PD-1 expression on Melan-A-reactive T cells increases during progression to metastatic disease

Programmed death 1 (PD-1) is known as an important factor for the development of tolerogenicity. This has been proven in chronic viral infections and different tumor models. To address the role of PD-1 and its ligand programmed death ligand 1 (PD-L1) in different stages of malignant melanoma, we investigated peripheral blood and tumor tissues in regard to overall survival (OS) and prognostic relevance. One hundred samples of peripheral blood mononuclear cells from HLA-A2(+) patients with malignant melanoma (Stages I-IV) were analyzed in seven color FACS combined with multimer analyses for the immunodominant epitope of Melan-A (peptide A2/Melan-A(p26-35mod) ). Corresponding formalin-fixed paraffin-embedded tissues of primary tumor and distant organ metastases from 37 cases were analyzed by immunohistochemistry for Melan-A, PD-L1 and PD-1 expression. Compared to the total CD8(+) T cell population, PD-1 expression by A2/Melan-A(+) CD8(+) T cells was over-represented in melanoma stages III and IV (p < 0.001). Although elevation of PD-1(+) Melan-A(+) CD8(+) T cells had no significant influence on OS, a positive correlation was observed between PD-L1 expression on melanoma cells and OS (p = 0.05). Correlation of advanced tumor stage with increased A2/Melan-A-multimer(+) PD-1(+) T cells in the peripheral blood suggest that blocking of PD-1 could have therapeutic potential in advanced stage melanoma.     

Homeostatic proliferation plus regulatory T-cell depletion promotes potent rejection of B16 melanoma.

PURPOSE: To investigate the antitumor efficacy of T-cell anergy reversal through homeostatic proliferation and regulatory T-cell (Treg) depletion in a clinically relevant murine adoptive immunotherapy model. EXPERIMENTAL DESIGN: B16 melanoma cells were engineered to express the model SIYRYYGL (SIY) antigen to enable immune monitoring. Tumor-specific T cells expanded in tumor-challenged wild-type hosts but became hyporesponsive. To examine whether lymphopenia-induced homeostatic proliferation could reverse tumor-induced T-cell anergy, total splenic T cells were transferred into lymphopenic RAG2-/- mice or control P14/RAG2-/- mice. Tumor growth was measured, and SIY-specific immune responses were monitored using ELISPOT and SIY/K(b) tetramers. To determine whether Treg depletion could synergize with homeostatic proliferation, RAG2-/- mice received total or CD25-depleted T cells, followed or preceded by B16.SIY challenge. This approach was further investigated in wild-type mice lymphodepleted with sublethal total body irradiation. RESULTS: Adoptive transfer of total splenic T cells into RAG2-/- mice moderately affected the growth rate of B16.SIY. As Treg expansion occurred in tumor-bearing mice, CD25+ T cells were depleted from total T cells before adoptive transfer. Interestingly, transfer of CD25-depleted T cells into RAG2-/- mice resulted in potent rejection of B16 melanoma in both prophylactic and short-term preimplanted tumor settings and was associated with maintained T-cell effector function. Using a clinically applicable approach, wild-type mice were lymphodepleted using sublethal total body irradiation, which similarly supported tumor rejection upon transfer of CD25-depleted T cells. CONCLUSIONS: Our results indicate that combined CD25 depletion and homeostatic proliferation support a potent antitumor immune response--an approach with potential for clinical translation.     

