以树突状细胞为基础的基因治疗与前列腺癌

树突状细胞 (DC)是目前发现的功能最强大的抗原递呈细胞 ,已有大量的研究表明 ,DC在激活和维持肿瘤特异性T细胞免疫上起着关键性作用。DC的生物学特性、与前列腺癌的关系、以树突状细胞为基础的基因疗法治疗前列腺癌、DC的应用前景等已取得有价值的初步成果。     

以树突状细胞为基础的基因治疗与前列腺癌

树突状细胞(DC)是目前发现的功能最强大的抗原递呈细胞，已有大量的研究表明，DC在激活和维持肿瘤特异性T细胞免疫上起着关键性作用。DC的生物学特性、与前列腺癌的关系、以树突状细胞为基础的基因疗法治疗前列腺癌、DC的应用前景等已取得有价值的初步成果。     

肿瘤细胞RNA加载树突状细胞治疗前列腺癌的实验研究

目的 将小鼠前列腺癌细胞株(RM-1)的RNA加载树突状细胞(dendritic cell,DC),探讨其体内外诱导特异性CTL反应和抗肿瘤免疫的作用.方法 将RM-1细胞的RNA作为肿瘤抗原加载小鼠骨髓来源的DC,构建DC瘤苗(RNA-DC);混合淋巴细胞反应(MLR)检测DC瘤苗刺激T细胞的增殖能力,MTT法检测DC瘤苗诱导特异性CTL的杀伤活性;ELISA法测定DC瘤苗诱导细胞因子IL-2和IFN-γ的作用;体内实验检测DC瘤苗的抗前列腺癌免疫治疗作用和免疫保护作用.结果 DC瘤苗刺激T细胞增殖能力明显增强,能够诱导小鼠产生特异性CTL,对RM-1肿瘤细胞具有明显杀伤作用,细胞上清液中IL-2和IFN-γ的水平升高;经RNA-DC治疗的荷瘤小鼠瘤体生长减慢,存活期延长.DC瘤苗对小鼠具有免疫保护作用,能有效抵抗肿瘤细胞的攻击.结论 将前列腺癌细胞RNA加载DC,能够有效诱导抗肿瘤免疫反应和免疫保护功能,为前列腺癌的DC免疫治疗提供了良好的实验基础.     

转染干扰素-γ诱导蛋白-10基因构建树突状细胞前列腺癌瘤苗及其抗肿瘤免疫作用的检测

目的 将小鼠前列腺癌细胞株RM-1裂解产物加载树突状细胞(DC)后，转染干扰素-γ诱导蛋白-10(IP-10)基因构建DC瘤苗，探讨该瘤苗对小鼠抗肿瘤免疫反应的诱导作用。方法 将RM-1细胞的裂解产物作为肿瘤抗原加载小鼠骨髓来源的DC，并通过脂质体法转染IP-10基因，构建DC瘤苗；检测DC瘤苗的抗前列腺癌免疫治疗作用和免疫保护作用。结果 转染DC强表达IP-10，其上清对淋巴细胞有较强的趋化作用；构建的DC瘤苗能诱导特异性抗前列腺癌免疫反应，经瘤苗处理的荷瘤小鼠瘤体生长减慢，存活期延长；瘤苗还具有明显的免疫保护作用。结论 构建的前列腺癌DC瘤苗在体内能有效诱导抗肿瘤免疫反应和免疫保护功能。     

前列腺癌肿瘤免疫微环境的研究进展

免疫治疗在肿瘤治疗中的作用越来越重要,但目前对于前列腺癌的肿瘤免疫微环境的相关研究相对较少,这在很大程度上阻碍了免疫疗法在前列腺癌中的临床应用。本文从前列腺癌的肿瘤免疫微环境的主要组成及影响因素等方面的研究进展进行综述,以期为前列腺癌的免疫治疗选择提供借鉴。     

