses in the tumor tissues is the key to the success of cancer immunotherapy. Current strategies leverage altering the signals T cells sense in the tumor microenvironment (TME). Checkpoint inhibitor-based approaches block inhibitory signals such as PD-1 whereas cytokine-based therapies increase the level of immune-stimulatory cytokines such as IL-2. Besides extrinsic signals, the genetic circuit within T cells also participates in determining the nature and trajectory of antitumor immune responses. Here, we showed that efficacy of the IL33-based tumor immunotherapy was greatly enhanced in mice with T cell-specific Eomes deficiency. Mechanistically, we demonstrated that Eomes deficient mice had diminished proportions of exhausted/dysfunctional CD8+ T cells but increased percentages of tissue resident and stem-like CD8+ T cells in the TME. In addition, the IFNγ+TCF1+ CD8+ T cell subset was markedly increased in the Eomes deficient mice. We further demonstrated that Eomes bound directly to the transcription regulatory regions of exhaustion and tissue residency genes. In contrast to its role in inhibiting T cell immune responses at the tumor site, Eomes promoted generation of central memory T cells in the peripheral lymphoid system and memory recall responses against tumor growth at a distal tissue site. Finally, we showed that Eomes deficiency in T cells also resulted in increased efficacy of PD-1-blockade tumor immunotherapy. In all, our study indicates that Eomes plays a critical role in restricting prolonged T cell-mediated antitumor immune responses in the TME whereas promoting adaptive immunity in peripheral lymphoid organs.

4-1BB Agonism Combined With PD-L1 Blockade Increases the Number of Tissue-Resident CD8+ T Cells and Facilitates Tumor Abrogation.

Although the milestone discovery of immune checkpoint blockade (ICB) has been translated into clinical practice, only a fraction of patients can benefit from it with durable responses and subsequent long-term survival. Here, we tested the anti-tumor effect of combining PD-L1 blockade with 4-1BB costimulation in 3LL and 4T1.2 murine tumor models. Dual treatment induced further tumor regression and enhanced survival in tumor-bearing mice more so than PD-L1 and 4-1BB mAb alone. It was demonstrated that dual anti-PD-L1/anti-4-1BB immunotherapy increased the number of intratumoral CD103+CD8+ T cells and altered their distribution. Phenotypically, CD103+CD8+ T cells expressed a higher level of 4-1BB and PD-1 than their CD103- counterparts. Administration of PD-L1 mAb and 4-1BB mAb further increased the cytolytic capacity of CD103+CD8+ T cells. In vivo, CD103-CD8+ T cells could differentiate into CD103+CD8+ progeny cells. In a human setting, more CD8+ T cells differentiated into CD103+CD8+ T cells in the peripheral tumor region of lung cancer tissues than in the central tumor region. Collectively, infiltrated CD103+CD8+ T cells served as a potential effector T cell population. Combining 4-1BB agonism with PD-L1 blockade could increase tumor-infiltrated CD103+CD8+T cells, thereby facilitating tumor regression.

Association between interleukin-36γ and tumor progression in non-small cell lung cancer.

Immunotherapy is effective in improving the survival and prognosis of patients with non-small cell lung cancer (NSCLC), and identifying effective immunomarkers is important for immunotherapy. Interleukin (IL)-36γ is a novel immunomarker that has an important function in the antitumor immune response. The present study investigated the association between IL-36γ and NSCLC to provide novel insight into immunotherapy for patients with NSCLC. Tissue microarrays of lung adenocarcinoma and squamous cell carcinoma were purchased for immunohistochemical analysis of IL-36γ expression levels and clinical parameters. In addition, fresh clinical NSCLC and adjacent normal tissue samples were collected to analyze IL-36γ mRNA expression levels using quantitative PCR. IL-36γ protein was primarily located in the cytoplasm, with a small quantity in the nucleus, and IL-36γ mRNA and protein expression levels in lung cancer tissues were significantly higher compared with those in adjacent normal tissues. Elevated IL-36γ protein expression levels were significantly associated with a higher tumor grade of lung adenocarcinoma; however, IL-36γ mRNA expression levels were inversely associated with the clinical Tumor-Node-Metastasis stage in patients with lung squamous cell carcinoma. In addition, patients with adenocarcinoma with high IL-36γ protein expression levels tended to longer post-operative survival times. These findings indicate that IL-36γ may have potential as an immunomarker for prediction of tumor progression and survival in patients with NSCLC.

