Mycobacterium smegmatis enhances shikonin-induced immunogenic cell death—an efficient in situ tumor vaccine strategy

Tumor vaccines are a promising avenue in cancer immunotherapy.Despite the progress in targeting specific immune epitopes,tumor cells lacking these epitopes can evade the treatment.Here,we aimed to construct an efficient in situ tumor vaccine called Vac-SM,utilizing shikonin(SKN)to induce immunogenic cell death(ICD)and Mycobacterium smegmatis as an immune adjuvant to enhance in situ tumor vaccine efficacy.SKN showed a dose-dependent and time-dependent cytotoxic effect on the tumor cell line and induced ICD in tumor cells as evidenced by the CCK-8 assay and the detection of the expression of relevant indicators,respectively.Compared with the control group,the in situ Vac-SM injection in mouse subcutaneous metastatic tumors significantly inhibited tumor growth and distant tumor metastasis,while also improving survival rates.Mycobacterium smegmatis effectively induced maturation and activation of bone marrow-derived dendritic cells(DCs),and in vivo tumor-draining lymph nodes showed an increased maturation of DCs and a higher proportion of effector memory T-cell subsets with the Vac-SM treatment,based on flow cytometry analysis results.Collectively,the Vac-SM vaccine effectively induces ICD,improves antigen presentation by DCs,activates a specific systemic antitumor T-cell immune response,exhibits a favorable safety profile,and holds the promise for clinical translation for local tumor immunotherapy.

Immuno-protective effect of tumor cell vaccine on Kunming mice bearing Ehrlich ascites tumor

AIM To evaluate the immunity of chemically modified tumor cell vaccine.METHODS Tumor cell vaccines (TCV) were prepared by incubating the live Ehrlich ascites tumor cells with concanavalin A-mitomycin C (ConA-MMC), mitomycin C (MMC), concanavalin A-glutaraldehyde (ConA-Glu), glutaraldehyde (Glu), or paraformaldehyde (Para), respectively. The whole cell or soluble forms of the vaccines were administered intraperitoneally into Kunming mice once a week for three times prior to the intraperitoneal inoculation of a lethal dose of live tumor cells. A second challenge with live tumor cells was given four weeks later. Survival and antibody production of the mice were analyzed.RESULTS After the first challenge, the mice, received whole TCV of ConA-MMC, MMC (P＜0.01) and Glu (P＜0.05) promoted survival incidence than the controls. All the treated mice had the survival time prolonged. ConA-MMC vaccine treated mice had longer survival days than that of ConA-Glu ones (P＜0.05). For the soluble TCV immunized mice, those treated with vaccines of Para (P＜0.01), ConA-Para and ConA-Glu (P＜0.05) had longer survival periods compared with that of the controls. Following the second challenge, survival incidence of the mice received vaccines of ConA-MMC, MMC, ConA-Glu or Glu was significantly increased (P＜0.01). Moreover, all the treated mice had the survival time prolonged, and ConA-MMC vaccine treated mice had longer survival days than that of Para treated ones (P＜0.05). Antibodies against Ehrlich ascites tumor cells were found to be positive in sera of the mice treated with whole TCV of ConA-MMC.CONCLUSION Ehrlich ascites tumor cells are immunogenic when treated with ConA-MMC, MMC, ConA-Glu, Glu or Para, which might act as safe and effective tumor vaccines with safety and effectiveness.

Immunotherapeutic effects of dendiritic cells vaccine pulsed with tumor cell lysate in mice with pancreatic carcinoma

Objective To observe the immunotherapeutic effects of dendritic cells vaccine pulsed with tumor cell lystate on mice with pancreatic carcinoma. Methods Dendritic cells (MTSC4) were pulsed with tumor cells lysate. The immune preventative and immnotherapeutic effects of DC vaccines on mice with pancreatic carcinoma were assessed. Results After vaccination of the DC vaccines,mice remained tumor-free for at least 25 days in DCs vaccines group,but in other groups the subcutaneous implantation tumorigenesis were found beginning 3 to 9 days. CTL stimulated by DC vaccines effected cytolytic activity against pancreatic carcinoma cells. The survival period was obviously prolonged in DCs vaccines group (56 ±9)d than in other groups P【0.01) and tumors (1.4 ±0.8)g in DCs vaccines group were significantly smaller than that in other groups (P 【 0. 05). Conclusion Tumor cell lysate-pulsed dendrtic cells vaccines can induce a specific and effective immune response against pancreatic carcinoma cell implanted in mice.

