综述:髓系衍生的抑制性细胞与肿瘤免疫耐受关系的研究进展

髓系衍生的抑制性细胞(myeloid-derived suppressor cells,MDSCs),是在肿瘤等病理因素的作用下髓系细胞发生分化障碍所产生的不同阶段髓系祖细胞的集合,具有广谱而强大的免疫抑制功能,是免疫系统的重要负性调节组件之一.研究表明:肿瘤微环境中的多种细胞因子或生长因子可通过激活相应的信号通路促进MDSCs扩增及活化,MDSCs进而通过多种机制抑制包括T细胞在内的多种免疫细胞的功能而促进肿瘤个体免疫耐受的发生.临床研究表明:肿瘤患者体内MDSCs的水平与肿瘤临床病程进展密切相关,基于MDSCs的免疫治疗也有望成为肿瘤免疫治疗的新策略.本文主要介绍了肿瘤中MDSCs的表型鉴定、扩增及活化机制、发挥免疫抑制作用的途径及机制、肿瘤中MDSCs的临床意义以及本领域需要解决的问题,以期对MDSCs在肿瘤免疫耐受中的作用进展提供参考.     

髓系衍生的抑制性细胞与肿瘤免疫耐受关系的研究进展

髓系衍生的抑制性细胞(myeloid-derived suppressor cells,MDSCs),是在肿瘤等病理因素的作用下髓系细胞发生分化障碍所产生的不同阶段髓系祖细胞的集合,具有广谱而强大的免疫抑制功能,是免疫系统的重要负性调节组件之一.研究表明:肿瘤微环境中的多种细胞因子或生长因子可通过激活相应的信号通路促进MDSCs扩增及活化,MDSCs进而通过多种机制抑制包括T细胞在内的多种免疫细胞的功能而促进肿瘤个体免疫耐受的发生.临床研究表明:肿瘤患者体内MDSCs的水平与肿瘤临床病程进展密切相关,基于MDSCs的免疫治疗也有望成为肿瘤免疫治疗的新策略.本文主要介绍了肿瘤中MDSCs的表型鉴定、扩增及活化机制、发挥免疫抑制作用的途径及机制、肿瘤中MDSCs的临床意义以及本领域需要解决的问题,以期对MDSCs在肿瘤免疫耐受中的作用进展提供参考.     

成纤维细胞激活蛋白alpha与肿瘤免疫抑制的研究进展

成纤维细胞激活蛋白alpha（Fibroblast activation protein-alpha,FAP-alpha）是一种跨膜丝氨酸蛋白酶,高度表达在90 %的上皮性肿瘤的 间质--肿瘤相关成纤维细胞（Tumor association fibroblast,TAF）上。FAPalpha在促进上皮性肿瘤的恶性进展中起着十分重要的作用, 近年来研究发现,FAP琢在肿瘤微环境中发挥免疫抑制的作用。研究FAPalpha在肿瘤免疫抑制中的作用,已成为肿瘤研究的新的热 点。为基于以FAP-alpha为靶标的抗肿瘤免疫治疗提供参考,本文围绕引起肿瘤免疫抑制的因素、FAPalpha与肿瘤免疫抑制的研究进展 以及FAP-alpha在肿瘤的发展进程的作用作一综述。     

T细胞肿瘤免疫治疗的研究进展

随着科学技术的不断发展,人类对肿瘤疾病认识的不断深入,也带来了医学界对肿瘤治疗模式的改变。通过现代生物技术调节机体的免疫功能状态,利用人体自身免疫系统来治疗肿瘤疾病,并取得了很大的成效。肿瘤免疫治疗成为继手术、化疗和放疗之后的第四种有效治疗肿瘤的方法。用于肿瘤免疫治疗的细胞主要有:T淋巴细胞(T lymphocyte)、树突细胞(dendritic cell,DC)、自然杀伤细胞(natural killer cell,NK cell)、细胞因子诱导的杀伤细胞(cytokine-induced killer cell,CIK cell)以及DC-CIK细胞(dendritic cell-cytokine-induced killer cell)。在肿瘤的发生和发展过程中,T细胞介导的细胞免疫发挥着重要的作用。因此,探索T细胞肿瘤免疫治疗一直是肿瘤免疫研究领域的研究热点,现就T细胞相关的肿瘤免疫疗法研究进展作一综述。     