肝癌免疫微环境与免疫治疗：研究进展与发展趋势

肝癌微环境主要由肿瘤相关巨噬细胞、肿瘤相关中性粒细胞、骨髓源性抑制细胞、肿瘤相关成纤维细胞和肿瘤浸润性淋巴细胞等细胞组分,以及细胞外基质、细胞因子等非细胞组分组成。免疫微环境在肝癌进程、免疫逃逸和治疗抵抗中发挥重要作用。近期,以调变炎症免疫微环境为基础的免疫治疗取得突破性进展,免疫疗法的出现为肝癌治疗提供了全新的选择,但仍存在客观缓解率较低、不良反应多和耐药问题。因此,深入研究微环境在肝癌发生发展中的作用及探索免疫治疗的未来发展趋势可提高现有治疗手段的应答率,对肝癌精准诊断与治疗有重要的理论价值和临床意义。     

前列腺癌肿瘤相关成纤维细胞的研究进展与临床价值

前列腺癌是男性泌尿生殖系统最常见的恶性肿瘤之一, 严重威胁着男性生命健康。前列腺癌发生转移或去势抵抗不仅取决于癌细胞自身, 也取决于癌细胞所处的肿瘤微环境。肿瘤相关成纤维细胞是前列腺癌肿瘤微环境中的重要组成部分, 在调节肿瘤增殖、转移、代谢和免疫逃逸等方面发挥多重作用。近年来单细胞转录组学、空间转录组学及代谢组学等多组学技术深入阐明肿瘤相关成纤维细胞(CAFs)的特征及其在前列腺癌促癌抑癌作用中的调节机制, 这让我们进一步了解到CAFs与前列腺癌细胞间信息交流。本文就CAFs的生物学特性及其在前列腺癌中的研究进展与临床价值作一综述, 为前列腺癌的临床治疗提供新思路。     

泌尿系肿瘤治疗新策略-树突状细胞疫苗免疫治疗

树突状细胞(DC)作为目前已知的功能最强的抗原提呈细胞,也是抗原特异性免疫应答的始动者,可在体内外向T细胞提呈抗原并诱发CIL反应,在抗肿瘤免疫中发挥重要作用.近年来采用DC疫苗进行肿瘤免疫治疗研究获得一些突破性进展.本文就DC在肿瘤免疫中的作用机制、与泌尿系肿瘤免疫逃逸的关系、DC疫苗免疫治疗原理与制备方法及其在泌尿系肿瘤治疗方面的最新研究进展作一综述.     

树突细胞的免疫调节功能及其影响因素

树突细胞(DC)是体内功能最强的专职抗原呈递细胞,它在调控机体对自身或非自身抗原产生适当的免疫应答方面起非常重要的作用。DC是一群异质性的细胞,不同亚型的DC具有不同的功能。组织微环境、DC的成熟状态、DC表面的免疫分子以及局部组织基质细胞(如肝星状细胞)等与DC的功能有关。通过改变DC表面的一些关键分子的表达能够调控DC诱导的免疫反应。阐明决定DC诱导免疫耐受功能的关键分子以及DC选择性触发T细胞向辅助性T细胞(Th)1、Th2、Th17、调节性T细胞等不同方向分化的关键因素对寻找用新的方法来调控机体免疫反应具有重大意义。     

泌尿系肿瘤治疗新策略—树突状细胞疫苗免疫治疗

树突状细胞（DC）作为目前已知的功能最强的抗原提呈细胞，也是抗原特异性免疫应答的初始者，可在体内外向T细胞提呈抗原并诱发CTL反应，在抗肿瘤免疫中发挥重要作用。近年来采用DC疫苗进行肿瘤免疫治疗研究获得一些突破性进展。本文就DC在肿瘤免疫中的作用机制、与泌尿系肿瘤免疫逃逸的关系、DC疫苗免疫治疗原理与制备方法及其在泌尿系肿瘤治疗方面的最新研究进展作一综述。     

