人T淋巴细胞白血病不同细胞株的混合抗原肽诱导特异性CTLs细胞毒效应及其交叉反应性分析

目的探讨T淋巴细胞白血病不同细胞株的混合抗原肽诱导特异性抗瘤免疫的作用及不同细胞株混合抗原肽之间的交叉反应性。方法从不同白血病细胞株中分别制备混合抗原肽,与Hsp70体外结合,观察Hsp70-抗原肽复合物对人外周血单个核细胞(PBMC)的激活增殖作用;以激活增殖的PBMC为效应细胞,对不同的靶细胞进行体外杀伤试验。结果不同白血病细胞株的抗原肽为混合肽,经Hsp70提呈均能够有效激活PBMC,并能使激活的PBMC增殖,增殖活化的PBMC可以特异性杀伤与抗原肽对应的白血病细胞;Hut78-肽和Molt-4-肽激活的PBMC对Hut78细胞、Molt-4细胞和Jurkat细胞的细胞毒作用均显著高于HL-60-肽激活的PBMC(P<0.05)。而Hut78/Molt-4-肽激活的PBMC对Jurkat细胞的杀伤作用则显著高于Hut78-肽和Molt-4-肽单独激活的PBMC(P<0.05)。结论不同T淋巴细胞白血病细胞株来源的混合抗原肽均能够诱导特异性抗肿瘤免疫,其所含的抗原肽之间存在交叉性,通过多株来源的抗原肽混合,这种交叉性可以被放大。     

HSP70-Id复合物修饰的树突状细胞体外诱导特异性抗肿瘤作用

目的观察人慢性B淋巴细胞性白血病（B-CLL）细胞的独特型抗原Id-ScFv与热休克蛋白70（HSP70）形成复合物修饰的树突状细胞（DC）体外诱导特异性抗肿瘤作用,并初步探讨其机制。方法将HSP70与Id-ScFv体外结合形成复合物HSP70-Id,修饰自人外周血单核细胞获取的DC。倒置相差显微镜观察DC的形态特征;流式细胞仪检测修饰前后DC的表型变化,酶联免疫吸咐试验（ELISA）检测DC分泌的白细胞介素12（IL-12）和肿瘤坏死因子-α（TNF-α）,四甲基偶氮唑蓝（MTT）法检测修饰的DC对自身淋巴细胞的激活和增殖作用,流式细胞仪检测激活的自身淋巴细胞T细胞亚群的变化,台盼蓝染色法检测其对Daudi、K562和HepG2等细胞的杀伤作用。结果DC体外诱导培养成功,HSP70-Id复合物可使DC成熟,镜下可见典型的DC形态,其CD1a表达率为20％-30％,CD83表达率〉72％,CD86和HLA-DR表达显著增加（P〈0．05）,上清中IL-12、TNF-α亦显著高于DC对照组（P〈0．01）。HSP70-Id复合物修饰的DC激活自身淋巴细胞,对Daudi细胞的杀伤率为71．24％,而对K562细胞杀伤作用较弱,对HepG2细胞无明显作用。其淋巴细胞亚群中,CD4^＋T细胞、CD8^＋T细胞的比例均显著增加,分别为56．51％和70．21％,CD4^＋T细胞／CD8^＋T细胞比值由空白对照组的1．49倒置为0．81。结论HSP70-Id复合物修饰的DC生物学活性增强,经其刺激后,传代培养的淋巴细胞可产生高效而特异性的抗肿瘤免疫效应,可能是CD4^＋T细胞、CD8^＋T细胞及DC协同作用的结果。     

