4-1BB与肿瘤特异性免疫治疗研究进展

4-1BB(CD137)是新近发现的一种新型共刺激分子,其单独作用(抗4-1BBMoAb或4-1BBL)及联用其他共刺激分子(如B7-1)或细胞因子(如IL-12)显示了强效的抗肿瘤作用,且联用较单用时更显著、持久.现主要从4-1BBL、抗4-1BB-MoAb及联用B7-1、IL-12等方面作一综述.     

Polarization effects of 4-1BB during CD28 costimulation in generating tumor-reactive T cells for cancer immunotherapy

Using murine tumor-draining lymph node (TDLN) cells, we investigated the polarization effect of 4-1BB (CD137) during CD28 costimulation in generating antitumor T cells. Costimulation of TDLN cells through the newly induced 4-1BB molecules, CD3, and CD28 using monoclonal antibodies significantly enhanced cell proliferation. The greater cell yield with 4-1BB signaling appeared to be related to the inhibition of activation-induced cell death. Activation of TDLN cells through 4-1BB in addition to CD3/CD28 signaling shifted T-cell responses toward a type 1 cytokine pattern because 4-1BB ligation plus CD3/CD28 stimulation significantly augmented type 1 cytokine (e.g., IFN-gamma) and granulocyte macrophage colony-stimulating factor secretion. By contrast, type 2 cytokine (e.g., interleukin 10) secretion by the activated TDLN cells was significantly reduced. The in vivo antitumor reactivity of TDLN cells activated through 4-1BB in conjunction with CD3/CD28 pathways was examined using an adoptive immunotherapy model. The number of pulmonary metastases was significantly reduced and survival was prolonged after the transfer of anti-CD3/anti-CD28/anti-4-1BB-activated TDLN cells compared with an equivalent number of cells activated without anti-4-1BB. The antitumor effect through 4-1BB involvement during CD28 costimulation was dependent on IFN-gamma production and abrogated after IFN-gamma neutralization. By contrast, interleukin 10 neutralization resulted in significantly enhanced tumor regression. These results indicate that costimulation of TDLN cells through newly induced 4-1BB and CD3/CD28 signaling can significantly increase antitumor reactivity by shifting T-cell responses toward a type 1 cytokine pattern while concomitantly decreasing type 2 responses.     

Tumor expression of 4-1BB ligand sustains tumor lytic T cells

Inadequate costimulation by solid tumors is generally believed to induce immune tolerance during primary tumor growth. We looked for tumor-specific immunity vs. tolerance in patients with Ewing's sarcoma. Circulating T cells from patients with progressively growing Ewing's tumors displayed MHC restricted tumor-induced proliferation and robust tumor lysis. Tumor-reactive T cells reside within the memory CD3+CD8+ subset and are CD28-/4-1BB+. Autologous Ewing's tumors expressed 4-1BBL, and tumor-induced T cell proliferation and activation required costimulation by 4-1BBL. Stimulation of PBL with anti-CD3/4-1BBL, but not anti-CD3/anti-CD28 induced tumor lytic effectors. Similarly, in a xenograft model, anti-CD3/4-1BBL expanded T cells controlled primary growth and prevented metastasis of autologous tumors while nonactivated and anti-CD3/anti-CD28 activated CD8+ cells did not. These results question prevailing models of tumor induced tolerance accompanying progressive tumor growth; rather, we show coexistence of progressive tumor growth and anti-tumor immunity, with costimulation provided by the tumor itself. They further demonstrate a potential new therapeutic role for 4-1BBL mediated costimulation in expanding tumor reactive CTLs for use in the adoptive immunotherapy of cancer.     