肿瘤浸润性树突状细胞与粘蛋白MUC1在前列腺癌与前列腺增生中的表达研究

目的 :探讨上皮特异性肿瘤蛋白 (MUC1)与肿瘤浸润性树突状细胞 (TIDC)在前列腺癌及前列腺增生组织中的表达。　方法 :采用免疫组织化学SP法检测MUC1和TIDC在 30例前列腺癌、2 0例前列腺增生组织的表达。结果 :MUC1在前列腺癌、前列腺增生组织中均表达 ,MUC1的染色分型同肿瘤的病理分级密切相关 (P <0 .0 0 1)。TIDC的数量在高分化与低分化前列腺癌间差异有显著性 (P <0 .0 0 1)。　结论 :MUC1的表达模式和TIDC数量的监测可以作为前列腺癌恶性程度和预后的判断指标。TIDC的减少可能是肿瘤免疫逃逸和耐受的重要环节 ,肿瘤细胞表面高密度的MUC1可能参与前列腺癌侵袭转移和激素耐受机制。     

胃癌微环境中树突状细胞浸润的临床意义

目的 探讨胃癌微环境中肿瘤浸润性树突状细胞(TIDC)与癌细胞浸润程度、淋巴结转移及患者术后存活时间的关系。方法 采用免疫组织化学方法,运用抗S-100检测100例胃癌组织中的TIDC,并分析其与临床病理参数及生存率的关系。结果 TIDC在胃癌组织中的阳性率为41.0％(41/100),其与癌细胞浸润程度无相关性(P>0.05)。56例有淋巴结转移的患者中,TIDC阳性者淋巴结转移率为56.1％,阴性者为43.9％,两者比较差异无显著性意义(P>0.05);第2站以上淋巴结转移率,TIDC阳性者为29.7％,而阴性者为70.3％,两者比较,差异有显著性意义(P<0.05)。TIDC阳性和阴性患者5年生存率分别为59.0％和37.7％,两者比较.差异有显著性意义(P<0.05)。结论 TIDC阳性与癌细胞浸润程度无相关性,但与第2站以上淋巴结转移和患者术后生存率密切相关。     

Dendritic cells transduced with a PSMA-encoding adenovirus and cocultured with autologous cytokine-induced lymphocytes induce a specific and strong immune response against prostate cancer cells

ObjectiveThe lack of curative therapies for advanced prostate cancer (PCa) has prompted a search for novel treatments such as immunotherapy. In this study, we analyzed whether dendritic cells (DCs) from healthy donors transduced with a PSMA-encoding adenovirus (Ad-PSMA) and cocultured with autologous cytokine-induced killer cells (CIKs) can induce a strong specific immune response against PCa cells in vitro.Materials and MethodsAd-PSMA was constructed by DNA recombination. DCs and CIKs were prepared by cytokines induction from peripheral blood mononuclear cells, and flow cytometry was used to measure the phenotypes of DCs and CIKs. DCs were transduced with Ad-PSMA and then cocultured with autologous CIKs. The cytotoxicity of the cocultured cells against specific target LNCaP cells and control targets DU145 and PC3 cells was analyzed by a 4-h LDH release assay.ResultsDCs were transduced with Ad-PSMA with transfection efficiency of 70% and the transduction did not alter typical morphology of mature DCs. The PSMA protein was effectively expressed in DCs, which were transfected with Ad-PSMA. Ad-PSMA-transduced DCs stimulated CIKs strongly to lyse about 75% of PSMA-expressing PCa cells. Furthermore, the cocultivation of Ad-PSMA-transduced DCs with CIKs could significantly increase the production of interferon-γ after restimulated with PSMA peptide mixtures.ConclusionsThe data demonstrate that DCs, which were transduced with a PSMA-expressing adenovirus and cocultured with autologous CIKs, induce a PSMA-specific, strong immune response against PCa cells. Therefore, this approach may have a potential for an adoptive immunotherapy for patients with advanced PCa.     

Kidney Dendritic Cells Become Pathogenic during Crescentic Glomerulonephritis with Proteinuria