调节性T细胞与胶质瘤的免疫治疗

调节性T细胞（regulatory T cell,Treg）是一群具有抑制其它免疫细胞功能的起负性调控的细胞群. Treg细胞能抑制多种免疫细胞,如CD4+T和CD8+T淋巴细胞、NK细胞、B淋巴细胞以及树突状细胞的活化和增殖,是体内维持免疫系统稳定,防止出现自身免疫性疾病重要因素.最新研究表明,Treg细胞在肿瘤免疫逃逸中也发挥重要作用. 肿瘤细胞通过扩增或招募Treg细胞,抑制机体对肿瘤的免疫作用,由此可知,Treg细胞在肿瘤的发生和发展过程中发挥重要作用. 因此,抑制Treg细胞的活性和数量是包括胶质瘤在内的肿瘤免疫治疗有效的方式.     

成纤维细胞激活蛋白α与肿瘤免疫抑制的研究进展

成纤维细胞激活蛋白α(Fibroblast activation proteinα,FAPα)是一种跨膜丝氨酸蛋白酶,高度表达在90%的上皮性肿瘤的间质--肿瘤相关成纤维细胞(Tumor association fibroblast,TAF)上。FAPα在促进上皮性肿瘤的恶性进展中起着十分重要的作用,近年来研究发现,FAPα在肿瘤微环境中发挥免疫抑制的作用。研究FAPα在肿瘤免疫抑制中的作用,已成为肿瘤研究的新的热点。为基于以FAPα为靶标的抗肿瘤免疫治疗提供参考,本文围绕引起肿瘤免疫抑制的因素、FAPα与肿瘤免疫抑制的研究进展以及FAPα在肿瘤的发展进程的作用作一综述。     

PD-1相关免疫调节应用的研究进展

程序性细胞死亡因子1(programmed cell death 1,PD-1)是一种共刺激分子,属于CD28家族,呈诱导性表达于活化的T细胞、B细胞和NK细胞表面,与其配体作用传递抑制性信号,发挥负向调控作用,这一信号通路在自身免疫性疾病、肿瘤发生、慢性病毒感染中具有重要的生物学意义。通过研究PD-1及其配体与临床疾病的相关性,阐明其作用机理后,利用信号调节可以达到维持自身耐受、抑制肿瘤、抗病毒和提高机体免疫应答等免疫治疗的目的。本文对PD-1及其配体的生物学功能,免疫治疗等方面的进展进行回顾。     

肿瘤免疫治疗中NK细胞的激活策略及研究进展

NK细胞(natural killer cell)是机体固有免疫系统中一类重要的淋巴样细胞,在免疫调节中发挥重要作用.NK细胞MHC Ⅰ非限制性杀伤肿瘤细胞的特性受到人们广泛关注.然而肿瘤组织浸润难、杀伤活性弱、免疫监视功能低的缺陷极大限制了NK细胞的活性.因此,本文总结了肿瘤免疫治疗中NK细胞激活的机制,探讨了NK细...     

肾移植后恶性肿瘤患者调节性免疫细胞的变化研究

目的:探讨肾移植后发生恶性肿瘤患者调节性免疫细胞的变化。方法:收集2010年5月-2018年3月来我院进行肾移植手术的患者,肿瘤组共20例患者,病理诊断为肾脏及输尿管恶性肿瘤,对照组共20例患者,移植肾功能稳定;分离各组患者外周血淋巴细胞,流式细胞术检测调节性T细胞(Treg细胞)、调节性B细胞(Breg细胞)和滤泡调节性T细胞(Tfr细胞)的比例。结果:流式细胞学检测的结果发现,淋巴细胞中CD4~+T细胞比例在对照组和肿瘤组之间没有显著的差别(P0.05),肿瘤组中CD4+CD25+Foxp3+Treg细胞比例显著的高于对照组,增加了1.29倍(P0.05);CD19+B细胞比例在对照组和肿瘤组之间没有显著的差别(P0.05),肿瘤组中CD19+TGF-β+Breg细胞比例显著的高于对照组,增加了2.69倍(P0.05);肿瘤组中CD4+CXCR5+Foxp3+Tfr细胞比例显著的高于对照组,增加了2.74倍(P0.05)。结论:肾移植后发生恶性肿瘤患者外周血中Treg细胞、Tfr细胞和Breg细胞比例均显著升高,我们的研究为肾移植后临床用药和免疫状态的检测提供了一定的理论依据。     

