微波消融治疗骨肉瘤诱导免疫原性细胞死亡的机制研究

目的 探讨是否经微波消融导致肿瘤细胞死亡引起免疫原性肿瘤抗原释放,从而诱导肿瘤特异性免疫反应。方法 3种分别来源于小鼠、大鼠和人类骨肉瘤细胞系作为微波消融模型。在体外消融和原位消融过程中,通过对不同灭活时间及不同实验组设计,检测具有免疫原性分子的表达水平变化。结果 将经体外消融的肿瘤细胞或上清液作为肿瘤疫苗,再植入荷瘤动物模型后,肿瘤细胞生长得到了显著抑制。该效应的产生与疫苗诱导的特异性CD₈(+) T细胞密切相关。效应细胞作用的发挥是通过释放IFN-γ和TNF-α细胞因子来实现,该过程又启动了Fas/FasL介导的细胞凋亡机制。结论 本研究表明经微波消融处理的骨肉瘤细胞可用于诱导特定的抗肿瘤免疫效应。微波原位消融技术联合免疫治疗可望为那些因对化疗不敏感患者提供更多治疗选择。     

放疗联合免疫治疗的相关机制及研究进展

近年来,恶性肿瘤的发病率越来越高,而肿瘤的各种治疗技术也在不断提高,治疗方案不断完善。放疗主要是通过放射线对局部肿瘤细胞的杀伤来达到治疗效果,而在放疗过程中,可以诱导或提高抗肿瘤免疫反应。合适的放疗剂量、分割模式联合一定的免疫治疗在肿瘤的治疗中越来越起到重要的作用。本文综述了放疗增强抗肿瘤免疫反应的相关机制及放疗联合免疫治疗研究现状和发展前景。     

冷冻消融与原位肿瘤疫苗

近年来,经皮冷冻消融广泛用于实体性肿瘤的治疗.随着现代免疫学技术的发展,对冷冻免疫反应机制的探讨更加深入.而有关原位肿瘤疫苗的研究,将冷冻消融与免疫治疗有机结合起来,为肿瘤的综合治疗提供了新模式.     

晚期肝细胞癌免疫治疗及射频消融的研究进展

摘 要：肝细胞癌（hepatocellular carcinoma，HCC）约占原发性肝癌的75%～85%。HCC发病率高，早期诊断率低，预后较差。高达70%～80%的患者在确诊时已处于中晚期，5年生存率仅18%。免疫治疗是晚期HCC的重要治疗方法之一，射频消融也是重要的局部介入治疗方法。射频消融可直接作用于肿瘤，通过局部治疗毁损病灶，暴露抗原，引起自身免疫反应，联合免疫治疗协同激活全身免疫系统，助力免疫治疗。因此，免疫治疗联合个体化射频消融治疗成为了一种新兴的治疗策略。全文综述HCC的免疫治疗、射频消融治疗以及两种方式联合治疗的研究进展。     

DC肿瘤融合瘤苗抗肿瘤效应的实验研究

目的:观察DC与肿瘤细胞融合后的瘤苗体内诱导的抗肿瘤免疫应答以及对荷瘤小鼠的治疗作用.方法:应用免疫磁珠分选和贴壁培养方法收集融合细胞,应用3H-TdR掺入法、4h51Cr释放法观察T细胞增殖反应的能力和CTL活性,并观察瘤苗对荷瘤小鼠保护性免疫反应和免疫治疗作用.结果:DC肿瘤融合瘤苗具有强烈的激活T细胞增殖和抗原提呈的能力,在体外、体内诱导出更强的特异CTL细胞毒活性,使免疫小鼠产生一定的免疫保护作用,抵抗Hepa1-6肝癌细胞的再次攻击,使治疗的小鼠肿瘤的生长明显缓慢,具有更明显的治疗作用.结论:DC与肿瘤细胞融合后进行体内免疫和治疗,能诱导出显著的抗肿瘤免疫反应,为DC介导的肿瘤免疫治疗开辟了新的途径.     

热疗与树突状细胞联合治疗肿瘤的研究进展

热疗可通过提高机体免疫效应细胞活性、诱导免疫效应细胞再分布、影响细胞因子表达等作用调节机体的免疫功能,抑制肿瘤生长和转移.基于热疗可调节机体免疫功能,研究热疗与各种免疫疗法联合应用的协同效应,为利用热效应治疗肿瘤提供实验依据.目前,树突状细胞(DC)的免疫治疗在抗肿瘤研究中备受关注,热疗与DC联合治疗肿瘤,二者取长补短,产生协同作用,从而提高抗肿瘤免疫.     