It is unclear why kidney dendritic cells attenuate some models of kidney disease but aggravate others. Kidney dendritic cells ameliorate the early phase of nonaccelerated nephrotoxic nephritis, a murine model of crescentic glomerulonephritis, but their effect on the later phase is unknown. Here, we report that kidney dendritic cells at later stages of nephrotoxic nephritis expressed higher levels of costimulatory molecules but lower levels of the cosuppressor molecule ICOS-L and started production of IL-12/23p40 and TNF-α. Furthermore, we noted that kidney dendritic cells captured more filterable antigen in proteinuric mice at late time points of nephrotoxic nephritis and started to capture molecules that were too large for filtration by a healthy kidney. They presented filtered antigen to Th cells, which responded by producing the proinflammatory cytokines IL-2, IFN-γ, TNF-α, IL-6, and IL-17. Notably, production of the suppressive cytokine IL-10 further increased in late nephrotoxic nephritis. Depletion of kidney dendritic cells at a late stage attenuated nephrotoxic nephritis, in contrast to the exacerbation observed with depletion at an early stage, indicating that their acquired proinflammatory phenotype adversely affected disease. These findings indicate that the intrarenal inflammatory microenvironment determines how kidney dendritic cells affect nephritis. In addition, proteinuria may harm the kidney by providing dendritic cells with more antigens to stimulate potentially pathogenic Th cells.     

Dendritic cell subsets in human bronchoalveolar lavage fluid after segmental allergen challenge

BACKGROUND: Dendritic cells control pulmonary immune reactions. Characteristics of dendritic cells in human bronchoalveolar lavage fluid (BALF) after allergen challenge are unknown. METHODS: 7 patients with allergic asthma (median 23 years, range 19-25 years) underwent segmental challenge and were lavaged 10 min and 24 h after challenge. Dendritic cell subsets and surface markers in BALF and in peripheral blood were analysed using four-colour flow cytometry. RESULTS: Plasmacytoid dendritic cells (pDCs, median 0.06%, range 0.01-0.08%) and myeloid dendritic cells (mDCs, median 0.47%, range 0.27-0.87%) were detectable in BALF from control segments. CD1a-positive dendritic cells in BALF were identified as a subpopulation of mDCs. Both pDCs (median 0.56%, range 0.09-1.83%) and mDCs (median 1.82%, range 0.95-2.29%) increased significantly in BALF 24 h (p = 0.018 compared with the control segments for pDCs and mDCs), but not 10 min, after allergen challenge. The percentage increase in pDCs was higher than that of mDCs after allergen challenge, as reflected by an enhanced pDC:mDC ratio after allergen challenge. In peripheral blood, there was a significant decrease in mDCs (p = 0.038) and a trend to a decrease in pDCs (p = 0.068) 24 h after allergen challenge. Analysis of dendritic cell surface molecules showed that after allergen challenge, BALF dendritic cells have a less mature phenotype compared with BALF dendritic cells from control segments. CONCLUSION: Using a comprehensive strategy to analyse dendritic cell subsets in human BALF, we have shown for the first time that both myeloid and plasmacytoid dendritic cells accumulate in the airway lumen after allergen challenge in patients with asthma.     

Dendritic cell-based immunotherapy of renal cell carcinoma

Dendritic cells potently stimulate antigen-specific immune responses and recent data indicate that they are also capable of eliciting antitumor immune responses. We are performing a pilot study which tests the safety and efficacy of antigen-loaded, cultured blood dendritic cells in patients with metastatic renal cell carcinoma. Dendritic cells are simultaneously pulsed with lysate from autologous tumor cells and with the immunogenic protein keyhole limpet hemocyanin. During the pulse, the cells are activated with a combination of tumor necrosis factor-alpha and prostaglandin E2. Patients receive 5-10 X 10(6) dendritic cells per intravenous infusion and up to six infusions at monthly intervals. The first results demonstrate that this treatment modality is very well tolerated and can be associated with strong immunological and clinical responses. The present article discusses the importance of dendritic cell maturation and the role of helper antigens in dendritic cell-based immunotherapy.     

Role of zinc in the pathogenesis and treatment of prostate cancer: critical issues to resolve

The most consistent and persistent biochemical characteristic of prostate cancer (PCa) is the marked decrease in zinc and citrate levels in the malignant cells. This relationship provides compelling evidence that the lost ability of the malignant cells to accumulate zinc is an important factor in the development and progression of prostate malignancy. In addition, this relationship provides a rational basis for the concept that restoration of high zinc levels in malignant cells could be efficacious in the treatment and prevention of PCa. Epidemiological studies regarding dietary zinc effects on PCa have been conflicting and confusing. The purpose of this presentation is to present a current state of information regarding zinc relationships in the pathogenesis and treatment of PCa. We also hope to bring more attention to the medical and research community of the critical need for concerted clinical and basic research regarding zinc and PCa.     

