IFN-γ在肿瘤免疫及免疫治疗中的作用

IFN-γ在抗肿瘤过程中发挥了重要作用,近年来人们逐渐认识到了其在肿瘤免疫治疗中的必要性。IFN-γ作用于肿瘤发生发展的全过程,其在抗肿瘤方面的作用机制主要分为免疫机制和非免疫机制。IFN-γ可以直接抑制肿瘤细胞增殖、促进肿瘤细胞凋亡、抑制肿瘤血管生成,协同固有免疫和适应性免疫的NK、NKT细胞、γδT细胞以及CD4 + /CD8 + T细胞等完成肿瘤杀伤。然而也有报道IFN-γ的促肿瘤作用,主要表现为在长期慢性炎症和肿瘤微环境中重塑免疫微环境促进免疫逃逸。因此,在肿瘤免疫治疗中要注意IFN-γ的双向效应,防止产生定向选择造成肿瘤免疫抑制。     

调节性T细胞在肿瘤免疫和肿瘤免疫治疗中的作用

肿瘤局部存在多种类型的免疫抑制性细胞,其中调节性T细胞 (regulatory T cell,Treg)在肿瘤的发生、发展过程中发挥着极为重要的作用。Treg通过多种机制抑制免疫效应细胞的功能,是肿瘤免疫逃逸的关键因素。这些机制包括分泌抑制性细胞因子抑制效应细胞功能、分泌颗粒酶和穿孔素杀伤效应细胞、干扰效应细胞的代谢功能,以及通过调控树突状细胞影响Treg的分化和增殖,等等。Treg的深入研究为肿瘤免疫治疗提供了新的思路,以Treg及相关免疫抑制性分子作为靶点,通过特异性或非特异性清除Treg、控制Treg的数量和功能等开展肿瘤免疫治疗具有良好的临床应用前景。     

外泌体PD-L1在肿瘤免疫逃逸中的作用及应用研究进展

摘 要：肿瘤细胞表面的PD-L1主要通过与其在T细胞上表达的受体PD-1结合来抑制T细胞的抗肿瘤活性,在肿瘤免疫逃逸中起着关键作用。PD-1/PD-L1抑制剂已成为抗肿瘤治疗的一大突破性进展,然而,免疫疗法的有效率仍然有限。因此仍需进一步探索PD-L1介导的免疫逃逸机制。PD-L1除了表达于肿瘤细胞表面外,还可存在于肿瘤细胞分泌的外泌体表面（exosomal PD-L1,ExoPD-L1）,其与肿瘤细胞表面的PD-L1具有相同的膜拓扑结构,在抗肿瘤免疫应答中发挥着重要的调节作用。全文综述ExoPD-L1对局部和系统免疫反应的影响及促肿瘤生长等方面的研究成果,并讨论ExoPD-L1作为诊断和免疫治疗疗效、预后等预测因子的潜在意义,以及在临床上应用特异性外泌体合成抑制剂联合免疫治疗的新型治疗策略。     

锌指蛋白调控肿瘤免疫原性的作用及其机制的研究进展

寻找对肿瘤免疫原性具有关键调控作用的生物治疗靶点是抑制肿瘤免疫逃逸、提高肿瘤免疫治疗效果的关键。锌指蛋白（ZFP）通过与DNA、RNA、蛋白质的相互作用,调控肿瘤抗原的形成、肿瘤表面MHC分子及其共刺激分子的表达、损伤相关分子模式的释放等,影响肿瘤细胞的免疫原性及肿瘤微环境（TME）中免疫细胞的分布和功能,进而在调节抗肿瘤免疫应答和肿瘤免疫逃逸中发挥重要作用。近年来,临床前及临床研究探索将ZFP 相关的生物治疗方法应用于肿瘤免疫治疗,主要聚焦在免疫检查点阻断治疗、免疫细胞治疗,以及免疫治疗联合治疗策略展现出了可喜的应用前景。     

肿瘤免疫逃逸作用机制及在食管癌中的研究进展

肿瘤免疫逃逸对于肿瘤的存活和进展至关重要。肿瘤细胞可通过募集抑制性免疫细胞及分子来抑制抗肿瘤免疫应答,导致肿瘤逃逸。食管癌患者的病死率居于世界肿瘤致死疾病的第6位,尽管在诊断和治疗方面取得了一定进展,但其预后依然较差。通过对食管癌免疫逃逸机制的探索,可以为食管癌治疗提供新思路。本文就肿瘤免疫逃逸相关因子作用机制及在食管癌中的研究进展做一综述。      