PD-1/PD-L1通路在乳腺癌治疗中的作用及意义

程序性死亡受体1（programmed death-1,PD-1,CD279）为共刺激受体CD28超家族成员,主要表达在活化T细胞、B细胞、单核细胞以及自然杀伤细胞表面。程序性死亡配体1（programmed death-ligand 1,PD-L1,CD274）为PD-1的一个重要配体,广泛表达于肿瘤细胞以及抗原呈递细胞（APC）表面。以PD-1/PD-L1为靶点的肿瘤免疫治疗为肿瘤治疗开辟了新的道路。PD-1通过与PD-L1和(或)PD-L2结合,抑制T细胞活化,诱导T细胞凋亡,在肿瘤免疫逃逸中起着重要的作用。目前PD-1/PD-L1信号通路成为免疫靶向治疗的新靶点,相关研究在非小细胞肺癌、晚期黑色素瘤等多种恶性肿瘤领域有重大进展,研究发现PD-L1 在多种肿瘤细胞包括乳腺癌中表达上调,提示 PD-1/PD-L1通路可能参与肿瘤的免疫逃逸。本文将针对PD-1/PD-L1通路在乳腺癌治疗中的作用及意义进行综述。     

Blockade of PD-L1 (B7-H1) augments human tumor-specific T cell responses in vitro

Human tumors frequently escape immune destruction, despite the presence of cytotoxic T cells (CTL) recognizing tumor-associated antigens (TAA). We have previously shown that programmed death ligand-1 (PD-L1), a recently identified ligand of the B7 superfamily, is expressed on murine tumors and can inhibit antitumor immune responses. To evaluate the clinical relevance of our animal model findings, we examined human tumors and tumor-specific T cells. We found PD-L1 to be constitutively expressed on human renal cell carcinoma (RCC) cell lines and upregulated on human melanoma cell lines upon exposure to interferon-gamma. Similarly, we found binding of anti-PD-L1 monoclonal antibody (mAb) on frozen sections from RCC and melanomas, but not on normal tissues. The corresponding inhibitory receptor of PD-L1, PD-1, revealed a higher expression on tumor-infiltrating lymphocytes than on peripheral blood lymphocytes (PBL) from melanoma patients upon specific antigen stimulation. Stimulation of PBL from healthy donors with peptide-loaded dendritic cells in the presence of anti-PD-L1 mAb altered neither the total T cell numbers after expansion, nor the percentage of peptide-specific CTL, when providing a T cell help by addition of cytokines. However, when stimulating TAA-specific CTL and T helper cells with Ag-pulsed dendritic cells in the absence of exogenous cytokines, PD-L1 blockade increased the cytokine production. Similar to the data achieved in the murine system, the blockade of PD-L1 on human tumors resulted in enhanced cytolytic activity of TAA-specific CTLs and cytokine production of TAA-specific T helper cells when interacting directly with the tumor. In summary, our data suggest that PD-L1/PD-1 interactions negatively regulate T cell effector functions predominantly in the absence of exogenous cytokine support, indicating an important role for this pathway in tumor evasion.     

Depletion of CD25(+) CD4(+) T cells and treatment with tyrosinase-related protein 2-transduced dendritic cells enhance the interferon alpha-induced, CD8(+) T-cell-dependent immune defense of B16 melanoma.

Transduction of B16 melanoma cells with IFN alpha (B16-IFN alpha) enhances CD8(+) T-cell-dependent tumor immunity in mice, resulting in delayed outgrowth in vivo. Here we provide evidence that CD4(+) T cells down-regulate the IFN alpha-induced tumor immune defense. Importantly, depletion of regulatory CD25(+) CD4(+) T cells prevented growth of B16-IFN alpha in most mice and promoted long-lasting protective tumor immunity. Rejection of B16-IFN alpha could also be achieved with therapeutic injections of dendritic cells genetically engineered to express the melanoma antigen tyrosinase-related protein 2. These results support the development of novel strategies for the immunotherapy of melanoma using IFN alpha in combination with elimination of regulatory T cells or antigen-specific immunization.     