4-1BB基因在不同分化胃癌细胞株中的表达

目的：研究共刺激因子4-1BB在人胃高分化腺癌细胞株MKN-28、人胃中分化腺癌细胞株SGC-7901、人胃低分化腺癌细胞株BGC-823、人胃粘液腺癌细胞株MGC-803中的表达及其生物学意义。方法：用RT-PCR法测定胃癌细胞株中4-1BB mRNA表达;免疫细胞化学法测定胃癌细胞株中4-1BB蛋白表达;MTT法测定人淋巴细胞对胃癌细胞的体外杀伤活性;ELISA法检测人淋巴细胞与胃癌细胞共培养上清液中IL-2、IL-10、TNF-α的含量。结果：RT-PCR结果示4-1BB mRNA表达率从高到低依次为：MGC-803（77.30%）、BGC-823（71.68%）、SGC-7901（40.06%）、MKN-28（37.65%）。免疫细胞化学结果显示4-1BB着色程度由深到浅依次为：MGC-803、BGC-823、SGC-7901、MKN-28。MTT结果显示各时间段（24、48、72h）不同效靶比（10∶1,20∶1,40,∶1）下,人淋巴细胞对胃癌细胞的体外杀伤活性由高到低的顺序为：MKN-28、SGC-7901、BGC-823、MGC-803。ELISA结果显示在各效靶细胞比下,人淋巴细胞与胃癌细胞共培养上清液中IL-2、TNF-α的含量由高到低的顺序均为：MKN-28、SGC-7901、BGC-823、MGC-803。而IL-10的含量由高到低的顺序为：MGC-803、BGC-823、SGC-7901、MKN-28。结论：人胃癌细胞株MKN-28、SGC-7901、BGC-823、MGC-803中4-1BB基因的mRNA和蛋白均有表达,且胃癌细胞株的恶性程度越高其4-1BB表达水平越高;淋巴细胞对低表达4-1BB胃癌细胞的杀伤力较高;提示4-1BB可能通过抑制细胞因子TNF-α、IL-2和促进细胞因子IL-10的产生调节肿瘤免疫。     

Expression of co-stimulatory 4-1BB ligand induces significant tumor regression and protective immunity

Co-stimulatory molecules play an important role in initiating antitumor immune responses. Engineered tumor cells expressing co-stimulatory molecules have been used as cancer vaccines in both experimental tumor models and clinical trials. In this study, we cloned a cDNA gene coding for the mouse co-stimulatory molecule 4-1BBL by RTPCR. The expression vector pCI-4-1BBL was constructed by DNA recombinant technology and further transfected into a moderately immunogenic EL4 and a poorly immunogenic BL6-10 tumor cell line. Expression of the co-stimulatory molecule 4-1BBL is able to induce tumor regression of EL4/4-1BBL but not BL6-10/4-1BBL tumor cell line in syngeneic BALB/c mice. The tumor regression which is mainly mediated by CD8+ T cells further leads to protective immunity against the parental EL4 tumor. Our results thus indicate the potential utility of engineered tumor cells expressing co-stimulatory molecule 4-1BBL, especially in combination with other co-stimulatory molecules such as B7-1 in cancer vaccine.     

A functional anti-human 4-1BB ligand monoclonal antibody that enhances proliferation of monocytes by reverse signaling of 4-1BBL

4-1BB Ligand (4-1BBL), a transmembrane molecule, member of the tumor necrosis factor ligand superfamily, is an important costimulatory molecule in the immune response. In this study a functional anti-human 4-1BBL MAb 1F1 was obtained and the specificity of this MAb was verified by flow cytometry and Western blotting. This MAb effectively recognized the 4-1BBL molecule expressed on a series of malignant cell lines as well as on DC and monocytes and it inhibited the proliferation of T lymphocytes, costimulated by soluble 4-1BBL and agonist anti-human CD3 MAb. Furthermore, we demonstrated that MAb 1F1 induced an impressive proliferation of monocytes from peripheral blood by triggering the reverse signal through 4-1BBL. This functional anti-human 4-1BBL MAb provides a valuable tool for further study of biological functions as well as signal transduction of 4-1BBL/4-1BB.     

4-1BB在肿瘤治疗中的作用

4-lBB是肿瘤坏死因子受体(TNFR)超家族成员,具有影响T细胞扩增和存活的功能特性.通过4-1BBL或者抗4-1BB单克隆抗体干预4-1BB协同刺激途径可能对肿瘤有治疗作用.最近提出的s4-1BBL即4-1BBL可溶性形式,对恶性血液病的诊断和治疗以及判断预后有一定价值.现综述有关4-lBB在肿瘤治疗中的研究进展.     