Fertility preservation in BRCA mutation carriers-efficacy and safety issues: a review.

BRCA mutation carriers face various situations that influence their fertility potential. There is still a lack of guideline or expert consensus on Fertility Preservation (FP) in BRCA mutation carriers and the necessity and safety of FP in BRCA mutation carriers is still in dispute. This review aims to focus on the population of BRCA mutation carriers by analyzing the existing FP strategies, comprehensively comparing the pros and cons of each strategy and its applicability.FP is a suggestion for BRCA mutation carriers with birth planning. Different FP strategies have different characteristics. Considering the particularity of BRCA mutation carriers, multiple factors need to be carefully considered. This review focuses on the applicability of each FP method for carriers under various circumstances. Available FP strategies including oocyte cryopreservation, ovarian tissue cryopreservation, preimplantation genetic diagnosis, and egg/embryo donation are analyzed by comparing existing methods comprehensively. In the attempt to provide an up-to-date decision-making guidance. Conditions taking into consideration were the carrier's age, the risk of breast and ovarian metastasis, plans for oncotherapy, FP outcome, time available for FP intervention and accessibility.Overall, FP is necessary and safe for BRCA mutation carriers. Among all available FP methods, oocyte cryopreservation is the most reliable procedure; ovarian tissue cryopreservation is the only way for preserving both fertility and endocrine function, recommended for pre-pubertal carriers and when time is limited for oocyte stimulation. A clear framework provides frontline clinical practitioners a new thought and eventually benefit thousands of BRCA mutation carriers.

Inflammation induced by incomplete radiofrequency ablation accelerates tumor progression and hinders PD-1 immunotherapy.

Radiofrequency ablation (RFA) promotes tumor antigen-specific T cell responses and enhances the effect of immunotherapy in preclinical settings. Here we report that the existence of remnant tumor masses due to incomplete RFA (iRFA) is associated with earlier new metastases and poor survival in patients with colorectal cancer liver metastases (CRCLM). Using mouse models, we demonstrate that iRFA promotes tumor progression and hinders the efficacy of anti-PD-1 therapy. Immune analysis reveals that iRFA induces sustained local inflammation with predominant myeloid suppressor cells, which inhibit T cell function in tumors. Mechanistically, tumor cell-derived CCL2 is critical for the accumulation of monocytes and tumor-associated macrophages (TAMs). The crosstalk between TAMs and tumor cells enhances the CCL2 production by tumor cells. Furthermore, we find that administration of a CCR2 antagonist or the loss of CCL2 expression in tumor cells enhances the antitumor activity of PD-1 blockade, providing a salvage alternative for residual tumors after iRFA.

IL-36ß Promotes CD8+ T Cell Activation and Antitumor Immune Responses by Activating mTORC1.

Cytokine-amplified functional CD8+ T cells ensure effective eradication of tumors. Interleukin 36α (IL-36α), IL-36ß, and IL-36γ share the same receptor complex, composed of the IL-36 receptor (IL-36R), and IL-1RAcP. Recently, we revealed that IL-36γ greatly promoted CD8+ T cell activation, contributing to antitumor immune responses. However, the underlying mechanism of IL-36-mediated CD8+ T cell activation remains understood. In the current study, we proved that IL-36ß had the same effect on CD8+ T cell as IL-36γ, and uncovered that IL-36ß significantly activated mammalian target of rapamycin complex 1 (mTORC1) of CD8+ T cells. When mTORC1 was inhibited by rapamycin, IL-36ß-stimulated CD8+ T cell activation and expansion was drastically downregulated. Further, we elucidated that IL-36ß-mediated mTORC1 activation was dependent on the pathway of phosphatidylinositol 3 kinase (PI3K)/Akt, IκB kinase (IKK) and myeloid differentiation factor 88 (MyD88). Inhibition of PI3K or IKK by inhibitor, or deficiency of MyD88, respectively, suppressed mTORC1 signal, causing arrest of CD8+ T cell activation. Additionally, it was validated that IL-36ß significantly promoted mTORC1 activation and antitumor function of CD8+ tumor-infiltrating lymphocytes (TILs) in vivo, resulting in inhibition of tumor growth and prolongation of survival of tumor-bearing mice. Taken together, we substantiated that IL-36ß could promote CD8+ T cell activation through activating mTORC1 dependent on PI3K/Akt, IKK and MyD88 pathways, leading to enhancement of antitumor immune responses, which laid the foundations for applying IL-36ß into tumor immunotherapy.