热疗与树突状细胞联合治疗肿瘤的研究进展

热疗可通过提高机体免疫效应细胞活性、诱导免疫效应细胞再分布、影响细胞因子表达等作用调节机体的免疫功能,抑制肿瘤生长和转移.基于热疗可调节机体免疫功能,研究热疗与各种免疫疗法联合应用的协同效应,为利用热效应治疗肿瘤提供实验依据.目前,树突状细胞(DC)的免疫治疗在抗肿瘤研究中备受关注,热疗与DC联合治疗肿瘤,二者取长补短,产生协同作用,从而提高抗肿瘤免疫.     

肝癌免疫治疗及基因治疗进展

近年来,由于分子生物学的迅猛发展,以及基因重组技术的进步,使得肿瘤的生物治疗成为继手术、放疗、化疗之后的第四种肿瘤治疗模式。肿瘤免疫治疗与基因治疗作为生物治疗的方式更充满了生机和活力。本文就国内外有关肝癌免疫治疗与基因治疗研究的热点作一综述。1肝癌的免疫治疗1．1主动免疫治疗1．1．1特异性主动免疫治疗特异性主动免疫治疗的关键是肿瘤的抗原问题,人们有可能在分子或基因水平研究诱导肿瘤抗原的表达,促进免疫系统对肿瘤抗原的识别,唤起宿主的主动免疫反应。ChmgWL等L‘］应用激活的B淋巴细胞与肿瘤细胞融合形成杂交…     

雷公藤内酯醇对人宫颈癌细胞的凋亡诱导效应

目的:探讨腺病毒介导AFP基因修饰的DC(AFP-DC)瘤苗经不同途径免疫后机体抗肿瘤免疫应答反应.方法:采用皮下注射、静脉注射和瘤体注射三种途径回输AFP-DC瘤苗,比较观察AFP-DC瘤苗对荷瘤小鼠免疫治疗作用,应用4h51cr释放杀伤实验、T细胞与NK体内剔除实验等方法,观察AFP-DC瘤苗对荷瘤小鼠免疫治疗作用及保护性免疫反应.结果:皮下注射AFP-DC瘤苗治疗效果在抑制肿瘤生长、延长小鼠存活期方面都明显优于瘤体内注射或尾静脉注射(P＜0.05),AFP-DC瘤苗体内能更有效地诱导特异CTL细胞毒活性,能使免疫动物产生一定的免疫保护作用,抵抗肿瘤细胞的再攻击.在AFP-DC瘤苗诱导抗肿瘤免疫排斥反应过程中,必需有CD4 T和CD8 T细胞的参与;而在其效应阶段,则依赖于CD8 T细胞的参与,CD4 T细胞为非必需;在免疫诱导及效应阶段剔除NK细胞对抗肿瘤免疫应答无明显影响.结论:皮下注射AFP-DC瘤苗能有效诱导机体产生抗肿瘤免疫反应,为DC介导的肝癌免疫治疗开辟了新的途径.     

补体系统与肿瘤免疫的研究进展

补体系统是先天免疫反应的重要组成部分,但其生物学意义远远超出了简单的非特异性防御。在肿瘤微环境中,补体系统对肿瘤的发生、发展起着双重调控作用,影响免疫应答的结果。通过对免疫系统的调节以及对肿瘤细胞的直接杀伤作用,补体促进了免疫监视并抑制肿瘤进展;然而,过度激活的补体可以通过多种途径影响宿主免疫反应,是炎症、免疫抑制和肿瘤进展之间的重要环节。在抗肿瘤免疫治疗过程中靶向补体系统有助于克服免疫抑制,产生抗肿瘤免疫反应。本文对补体系统与肿瘤免疫的研究进展进行综述,旨在为抗肿瘤免疫治疗提供选择。      

热休克蛋白与肝肿瘤热消融的抗肿瘤免疫研究进展

热消融治疗肝肿瘤能够提高机体抗肿瘤免疫水平,还能改变肿瘤细胞热休克蛋白(HSP)的表达水平和定位分布,甚至使之释放到细胞外,而HSP可以通过多个环节参与获得性和天然免疫过程,HSP的细胞膜表达增加和细胞外释放可能起着重要作用。     