肿瘤相关成纤维细胞与成纤维细胞活化蛋白在肿瘤免疫治疗中的研究进展

除了依赖于肿瘤细胞自身的恶性增殖以外,肿瘤的发生和发展还依赖于肿瘤细胞与肿瘤间质微环境的相互作用。肿瘤间质中存在的肿瘤相关成纤维细胞（tumor-associatedfibroblasts,TAF）能够诱导免疫抑制,是肿瘤免疫治疗中的一大障碍。在TAF上存在一种成纤维细胞激活蛋白（fibroblast activationprotein,FAP）,它在细胞表面发挥作用,是一种膜丝氨酸肽酶,是Ⅱ型丝氨酸蛋白酶家族成员之一,具有二肽肽酶及胶原酶活性,在肿瘤微环境中表达FAP的肿瘤相关成纤维细胞是最早被鉴定的一种肿瘤间质细胞类型。它由肿瘤问质中的成纤维细胞与癌细胞相互作用而活化,是肿瘤微环境中最主要的宿主细胞,具有促进肿瘤细胞生长、侵袭及免疫抑制的作用,而且基因组稳定不易耐药,有望成为肿瘤免疫治疗的新靶标。就靶向TAF和FAP在肿瘤免疫治疗中的研究做一综述,为基于肿瘤间质微环境的免疫治疗提供参考。     

B cell subsets and dysfunction of regulatory B cells in IgG4-related diseases and primary Sj?gren’s syndrome: the similarities and differences

Introduction

IgG4-related disease (IgG4-RD) is a multisystem-involved autoimmune disease. Abnormally activated and differentiated B cells may play important roles. Regulatory B cells (Breg) are newly defined B cell subgroups with immunosuppressive functions. In this study, we investigated the differences of B cell subsets, the expressions of co-stimulatory molecules on B cells, and the function of Breg cells in patients with IgG4-RD, primary Sjögren’s syndrome (pSS) as well as in healthy controls (HC).

Methods

Newly diagnosed IgG4-RD patients (n = 48) were enrolled, 38 untreated pSS patients and 30 healthy volunteers were recruited as disease and healthy controls. To analyze B cell subsets and B cell activity, PBMCs were surface stained and detected by flow cytometry. The function of Breg cells was tested by coculturing isolated CD19 + CD24^hiCD38^hi Breg cells with purified CD4 + CD25- T cells. Serum cytokines were measured by ELISA and cytometric bead array. Relationship between clinical data and laboratory findings were analyzed as well.

Results

Compared with pSS patients and HC, IgG4-RD patients had a lower frequency of peripheral Breg cells. Interestingly, CD19 + CD24-CD38^hi B cell subsets were significantly higher in peripheral B cells from IgG4-RD patients than in pSS patients and HC, which correlated with serum IgG4 levels. The expression of BAFF-R and CD40 on B cells was significantly lower in IgG4-RD patients compared with those in pSS patients and HC. Unlike HC, Breg cells from pSS patients lacked suppressive functions.

Conclusions

B cells in patients with IgG4-RD and pSS display a variety of abnormalities, including disturbed B cell subpopulations, abnormal expression of key signaling molecules, co-stimulatory molecules, and inflammatory cytokines. In addition, a significantly increased B cell subset, CD19 + CD24-CD38^hi B cells, may play an important role in the pathogenesis of IgG4-RD.     