4-1BB／4-1BBL介导DC和T细胞共刺激作用的研究进展

4-1BB（CDl37）和4-1BB配体（4—1BBL）属于肿瘤坏死因子／肿瘤坏死因子受体（TNF／TNFR）超家族成员，在树突状细胞（DC）及部分T细胞上表达。4-1BB和4-1BBL相互作用，通过一系列信号转导，激发未成熟DC的分化成熟，并且通过TRAF2和MAPK途径，使未成熟Dc介导初始型T细胞活化进而向Thl型细胞转化，从而产生有效的记忆性CTL和效应性CTL。深人探讨4-1BB和4-1BBL的作用机制，可能为肿瘤等疾病的治疗提供新思路。     

CD40 ligand immunotherapy in cancer: an efficient approach

Cancer cells do not elicit a clinically sufficient anti-tumor immune response that results in tumor rejection. Recently, many investigators have been trying to enhance anti-tumor immunity and encouraging results have been reported. This review will discuss current anti-cancer immunotherapy; interleukin-2 therapy, tumor vaccine secreting Granulocyte macrophage-colony stimulating factor, dendritic cells fused with tumor cells, and CD40 ligand immunotherapy. Moreover, we introduce our two kinds of CD40 ligand immuno-genetherapy; (1) oral CD40 ligand gene therapy against lymphoma using attenuated Salmonella typhimurium (published in BLOOD 2000), (2) cancer vaccine transfected with CD40 ligand ex vivo for neuroblastoma (unpublished). Both approaches resulted in a high degree of protection against the tumor progression and they are simple and safe in the murine system.     

Immunomodulatory gene therapy with interleukin 12 and 4-1BB ligand: long- term remission of liver metastases in a mouse model

BACKGROUND: The success of immunomodulatory cancer therapy is frequently hampered by the transient nature of the antitumor immune response. We have shown previously in a mouse model that interleukin 12 (IL-12) generates a strong natural killer (NK) cell-mediated antitumor response and reduces liver metastases induced by a colon carcinoma cell line. However, only a small percentage of the treated animals developed the cytotoxic T-lymphocytic response required for a long-term systemic antitumor immunity. 4-1BB is a co-stimulatory molecule expressed on the surface of activated T cells. Interaction of 4-1BB with its natural ligand (4-1BBL) has been shown to amplify T-cell (especially CD8+)-mediated immunity. In this study, we investigated the effects of adenovirus-mediated gene therapy delivering both IL-12 and 4-1BBL genes on mice with hepatic metastases induced by colon cancer cells. METHODS: Syngeneic BALB/c mice received intrahepatic injection of poorly immunogenic MCA26 colon cancer cells. Various combinations of replication-defective adenoviruses expressing IL-12 and 4-1BBL genes were injected into the established liver tumors. Changes in tumor size and animal survival were then monitored. All statistical tests were two-sided. RESULTS: The long-term survival rate of mice treated with the combination of IL-12 and 4-1BBL was significantly improved over that of animals in the control group (P =.0001). In vivo depletion of NK cells or CD8+ T cells completely abolished the long-term survival advantage of the IL-12 plus 4-1BBL-treated animals (P<.002). Moreover, the systemic immunity induced by this combination treatment protected these animals against a subcutaneous challenge with parental MCA26 cells. CONCLUSION: Adenovirus-mediated transfer of IL-12 and 4-1BBL genes directly into liver tumors resulted in tumor regression that required both NK and CD8+ T cells and generated a potent, long-lasting antitumor immunity.     