肿瘤免疫逃逸机制的研究进展

从肿瘤产生的免疫抑制性细胞因子、肿瘤细胞表面MHC抗原表达缺陷及肿瘤Fas/FasL表达等方面讨论肿瘤发生免疫逃逸的机制 ,对探讨肿瘤发生发展机制并针对性地提出肿瘤治疗方案具有重要意义。     

免疫衰老及其在肿瘤中的作用

免疫衰老是指机体随着年龄增长而出现的免疫器官、免疫细胞等的结构与功能性衰退,导致免疫监视能力下降,从而引起肿瘤免疫逃逸发生,促使癌症的发生发展.机体固有免疫功能衰退表现在巨噬细胞和自然杀伤细胞对肿瘤细胞的直接清除作用减弱,树突状细胞的肿瘤抗原呈递能力下降;而获得性免疫功能的衰退主要表现在CD8+T细胞毒性的下降并分泌促肿瘤生长因子.干预免疫衰老可为临床肿瘤防治提供新思路.     

免疫检查点在肿瘤治疗中的作用机制及研究进展

免疫检查点是指免疫系统中存在的一些抑制性信号通路,通过调节外周组织中免疫反应的持续性和强度避免组织损伤,并参与维持对于自身抗原的耐受。利用免疫检查点的抑制性信号通路抑制T细胞活性是肿瘤逃避免疫杀伤的重要机制。近年来,靶向共抑制分子如CTLA-4和PD-1开发的抗体药物在临床应用中获得了巨大成功,使得肿瘤免疫治疗成为最令人瞩目的研究领域。因此靶向免疫检查点在抗肿瘤免疫治疗中有着广阔的应用前景。     

干扰素在肿瘤免疫中的双重作用

干扰素（interferon,IFN）是最早发现的一类抗病毒感染的细胞因子,主要分为3类,即Ⅰ型、Ⅱ型和Ⅲ型IFN。IFN可通过JAK-STAT依赖和非依赖的的信号途径参与机体多种生命活动过程,如抗病毒感染、调节细胞增殖、调节机体免疫应答等。此外,IFN在肿瘤免疫中也发挥着重要的作用。Ⅰ型IFN可以激活DC释放肿瘤坏死因子相关凋亡诱导配体（tumor necrosis factor-related apoptosis inducing ligand,TRAIL）,从而增强NK细胞的细胞毒活性,或直接杀伤肿瘤细胞;Ⅱ型IFN通过活化CTL杀伤肿瘤细胞,并通过提高肿瘤细胞主要组织相容性复合物（major histocompatibility complex,MHC）类分子的表达以增强CTL对肿瘤的识别,或通过调节细胞的代谢间接抑制肿瘤的进展。但在一定条件下,IFN又可以上调Treg、Th17细胞的数量,诱导髓系抑制性细胞（myeloid-derived suppressor cell,MDSC）在肿瘤微环境中的浸润,从而发挥免疫抑制效应,促进肿瘤细胞的免疫逃逸。因此,IFN在肿瘤免疫中是一把“双刃剑”。深入研究IFN在肿瘤免疫中的作用及其机制,探索以IFN为基础的肿瘤治疗新途径（如IFN为主的免疫化学疗法）,对改善肿瘤治疗效果具有重要的指导意义。     

非经典HLA-Ⅰ类分子HLA-G在肿瘤免疫逃逸中的作用

HLA G是非经典的HLA Ⅰ类基因 ,其编码产物的组织分布有限 ,主要分布在母胎组织的接触界面 ,在一些肿瘤中也有分布。多态性相对不明显 ,可通过与杀伤细胞抑制受体 (KIR)结合 ,发挥抑制NK细胞和T细胞的效应。     

Eliciting pyroptosis to fuel cancer immunotherapy: mechanisms and strategies

Immune checkpoint blockade(ICB) therapy has recently shown promise in treating several malignancies. However, only a limited number of patients respond to this treatment, partially because of the “immune cold” condition of the tumor immune microenvironment. Pyroptosis is a type of gasdermin-mediated programmed cell death that often leads to inflammation and immune responses. Many studies on the mechanism and function of pyroptosis have led to increasing recognition of the role of pyroptosis in m...     