综述: 代谢重编程在调控肿瘤免疫微环境中的作用

肿瘤免疫治疗的成功揭示了宿主免疫在抵抗癌细胞增殖方面的重要作用以及抗肿瘤免疫治疗的可行性．但是具有免疫抑制作用的肿瘤微环境仍然是限制肿瘤免疫治疗进展的重要瓶颈．肿瘤微环境会诱发肿瘤细胞代谢发生重编程,此过程会导致肿瘤细胞与宿主免疫细胞竞争利用营养物质,肿瘤细胞来源的代谢产物或废物可通过多种方式影响免疫细胞的激活及效应功能的发挥,最终达到促使肿瘤细胞存活及增殖的目的．因此,本文就微环境条件下肿瘤细胞代谢重编程及其代谢产物对免疫微环境的影响展开讨论,以期为肿瘤免疫治疗提供理论基础及新的思路．     

肾透明细胞癌中免疫检查点相关的免疫逃逸机制的研究进展

摘要：近年来,免疫治疗在晚期肾透明细胞癌的治疗中异军突起,使人们对于肾癌治疗有了全新的认识。肿瘤免疫治疗药物是通过抑制免疫检查点从而抑制肿瘤细胞免疫逃逸,使免疫细胞可以杀伤肿瘤细胞来发挥治疗作用。因此,了解肾透明细胞癌中免疫检查点相关免疫逃逸机制对于制定有效的治疗策略以及开发新的免疫治疗药物至关重要。本文对目前肾透明细胞癌中主要的免疫检查点（PD-1/PD-L1、CTLA-4、B7-H4、LAG-3、TIM-3和HLA-G）相关的免疫逃逸机制进行综述。     

Combined blockade of TIM-3 and TIM-4 augments cancer vaccine efficacy against established melanomas

Cancer vaccines have been developed to instruct the endogenous immune responses to autologous tumors and to generate durable clinical responses. However, the therapeutic benefits of cancer vaccines remain insufficient due to the multiple immunosuppressive signals delivered by tumors. Thus, to improve the clinical efficacy of cancer immunotherapy, it is important to develop new modalities to overcome immunosuppressive tumor microenvironments and elicit effective antitumor immune responses. In this study, we show that novel monoclonal antibodies (mAbs) specifically targeting either T cell immunoglobulin mucin protein-3 (TIM-3) or T cell immunoglobulin mucin protein-4 (TIM-4) enhance the therapeutic effects of vaccination against established B16 murine melanomas. This is true for vaccination with irradiated B16 melanoma cells engineered to express the flt3 ligand gene (FVAX). More importantly, combining anti-TIM-3 and anti-TIM-4 mAbs markedly increased vaccine-induced antitumor responses against established B16 melanoma. TIM-3 blockade mainly stimulated antitumor effector activities via natural killer cell-dependent mechanisms, while CD8⁺ T cells served as the main effectors induced by anti-TIM-4 mAb. Our findings reveal that therapeutic manipulation of TIM-3 and TIM-4 may provide a novel strategy for improving the clinical efficacy of cancer immunotherapy.     

Absence of Ig V region gene somatic hypermutation in advanced Burkitt's lymphoma

Somatic hypermutation of rearranged Ig V region gene plays a major role in generating antibody diversity. Recently, V mutation has been established as a major mechanism of tumor escape from anti-Id immunotherapy. We cloned and sequenced the expressed Ig H and L chain V regions from a case of B acute lymphoblastic leukemia in order to evaluate B cell stages associated with V region mutation, and to determine which tumors would be better suited to Id directed immunotherapy. A consensus VH and V lambda sequence representing tumor at diagnosis was obtained by conventional cDNA cloning in lambda gt10 from a heterohybridoma. Primers which flanked both V regions were used in a modified polymerase chain reaction to generate multiple independent sequences from tumor cells harvested at relapse. In order to exclude mutations due to infidelity of the amplification procedure, single cDNA templates of known sequence were also amplified. The polymerase chain reaction proved to be an effective procedure to obtain multiple clones, but replication in M13 was associated with a low rate of base misincorporation. The results indicate that there is no evidence for biologically significant ongoing mutation in this t(8;14) B cell tumor when comparing sequences at diagnosis and relapse. Thus, V somatic mutation may be restricted to a discrete B cell stage whose malignant counterpart is follicular lymphoma.     