HIFU治疗后肿瘤抗原对树突状细胞的活化及其抗肿瘤效应

目的：探讨HIFU治疗小鼠H22抑制性肝癌后产生的肿瘤抗原对机体抗肿瘤免疫功能增强的机制。方法：正常小鼠骨髓中提取骨髓细胞,在rmIL-4、rmGM-CSF奈件下培养7d,制备小鼠骨髓树突状细胞,用HIFU治疗小鼠移植性肝癌后产生的肿瘤抗原活化树突状细胞,再用活化后的树突状细胞激活T淋巴细胞为细胞毒性T细胞,用MTT法检测CTL在体外特异性杀伤肿瘤靶细胞的能力。结果：B16肿瘤HSP70-肽复合物组和H22肿瘤HSP70-肽复合物组的脾淋巴细胞的增殖率均高于阴性对照组、H22肿瘤粗提物组和HIFU后H22肿瘤粗提物组,P〈0．001;但两组之间差异无统计学意义,P〉0．05。H22肿瘤HSP70-肽复合物组CTL对H22肿瘤细胞的杀伤率为70．0％,明显高于阴性对照组、H22肿瘤粗提物组和HIFU后H22肿瘤粗提物组（P〈0．001）,但对非靶细胞B16肿瘤的杀伤率与上述各组的差异无统计学意义;B16肿瘤HSP70-肽复合物组CTL对B16肿瘤细胞的杀伤率为78．5％,对H22细胞的杀伤率为21．4％,表明CTL对肿瘤细胞的杀伤作用具有特异性。结论：HIFU治疗后坏死肿瘤组织中的HSP70-肽复合物作为肿瘤疫苗,通过活化DC和刺激T淋巴细胞增殖为CTL,发挥特异性抗肿瘤免疫功能。     

热休克蛋白受体的研究进展

热休克蛋白(HSP)肽复合物可以激活肿瘤特异性CTL反应,HSP受体的发现为阐明其作用机理提供了有力的证据。HSP通过与抗原提呈细胞(APC)上的受体结合而内化,经MHC Ⅰ类呈递途径诱导特异的抗瘤免疫应答。HSP受体具有饱和性、竞争性、特异性。HSP与树突状细胞(DC)上的受体结合后可促使DC成熟、分泌细胞因子和趋化因子并下调DC上HSP受体的表达。     

中药影响树突状细胞抗肿瘤免疫作用的研究进展

1树突状细胞及其功能树突状细胞(dendritic cell,DC)因其形态而得名,是目前已知的功能最强大的抗原提呈细胞(antigen-presenting cell,APC),它们可以加工处理抗原并以抗原肽-MHCⅡ类分子复合物的形式将抗原信息提呈给T细胞,特别是能激活初始型T细胞,诱发特异性免疫应答。其激活T细胞的能力是巨噬细胞的100~10000倍。DC起源于多能造血干细胞,分为髓样DC和淋巴样DC两种(也有人称之为DC1、DC2),两者表达的抗原及功能不同,DC1主要诱导Th0向Th1分化,而DC2主要诱导Th0向Th2分化。DC广泛分布于脑以外的全身各组织,但是数量很少,不足外…     

树突状细胞在肿瘤免疫中的研究进展

树突状细胞(DC)是最强的抗原提呈细胞(APC),APC捕获抗原提呈给T、B淋巴细胞,从而引发一系列的免疫应答。肿瘤患者体内由于肿瘤的调变可以降低DC提呈功能,使淋巴细胞杀伤肿瘤的效率减弱,目前DC体外可以大量扩增,故各种DC疫苗和DC细胞治疗应运而生,通过抗原负载的DC提高抗原提呈能力,激活细胞毒T细胞(CTL)的杀伤能力,治疗肿瘤,但抗原负载的方法很多．哪种抗原负载提高提呈功能的效率最高,每一种肿瘤的抗原有其特异性。这些都是DC疫苗广泛开展的障碍,而且DC疫苗在免疫系统低下的老年人群由于淋巴细胞的免疫应答功能下降,可能会免疫失败,这些都值得我们进一步思考应对策略。     