Combining radiotherapy and immunotherapy: a revived partnership

Ionizing radiation therapy (RT) is an important local modality for the treatment of cancer. The current rationale for its use is based largely on the ability of RT to kill the cancer cells by a direct cytotoxic effect. Nevertheless, considerable evidence indicates that RT effects extend beyond the mere elimination of the more radiosensitive fraction of cancer cells present within a tumor at the time of radiation exposure. For instance, a large body of evidence is accumulating on the ability of RT to modify the tumor microenvironment and generate inflammation. This might have far-reaching consequences regarding the response of a patient to treatment, especially if radiation-induced tumor cell kill were to translate into the generation of effective antitumor immunity. Although much remains to be learned about how radiation can impact tumor immunogenicity, data from preclinical studies provide the proof of principle that different immunotherapeutic strategies can be combined with RT to enhance antitumor effects. Conversely, RT could be a useful tool to combine with immunotherapy. This article will briefly summarize what is known about the impact of RT on tumor immunity, including tumor-associated antigens, antigen-presenting cells, and effector mechanisms. In addition, the experimental evidence supporting the contention that RT can be used as a tool to induce antitumor immunity is discussed, and a new approach to radioimmunotherapy of cancer is proposed.     

Antitumor immunity induced by laser immunotherapy and its adoptive transfer

The ideal cancer treatment modality should not only cause tumor regression and eradication but also induce a systemic antitumor immunity, which is essential for control of metastatic tumors and for long-term tumor resistance. Laser immunotherapy using a laser, a laser-absorbing dye, and an immunoadjuvant has induced such long-term immunity in treatment of a mammary metastatic tumor. The successfully treated rats established total resistance to multiple subsequent tumor challenges. To further study the mechanisms of the antitumor immunity induced by this novel treatment modality, passive adoptive transfer was performed using splenocytes as immune cells. The spleen cells that were harvested from successfully treated tumor-bearing rats provided 100% immunity in the naive recipients. The passively protected first cohort rats were immune to tumor challenge with an increased tumor dose; their splenocytes also prevented the establishment of tumor in the second cohort of naive recipient rats. This immunity transfer was accomplished without the usually required T-cell suppression in recipients.     

An Immunogram for the Cancer-Immunity Cycle: Towards Personalized Immunotherapy of Lung Cancer

IntroductionThe interaction of immune cells and cancer cells shapes the immunosuppressive tumor microenvironment. For successful cancer immunotherapy, comprehensive knowledge of antitumor immunity as a dynamic spatiotemporal process is required for each individual patient. To this end, we developed an immunogram for the cancer-immunity cycle by using next-generation sequencing.MethodsWhole exome sequencing and RNA sequencing were performed in 20 patients with NSCLC (12 with adenocarcinoma, seven with squamous cell carcinoma, and one with large cell neuroendocrine carcinoma). Mutated neoantigens and cancer germline antigens expressed in the tumor were assessed for predicted binding to patients’ human leukocyte antigen molecules. The expression of genes related to cancer immunity was assessed and normalized to construct a radar chart composed of eight axes reflecting seven steps in the cancer-immunity cycle.ResultsThree immunogram patterns were observed in patients with lung cancer: T-cell–rich, T-cell–poor, and intermediate. The T-cell–rich pattern was characterized by gene signatures of abundant T cells, regulatory T cells, myeloid-derived suppressor cells, checkpoint molecules, and immune-inhibitory molecules in the tumor, suggesting the presence of antitumor immunity dampened by an immunosuppressive microenvironment. The T-cell–poor phenotype reflected lack of antitumor immunity, inadequate dendritic cell activation, and insufficient antigen presentation in the tumor. Immunograms for both the patients with adenocarcinoma and the patients with nonadenocarcinoma tumors included both T-cell–rich and T-cell–poor phenotypes, suggesting that histologic type does not necessarily reflect the cancer immunity status of the tumor.ConclusionsThe patient-specific landscape of the tumor microenvironment can be appreciated by using immunograms as integrated biomarkers, which may thus become a valuable resource for optimal personalized immunotherapy.     