4-1BB/4-1BBL在树突状细胞上的表达及其生物学意义

41BB/41BB配体（41BBL）属于肿瘤坏死因子受体/肿瘤坏死因子超家属成员,是机体特异性免疫应答中一对重要的共刺激分子，41BB/41BBL相互作用产生的共刺激信号在维持T细胞的增殖、活化及功能介导中发挥了重要作用。最新研究发现,41BB/41BBL共表达于树突状细胞（dendritic cells , DC），通过激发41BB/41BBL为DC活化提供了新的思路，进而增强DC激发T细胞的能力。因此，调节41BB/41BBL信号在以DC为主介导的肿瘤免疫中具有广阔的应用前景。     

Adjuvant effect of a natural TLR4 ligand on dendritic cell-based cancer immunotherapy

The clinical efficacy of dendritic cell (DC) vaccine in cancer patients has been unsatisfactory due, at least in part, to the deficiency of maturation and impaired migration of ex vivo generated DCs to the draining lymph nodes. To solve this problem, we used angelan, a natural TLR4 ligand, to enhance the maturation and migration of DCs. Angelan increased the expression of MHC-I/II, CD80, and CD86, DC maturation markers, through the NF-κB pathway. This compound also increased CCR7 expression in DCs through NF-κB and p38 pathway and enhanced their migration against CCL19, which is a key chemokine that guides DCs into lymph nodes. We also showed that angelan enhanced in vivo DC homing from tissues to draining lymph nodes. When treated to DCs in vitro and vivo, angelan increased antitumor activity of DCs in B16F10 syngeneic tumor model. Taken together, the present data suggest that a natural TLR4 ligand might be helpful for overcoming the disadvantages of DC-based cancer therapy, such as impaired maturation and poor migration in cancer patients.     

共刺激分子4-1BB与肿瘤治疗的研究进展

近年来,诸如PD-1,PD-L1等免疫检查点为靶点的单克隆抗体成为了肿瘤免疫治疗的热点,其作用机制是阻断T细胞表面的共抑制分子与配体的相互作用,从而激活T细胞进行肿瘤免疫应答.共刺激分子4-1BB(CD137)又名肿瘤坏死因子超家族受体9,多表达于活化的T细胞表面,也可表达于粒细胞或树突状细胞表面.4-1BB在免疫应答...     

4-1BB/4-1BBL在胃癌组织及其外周血中的表达及临床意义

目的探讨胃癌局部免疫与全身免疫状态。方法应用流式细胞术,测定胃癌患者癌组织及外周血中T淋巴细胞亚群、NK细胞水平,同时测定癌组织、癌周正常胃黏膜、淋巴结及外周血单个核细胞中4-1BB、4-1BBL含量。结果胃癌患者外周血中CD3^＋、CD4^＋、CD4^＋/CD8^＋比值和NK细胞表达水平均显著高于胃癌组织（P〈0.05）,CD8^＋细胞计数反之（P〈0.05）。4-1BB表达量由低到高的顺序为外周血单个核细胞、正常胃黏膜、淋巴结、癌组织、癌组织中单个核细胞;其中癌组织明显高于正常黏膜（P〈0.05）,有统计学意义;外周血单个核细胞中4-1BB表达量明显低于其他组织,有统计学意义（P〈0.01）。癌组织中4-1BBL表达量低于正常黏膜,有统计学意义（P〈0.05）。癌组织中4-1BB表达量与CD4^＋/CD8^＋比值、NK细胞表达水平呈负相关关系,4-1BBL与CD4^＋/CD8^＋比值、NK细胞表达水平呈正相关关系,有统计学意义（P〈0.05）。结论胃癌组织内免疫力低下,处于免疫抑制状态,胃癌组织的低免疫状态与4-1BBL缺乏有关;4-1BB与胃癌患者局部和全身的免疫状态亦有密切关系。总之,胃癌组织中4-1BB/4-1BBL的表达失衡与胃癌的免疫逃逸、低免疫状态有关。     

Combination therapy with anti-CTL antigen-4 and anti-4-1BB antibodies enhances cancer immunity and reduces autoimmunity