Interleukin-33, a Potential Cytokine Expressed in Tumor Microenvironment Involves in Antitumor Immunotherapy Through Facilitates CD8+ T Cells.

Interleukin-33 (IL-33) is a cytokine with pleiotropic functions in various diseases; however, its role in the antitumor immune response is still unclear. We found the expression of IL-33/ST2 in nonsmall cell lung tumor microenvironment. Furthermore, we found that IL-33 promoted effector functions of CD8+ T cells that play a critical role in antitumor immune response. In addition, we found that IL-33 enhanced tumor vaccine effector functions in mice. Altogether, these findings suggest that IL-33, through facilitates CD8+ T cells in microenvironment to provide a profound effect in antitumor immunotherapy.

MicroRNA-203 Increases Cell Radiosensitivity via Directly Targeting Bmi-1 in Hepatocellular Carcinoma.

BACKGROUND: B-cell-specific moloney leukemia virus insertion site 1 (Bmi-1) plays important roles in various cancers, but its regulation through microRNAs (miRNAs) and its functions in hepatocellular carcinoma (HCC) remains unclear. METHODS: We evaluated the expression and prognostic significance of Bmi-1 in HCC by using tissue samples and The Cancer Genome Atlas (TCGA) data sets. The relationship between miRNAs and Bmi-1 was verified by bioinformatics prediction and immunofluorescence. Colony formation and apoptosis assays were used to reveal the effect of miR-203 on radiosensitivity. RESULTS: The Bmi-1 mRNA and protein were upregulated in HCC tissues. Cox regression multivariate analyses showed that Bmi-1 overexpression was an independent prognostic parameter for HCC patients. The expression level of Bmi-1 was negatively associated with miR-203 levels in HCC tissues. Dual-luciferase reporter assays showed that miR-203 could target the 3' untranslated region (3'-UTR) of Bmi-1 directly. Overexpression of miR-203 in HepG2 and Smmc-7721 cells increases their sensitivity to ionizing radiation in vitro and in vivo. Moreover, the improved cell radiosensitivity induced by miR-203 could be rescued by restoration of Bmi-1 expression. CONCLUSIONS: Bmi-1 could improve the predictive accuracy for HCC patients' survival. Moreover, miR-203 enhance cell radiosensitivity in vitro and in vivo by targeting Bmi-1 in HCC.

ATF4 Regulates CD4+ T Cell Immune Responses through Metabolic Reprogramming.

T cells are strongly regulated by oxidizing environments and amino acid restriction. How T cells reprogram metabolism to adapt to these extracellular stress situations is not well understood. Here, we show that oxidizing environments and amino acid starvation induce ATF4 in CD4+ T cells. We also demonstrate that Atf4-deficient CD4+ T cells have defects in redox homeostasis, proliferation, differentiation, and cytokine production. We further reveal that ATF4 regulates a coordinated gene network that drives amino acid intake, mTORC1 activation, protein translation, and an anabolic program for de novo synthesis of amino acids and glutathione. ATF4 also promotes catabolic glycolysis and glutaminolysis and oxidative phosphorylation and thereby provides precursors and energy for anabolic pathways. ATF4-deficient mice mount reduced Th1 but elevated Th17 immune responses and develop more severe experimental allergic encephalomyelitis (EAE). Our study demonstrates that ATF4 is critical for CD4+ T cell-mediated immune responses through driving metabolic adaptation.

Lower expression level of IL-33 is associated with poor prognosis of pulmonary adenocarcinoma.

