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941.
Si T  Guo Z  Hao X 《Cryobiology》2008,57(1):66-71
Objective: To assess whether a specific cytotoxic T-cell response can be induced in patients with prostate cancer after cryoablation.Material and Methods: Twenty Patients with high-risk prostate cancer underwent cryoablation. Blood was sampled prior to, 4 and 8 weeks after treatment. Serum cytokine levels were analyzed by ELISA, and the Th1/Th2 ratio was estimated from the IFN-γ/IL-4 ratio. Peripheral blood mononuclear cells (PBMC) were stimulated with autologous prostate cancer-derived protein lysates, and frequency of tumor-specific T-cells was tested ex vivo in an IFN-γ ELISPOT assay. To assess cytolytic activity, T-cells were co-incubated with human prostate cancer cells, LNCaP, or with renal cancer cells, GRC-1, and release of cytosolic adenylate kinase was measured by a luciferase assay.Result: 4 weeks after cryoablation significantly higher levels of TNF-α and IFN-γ were observed compared to before treatment, and to 8 weeks after treatment. No changes in IL-4 or IL-10 were observed. The Th1/Th2 ratio (10.47 ± 0.80), 4 weeks after treatment, was increased compared to before treatment (3.98 ± 0.45), but decreased 8 weeks later (7.65 ± 0.64). Tumor-specific T-cell responses were evident after cryosurgery in PBMC. Cytolytic activity against LNCaP was increased 4 weeks after treatment compared to before treatment (594.49 ± 154.84 versus 4.20 ± 0.68, P < 0.01), but was decreased 8 weeks later (79.70 ± 18.73). No response was found in cytolytic activity against GRC-1.Conclusion: Cryoablation of prostate cancer can improve tumor-specific cytotoxic T-cell stimulation with a dramatically increased tumor specific cytolytic activity. However, the response is not sufficiently maintained to prevent cancer relapse.  相似文献   
942.
Since the days of Medawar, the goal of therapeutic tolerogenesis has been a “Holy Grail” for immunologists. While knowledge of cellular and molecular mechanisms of this process has been increasing at an exponential rate, clinical progress has been minimal. To provide a mechanistic background of tolerogenesis, we overview common processes in the naturally occurring examples of: pregnancy, cancer, oral tolerance and anterior chamber associated immune deviation. The case is made that an easily accessible byproduct of plastic surgery, the adipose stromal vascular fraction, contains elements directly capable of promoting tolerogenesis such as T regulatory cells and inhibitory macrophages. The high content of mesenchymal and hematopoietic stem cells from this source provides the possibility of trophic/regenerative potential, which would augment tolerogenic processes by decreasing ongoing inflammation. We discuss the application of this autologous cell source in the context of rheumatoid arthritis, concluding with some practical examples of its applications.  相似文献   
943.
Lymphocyte egress from lymph nodes requires the G-protein-coupled sphingosine 1-phosphate receptor-1 (S1P1). The activation antigen CD69 associates with and inhibits the function of S1P1, inhibiting egress. Here we undertook biochemical characterization of the requirements for S1P1-CD69 complex formation. Domain swapping experiments between CD69 and the related type II transmembrane protein, NKRp1A, identified a requirement for the transmembrane and membrane proximal domains for specific interaction. Mutagenesis of S1P1 showed a lack of requirement for N-linked glycosylation, tyrosine sulfation, or desensitization motifs but identified a requirement for transmembrane helix 4. Expression of CD69 led to a reduction of S1P1 in cell lysates, likely reflecting degradation. Unexpectedly, the S1P1-CD69 complex exhibited a much longer half-life for binding of S1P than S1P1 alone. In contrast to wild-type CD69, a non-S1P1 binding mutant of CD69 failed to inhibit T cell egress from lymph nodes. These findings identify an integral membrane interaction between CD69 and S1P1 and suggest that CD69 induces an S1P1 conformation that shares some properties of the ligand-bound state, thereby facilitating S1P1 internalization and degradation.  相似文献   
944.