Hsp70-肿瘤抗原肽复合物防治小鼠黑色素瘤B16肺转移的作用

目的:探讨热休克蛋白70-肿瘤抗原肽复合物(Hsp70-antigen peptide complexes)对小鼠黑色素瘤B16转移的防治作用.方法:分别从小鼠腿部接种的B16实体瘤及小鼠肺B16转移灶提取混合抗原肽,体外与Hsp70结合制得复合物,此复合物免疫小鼠后用于预防或治疗经尾静脉接种转移至肺的B16黑色素瘤,观察其对肿瘤转移的防治作用.结果:Hsp70-肿瘤抗原肽复合物免疫后肺转移灶节结数显著减少(P＜0.01),体外脾细胞表现出对B16较高的杀伤率(P＜0.01);并对肺转移灶有显著的治疗作用(P＜0.01),而从B16实体瘤提取的混合抗原肽制得的复合物比从肺转移灶提取的混合抗原肽制得复合物有更好的治疗效果(P＜0.01),表现出体外脾细胞对B16更高的杀伤率(0.01＜P＜0.05).结论:Hsp70-肿瘤抗原肽复合物对肿瘤的转移有明显的防治作用,而从实体瘤提取的混合抗原肽比从转移灶提取的混合抗原肽更为有效.     

H22细胞全细胞抗原负载的树突状细胞激活肿瘤浸润性淋巴细胞抗小鼠肝癌的实验

目的探讨H22小鼠肝癌细胞（H22细胞）全细胞抗原致敏的树突状细胞激活肿瘤浸润淋巴细胞抗小鼠肝癌细胞活性。方法取得小鼠骨髓细胞并诱导生成树突状细胞,由冻融法制备的H22细胞全细胞抗原致敏,然后用已致敏的树突状细胞激活肿瘤浸润性淋巴细胞,测定致敏前后的DC表面抗原CD11c、CD80、CD86、CD40、MHCⅡ,并评估激活前后的TIL对H22细胞的杀伤活性,同时脾淋巴细胞作为杀伤对照。结果CD11c阳性细胞中CD80、CD86、CD40、MHCⅡ阳性细胞所占比例在致敏后的DC表现为明显上调。经致敏后成熟DC激活的TIL对H22细胞杀伤活性明显高于未激活的TIL,并高于激活或未激活的小鼠脾脏淋巴细胞。结论在H22细胞全抗原致敏后,小鼠成熟DC中CD80、CD86、CD40、MHCⅡ的表达率明显高于未成熟DC。经H22细胞全细胞抗原致敏的DC能诱导活化TIL,明显提高其在体外对H22细胞的杀伤活性。     

树突状细胞抗肿瘤免疫的研究进展

树突状细胞（dendritic cell，DC）是功能最强的抗原呈递细胞（antigen presenting cell，APC）。DC均来源于体内多能造血干细胞，主要分为髓系DC与淋巴系DC；按发育程度分为不成熟DC和成熟DC；按诱导免疫反应分为DC1和DC2两个亚群。DC前体细胞由骨髓进入外周血，再分布到全身各组织。DC可通过摄取、加工和提呈抗原，在其表面表达大量的MHC-肽复合物，上调共刺激分子及向外周淋巴组织迁移等作用，激活T细胞和诱导机体产生特异性免疫反应。目前，无论在动物模型和人体实验都可以用多种不同的前体细胞沿不同的分化途径在体外诱导扩增DC。以DC为基础的肿瘤疫苗已被广泛研究并应用于临床。     

重组可溶性PD-1免疫抑制性受体增强抗小鼠H22肝癌的免疫效应

目的:探讨真核表达PD-1的重组可溶性分子(sPD-1)增强肿瘤局部免疫效应的作用机制.方法:采用半定量RT-PCR方法检测PD-1的配体PD-L1和PD-L2在小鼠H22肝癌细胞和癌组织中的表达水平,流式细胞仪检测其在激活T细胞表面的表达;体外细胞杀伤实验检测sPD-1作用于肿瘤细胞或脾细胞对Hsp70-H22抗原肽复合物激活的脾细胞杀伤H22肝癌细胞的影响;体内抑瘤实验评价局部转染表达sPD-1的抗瘤作用.结果:H22肿瘤细胞本身表达PD-L1基因,PD-L1和PD-L2基因在癌组织中的表达高于正常肌肉组织和单纯癌细胞;PD-L1亦表达于激活的T细胞表面;sPD-1可增强抗原特异性激活的淋巴细胞对肿瘤细胞的杀伤效应;在肿瘤接种部位肌注转染表达sPD-1可显著抑制H22肿瘤生长.结论:在肿瘤局部表达可溶性受体sPD-1阻抑PD-L/PD-1通路,既可作用于免疫细胞来提高其正向免疫力,同时也可拮抗H22细胞通过PD-L对免疫细胞的抑制作用,可望成为提高肿瘤基因治疗疗效的一种新手段.     