OBJECTIVE: Lung cancer is one of the deadliest malignancies. The immune checkpoint-blockade (ICB) tumor therapy has led to striking improvement of long-term survival for some lung cancer patients. However, the response rate of immunotherapy is still low for lung cancer. Studying the tumor microenvironment (TME) should shed light on improvement of immunotherapy of lung cancer. Interleukin-33 (IL-33), an "alarmin" cytokine, has been implicated in tumor associated immune responses and inflammatory diseases of the lung. The role of IL-33 in lung cancer progression, however, remains elusive. This study is designed to characterize IL-33 expression in lung tumor tissues and establish the clinical significance of IL-33 in non-small cell lung cancer lung cancer (NSCLC). MATERIALS AND METHODS: Tumor tissue specimens from patients suffering from NSCLC were analyzed for expression of IL-33 protein by immunohistochemistry and expression of IL-33 and ST2 mRNA by RT-quantitative PCR (RT-QPCR). The expression data were analyzed for their association with clinical and pathological parameters of NSCLC. In addition, the association between expression levels of IL-33 mRNA and patient survival was determined using 5 independent expression profiling datasets of human lung cancer. RESULTS AND CONCLUSION: The expression levels of IL-33 and ST2 were significantly down-regulated in both adenocarcinoma and squamous cell carcinoma of the lung when compared to adjacent normal lung tissues. In addition, the level of IL-33 protein was inversely correlated with tumor grade and size. Moreover, analysis of TCGA and GEO lung cancer expression datasets revealed that higher expression levels of IL-33 mRNA were correlated with longer overall survival of patients suffering from adenocarcinoma of the lung. These data indicate that the expression levels of IL-33 are inversely associated with lung cancer progression, consistent with the hypothesis that IL-33 is involved in immune surveillance of NSCLC.

Decreased IFIT2 Expression Promotes Gastric Cancer Progression and Predicts Poor Prognosis of the Patients.

BACKGROUND/AIMS: The status of interferon (IFN) signaling pathway has been shown to be closely associated with the response of immune checkpoint blockade therapy against advanced human cancers. IFN-induced protein with tetratricopeptide repeats 2 (IFIT2), also known as IFN-stimulated gene 54 (ISG54), is one of the most highly responsive ISGs, which can inhibit the proliferation and migration of cancer cells, and regulate viral replication, resulting in anti-cancer and anti-viral effects. In the present study, we aimed to investigate the role of IFIT2 in human gastric cancer. METHODS: Immunohistochemistry assay was used to investigate the correlation between the IFIT2 expression in cancer tissues and clinical parameters of gastric cancer patients. Knockdown of IFIT2 was performed using RNAi to assess the role of IFIT2 in the regulation of biological behaviors in human gastric cancer cell lines. RESULTS: IFIT2 expression in gastric cancer tissues was significantly associated with tumor stage and postoperative prognoses of the patients. Moreover, decreased IFIT2 expression in human gastric cancer cell lines SGC-7901 and AGS significantly increased the cell viability, cell migration and the ratios of cells in S phase. CONCLUSION: Our present study demonstrated that the decreased IFIT2 expression could promote the gastric cancer progression and predict poor therapeutic outcomes of the patients.

Prognostic role of tumor-infiltrating lymphocytes in gastric cancer: a meta-analysis.

BACKGROUND: In patients with gastric cancer, the prognostic value of tumor-infiltrating lymphocytes (TILs) is still controversial. A meta-analysis was performed to evaluate the prognostic value of TILs in gastric cancer. MATERIALS AND METHODS: We identify studies from PubMed, Embase and the Cochrane Library to assess the prognostic effect of TILs in patients with gastric cancer. Fixed-effects models or random-effects models were used estimate the pooled hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS), which depend on the heterogeneity. RESULTS: A total of 31 observational studies including 4,185 patients were enrolled. For TILs subsets, the amount of CD8+, FOXP3+, CD3+, CD57+, CD20+, CD45RO+, Granzyme B+ and T-bet+ lymphocytes was significantly associated with improved survival (P < 0.05); moreover, the amount of CD3+ TILs in intra-tumoral compartment (IT) was the most significant prognostic marker (pooled HR = 0.52; 95% CI = 0.43-0.63; P < 0.001). However, CD4+ TILs was not statistically associated with patients' survival. FOXP3+ TILs showed bidirectional prognostic roles which had positive effect in IT (pooled HR = 1.57; 95% CI = 1.04-2.37; P = 0.033) and negative effect in extra-tumoral compartment (ET) (pooled HR = 0.76; 95% CI = 0.60-0.96; P = 0.022). CONCLUSIONS: This meta-analysis suggests that some TIL subsets could serve as prognostic biomarkers in gastric cancer. High-quality randomized controlled trials are needed to decide if these TILs could serve as targets for immunotherapy in gastric cancer.