Prognostic value of programmed death-1, programmed death-ligand 1, programmed death-ligand 2 expression,and CD8(+) T cell density in primary tumors and metastatic lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma

Background: Anti-programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) immunotherapy has been proved to be effective on gastric cancer in ongoing clinical trials. However, the value of PD-L1 in predicting responses of patients with gastric cancer to anti-PD-1/PD-L1 immunotherapy is controversial. Some studies suggested that intra- and inter-tumoral heterogeneity of PD-L1 expression might explain the controversy. This study aimed to analyze the expression of PD-L1, PD-L2, and PD-1 as well as CD8(+) T-cell density in primary tumors and lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma to explore the heterogeneity of PD-1 signaling pathway molecules. Methods: In primary tumors and metastatic as well as non-metastatic lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma, we detected PD-L1 and PD-L2 expression with immunohistochemistry. CD8(+) T-cell density in primary tumors and PD-1 expression on CD8(+) T cells were detected with immunofluorescence. Uni-variate analysis was used to determine the prognostic values of them. Cox proportional hazard regression model was used to identify independent risk factors that affect patients' overall survival and disease-free survival. Results: Among 119 eligible patients who had undergone surgical resection, the positive rate of PD-L1 was higher in metastatic lymph nodes than in primary tumors (45.4％ vs. 38.7％,P= 0.005); the positive rate of PD-1 on CD8(+) T cells was significantly higher in primary tumors and metastatic lymph nodes than in tumor-free lymph nodes (both P < 0.001). The intensity of PD-1 expression on CD8(+) T cells in primary tumors and in metastatic lymph nodes were stronger than that in tumor-free lymph nodes from the same patient. Beside, the positive rate of PD-L2 did not show any differences between primary tumors and metastatic lymph nodes. In multivariate analysis, PD-L1 expression, PD-L2 expression, a low density of CD8(+) T cells in primary tumors, and PD-1 expression on CD8(+) T cells in primary tumors were associated with poor prognosis.Conclusion: The expression of PD-L1 is heterogeneous in primary tumors and in metastatic lymph nodes from patients with stage T1-4N+M0 gastric adenocarcinoma, which might explain the inconsistent results in assessing the prognostic value of PD-L1 expression in previous studies.     

PD-1/PD-L1 interactions contribute to functional T-cell impairment in patients who relapse with cancer after allogeneic stem cell transplantation

Tumor relapses remain a serious problem after allogeneic stem cell transplantation (alloSCT), despite the long-term persistence of minor histocompatibility antigen (MiHA)-specific memory CD8(+) T cells specific for the tumor. We hypothesized that these memory T cells may lose their function over time in transplanted patients. Here, we offer functional and mechanistic support for this hypothesis, based on immune inhibition by programmed death-1 (PD-1) expressed on MiHA-specific CD8(+) T cells and the associated role of the PD-1 ligand PD-L1 on myeloid leukemia cells, especially under inflammatory conditions. PD-L1 was highly upregulated on immature human leukemic progenitor cells, whereas costimulatory molecules such as CD80 and CD86 were not expressed. Thus, immature leukemic progenitor cells seemed to evade the immune system by inhibiting T-cell function via the PD-1/PD-L1 pathway. Blocking PD-1 signaling using human antibodies led to elevated proliferation and IFN-γ production of MiHA-specific T cells cocultured with PD-L1-expressing leukemia cells. Moreover, patients with relapsed leukemia after initial MiHA-specific T-cell responses displayed high PD-L1 expression on CD34(+) leukemia cells and increased PD-1 levels on MiHA-specific CD8(+) T cells. Importantly, blocking PD-1/PD-L1 interactions augment proliferation of MiHA-specific CD8(+) memory T cells from relapsed patients. Taken together, our findings indicate that the PD-1/PD-L pathway can be hijacked as an immune escape mechanism in hematological malignancies. Furthermore, they suggest that blocking the PD-1 immune checkpoint offers an appealing immunotherapeutic strategy following alloSCT in patients with recurrent or relapsed disease.     