Induced antitumor immunity against DMBA-4 metastatic mammary tumors in rats using laser immunotherapy

Induced antitumor immunity is a highly effective and long-term cure for cancer, particularly for metastatic tumors. Laser immunotherapy was developed to induce such an immunologic response. It involves intratumoral administration of a light-absorbing dye and a specially formulated immunoadjuvant, followed by noninvasive irradiation of a near-infrared laser. Treatment of DMBA-4 metastatic mammary tumors in rats with this approach has resulted in local control of primary tumors and eradication of untreated distant metastases. After laser immunotherapy, rats were resistant to tumor rechallenge and developed immunity, which could be adoptively transferred. To better understand the immunity induced in this tumor model, immunization using freeze-thaw DMBA-4 cell lysates was performed, followed by tumor challenge 21 days later. Tumor cell lysate immunization delayed the emergence of metastases but did not provide immunity against the tumor challenge. Also performed was surgical resection of primary tumors before the observation of metastatic tumors. Removal of primary tumors was unsuccessful at changing the course of tumor progression. Tumors re-emerged at the primary sites, and metastases developed at multiple remote sites. In contrast, tumor-bearing rats successfully treated by laser immunotherapy experienced tumor regression and eradication and developed strong resistance to repeated challenges by tumor cells of the same type. Our results show that laser immunotherapy could have potential for the treatment of metastatic tumors by inducing tumor-specific, long-lasting immunity.     

微波消融术联合免疫治疗在肿瘤治疗中的应用及进展

微波消融术适用于多种组织类型的肿瘤,具有创伤小、消融范围广、临床疗效好等优点.微波消融不仅可以通过热效应杀灭肿瘤细胞,其产生的免疫效应在肿瘤的后续治疗中也起到了重要的作用.本文通过总结微波消融对肿瘤免疫微环境的作用,分析微波消融联合免疫治疗的临床疗效,尤其是对PD-1/PD-L1轴的作用,并展望微波消融联合肿瘤免疫治疗...     

The combination therapy of α‐galactosylceramide and 5‐fluorouracil showed antitumor effect synergistically against liver tumor in mice

α‐Galactosylceramide (α‐GalCer) has been reported to be therapeutic against metastatic liver tumors in mice. However, little is known regarding the efficacy of combined chemo‐immunotherapy using α‐GalCer and anticancer drugs. In this study, we evaluated the antitumor effect of the combination therapy of α‐GalCer and 5‐fluorouracil (5‐FU) against liver tumors of MC38 colon cancer cells. The liver weights of tumor‐bearing mice treated with the combination were significantly lower than those of nontreated mice and of mice treated with 5‐FU or α‐GalCer alone. No toxic effects on the liver and renal functions were observed in any of the treatment groups. α‐GalCer treatment induced significant activation of liver NK cells in vivo, but 5‐FU treatment did not. 5‐FU treatment resulted in a significant upregulation of NKG2D activating molecules (Rae‐1 and H60) and DNAM‐1 ligands (CD112 and CD155) on MC38 cells, but α‐GalCer did not. The cytolytic activity of α‐GalCer‐activated liver mononuclear cells against 5‐FU‐treated MC38 cells was significantly higher than that against nontreated cells. The increase of the cytolytic activity induced by 5‐FU partially depended on NKG2D‐Rae‐1 or H60 signals. Depletion of NK cells significantly inhibited the antitumor efficacy of 5‐FU against MC38 liver tumors, which suggested that the antitumor effect of 5‐FU partially depended on the cytolytic activity of NK cells. These results demonstrated that the combination therapy of α‐GalCer and 5‐FU produced synergistic antitumor effects against liver tumors by increasing the expression of NK activating molecules on cancer cells. This study suggests a promising new chemo‐immunotherapy against metastatic liver cancer.     

Vascular attack by 5,6-dimethylxanthenone-4-acetic acid combined with B7.1 (CD80)-mediated immunotherapy overcomes immune resistance and leads to the eradication of large tumors and multiple tumor foci