肿瘤坏死因子受体相关因子6(TRAF6)是一种重要的接头蛋白,在Toll样受体/白细胞介素-1受体(TLR/IL-1R)超家族所触发的信号通路中起重要作用,与先天性免疫密切相关。文章研究了尼罗罗非鱼(Oreochromis niloticus)traf6的表达模式和初步的功能。在健康鱼中,traf6转录本广泛表达于所有受检组织中,在血液中表达水平最高,在肝脏中最低。在不同的胚胎发育阶段也检测到traf6的表达。在无乳链球菌体内感染后,大多数受检组织中traf6 mRNA的表达量上调。此外,LPS、Poly I:C和S.agalactiae可显著诱导尼罗罗非鱼巨噬细胞traf6的表达。此外,在HEK293T细胞中过表达表明,TRAF6分布于细胞质中,可显著提高NF-κB的活性。免疫共沉淀(Co-IP)实验表明,TRAF6可与IRAK1(白细胞介素-1受体相关激酶1)相互作用,IRAK1在TLR/IL-1R信号通路中也起重要作用。在体内,TLR2、TLR21和TLR13b的过表达可上调traf6 mRNA的表达水平,表明TRAF6参与了TLR2、TLR21和TLR13b介导的信号转导,提示TRAF6在病原体入侵的免疫应答中起重要作用。  相似文献   
945.
The Tn antigen (α-GalNAc-O-Ser/Thr) is one of the most specific human cancer-associated structures. This antigen, together with mucins, the major carriers of O-glycosylated tumor antigens in adenocarcinomas, are being evaluated as anti-cancer immunotherapeutic targets. In particular, the MUC6 protein, which is normally expressed only in gastric tissues, has been detected in intestinal, pulmonary, colorectal, and breast carcinomas. To develop anti-cancer vaccines based on the Tn antigen, we produced MUC6 proteins with different Tn density by using mixtures of recombinant ppGalNAc-T1, -T2, and -T7. The obtained glycoproteins were characterized and analyzed for their immunological properties, as compared with the non-glycosylated MUC6. We show that these various MUC6:Tn glycoproteins were well recognized by both MUC6 and Tn-specific antibodies. However, Tn glycosylation of the MUC6 protein strongly affected their immunogenicity by partially abrogating Th1 cell responses, and promoting IL-17 responses. Moreover, the non-glycosylated MUC6 was more efficiently presented than MUC6:Tn glycoproteins to specific T CD4(+) hybridomas, suggesting that Tn glycosylation may affect MUC6 processing or MHC binding of the processed peptides. In conclusion, our results indicate that Tn glycosylation of the MUC6 protein strongly affects its B and T cell immunogenicity, and might favor immune escape of tumor cells.  相似文献   
946.
李珊  吴海  申可佳  蔡光先  谭周进  蔡锐  李迎秋 《生物磁学》2011,(12):2251-2253,2257
目的:考察薏米黄酒对机体免疫和肠道功能的调节作用。方法:将ICR小鼠随机分为3组:对照组、模型组和给药组。首先对模型组和给药组注射环磷酰胺造模,0.15 ml/d/只,连续3d,第4d开始对照组和模型组灌胃生理盐水0.3 ml/d/只,给药组灌胃薏米黄酒0.3 ml/d/只,连续灌胃14d。第1、4、18d对各组小鼠称重;第18d处死小鼠解剖取脾脏、胸腺称重并计算脏器系数;取肠道内容物做肠道微生物培养。结果:薏米黄酒与小鼠的体重变化无关;给药组脾脏系数高于对照组有统计学意义(P〈0.05),胸腺系数高于对照组和模型组均有统计学意义(P〈0.05);给药组细菌总数、大肠杆菌数和乳酸菌数高于模型组和对照组且有显著统计学意义(P〈0.01),真菌数量低于模型组和对照组有统计学意义(P〈0.05)。结论:该薏米黄酒对机体免疫和肠道功能有一定的调节作用。  相似文献   
947.