Advances in inducing adaptive immunity using cell-based cancer vaccines: clinical applications in pancreatic cancer

The incidence of pancreatic ductal adenocarcinoma(PDA) is on the rise, and the prognosis is extremely poor because PDA is highly aggressive and notoriously difficult to treat. Although gemcitabine- or 5-fluorouracil-based chemotherapy is typically offered as a standard of care, most patients do not survive longer than 1 year. Therefore, the development of alternative therapeutic approaches for patients with PDA is imperative. As PDA cells express numerous tumor-associated antigens that are suitable vaccine targets, one promising treatment approach is cancer vaccines. During the last few decades, cell-based cancer vaccines have offered encouraging results in preclinical studies. Cell-based cancer vaccines are mainly generated by presenting whole tumor cells or dendritic cells to cells of the immune system. In particular, several clinical trials have explored cell-based cancer vaccines as a promising therapeutic approach for patients with PDA. Moreover, chemotherapy and cancer vaccines can synergize to result in increased efficacies in patients with PDA. In this review, we will discuss both the effect of cell-based cancer vaccines and advances in terms of future strategies of cancer vaccines for the treatment of PDA patients.

Enhancing Antitumor by Immunization with Fusion of Dendritic Cells and Engineered Tumor Cells

A novel approach for a dentritic cells (DCs) based tumor vaccine was developed for the formation of hybrid engineered J558 after fusion with DCs. To make the hybrid tumor vaccine generate more efficient specific CTL cytotoxicity against wild type tumor cells, we genetically engineered tumor cells with mIL 12 gene prior to the cell fusion. mIL 12 was detected at 870±60 pg/(10 5 cells/ml) in the culture supernatants and the fusion ratio was about 30 % by the co focal microscopic analysis. Vaccination of mice with DCs fused with engineered J558 induced more efficient tumor specific CTL cytotoxicity against wild type tumor cells in vitro and with efficient antitumor immunity in vivo . These results suggest that this approach of using DCs fused with engineered tumor cells could be applied in clinical settings of DCs based cancer vaccines.

Tumor neoantigens: Novel strategies for application of cancer immunotherapy

Neoantigen-targeted immunotherapy is a rapidly advancing field that holds great promise for treating cancer.The recognition of antigens by immune cells is a crucial step in tumor-specific killing,and neoantigens generated by mutations in cancer cells possess high immunogenicity and are selectively expressed in tumor cells,making them an attractive therapeutic target.Currently,neoantigens find utility in various domains,primarily in the realm of neoantigen vaccines such as DC vaccines,nucleic acid vaccines,and synthetic long peptide vaccines.Additionally,they hold promise in adoptive cell therapy,encompassing tumor-infiltrating cells,T cell receptors,and chimeric antigen receptors which are expressed by genetically modified T cells.In this review,we summarized recent progress in the clinical use of tumor vaccines and adoptive cell therapy targeting neoantigens,discussed the potential of neoantigen burden as an immune checkpoint in clinical settings.With the aid of state-of-the-art sequencing and bioinformatics technologies,together with significant advancements in artificial intelligence,we anticipated that neoantigens will be fully exploited for personalized tumor immunotherapy,from screening to clinical application.