NK and CD8+ T cell-mediated eradication of poorly immunogenic B16-F10 melanoma by the combined action of IL-12 gene therapy and 4-1BB costimulation

In previous reports, systemic administration of a stimulatory monoclonal antibody directed against the 4-1BB receptor had no effect on survival or tumor burden in mice inoculated with the poorly immunogenic B16-F10 melanoma. We combined IL-12 gene transfer with 4-1BB costimulation to explore a previously noted cooperative anti-tumor effect against this model tumor. We hypothesize that the innate immune response mediated by IL-12-activated natural killer (NK) cells initiates the activation of the immune system, leading to the priming of T cells, whereas 4-1BB costimulation enhances the function of primed tumor-specific T cells. The effect of the combination therapy on the growth of subcutaneous (s.c.) tumors and pulmonary metastasis was examined. The combination therapy significantly retarded the growth of subcutaneously-inoculated tumors, and 50% of tumor-bearing mice survived with complete tumor regression. In contrast, neither IL-12 gene transfer nor anti-4-1BB antibody administration alone was as effective. Enhanced CTL activity against both B16-F10 tumor cells and TRP-2-pulsed EL4 syngeneic tumor cells was observed in tumor-bearing animals treated with the combination therapy 2 weeks after treatment and, in long-term survivors from this combination therapy, at >120 days. In a pulmonary metastatic model, only the combination therapy generated significant protection against metastasis. In vivo depletion of NK or CD8(+) but not CD4(+) subsets eliminated the protective immunity. Furthermore, NK cell depletion significantly reduced both tumor-specific CTL activity and the number of tumor-specific IFN-gamma-producing cells, suggesting that this synergistic effect requires the participation of both NK and CD8(+) T cells.     

B7.1 expression eliminates tumor resistance to IL-12 gene therapy

IL-12 gene therapy results in tumor regression in some, but not all, murine models. We hypothesized that expression of B7.1 on the tumor cell surface was necessary for IL-12-mediated tumor regression. In addition, we hypothesized that all cells must express B7.1 for this to be effective. To evaluate this hypothesis, tumor nodules were established in mice with either wild-type B16 melanoma or with B16 melanoma modified to express B7.1. IL-12 cDNA was transferred to the tumor by particle-mediated gene transfer. All tumors modified to express B7.1 regressed completely after IL-12 cDNA treatment. When the percent of B7.1-transfected B16 cells was decreased to 50%, no animals survived after treatment. Animals rendered tumor-free were then challenged with wild-type B16. Fifty percent of mice was protected from this tumor challenge. Expression of CD28 (the stimulatory B7.1 ligand) was significantly increased in both CD8(+) T cells and natural killer cell populations of mice rejecting tumor challenge compared to mice with tumor growth. These results suggest that the costimulatory molecule B7.1 is required for initial tumor sensitivity to IL-12 gene therapy and that protection from subsequent challenge with B7.1 (-) tumor is mediated by CD28(+) immune effector cells.     

PD-1/PD-Ls在EBV阳性T/NK淋巴组织增殖性疾病中的表达及临床意义

  目的  探讨程序性细胞死亡蛋白-1（programmed cell death protein 1,PD-1）、程序性细胞死亡蛋白-2配体（programmed death-ligand 2,PD-L2）及程序性细胞死亡蛋白-1配体（programmed death-ligand 1,PD-L1）在EB病毒（Epstein-Barr virus,EBV）阳性T/NK淋巴组织增殖性疾病[Epstein-Barr virus-positive T/natural killer（NK）-cell lymphoproliferative disease,EBV（+）-T/NKLPD]中的表达及临床意义。  方法  收集2013年1月至2017年12月郑州大学第一附属医院17例EBV（+）-T/NK-LPD患者的病理石蜡包埋组织,其中男性12例,女性5例,年龄为10~82岁,平均年龄29岁,Ⅰ级4例,Ⅱ级7例,Ⅲ级3例,种痘水疱病样淋巴组织增殖性疾病3例。采用免疫组织化学SP法检测PD-1、PD-L1和PD-L2在人EBV（+）-T/NK-LPD组织中的表达,并采用Fisher确切概率法、Spearman秩相关,分析其与临床病理学参数、病理分级及患者预后之间的关系。  结果  在17例组织标本中,PD-1表达阳性12例,PD-L1表达阳性6例,PD-L2表达阳性5例。PD-1、PD-L2的表达与预后无显著相关性（P>0.05）,PD-L1的表达与预后呈正相关（P < 0.05）。PD-L1、PD-L2的表达与年龄、性别、LDH水平及Ki-67表达水平之间无显著相关性（P>0.05）。PD-1及PDL2的表达与病理分级之间无显著相关性（r=0.141,r=-0.149,均P>0.05）,而PD-L1的表达与病理分级之间呈负相关（r=-0.563）,PD-L1的表达与病理分级之间的相关关系具有统计学意义（P < 0.05）。  结论  PD-1、PD-L1和PD-L2在EBV（+）-T/NK-LPD病理组织中异常表达,虽然PD-1的表达与预后、病理分级之间无显著相关性,但在EBV（+）T/NK-LPD中显著高表达,PD-1/PD-Ls信号通路可能成为EBV（+）-T/NK-LPD免疫治疗的潜在新靶点。      