IDO与肿瘤免疫逃逸研究进展

吲哚胺2,3-双加氧酶(Indoleamine 2,3-dioxygenase, IDO)是一种免疫调节酶,能够抑制效应T细胞和NK细胞的增殖与功能,并且与调节性T细胞形成了正反馈调节环路,抑制微环境内的抗肿瘤免疫应答,在肿瘤的免疫逃逸中发挥着重要作用。肿瘤细胞可以募集能够表达IDO的树突状细胞(dendritic cells, DC)进入肿瘤微环境,在肿瘤浸润组织和引流淋巴结中都可以发现高水平表达IDO的DC。IDO的免疫抑制效应可以被其竞争性抑制剂1-甲基色氨酸(1-methyl-tryptophan, 1-MT)所阻断,其异构体D-1-MT在前临床试验中可以干扰肿瘤细胞的免疫逃逸,显著增强放疗、化疗和免疫治疗的疗效,有望成为一种新的抗肿瘤药物。     

Immunogenic Cell Death Role in Urothelial Cancer Therapy

Purpose: Bladder cancer is the 13th most common cause of cancer death with the highest lifetime cost for treatment of all cancers. This scoping review clarifies the available evidence on the role of a novel therapeutic approach called immunogenic cell death (ICD) in urothelial cancer of the bladder. Methods: In accordance with the recommendations of the Joanna Briggs Institute, we searched MEDLINE (Ovid), EMBASE, CENTRAL databases, and supplemented with manual searches through the conferences, Google scholar, and clinicaltrials.gov for published studies up to April 2022. We included literature that studied molecular mechanisms of ICD and the role of certain danger-associated molecular patterns (DAMPs) in generating ICD, safety and efficacy of different ICD inducers, and their contributions in combination with other urothelial cancer treatments. Results: Oncolytic viruses, radiotherapy, certain chemo/chemo radiation therapy combinations, photodynamic therapy, and novel agents were studied as ICD-inducing treatment modalities in the included studies. ICD was observed in vitro (murine or human urothelial carcinoma) in ten studies, eight studies were performed on mouse models (orthotopic or subcutaneous), and five clinical trials assessed patient response to ICD inducing agents. The most common studied DAMPs were Calreticulin, HMGB1, ATP, and Heat Shock Proteins (HSP) 70 and 90, which were either expressed on the cancer cells or released. Conclusion: ICD inducers were able to generate lasting antitumor immune responses with memory formation in animal studies (vaccination effect). In clinical trials these agents generally had low side effects, except for one trial, and could be used alone or in combination with other cancer treatment strategies in urothelial cancer patients.     

High hydrostatic pressure induces immunogenic cell death in human tumor cells

Recent studies have identified molecular events characteristic of immunogenic cell death (ICD), including surface exposure of calreticulin (CRT), the heat shock proteins HSP70 and HSP90, the release of high‐mobility group box protein 1 (HMGB1) and the release of ATP from dying cells. We investigated the potential of high hydrostatic pressure (HHP) to induce ICD in human tumor cells. HHP induced the rapid expression of HSP70, HSP90 and CRT on the cell surface. HHP also induced the release of HMGB1 and ATP. The interaction of dendritic cells (DCs) with HHP‐treated tumor cells led to a more rapid rate of DC phagocytosis, upregulation of CD83, CD86 and HLA‐DR and the release of interleukin IL‐6, IL‐12p70 and TNF‐α. DCs pulsed with tumor cells killed by HHP induced high numbers of tumor‐specific T cells. DCs pulsed with HHP‐treated tumor cells also induced the lowest number of regulatory T cells. In addition, we found that the key features of the endoplasmic reticulum stress‐mediated apoptotic pathway, such as reactive oxygen species production, phosphorylation of the translation initiation factor eIF2α and activation of caspase‐8, were activated by HHP treatment. Therefore, HHP acts as a reliable and potent inducer of ICD in human tumor cells.     

Concepts and mechanisms underlying chemotherapy induced immunogenic cell death: impact on clinical studies and considerations for combined therapies

Chemotherapy has historically been thought to induce cancer cell death in an immunogenically silent manner. However, recent studies have demonstrated that therapeutic outcomes with specific chemotherapeutic agents (e.g. anthracyclines) correlate strongly with their ability to induce a process of immunogenic cell death (ICD) in cancer cells. This process generates a series of signals that stimulate the immune system to recognize and clear tumor cells. Extensive studies have revealed that chemotherapy-induced ICD occurs via the exposure/release of calreticulin (CALR), ATP, chemokine (C–X–C motif) ligand 10 (CXCL10) and high mobility group box 1 (HMGB1). This review provides an in-depth look into the concepts and mechanisms underlying CALR exposure, activation of the Toll-like receptor 3/IFN/CXCL10 axis, and the release of ATP and HMGB1 from dying cancer cells. Factors that influence the impact of ICD in clinical studies and the design of therapies combining chemotherapy with immunotherapy are also discussed.     