Immunotherapy for advanced or recurrent hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is associated with high morbidity and mortality,and is prone to intra-and extrahepatic metastasis due to the anatomical and functional characteristics of the liver.Due to the complexity and high relapse rate associated with radical surgery or radiofrequency ablation,immune checkpoint inhibitors(ICIs)are increasingly being used to treat HCC.Several immunotherapeutic agents,along with their combinations,have been clinically approved to treat advanced or recurrent HCC.This review discusses the leading ICIs in practice and those currently undergoing randomized phase 1-3 trials as monotherapy or combination therapy.Furthermore,we summarize the rapidly developing alternative strategies such as chimeric antigen receptor-engineered T cell therapy and tumor vaccines.Combination therapy is a promising potential treatment option.These immunotherapies are also summarized in this review,which provides insights into the advantages,limitations,and novel angles for future research in establishing viable and alternative therapies against HCC.

RNA vaccines for anti-tumor therapy

The immune system is able to recognize tumor antigens and this has been the basis for the development of cancer immunotherapies. The immune system can be instructed to recognize and attack tumor cells by means of vaccination strategies. One such strategy involves the delivery of tumor antigen as genetic material. Herewith we describe the use of RNA encoding tumor antigens for vaccination purposes in tumor settings. RNA has features that are interesting for vaccination. Upon transfection, the RNA has no possibility of integration into the genome, and the tumor translated proteins enter the intrinsic antigen processing pathway thus enabling presentation by MHC-I molecules. This can specifically activate cytotoxic CD8 T cells that can attack and kill tumor cells. RNA can be delivered as a naked molecule for vaccination purposes or can be used to transfect dendritic cells. The combination of RNA technology with dendritic cell vaccination provides a powerful tool for cancer immunotherapies.

Clinical and Immunological Effects in Patients with Advanced Non-Small Cell Lung-Cancer after Vaccination with Dendritic Cells Exposed to an Allogeneic Tumor Cell Lysate

Background: We evaluated the clinical and immunological effects of dendritic cell (DC) vaccination of patients with NSCLC. Autologous DCs were pulsed with a MAGE containing allogeneic melanoma cell lysate (MelCancerVac?, Dandrit Biotech,Copenhagen,Denmark). Imiquimod cream, proleukin and celecoxib were used as adjuvants to the vaccines. The objective of the study was to evaluate specific T cell response in vitro by IFNg EliSpot. Secondary objectives were overall survival, response and quality of life (QoL). Results: Twenty-two patients initiated the vaccination program consisting of ten vaccinations. Seven patients remained in stable disease (SD) three months after the first vaccination. After ten vaccinations (six months), four patients still showed SD and continued vaccinations on a monthly basis. These four patients received a total of 12, 16, 26 and 35 vaccinations, respectively. Five patients showed an unexpectedly prolonged survival. The treatment was well tolerated and only minor adverse events were reported. Quality of life did not change during the study period. In four of the seven patients with SD, vaccine-specific T cells were detected by IFNγ EliSpot assays, whereas only one patient with progressive disease (PD) showed vaccine-specific responses. Conclusion: This DC-based vaccine trial has indicated a correlation between vaccine-specific immunity and sustained SD. Furthermore, we observed an unexpectedly prolonged survival in some patients, which may indicate delayed effect of DC vaccination after completion of the treatment. A prospective randomized phase-IIb or -III is needed to further evaluate the use of MelCancerVac? vaccine treatment in patients with progressive NSCLC.

Protective antitumor immunity induced by tumor cell lysates conjugated with diphtheria toxin and adjuvant epitope in mouse breast tumor models

Cancer cell vaccine-based immunotherapy has received increasing interest in many clinical trials involving patients with breast cancer. Combining with appropriate adjuvants can enhance the weak immunogenic properties of tumor cell lysates (TCL). In this study, diphtheria toxin (DT) and two tandem repeats of mycobacterial heat shock protein 70 (mHSP70) fragment 407-426 (M2) were conjugated to TCL with glutaraldehyde, and the constructed cancer cell vaccine was named DT-TCL-M2. Subcutaneous injection of DT-TCL-M2in mice effectively elicited tumor-specific polyclonal immune responses, including humoral and cellular immune responses. High levels of antibodies against TCL were detected in the serum of immunized mice with ELISA and verified with Western blot analyses. The splenocytes from immunized mice showed potent cytotoxicity on Ehrlich ascites carcinoma cells. Moreover, the protective antitumor immunity induced by DT-TCL-M2 inhibited tumor growth in a mouse breast tumor model. DT-TCL-M2 also attenuated tumor-induced angiogenesis and slowed tumor growth in a mouse intradermal tumor model. These findings demonstrate that TCL conjugated with appropriate adjuvants induced effective antitumor immunity in vivo. Improvements in potency could further make cancer cell vaccines a useful and safe method for preventing cancer recurrence after resection.