Effector cell-derived lymphotoxin alpha and Fas ligand, but not perforin, promote Tc1 and Tc2 effector cell-mediated tumor therapy in established pulmonary metastases

Cytolytic CD8(+) effector cells fall into two subpopulations based on cytokine secretion. Type 1 CD8(+) T cells (Tc1) secrete IFN-gamma, whereas type 2 CD8(+) T cells (Tc2) secrete interleukin (IL)-4 and IL-5. Although both effector cell subpopulations display Fas ligand (FasL) and tumor necrosis factor (TNF), tumor lysis is predominantly perforin dependent in vitro. Using an ovalbumin-transfected B16 lung metastasis model, we show that heightened numbers of adoptively transferred ovalbumin-specific Tc1 and Tc2 cells accumulated at the tumor site by day 2 after therapy and induced tumor regression that enhanced survival in mice with pulmonary metastases. Transfer of either TNF-alpha- or perforin-deficient Tc1 or Tc2 effector cells generated from specified gene-deficient mice showed no differences in therapeutic efficiency when compared with corresponding wild-type cells. In contrast, both Tc1 and Tc2 cells, derived from either FasL or TNF-alpha/lymphotoxin (LT) alpha double knockout mice, showed that therapeutic effects were dependent, in part, on effector cell-derived FasL or LTalpha. Six days after effector cell therapy, elevated levels of activated endogenous CD8/CD44(High) and CD4/CD44(High) T cells localized and persisted at sites of tumor growth, whereas donor cell numbers concomitantly decreased. Both Tc1 and Tc2 effector cell subpopulations induced endogenous antitumor responses that were dependent, in part, on recipient-derived IFN-gamma and TNF-alpha. However, neither effector cell-mediated therapy was dependent on recipient-derived perforin, IL-4, IL-5, or nitric oxide. Collectively, tumor antigen-specific Tc1 and Tc2 effector cell-mediated therapy is initially dependent, in part, on effector cell-derived FasL or LTalpha that may subsequently potentiate endogenous recipient-derived type 1 antitumor responses dependent on TNF-alpha and IFN-gamma.     

PD-L1的表达与妇科恶性肿瘤预后关系的研究进展

程序性死亡蛋白1(Programmed death protein 1,PD-1)是T细胞上主要存在的一种抑制性受体。程序性死亡配体-1(Programmed death ligand-1,PD-L1,又称B7-H1)在心、肝、肾、肺等多个器官上皮细胞和内皮细胞中广泛表达。肿瘤发生时机体内的肿瘤微环境会使浸润性T细胞高表达PD-1,同时肿瘤细胞中PD-L1的表达上调,与PD-1受体相结合,导致肿瘤微环境中PD-1通路持续开放,进而导致T细胞凋亡,肿瘤细胞则逃脱机体的免疫监视,发生肿瘤免疫逃逸。本文就PD-L1表达与妇科恶性肿瘤预后关系的研究进展进行综述。     

Stromal PD-1/PD-L1 Expression Predicts Outcome in Colon Cancer Patients

Introduction

The programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) axis plays an important role in controlling immune suppression by down-regulating T effector cell activities, enabling tumor cells to escape from the host’s antitumor immunsurveillance. While only a small part of colon cancer cells express PD-L1, we sought to evaluate the differential impact of stromal and epithelial PD-L1 expression of primary tumors and liver metastasis on overall survival (OS) in colon cancer patients.