INDUCEMENT OF ANTITUMOR－IMMUNITY BY DC ACTIVATED BY HSP70－H22 TUMOR ANTIGEN PEPTIDE

Antigen peptides from tumor cells, bound with heat shock protein 70 (Hsp70), can induce specific antitumor immunity in vivo[1]. On the surface of dentritic cells (DC), the most powerful antigen-presenting cells in vivo, there is CD91[2] which is high-affinity receptor of Hsp70. Hsp70 from tumor cells can induce the maturation of DC[3]. After capturing tumor antigen, DC can be used as specific vaccine for immunotherapy of tumor[4]. Through DC-presenting pathway, limited amount of antig…     

Investigation of inducing effect of specific cytotoxicity of CTLS by antigen peptides from T lymphocytic leukemia cells

The key point in immunotherapy of tumor is the inducement of tumor specific CTL response in vivo, which is based on the specific recognition of TCR to tumor antigen peptides. It has been known that tumor antigen peptides are the products from the degradation of the products of some mutated genes in tumor cells[1]. During the malignant proliferation of tumor cells, mutations occur at a high frequency[2] so to result in the difference between the tumor antigen peptides of a given tumor in diff…     

Domain swapping in a COOH-terminal fragment of platelet factor 4 generates potent angiogenesis inhibitors

A few peptide residues in structurally important locations often determine biological functions of proteins implicated in the regulation of angiogenesis. We have shown recently that the short COOH-terminal segment PF-4(47-70) derived from platelet factor 4 (PF-4) is the smallest sequence that conserves potent antiangiogenic activity in vitro and in vivo. Here we show that modified COOH-terminal PF-4 peptides containing the sequence ELR (or related DLR), a critical domain present in proangiogenic chemokines, surprisingly elicit several times greater antiangiogenic potential than the original peptide. The modified peptides inhibit binding of iodinated vascular endothelial growth factor and fibroblast growth factor 2 to endothelial cell receptors, endothelial cell proliferation, migration, and microvessel assembly in the rat aortic ring model at lower doses than PF-4(47-70). On the differentiated chick chorioallantoic membrane, topical application of 40 micro g of modified peptides potently reduces capillary angiogenesis induced by vascular endothelial growth factor(165), a dose where peptide PF-4(47-70) was inactive. Established intracranial glioma in nude mice decreased significantly in size when treated locally with a total dose of 250 micro g of peptide PF-4(47-70)DLR (n = 10) compared with the same dose of the original PF-4(47-70) peptide (n = 10) or controls (n = 30). Tailored PF-4 peptides represent a new class of antiangiogenic agents with a defined mode of action and a strong in vivo activity.     

Adoptive transfer of human natural killer cells in mice with severe combined immunodeficiency inhibits growth of Hsp70-expressing tumors