Therapeutic tumor vaccines-a rising star to benefit cancer patients

Malignant tumors are still a worldwide threat to human health.Tumor treatment strategies are constantly evolving,and the advent of tumor immunotherapy has brought up hope to many types of tumors,especially for those that are refractory to conventional therapies including surgery,radiotherapy,and chemotherapy.Tumor vaccines can initiate or amplify an anti-tumor immune response in tumor patients through active immunization,and therefore occupy an important position in tumor immunotherapy.The main types of tumor vaccines include tumor cell vaccines,dendritic cell vaccines,polypeptide vaccines and nucleic acid vaccines.Due to factors such as poor antigen selection and suppressive tumor microenvironment,earliest tumor vaccines on clinical trials failed to achieve satisfactory clinical effects.However,with the development of second-generation genome sequencing technologies and bioinformatics tools,it is possible to predict neoantigens generated by tumor-specific mutations and therefore prepare personalized vaccines.This article summarizes the global efforts in developing tumor vaccines and highlights several representative tumor vaccines in each category.

In vivo fluorescence flow cytometry reveals that the nanoparticle tumor vaccine OVA@HA-PEI effectively clears circulating tumor cells

Tumor vaccine therapy offers significant advantages over conventional treatments,including reduced toxic side effects.However,it currently functions primarily as an adjuvant treatment modality in clinical oncology due to limitations in tumor antigen selection and delivery methods.Tumor vaccines often fail to elicit a sufficiently robust immune response against progressive tumors,thereby limiting their clinical efficacy.In this study,we developed a nanoparticle-based tumor vaccine,OVA@HA-PEI,utilizing ovalbumin(OVA)as the presenting antigen and hyaluronic acid(HA)and polyethyleneimine(PEI)as adjuvants and carriers.This formulation significantly enhanced the proliferation of immune cells and cytokines,such as CD3,CD8,interferon-
,and tumor necrosis factor-,in vivo,effectively activating an immune response against B16–F10 tumors.In vivofluorescenceflow cytometry(IVFC)has already become an effective method for monitoring circulating tumor cells(CTCs)due to its direct,noninvasive,and long-term detection capabilities.Our study utilized a laboratory-constructed IVFC system to monitor the immune processes induced by the OVA@HA-PEI tumor vaccine and an anti-programmed death-1(PD-1)antibody.The results demonstrated that the combined treatment of OVA@HA-PEI and anti-PD-1 antibody significantly improved the survival time of mice compared to anti-PD-1 antibody treatment alone.Additionally,this combination therapy substantially reduced the number of CTCs in vivo,increased the clearance rate of CTCs by the immune system,and slowed tumor progression.Thesefindings greatly enhance the clinical application prospects of IVFC and tumor vaccines.

胃癌免疫治疗的临床研究进展

晚期胃癌治疗选择有限,易发生化疗耐药。目前,包括免疫检查点抑制剂、过继细胞疗法、肿瘤疫苗、非特异免疫增强剂及细胞因子疗法在内的免疫疗法对胃癌显示出了良好的疗效。载体药物及3D打印技术也在临床前实验中取得了疗效。临床试验采用免疫肿瘤学单一疗法或联合免疫化学疗法来提高胃癌病人的总体生存时间和客观反应率。根据初步证据,我们相信免疫治疗可以积极影响自然病史,改善胃癌病人的预后。