The promise of cancer immunotherapy is that it will not only eradicate primary tumors but will generate systemic antitumor immunity capable of destroying distant metastases. A major problem that must first be surmounted relates to the immune resistance of large tumors. Here we reveal that immune resistance can be overcome by combining immunotherapy with a concerted attack on the tumor vasculature. The functionally related antitumor drugs 5,6-dimethylxanthenone-4-acetic acid (DMXAA) and flavone acetic acid (FAA), which cause tumor vasculature collapse and tumor necrosis, were used to attack the tumor vasculature, whereas the T-cell costimulator B7.1 (CD80), which costimulates T-cell proliferation via the CD28 pathway, was used to stimulate antitumor immunity. The injection of cDNA (60-180 microg) encoding B7.1 into large EL-4 tumors (0.8 cm in diameter) established in C57BL/6 mice, followed 24 h later by i.p. administration of either DMXAA (25 mg/kg) or FAA (300 mg/kg), resulted in complete tumor eradication within 2-6 weeks. In contrast, monotherapies were ineffective. Both vascular attack and B7.1 immunotherapy led to up-regulation of heat shock protein 70 on stressed and dying tumor cells, potentially augmenting immunotherapy. Remarkably, large tumors took on the appearance of a wound that rapidly ameliorated, leaving perfectly healed skin. Combined therapy was mediated by CD8+ T cells and natural killer cells, accompanied by heightened and prolonged antitumor cytolytic activity (P < 0.001), and by a marked increase in tumor cell apoptosis. Cured animals completely rejected a challenge of 1 x 10(7) parental EL-4 tumor cells but not a challenge of 1 x 10(4) Lewis lung carcinoma cells, demonstrating that antitumor immunity was tumor specific. Adoptive transfer of 2 x 10(8) splenocytes from treated mice into recipients bearing established (0.8 cm in diameter) tumors resulted in rapid and complete tumor rejection within 3 weeks. Although DMXAA and B7.1 monotherapies are complicated by a narrow range of effective doses, combined therapy was less dosage dependent. Thus, a broad range of amounts of B7.1 cDNA were effective in combination with 25 mg/kg DMXAA. In contrast, DMXAA, which has a very narrow range of high active doses, was effective at a low dose (18 mg/kg) when administered with a large amount (180 microg) of B7.1 cDNA. Importantly, combinational therapy generated heightened antitumor immunity, such that gene transfer of B7.1 into one tumor, followed by systemic DMXAA treatment, led to the complete rejection of multiple untreated tumor nodules established in the opposing flank. These findings have important implications for the future direction and utility of cancer immunotherapies aimed at harnessing patients' immune responses to their own tumors.     

Oncolytic virotherapy as a personalized cancer vaccine

Oncolytic virotherapy has demonstrated multimodal antitumor mechanisms in both preclinical and clinical settings for cancer treatment, including antitumor immunity. Compared with conventional immunotherapy, oncolytic viruses have the advantages of simultaneous cytoreduction and conferring personalized anticancer immunity, but without the need of personalized manufacture. Additionally, oncolytic viruses can be further engineered to delete immunosuppressive viral components and to insert transgenes that enhance antitumor immunity. Finally, combination with new immunomodulating agents (e.g., cyclophosphamide) or cell therapy approaches will likely further augment specific antitumor immunity of virotherapy. Virotherapy could become a new paradigm for potent, safe and practical therapeutic vaccines for cancer.     

Suppression of Tregs by anti‐glucocorticoid induced TNF receptor antibody enhances the antitumor immunity of interferon‐α gene therapy for pancreatic cancer

We have reported that interferon (IFN)‐α can attack cancer cells by multiple antitumor mechanisms including the induction of direct cancer cell death and the enhancement of an immune response in several pancreatic cancer models. However, an immunotolerant microenvironment in the tumors is often responsible for the failure of the cancer immunotherapy. Here we examined whether the suppression of regulatory T cells (Tregs) within tumors can enhance an antitumor immunity induced by an intratumoral IFN‐α gene transfer. First we showed that an intraperitoneal administration of an agonistic anti‐glucocorticoid induced TNF receptor (GITR) monoclonal antibody (mAb), which is reported to suppress the function of Tregs, significantly inhibited subcutaneous tumor growth in a murine pancreatic cancer model. The anti‐GITR mAb was then combined with the intratumoral injection of the IFN‐α‐adenovirus vector. The treatment with the antibody synergistically augmented the antitumor effect of IFN‐α gene therapy not only in the vector‐injected tumors but also in the vector‐uninjected tumors. Immunostaining showed that the anti‐GITR mAb decreased Foxp3⁺ cells infiltrating in the tumors, while the intratumoral IFN‐α gene transfer increased CD4⁺ and CD8⁺ T cells in the tumors. Therefore, the combination therapy strongly inclined the immune balance of the tumor microenvironment in an antitumor direction, leading to a marked systemic antitumor effect. The CCR5 expression on Tregs was downregulated in the antibody‐treated mice, which may explain the decrease of tumor‐infiltrating Tregs. The combination of Treg‐suppression by GITR mAb and the tumor immunity induction by IFN‐α gene therapy could be a promising therapeutic strategy for pancreatic cancer.