Physiological normal levels of androgen inhibit proliferation of prostate cancer cells in vitro

For more than 70 years, it has been believed that a severe reduction of serum androgen levels caused regression of prostate cancer （PCa） and that increasing androgen levels enhanced growth of PCa. However, numerous recent studies have questioned this traditional belief. In our study, LNCaP and MDA PCa 2b PCa cells were treated with various levels of androgens for 10 or 20 days, and the cell growth was measured with crystal violet mitogenic assay. The results indicated that the effect of androgens on the proliferation of PCa cells occurs in a biphasic pattern, with the androgen levels promoting optimal cell growth at approximately 0.23 ng m1-1 for LNCaP cells and between I and 2 ng m1-1 for MDA PCa 2b cells. Both of the optimal androgen levels are within the adult men＇s physiological low range （〈2.4 ng ml-1）. At lower concentrations than the optimal androgen level, increasing androgen concentration promoted the proliferation of PCa cells. However, at the higher concentrations, increasing androgen concentration resulted in a dose-dependent proliferative inhibition. We conclude that physiologically normal levels of androgen inhibit the proliferation of PCa cells in vitro. However, at very low levels androgens are essential for initial growth of PCa cells.     

TNF-alpha protects dendritic cells from prostate cancer-induced apoptosis

We have recently shown that human prostate cancer (PCa) cells induced apoptotic death of the most potent antigen-presenting cells, dendritic cells (DC), which are responsible for the induction of specific antitumor immune responses. Here we have evaluated the effect of murine PCa cells RM-1 on the survival of immature and tumor necrosis factor-alpha (TNF-alpha)-stimulated mature DC. PCa cells and DC were co-incubated for 24-48 h and DC apoptosis was assessed by morphologic criteria, Annexin V assay, and TUNEL staining. We have shown that co-incubation of RM-1 cells with DC is accompanied by an increased level of DC apoptosis, which was mediated by decreased expression of anti-apoptotic protein Bcl-2. Stimulation of DC maturation by TNF-alpha resulted in increased resistance of DC to PCa-induced apoptosis. In TNF-alpha treated mature DC, but not in immature DC, the expression of Bcl-2 was not blocked after exposure to RM-1-derived factors. Thus, these data suggest that TNF-alpha-induced maturation of DC increases their resistance to PCa induced apoptosis. This is likely to be due to the stabilizing of the expression of anti-apoptotic protein Bcl-2. The difference in the sensitivity of mature and immature DC to PCa-induced cell death should be considered during the design of DC-based clinical trials for PCa patients.Prostate Cancer and Prostatic Diseases (2001) 4, 221-227.     

Identification of an HLA-A*0201-restricted T-cell epitope derived from the prostate cancer-associated protein trp-p8

BACKGROUND: New concepts for the immunotherapy of prostate carcinoma (PCa) largely depend on the identification of suitable target antigens that are present in a high percentage of prostate tumors. Their expression in normal tissues should be restricted to the prostate and they should be immunogenic in vivo. The number of antigens displaying these properties is still limited. Here, we identify for the first time an immunogenic peptide derived from the prostate-specific protein transient receptor potential-p8 (trp-p8) that is recognized by cytotoxic T lymphocytes (CTLs) from PCa patients. METHODS: To determine the abundance of trp-p8 in prostate tumors, the expression level of trp-p8 mRNA was quantitatively analyzed in a panel of prostate cancer tissues. Trp-p8-derived human leukocyte antigen (HLA)-A*0201-restricted peptides were selected and tested for the in vitro activation of CTLs when loaded on autologous dendritic cells (DCs). RESULTS: Trp-p8 mRNA was found to be expressed in all prostate tumors and in the corresponding normal prostate tissue. Of five selected trp-p8-derived peptides, only peptide GLMKYIGEV was shown to activate specific CTLs, which effectively lysed PCa cells confirming the endogenous generation and presentation of this peptide by tumor cells. CONCLUSIONS: Our results suggest this antigen as a suitable target for the T-cell-based immunotherapy of PCa.