The majority of cancer antigens identified thus far have limited expression in normal tissues. It has been suggested that autoimmune disease is a necessary price for cancer immunity. This notion is supported by a recent clinical trial involving an anti-CTL antigen-4 (CTLA-4) antibody that showed significant clinical responses but severe autoimmune diseases in melanoma patients. To selectively modulate cancer immunity and autoimmunity, we used anti-CTLA-4 and anti-4-1BB antibodies to treat mice with a preexisting cancer, MC38. The combination of the two antibodies led to CD8 T-cell-mediated rejection of large established MC38 tumors and long-lasting immunity to the same tumor cells, although the same regimen was not effective for B16 melanoma. More importantly, whereas individual antibodies induced inflammation and autoimmune manifestations, combination therapy increased cancer immunity while reducing autoimmunity. The reduction of autoimmune effects correlates with an increased function of regulatory T cells. Our results suggest a novel approach to simultaneously enhance cancer immunity and reduce autoimmunity.     

4-1BB Protects Dendritic Cells from Prostate Cancer-Induced Apoptosis

It has been shown that human prostate cancer (PCa) cells induced apoptotic death of the most potent antigen-presenting cells, dendritic cells (DCs), which are responsible for the induction of specific antitumor immune responses. Here, we investigated the function of 4-1BB on protecting DCs from prostate cancer-induced apoptosis with an agonistic mAb to 4-1BB. RM-1 cells and DCs were co-incubated for 48 h and DC apoptosis was assessed by Annexin Vassay. TNF-α and IL-12 production were assessed by enzyme-linked immunosorbent assay (ELISA) and Bcl-2 and Bcl-xL on DCs were analyzed by Western blot. We have shown that co-incubation of RM-1 cells with DCs is accompanied by an increased level of DCs apoptosis. Triggering 4-1BB on DCs resulted in increased resistance of DCs to RM-1 cells-induced apoptosis, which was owing to the up-regulated expression of Bcl-2 and Bcl-xL, and increased secretion of TNF-αand IL-12. These results demonstrate that triggering 4-1BB on DCs could increased resistance of DCs to PCa-induced apoptosis.     

NKG2D配体在中晚期食管癌患者术后NK细胞免疫治疗中的作用

  目的  探讨NKG2D配体MHC-I类相关分子A（MHC class I-related molecules A,MICA）在中晚期食管癌患者术后化疗联合NK细胞免疫治疗中的作用。   方法  福建省肿瘤医院90例中晚期食管癌患者手术后,分为单纯化疗组40例、化疗联合NK细胞治疗MCIA阴性组（简称MICA-组）25例及化疗联合NK细胞治疗MICA阳性组（简称MICA+组）25例,比较其疗效。   结果  与单纯化疗组及MICA-组相比,MICA+组CD3+、CD4+T细胞阳性率、NK细胞阳性率及CD4+/CD8+比率明显高于治疗前[（64.2±6.4）% vs（51.3±5.6）%,（39.8±8.2）% vs（29.5±3.2）%,（25.3±2.1）% vs（16.4±4.3）%,（1.4±0.5）vs（1.1±0.7）;均P < 0.05],T-reg细胞明显低于治疗前[（6.3±4.5）% vs（17.3±2.4）%,P < 0.05]。3组疾病控制率及有效率无明显差异（P>0.05）。MICA+组KPS评分治疗后明显提高,MICA+组能明显改善化疗引起的白细胞减少、外周神经毒性症状,MICA+组疾病进展时间（time to progression,TTP）及总体生存时间（overall survival,OS）均明显延长（均P < 0.05）。但单纯化疗组及MICA-组之间差异无统计学意义（P>0.05）。   结论  食管癌组织MICA表达阳性的中晚期患者进行化疗联合自体NK细胞能有效能有效提高免疫力,改善患者生活质量,并能延长生存期,且回输安全、不良反应小。      

Oncolytic virus and anti-4-1BB combination therapy elicits strong antitumor immunity against established cancer