Immune‐checkpoint molecules on regulatory T‐cells as a potential therapeutic target in head and neck squamous cell cancers

Immune‐checkpoint inhibitors improve the survival of head and neck squamous cell carcinoma (HNSCC) patients. Although recent studies have demonstrated that the tumor immune microenvironment (TIME) has critical roles in immunotherapy, the precise mechanisms involved are unclear. Therefore, further investigations of TIME are required for the improvement of immunotherapy. The frequency of effector regulatory T‐cells (eTregs) and the expression of immune‐checkpoint molecules (ICM) on eTregs and conventional T‐cells (Tconvs) both in peripheral blood lymphocytes (PBL) and tumor‐infiltrating lymphocytes (TIL) from HNSCC patients were analyzed by flow cytometry and their distributions were evaluated by multi‐color immunofluorescence microscopy. High frequency eTreg infiltration into HNSCC tissues was observed and high expressions of CD25, FOXP3, stimulatory‐ICM (4‐1BB, ICOS, OX40 and GITR) and inhibitory‐ICM (programmed cell death‐1 [PD‐1] and cytotoxic T‐lymphocyte‐associated protein‐4 [CTLA‐4]) were found on invasive eTregs. In contrast, the expression of stimulatory‐ICM on Tconvs was low and the expression of inhibitory‐ICM was high. In addition, ICM‐ligands (programmed cell death‐1 [PD‐L1], galectin‐9 and CEACAM‐1) were frequently expressed on cancer cells. PD‐L1 and galectin‐9 were also expressed on macrophages. PD‐1⁺ T‐cells interacted with PD‐L1⁺ cancer cells or PD‐L1⁺ macrophages. This suggested that in TIL, eTregs are highly activated, but Tconvs are exhausted or inactivated by eTregs and immune‐checkpoint systems, and ICM and eTregs are strongly involved in the creation of an immunosuppressive environment in HNSCC tissues. These suggested eTreg targeting drugs are expected to be a combination partner with immune‐checkpoint inhibitors that will improve immunotherapy of HNSCC.     

Nano‐pulse stimulation induces potent immune responses,eradicating local breast cancer while reducing distant metastases

Nano‐pulse stimulation (NPS) as a developing technology has been studied for minimally invasive, nonthermal local cancer elimination for more than a decade. Here we show that a single NPS treatment results in complete regression of the poorly immunogenic, metastatic 4T1‐Luc mouse mammary carcinoma. Impressively, spontaneous distant organ metastases were largely prevented, even in those animals with incomplete tumor regression. All tumor‐free mice were protected from secondary tumor cell challenge, demonstrating a vaccine‐like effect. NPS treatment induced antitumor immunity, long‐term memory T cells, destruction of tumor microenvironment and reversal of the massive increase of immune suppressor cells in the tumor microenvironment and blood. NPS‐treated 4T1 cells exhibited release of damage‐associated molecular patterns (DAMPs), including calreticulin, HMGB1 and ATP, and activated dendritic cells. Those findings suggest that NPS is a potent immunogenic cell death inducer that elicits antitumor immunity to prevent distant metastases in addition to local tumor eradication.     

Immune therapy for human papillomaviruses-related cancers

Human papillomaviruses (HPVs) are a large family of double strand DNA viruses comprising more than 180 types. Infection with HPV is very common and it is associated with benign and malignant proliferation of skin and squamous mucosae. Many HPVs, considered low-risk such as HPV 6 and 11, produce warts; while high-risk viruses, such as HPVs 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, and 58, induce tumors. About 5% of all cancers in men and women are associated with HPV infection. Because there are not antiviral drugs for HPV infection, current therapies for low-risk HPV infections involve physical removal of the lesion by cryotherapy, trichloracetic acid, laser, or surgical removal. Surgical procedures are effective in the treatment of pre-cancerous lesions, however after these procedures, many recurrences appear due to new re-infections, or to failure of the procedure to eliminate the HPV. In addition, HPV can inhibit recognition of malignant cells by the immune system, leading to the development of cancer lesions. When this occurs, radiotherapy and chemotherapy are then used. Unfortunately, about 50% of the HPV-cancer patients still die. In the past decade, a better knowledge of the natural history of the virus-host interaction and of the immune response against this viral infection has brought new therapeutic strategies geared to modulate the immune system to generate an efficient virus-specific cytotoxic response. Novel HPV protein-expressing vaccines have shown some significant clinical efficacy and systemic HPV-specific cytotoxic T cell responses. This review will describe the current status of the several therapeutic strategies used to treat HPV-induced lesions, and discuss the various new therapies now being tested.