过继免疫治疗中DC-CIK的研究进展

目前,免疫细胞生物学和免疫分子生物学发展迅猛,由于其具备低毒性和高效率的特性,肿瘤免疫治疗在恶性肿瘤治疗中所起的作用引起了学者们的广泛关注,其中细胞介导的过继免疫治疗为当前研究的热点之一。过继免疫治疗(adoptive cellular immunotherapy,ACI)是目前恶性肿瘤治疗的新方向,它通过向细胞免疫功能低下者回输具有抗肿瘤活性的免疫细胞,直接杀伤或间接杀伤肿瘤细胞,使其获得抗肿瘤免疫力。树突状细胞(Dendritic cell DC)是专职抗原递呈细胞(antigen presenting cell APC)之一,在机体免疫应答的启始、调节、维持中发挥核心作用。细胞因子诱导的杀伤(cytokine induced killer CIK)细胞具有高效的MHC非限制性溶瘤活性,具有极其广泛的杀瘤范围。近年来,国内外大量研究表明,联合培养的DC-CIK抗肿瘤活性提升明显,患者预后生存期延长,效果显著。本文就DC与CIK生物学特点及抗肿瘤作用予以简要综述。     

Cytotoxic dendritic cells generated from cancer patients

Known for years as professional APCs, dendritic cells (DCs) are also endowed with tumoricidal activity. This dual role of DC as killers and messengers may have important implications for tumor immunotherapy. However, the tumoricidal activity of DCs has mainly been investigated in animal models. Cancer cells inhibit antitumor immune responses using numerous mechanisms, including the induction of immunosuppressive/ tolerogenic DCs that have lost their ability to present Ags in an immunogenic manner. In this study, we evaluated the possibility of generating tumor killer DCs from patients with advanced-stage cancers. We demonstrate that human monocyte-derived DCs are endowed with significant cytotoxic activity against tumor cells following activation with LPS. The mechanism of DC-mediated tumor cell killing primarily involves peroxynitrites. This observed cytotoxic activity is restricted to immature DCs. Additionally, after killing, these cytotoxic DCs are able to activate tumor Ag-specific T cells. These observations may open important new perspectives for the use of autologous cytotoxic DCs in cancer immunotherapy strategies.     

Entinostat,a histone deacetylase inhibitor,increases the population of IL-10+ regulatory B cells to suppress contact hypersensitivity

IL-10⁺ regulatory B (Breg) cells play a vital role in regulating the immune responses in experimental autoimmune encephalomyelitis, colitis, and contact hypersensitivity (CHS). Several sti-mulants such as lipopolysaccharide (LPS), CD40 ligand, and IL-21 spur the activation and maturation of IL-10⁺ Breg cells, while the epigenetic mechanism for the IL-10 expression remains largely unknown. It is well accepted that the histone acetylation/deacetylation is an important mechanism that regulates the expression of IL-10. We found that entinostat, an HDAC inhibitor, stimulated the induction of IL-10⁺ Breg cells by LPS in vitro and the formation of IL-10⁺ Breg cells to suppress CHS in vivo. We further demonstrated that entinostat inhibited HDAC1 from binding to the proximal region of the IL-10 expression promoter in splenic B cells, followed by an increase in the binding of NF-κB p65, eventually enhancing the expression of IL-10 in Breg cells.     

microRNA在实体肿瘤免疫反应中的调节作用

免疫反应的作用逐渐成为调节各种复杂癌症的关键因素。免疫治疗也逐渐成为癌症肿瘤的有效干预方式。肿瘤微环境包含不同类型的免疫细胞,这有助于调节抗肿瘤信号中先天性和适应性免疫系统之间的细微平衡。在这种环境下,肿瘤细胞与免疫细胞之间相互关联的机制有待广泛阐明,但目前已被证明,多种microRNA在实体肿瘤相关免疫细胞的发育和功能中起调控作用,其通过肿瘤及免疫细胞介导免疫抑制或免疫刺激因子分泌增强或抑制免疫应答,靶向调控肿瘤发生的相关免疫途径,从而在癌症起始、转移进展的所有阶段中起关键作用,近而在肿瘤免疫治疗中寻找新的治疗靶点。本文针对microRNA在肿瘤免疫反应中的相关调节进行综述。