Oncolytic virotherapy using vaccinia virus (Vv) has shown some encouraging antitumor responses in mouse models and patients, but the breadth of efficacy in clinical trials has been somewhat limited. Given that antitumor effects have correlated with increased host immune responses, we hypothesized that improved therapeutic outcomes may be achieved by using oncolytic virus (OV) in combination with a potent immune agonist reagent. In this study, we carried out a preclinical evaluation of a genetically engineered strain of oncolytic vaccinia virus (Vvdd) for its capacity to induce antitumor responses when combined with an agonist antibody (Ab) specific for the costimulatory molecule 4-1BB (CD137). In immune-competent syngeneic mouse models of cancer, this combination therapy significantly reduced the growth of established subcutaneous tumors relative to either treatment alone. Importantly, the development of pulmonary metastatic lesions was also reduced. Tumor growth inhibition was associated with increased numbers of CD11b(+) and CD11c(+) myeloid cells in the tumor draining lymph nodes, greater infiltration of CD8(+) effector T and natural killer (NK) cells, and a more sustained presence of neutrophils at the tumor site. Depletion of T or NK cells or neutrophils reduced efficacy, confirming their contribution to an effective therapeutic response. We further extended this conclusion through results from IFNγ-deficient mice. In summary, our findings offered a proof-of-concept for a combinatorial approach to enhance the antitumor efficacy of an OV, suggesting a strategy to improve their use as an immunotherapeutic treatment for cancer.     

Mechanisms involved in synergistic anticancer immunity of anti-4-1BB and anti-CD4 therapy

Anti-4-1BB-mediated anticancer effects were potentiated by depletion of CD4+ cells in B16F10 melanoma-bearing C57BL/6 mice. Anti-4-1BB induced the expansion and differentiation of polyclonal tumor-specific CD8+ T cells into IFN-gamma-producing CD11c+CD8+ T cells. The CD4+ cell depletion was responsible for facilitating immune cell infiltration into tumor tissues and removing some regulatory barriers such as T regulatory and indoleamine-2,3-dioxygenase (IDO)+ dendritic cells. Both monoclonal antibodies (mAb) contributed to the efficient induction of MHC class I molecules on the tumor cells in vivo. The effectors that mediated the anti-4-1BB effect were NKG2D+KLRG1+CD11c+CD8+ T cells that accumulated preferentially in the tumor tissues. Blocking NKG2D reduced the therapeutic effect by 20% to 26%, which may indicate that NKG2D contributes partially to tumor killing by the differentiated CD8+ T cells. Our results indicate that the combination of the two mAbs, agonistic anti-4-1BB and depleting anti-CD4, results in enhanced production of efficient tumor-killing CTLs, facilitation of their infiltration, and production of a susceptible tumor microenvironment.     

Cancer gene therapy of adenovirus-mediated anti-4-1BB scFv in immunocompetent mice

The use of immunostimulatory molecule genes aiming at enhancing anti-tumor immunity has emerged as a new approach to treat cancers. 4-1BB signaling, an important costimulatory pathway delivering a signal for T cell activation, survival and growth, has become one of the most promising targets for cancer immunotherapy. In this work, a recombinant nonreplicative adenovirus (Ad.4-1BB scFv) carrying a single-chain Fv fragments (scFv) specific for 4-1BB gene (anti-4-1BB scFv) was generated, haracterized and explored for its stimulation of anti-tumor immunity in immunocompetent C57BL/6 mice. Ad.4-1BB scFv could efficiently infect murine hepatoma Hepa 1-6 cells and induce anti-4-1BB scFv expression on the cell surface. Moreover, Ad.4-1BB scFv did not cause obvious cytotoxicity effect on human and murine tumor cell lines (A549, PLC/PRF/5, Hepa 1-6 and TC-1) even at a high MOI, which suggested Ad.4-1BB scFv had no direct effect on tumor cells. Intratumoral injection of Ad.4-1BB scFv to established Hepa 1-6 tumors significantly suppressed the tumor growth in C57BL/6 mice. The anti-tumor effect might be mainly attributed to the anti-4-1BB scFv-mediated immune activity, as evidenced by enhanced interferon-gamma-producing splenic cells and increased lymphocytes infiltration in the tumor microenvironment. These results indicated that nonreplicative adenovirus carrying the anti-4-1BB scFv gene possessed powerful in vivo anti-tumor efficacy and might be a valuable tool for cancer immunotherapy.