CD8(+) T cells specific for tumor antigens can be rendered dysfunctional by the tumor microenvironment through upregulation of the inhibitory receptors BTLA and PD-1

Cytotoxic T cells that are present in tumors and capable of recognizing tumor epitopes are nevertheless generally impotent in eliciting tumor rejection. Thus, identifying the immune escape mechanisms responsible for inducing tumor-specific CD8(+) T-cell dysfunction may reveal effective strategies for immune therapy. The inhibitory receptors PD-1 and Tim-3 are known to negatively regulate CD8(+) T-cell responses directed against the well-characterized tumor antigen NY-ESO-1. Here, we report that the upregulation of the inhibitory molecule BTLA also plays a critical role in restricting NY-ESO-1-specific CD8(+) T-cell expansion and function in melanoma. BTLA-expressing PD-1(+)Tim-3(-) CD8(+) T cells represented the largest subset of NY-ESO-1-specific CD8(+) T cells in patients with melanoma. These cells were partially dysfunctional, producing less IFN-γ than BTLA(-) T cells but more IFN-γ, TNF, and interleukin-2 than the highly dysfunctional subset expressing all three receptors. Expression of BTLA did not increase with higher T-cell dysfunction or upon cognate antigen stimulation, as it does with PD-1, suggesting that BTLA upregulation occurs independently of functional exhaustion driven by high antigen load. Added with PD-1 and Tim-3 blockades, BTLA blockade enhanced the expansion, proliferation, and cytokine production of NY-ESO-1-specific CD8(+) T cells. Collectively, our findings indicate that targeting BTLA along with the PD-1 and Tim-3 pathways is critical to reverse an important mechanism of immune escape in patients with advanced melanoma.     

Cereblon调节T细胞逆转PD-1抗体治疗肺癌耐药的研究进展

程序性细胞死亡受体1(programmed cell death receptor 1, PD-1)是一种跨膜蛋白,主要表达于T细胞,并与靶细胞上的PD-1配体,即细胞程序性死亡配体1(programmed cell death ligand 1, PD-L1)结合。PD-1作为一种免疫抑制分子,当PD-1与肿瘤细胞上的配体PD-L1结合时,抑制了T细胞的免疫功能,从而发生肿瘤的免疫逃逸,如外周效应T细胞的耗竭导致效应T细胞向调节性T细胞(regulatory T cells, Tregs)转化。为解决这一问题,利用PD-1抗体与T细胞上的PD-1结合,从而抑制T细胞表面的PD-1与肿瘤细胞表面的PD-L1相互作用,进而恢复T细胞杀伤肿瘤细胞的功能。以Nivolumab和Pembrolizumab为代表的PD-1抗体现已被批准用于晚期非小细胞肺癌的一线治疗。但在部分患者中出现了由于肿瘤细胞、T细胞及细胞因子的相互作用导致的耐药,降低了免疫治疗的疗效。因此,如何克服患者的耐药成为了当前待解决的主要问题。研究发现,Cereblon(CRBN)作为DDB1泛素环E3泛素连接酶复合物的底物受体及免疫调节药物唯一已知的结合受体,与CRBN调节剂(cereblon modulatory agents, CMs)结合可以通过上调T细胞的增殖、激活和代谢,发挥T细胞的免疫功能从而逆转PD-1抗体耐药。本文就T细胞的下调导致PD-1抗体治疗肺癌耐药的机制、CRBN调节T细胞的机制及CRBN调节剂治疗肺癌的研究进展进行综述。     

Clinical significance and therapeutic potential of the programmed death-1 ligand/programmed death-1 pathway in human pancreatic cancer.