Clinical Significance of Dynamics of Programmed Death Ligand-1 Expression on Circulating CD14+ Monocytes and CD19+ B Cells with the Progression of Hepatitis B Virus Infection.

Programmed death-1 (PD-1) expression has been revealed to be upregulated on T cells and contributes to T cell exhaustion in patients with hepatitis B virus (HBV) infection. In this study, we investigated the dynamic expression of programmed death ligand-1 (PD-L1), the ligand of PD-1, on circulating CD14+ monocytes and CD19+ B cells of HBV-infected patients at the stages of chronic HBV (CHB) infection, liver cirrhosis (LC), and hepatocellular carcinoma (HCC), respectively. The results showed that compared with healthy controls, the levels of PD-L1 expression on CD14+ and CD19+ populations were both upregulated in CHB, LC, and HCC groups. Although there was no significant difference of PD-L1 expression on CD14+ population among three disease groups, further analysis demonstrated that the frequency of CD14+PD-L1+ population was negatively correlated with HBV DNA load, the levels of alanine aminotransaminase (ALT), and the levels of aspartate aminotransferase (AST), respectively, at CHB stage, while it did not present significant correlation with such parameters at LC stage and was only positively correlated with HBV DNA load at HCC stage. Similarly, the levels of PD-L1 expression on CD19+ population also did not present much difference among three disease groups. Intriguingly, the frequencies of CD19+PD-L1+ population at CHB and LCC stages were both positively correlated with the levels of ALT and AST, but they were not significantly correlated with HBV DNA load. Thereby, the current study elucidated the dynamics of PD-L1 expression on monocytes and B cells, along with the dynamic regulation of PD-1 on T cells, which had a close relationship during the progression of HBV infection. Collectively, our findings demonstrated that in the course of HBV infection development, PD-L1 expression on CD14+ monocytes and CD19+ B cells varied and significantly correlated with clinical parameters, which could be utilized as a potential clinical indicator.

[Expression and clinical significance of IL-33 in patients with non-small cell lung cancer].

Objective To investigate the expression of interleukin 33 (IL-33) in cancer and adjacent non-cancerous tissues from patients with non-small cell lung cancer (NSCLC). Methods Real-time quantitative PCR was performed to detect the mRNA expression of IL-33 in 61 pairs of cancerous and adjacent non-cancerous tissues. In addition, immunohistochemistry was used to evaluate the expression and location of IL-33 on paraffin sections in selected 12 cases with different pathological types, to analyze the correlation of IL-33 expression with clinicopathological variables and overall survival. Results The expression of IL-33 mRNA in cancer tissues was significantly lower than that in adjacent non-cancerous tissues. The immunohistochemical results showed that IL-33 protein was mainly localized in the nucleus, and was obviously down-regulated in NSCLC. Besides, the expression of IL-33 was associated with histological type, but was not associated with age, gender, smoking history, differentiation status and pathological TNM stage. According to the Kaplan-Meier analysis, the expression of IL-33 mRNA was evidently associated with post-operative overall survival of patients suffering from NSCLC. Conclusion IL-33 may play an important role in the development of NSCLC and the targeted therapy.

PD-1 Blockade Boosts Radiofrequency Ablation-Elicited Adaptive Immune Responses against Tumor.