In vitro, tumor-selective Hsp70 plasma membrane localization correlates with increased sensitivity to lysis mediated by a subpopulation of human natural killer (NK) cells that adhere to plastic following cytokine stimulation. In the present study, we analyzed the capacity of adoptively transferred human NK cells in SCID/beige mice for local tumor control and prevention of metastatic dissemination of Hsp70-expressing CX(+) and non-expressing CX(-) tumors following orthotopic (o.t.) injection. Both tumor sublines were derived by cell sorting of the original cell line, CX2, and thus exhibit an identical MHC and adhesion molecule expression pattern but differ with respect to Hsp70 plasma membrane expression. Viability of adherent, human NK cells in SCID/beige mice up to 18 days and the capacity to migrate have been demonstrated. Growth of Hsp70-expressing and non-expressing CX(+) and CX(-) tumor cells was completely suppressed when 10 x 10(6) NK cells were injected into the i.p. cavity on day 4 after inoculation of 2.5 x 10(6) tumor cells. Although a single injection of 5 or 2.5 x 10(6) NK cells was not sufficient to suppress tumor growth completely in all mice, the reduction in size of CX(+) tumors was significantly greater than that of CX(-) tumors. To mimic the clinical situation, ex vivo stimulated NK cells were injected i.v. on day 4 after o.t. injection of tumor cells. Under these conditions, growth of Hsp70-expressing primary tumors and metastases was suppressed. If CX(-) tumor cells were injected, 3 of 9 mice developed Hsp70-negative primary tumors. However, none of these mice developed distant metastases. In summary, our data indicate that Hsp70 acts as a recognition structure for adherent NK cells in a SCID/beige mouse model.     

Inducible Hsp70 as target of anticancer immunotherapy: Identification of HLA-A*0201-restricted epitopes

The design of a broad application tumor vaccine requires the identification of tumor antigens expressed in a majority of tumors of various origins. We questioned whether the major stress-inducible heat shock protein Hsp70 (also known as Hsp72), a protein frequently overexpressed in human tumors of various histological origins, but not in most physiological normal tissues, constitutes a tumor antigen. We selected the p391 and p393 peptides from the sequence of the human inducible Hsp70 that had a high affinity for HLA-A*0201. These peptides were able to trigger a CTL response in vivo in HLA-A*0201-transgenic HHD mice and in vitro in HLA-A*0201+ healthy donors. p391- and p393-specific human and murine CTL recognized human tumor cells overexpressing Hsp70 in a HLA-A*0201-restricted manner. Tetramer analysis of TILs showed that these Hsp70 epitopes are targets of an immune response in many HLA-A*0201+ breast cancer patients. Hsp70 is a tumor antigen and the Hsp70-derived peptides p391 and p393 could be used to raise a cytotoxic response against tumors of various origins.     

来源于人膀胱癌细胞株EJ的HSP70负载的DC所激发的特异性CTL细胞的体外应答效应

Objective: To investigate whether human dendritic cells (DC) derived from peripheral blood mononuclear cells (PBMC), which were pulsed by heat shock protein 70 (HSP70) isolated from human bladder tumor cell lines of EJ, were able to induce peptide specific cytotoxic T-lymphocytes (CTL) response in vitro and give the experimental foundation for the future clinical trials of immunotherapy in bladder tumor. Methods: The EJ-derived HSP70 co-cultured with DC from the healthy volunteers' PBMC, along with the crude lysate (the supernatant before HSP70 purification) from EJ cells were used as the experimental groups and DC not pulsed by any tumor cells antigen were the blank control. The autologous T-lymphocytes were added into the above various DC groups, and after incubation, the stimulation indexes (SI) and interferon-γ (IFN-γ) were detected to evaluate the immune activities of various DC groups. The killing effects of CTL to target cells, EJ and Hela cells, were determined with 51Cr releasing test. Results: Both DC/HSP70 and DC/the crude lysate could effectively activate CTL in vitro and kill target cells EJ. The killing effect of DC/HSP70 to EJ was much stronger than DC/the crude lysate (the supernatant before HSP70 purification) (P < 0.05). DC without any tumor cell antigens had a lower killing power to EJ. Meanwhile, DC/ HSP70 had little killing power to Hela non-relevant to bladder tumor histopathologically as compared with EJ cells (P < 0.05). Conclusion: The DC pulsed by HSP70 derived from the autologous tumor cells could induce a peptide complexes specific CTL response to tumor cells, and the CTL response induced by the DC/HSP70 was stronger, which display the basis of the possible clinical application of DC/HSP70 for bladder tumor.