PURPOSE: The programmed death-1 ligand/programmed death-1 (PD-L/PD-1) pathway has been recently suggested to play a pivotal role in the immune evasion of tumors from host immune system. In this study, we tried to reveal the clinical importance and therapeutic potential of the PD-L/PD-1 pathway in pancreatic cancer, which is one of the most aggressive and intractable malignant tumors. EXPERIMENTAL DESIGN: We used immunohistochemistry to investigate PD-L expression in 51 patients with pancreatic cancer who underwent surgery and explored the therapeutic efficacy of blocking the PD-L1/PD-1 pathway in murine pancreatic cancer in vivo. RESULTS: PD-L1-positive patients had a significantly poorer prognosis than the PD-L1-negative patients, whereas there was no significant correlation of tumor PD-L2 expression with patient survival. PD-L1 expression was inversely correlated with tumor-infiltrating T lymphocytes, particularly CD8(+) T cells. These clinical data have suggested that the PD-L1/PD-1 pathway may be a critical regulator in human pancreatic cancer. Monoclonal antibodies against PD-L1 or PD-1 induced a substantial antitumor effect on murine pancreatic cancer in vivo. PD-L1 blockade promoted CD8(+) T-cell infiltration into the tumor and induced local immune activation. Furthermore, the combination of anti-PD-L1 monoclonal antibody and gemcitabine exhibited a significant synergistic effect on murine pancreatic cancer and resulted in complete response without overt toxicity. CONCLUSION: Our data suggest for the first time that PD-L1 status may be a new predictor of prognosis for patients with pancreatic cancer and provide the rationale for developing a novel therapy of targeting the PD-L/PD-1 pathway against this fatal disease.     

Augmented expression of programmed death-1 in both neoplastic and non-neoplastic CD4+ T-cells in adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATL) is a CD4(+)CD25(+) T-cell malignancy infected with human T-cell leukemia virus type-I (HTLV-I). HTLV-I infection causes the T-cell dysfunction, which contributes to the immunodeficient state of the patients. Programmed death-1 (PD-1) can negatively regulate T-cell response, when its ligand, PD-L1 or PD-L2 mainly expressed on antigen presenting cells, binds to this B7 family receptor. We investigated whether PD-1 is expressed on CD4(+) neoplastic (and/or non-neoplastic) cells or CD8(+) cytotoxic cells in peripheral blood mononuclear cells from 11 patients with ATL. By flow cytometry, we found that the levels of PD-1 expression on both CD4(+)CD25(+) and CD4(+)CD25(-) T-cell populations were increased in ATL patients compared to normal healthy volunteers, while PD-1 levels on CD8(+) T-cells were comparable between the patients and normal subjects. In stimulation with anti-CD3 antibody, the proliferation of PD-1-expressing T-cells from ATL patients was weak when compared to that of PD-1-nonexpressing normal T-cells. In addition to PD-1, PD-L1 was coexpressed on ATL cells in some patients, and PD-L1 expression was enhanced by stimulation with anti-CD3 antibody. Finally, the production of cytokines such as TNF-alpha by ATL cells was restored by blockade of PD-1/PD-L1 interaction. These findings suggest that CD4(+) T-cells are the main PD-1-expressing cells rather than CD8(+) T-cells in ATL patients, and both neoplastic and normal CD4(+) cells are exhausted as a result of PD-1 expression, and additionally PD-L1 expression on the neoplastic cell.     

Hyperprogressive disease during PD-1/PD-L1 blockade in patients with non-small-cell lung cancer

BackgroundImmune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade.Patients and methodsWe enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8⁺ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD.ResultsA total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868–7.440] and overall survival (HR, 5.079; 95% CI, 3.136–8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8⁺ T lymphocytes, a lower frequency of effector/memory subsets (CCR7⁻CD45RA⁻ T cells among the total CD8⁺ T cells) and a higher frequency of severely exhausted populations (TIGIT⁺ T cells among PD-1⁺CD8⁺ T cells) were associated with HPD and inferior survival rate.ConclusionHPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.