T细胞免疫反应载体疫苗在人类疾病预防和治疗中的应用

人类疾病,特别是传染病和癌症,对公共卫生安全和全球经济构成前所未有的挑战。预防和治疗性疫苗的开发是应对人类疾病的优先对策。本文综述了疫苗载体的免疫学原理、T细胞载体疫苗设计策略及疫苗研究进展,为新型疫苗的设计提供新的思路。T细胞可以在机体发生感染后分化成不同的效应T细胞群,它们可以起到清除病原体的作用,关于效应T细胞功能和机制的研究对于设计能够引发基于T细胞免疫的疫苗至关重要。目前很多病毒(例如HIV、HCMV感染)和肿瘤疫苗的研发都侧重于T细胞类疫苗,在所有疫苗种类中,激活T细胞免疫反应的载体疫苗具有显著优势。许多来源的载体,包括病毒载体、细菌载体和核酸载体,它们在抗原提呈能力、免疫原性和保护效力方面都有良好的表现。此外,还总结了T细胞载体疫苗设计的策略,包括确定适当的抗原提呈途径和载体递送途径、确保生物安全性、如何选择合适的疫苗的载体、各种载体疫苗的优缺点等,尤其是mRNA疫苗在应对新冠疫情中发挥了重要的作用。疫苗载体的技术进步将会加速新型疫苗的研发,并且能促进人们对突发公共卫生事件的应对。

新抗原脉冲树突状细胞疫苗在肿瘤免疫治疗中的作用

新抗原脉冲树突状细胞疫苗(Neo-DCVac)是一种新型肿瘤免疫治疗手段。新抗原是指肿瘤细胞突变产生的具有较强免疫原性和肿瘤特异性的肽段。Neo-DCVac是基于新抗原被树突状细胞摄取、加工后递呈并激活T细胞引发机体免疫反应,从而发挥抗肿瘤作用。在高通量测序基础上发展而来的个体化Neo-DCVac有望成为肿瘤精准免疫治疗的新方向。本文从个体化Neo-DCVac构建、在实体瘤中联合治疗的临床应用、适宜接种人群和目前存在的局限性等方面进行综述,旨在为肿瘤免疫治疗的相关研究提供参考。

Revolutionizing gastric cancer treatment:The potential of immunotherapy

Gastric cancer,a prevalent malignancy worldwide,ranks sixth in terms of frequency and third in fatality,causing over a million new cases and 769000 annual deaths.Predominant in Eastern Europe and Eastern Asia,risk factors include family medical history,dietary habits,tobacco use,Helicobacter pylori,and Epstein-Barr virus infections.Unfortunately,gastric cancer is often diagnosed at an advanced stage,leading to a grim prognosis,with a 5-year overall survival rate below 5%.Surgical intervention,particularly with D2 Lymphadenectomy,is the mainstay for early-stage cases but offers limited success.For advanced cases,the National Comprehensive Cancer Network recommends chemotherapy,radiation,and targeted therapy.Emerging immunotherapy presents promise,especially for unresectable or metastatic cases,with strategies like immune checkpoint inhibitors,tumor vaccines,adoptive immunotherapy,and nonspecific immunomodulators.In this Editorial,with regards to the article“Advances and key focus areas in gastric cancer immunotherapy:A comprehensive scientometric and clinical trial review”,we address the advances in the field of immunotherapy in gastric cancer and its future prospects.

免疫治疗在胃癌中的应用研究进展

胃癌是全球最常见的恶性肿瘤之一,由于胃癌筛查率低和早期症状轻微,多数患者在晚期才被确诊,影响预后。近年来,随着研究深入,胃癌的免疫治疗取得显著进展,尤其对不可切除和转移性病例效果显著,使其成为继手术、化疗、放疗和靶向治疗后的有效治疗方法。免疫治疗通过人为调控免疫系统生效,包括过继细胞疗法、免疫检查点抑制剂和肿瘤疫苗等。目前,免疫治疗虽然前景广阔,但在临床应用中仍面临诸多挑战和问题。本文就胃癌免疫治疗的临床应用以及存在的问题进行综述。