PURPOSE: Radiofrequency ablation (RFA) has been shown to elicit tumor-specific T-cell immune responses, but is not sufficient to prevent cancer progression. Here, we investigated immune-suppressive mechanisms limiting the efficacy of RFA. EXPERIMENTAL DESIGN: We performed a retrospective case-controlled study on patients with synchronous colorectal cancer liver metastases who had received primary tumor resection with or without preoperative RFA for liver metastases. Tumor-infiltrating T cells and tumoral PD-L1 expression in human colorectal cancer tissues were analyzed by immunohistochemistry. T-cell immune responses and PD-1/PD-L1 expression were also characterized in an RFA mouse model. In addition, the combined effect of RAF and PD-1 blockade was evaluated in the mouse RFA model. RESULTS: We found that RFA treatment of liver metastases increased not only T-cell infiltration, but also PD-L1 expression in primary human colorectal tumors. Using mouse tumor models, we demonstrated that RFA treatment of one tumor initially enhanced a strong T-cell-mediated immune response in tumor. Nevertheless, tumor quickly overcame the immune responses by inhibiting the function of CD8(+) and CD4(+) T cells, driving a shift to higher regulatory T-cell to Teff ratio, and upregulating PD-L1/PD-1 expression. Furthermore, we established that the combined therapy of RFA and anti-PD-1 antibodies significantly enhanced T-cell immune responses, resulting in stronger antitumor immunity and prolonged survival. CONCLUSIONS: The PD-L1-PD-1 axis plays a critical role in dampening RFA-induced antitumor immune responses, and this study provides a strong rationale for combining RFA and the PD-L1/PD-1 blockade in the clinical setting.

The increase of circulating PD-L1-expressing CD68(+) macrophage in ovarian cancer.

Tumor-associated macrophages (TAMs) have been characterized as a critical population of immunosuppressive cells in a variety of tumor types. PD-L1 (also termed B7-H1) has been described to exert co-inhibitory and immune regulatory functions. Here, in ovarian cancer, PD-L1 is selectively overexpressed on some TAM compared that of benign ovarian disease. When expanding the data in peripheral blood, the proportion of PD-L1(+)CD68(+) cell among CD68(+) cells and the intensity of PD-L1 staining on CD68(+) cell in healthy group were similar to that observed in ovarian cyst group; instead, these two measures were significantly higher in ovarian cancer group, thereafter related to TNM stage. Interestingly, intracellular levels of IL-10, IL-6, TNF-α, and IFN-γ in PD-L1(+)CD68(+) macrophage were higher than those in PD-L1(-)CD68(+) macrophage, especially IL-6 expression. Based on the PD-L1 receptor PD-1 expression on tumor-infiltrating cytotoxic cells, our data supported that expression of PD-L1 on TAM promoted apoptosis of T cells via interaction with PD-1 on CD8(+)T cells. Taken together, these results suggested that PD-L1-expressing macrophage represents a novel suppressor cell population in ovarian cancer, which contributes immune escape of ovarian cancer.

[IL-33 enhances cytokine secretion and killing function of peripheral blood mononuclear cells in vitro].

OBJECTIVE: To investigate whether interleukin 33 (IL-33) can enhance cytokine secretion and killing activity of peripheral blood mononuclear cells (PBMCs) in vitro. METHODS: PBMCs were harvested from healthy volunteers and stimulated with different combination of cytokines (CD3 mAb/CD28 mAb/IL-2, CD3 mAb/CD28 mAb/IL-2/IL-12, CD3 mAb/CD28 mAb/IL-2/IL-12/IL-33) in vitro. The cells of each group were collected after 72 hours. Total RNA were extracted and assayed by real-time quantitative PCR (qRT-PCR) for the levels of interferon γ (IFN-γ) and granzyme B. The cytotoxic activity of the cells targeting A549 human lung adenocarcinoma cells was detected by CCK-8 assay. The levels of programmed death-1 (PD-1) and IFN-γ were determined by flow cytometry. RESULTS: There was no significant difference in cell morphology observed by microscope among the three groups. In the cells stimulated in the presence of IL-33, the levels of IFN-γ and granzyme B mRNAs were significantly elevated, cell killing ability was strengthened, and the level of IFN-γ increased significantly, PD-1 level decreased when compared with the other two groups. CONCLUSION: IL-33 might enhance the function of PBMCs and then promote adaptive anti-tumor immune response.