为应用猕猴和树鼩动物模型研究毒品成瘾对神经/免疫系统的影响提供基础数据,对大麻素及阿片受体在正常猕猴和树鼩神经系统和免疫系统的表达进行初步确定.采集正常猕猴和树鼩新鲜组织(皮质、小脑、脑干、海马、脊髓、脾脏),应用半定量逆转录PCR和实时定量PCR的方法检测大麻素与阿片受体mRNA在猕猴和树鼩各组织中的表达情况.猕猴脑部各区包括脾脏均表达大麻索受体1(CNR1),而大麻素受体2(CNR2)只表达于脾脏内.三类阿片受体中,mu(μ)受体表达最为广泛,在以上各组织中均有表达;delta(δ)受体表达的组织最少,只在海马表达;kappa(κ)受体表达介于两者之间,分别在皮质、小脑、脑干、脊髓中表达.在树鼩组织中,CNR1和CNR2表达于整个大脑重要脑区中,且CNR1表达量高于同一区域内CNR2表达的鼍:脾脏中CNR2的表达较高,而CNR1不表达.三类阿片受体只有检测到μ受体在脑部与脾脏表达,且在各个脑区的表达量明显高于脾脏的表达量;δ体和κ受体在被检各个组织中均无表达.总体而言,两种大麻素受体在猕猴和树鼩体内表达情况与人类和鼠的情况类似,而三类阿片受体在猕猴体内表达情况与人类吏为接近.猕猴和树鼩可能可用于人类毒品成瘾的研究;猕猴在某些神经受体的表达更接近人类,其在研究毒品成瘾的机理和对免疫系统的影响方面仍有不可替代的地位.  相似文献   
948.
Allocation trade-offs of carotenoids between their use in the immune system and production of integumentary colouration have been suggested as a proximate mechanism maintaining honesty of signal traits. We tested how dietary carotenoid supplementation, immune activation and immune suppression affect intensity of coccidian infection in captive greenfinches Carduelis chloris, a passerine with carotenoid-based plumage. Immune activation with phytohaemagglutinin (PHA) decreased body mass among birds not supplemented with lutein, while among the carotenoid-fed birds, PHA had no effect on mass dynamics. Immune suppression with dexamethasone (DEX) induced loss of body mass and reduced the swelling response to PHA. DEX and PHA increased the concentration of circulating heterophils. Lutein supplementation increased plasma carotenoid levels but had no effect on the swelling response induced by PHA. PHA and DEX treatments did not affect plasma carotenoids. Immune stimulation by PHA suppressed the infection, but only among carotenoid-supplemented birds. Priming of the immune system can thus aid in suppressing chronic infection but only when sufficient amount of carotenoids is available. Our experiment shows the importance of carotenoids in immune response, but also the complicated nature of this impact, which could be the reason for inconsistent results in studies investigating the immunomodulatory effects of carotenoids. The findings about involvement of carotenoids in modulation of an immune response against coccidiosis suggest that carotenoid-based ornaments may honestly signal individuals’ ability to manage chronic infections.  相似文献   
949.
昆虫免疫防御系统的限制因素   总被引:4,自引:1,他引:4       下载免费PDF全文
本文主要针对昆虫对寄生物的免疫防御并从进化生态学的角度采阐述昆虫防御系统所存在的一些限制因素,如识别抗原失败、免疫特异性、防御代价、自体免疫、性别、资源利用率和寄生物的干扰等,而这些局限使得昆虫的免疫防御受到不同(自发或诱导的、广泛或具体的)免疫反应的影响。从而限制其持续的免疫防御。  相似文献   
950.
The relationships of EMG and muscle force with elbow joint angle were investigated for muscle modelling purposes. Eight subjects had their arms fixed in an isometric elbow jig where the biceps brachii was electrically stimulated (30 Hz) and also in maximum voluntary contraction (MVC). Biceps EMG and elbow torque transduced at the wrist were recorded at 0.175 rad intervals through 1.75 rad of elbow extension. The results revealed that while the torque-length relationship displayed the classic inverted U pattern in both evoked and MVC conditions, the force-length relationship displayed a monotonically increasing pattern. Analyses of variance of the EMG data showed that there were no significant changes in the EMG amplitudes for the different joint angles during evoked or voluntary contractions. The result also showed that electrical stimulation can effectively isolated the torque-angle and force-length relationships of the biceps brachii and that the myoelectric signal during isometric contraction is uniform regardless of the length of the muscle or the joint angle.  相似文献   
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