MHSP65-TCL疫苗对不同病理类型三阴性乳腺癌治疗效果的差异

目的评估及比较改良后的结核分枝杆菌热休克蛋白65-肿瘤细胞裂解物(MHSP65-TCL)疫苗对不同类型三阴性乳腺癌的疗效和差异。方法首先,生物信息学分析不同病理类型三阴性乳腺癌肿瘤微环境中免疫细胞浸润活化情况;其次,分析三阴性乳腺癌细胞中RACK1、Bcl-2、CTNNBL1等细胞活化因子,及细胞凋亡诱导因子PDL1、HMGB1、Fas-L在三阴性乳腺细胞中的丰度及其影响免疫细胞活化的信号通路。进而,在制备MHSP65-TCL去除TCL中的PDL1或增加TCL中Bcl-2,再通过体内外抗肿瘤实验,检测、比较两种方法治疗不同类型三阴性乳腺癌效果的差异。结果蛋白表达丰度的检测,MDA-MB-453细胞中HMGB1的表达量是最高的,但Bcl-2表达最低,结合各类型三阴性乳腺癌淋巴浸润,体外杀伤实验以及体内动物实验,3种不同类型的三阴性乳腺癌细胞尤其是LAR型细胞系MDA-MB-453,主要依赖HMGB1抑制免疫细胞。从TCL中去除HMGB1可以更为有效地提高MHSP65-TCL的抗肿瘤效果。结论阐明MHSP65-TCL疫苗对各类型三阴性乳腺癌疗效差异及机制,并建立起一种三阴性乳腺癌治疗的新方法。

TLR4在HSP70_(EC-TCV)冲激的DC成熟过程中的作用

观察TLR4在Hca-F榄香烯复合瘤苗来源的HSP70(HSP70EC-TCV)冲激处理的小鼠骨髓来源的DC成熟过程中的作用。用rmGM-CSF和rmIL-4诱导小鼠骨髓来源的DC,以HSP70EC-TCV或加入抗TLR4抗体30 min后再用HSP70EC-TCV冲激处理DC,流式细胞仪检测DC的CD40和CD86表达,ELISA法检测DC上清中IL-12和T细胞上清中IL-2浓度,MTT法检测T细胞对Hca-F细胞的杀伤率。结果表明,抗TLR4抗体对DC的CD40和CD86表达无明显影响,但对HSP70EC-TCV诱导DC分泌IL-12和进而致敏的T细胞分泌IL-2及产生杀瘤功能有明显的抑制作用。TLR4信号通路参与HSP70EC-TCV诱导DC成熟过程。

结肠癌细胞膜仿生铜基金属有机框架对DC的激活和促血管新生作用

目的:探讨结肠癌细胞膜包裹的铜基金属有机框架(MOF@CCM)的DC激活和促进血管新生的潜力。方法:首先构建1,3,5-苯三甲酸铜(Ⅱ)铜基金属有机框架(HKUST-1),在其外层包覆结肠癌CT26细胞膜,获得MOF@CCM,对其进行物理表征。用CCK-8法研究MOF@CCM的生物相容性,流式细胞术分析MOF@CCM对DC2.4成熟比例的影响,以验证MOF@CCM激活免疫细胞的潜力。通过血管生成实验验证MOF@CCM促人脐静脉内皮细胞(HUVEC)形成血管的能力。结果:成功制备了MOF@CCM,透射电镜观察显示其形状近似圆形,具有明显的核壳结构。MOF@CCM的平均粒径为(150.5±7.89)nm,平均Zeta电位为-(5.12±1.67)mV。体外实验结果显示,与对照组相比,MOF@CCM能够显著提高DC2.4成熟的比例(P<0.01)。此外,MOF和MOF@CCM均能促进HUVEC形成管状结构(P<0.05或P<0.01),且细胞膜修饰对MOF的促血管新生作用没有影响。结论:制备的MOF@CCM在所使用的剂量下具有良好的细胞相容性,能够显著促进DC2.4的成熟和促进HUVEC血管生成,有望成为抗结肠癌和促进组织修复的双功能治疗平台。