树突细胞与新生隐球菌

新生隐球菌( Cn) 是临床上重要的病原真菌, 树突细胞( DC) 则是最重要的抗原呈递细胞。作为宿主固有免疫和适应性免疫的联系枢纽,DC 对于识别病原、呈递抗原、诱导宿主免疫应答十分重要。许多研究证明,DC 可通过细胞表面的多种受体有效识别新生隐球菌抗原( CnAg) , 诱导宿主产生有效的细胞免疫应答。DC 本身也有一定的杀菌能力, 但DC 的不同亚群以及成熟状态对宿主的免疫防御功能有重要影响。另外, 隐球菌除具有甘露糖蛋白等主要免疫显性抗原外, 还有多种抑制机体保护性免疫应答的毒性因子。本文就近年来国内、外对两者之间复杂机制的研究进行概述。     

Isolation of Mouse Peritoneal Cavity Cells

The peritoneal cavity is a membrane-bound and fluid-filled abdominal cavity of mammals, which contains the liver, spleen, most of the gastro-intestinal tract and other viscera. It harbors a number of immune cells including macrophages, B cells and T cells. The presence of a high number of naïve macrophages in the peritoneal cavity makes it a preferred site for the collection of naïve tissue resident macrophages (1). The peritoneal cavity is also important to the study of B cells because of the presence of a unique peritoneal cavity-resident B cell subset known as B1 cells in addition to conventional B2 cells. B1 cells are subdivided into B1a and B1b cells, which can be distinguished by the surface expression of CD11b and CD5. B1 cells are an important source of natural IgM providing early protection from a variety of pathogens (2-4). These cells are autoreactive in nature (5), but how they are controlled to prevent autoimmunity is still not understood completely. On the contrary, CD5⁺ B1a cells possess some regulatory properties by virtue of their IL-10 producing capacity (6). Therefore, peritoneal cavity B1 cells are an interesting cell population to study because of their diverse function and many unaddressed questions associated with their development and regulation. The isolation of peritoneal cavity resident immune cells is tricky because of the lack of a defined structure inside the peritoneal cavity. Our protocol will describe a procedure for obtaining viable immune cells from the peritoneal cavity of mice, which then can be used for phenotypic analysis by flow cytometry and for different biochemical and immunological assays.     

Interplay between T cell receptor binding kinetics and the level of cognate peptide presented by major histocompatibility complexes governs CD8+ T cell responsiveness

Through a rational design approach, we generated a panel of HLA-A*0201/NY-ESO-1(157-165)-specific T cell receptors (TCR) with increasing affinities of up to 150-fold from the wild-type TCR. Using these TCR variants which extend just beyond the natural affinity range, along with an extreme supraphysiologic one having 1400-fold enhanced affinity, and a low-binding one, we sought to determine the effect of TCR binding properties along with cognate peptide concentration on CD8(+) T cell responsiveness. Major histocompatibility complexes (MHC) expressed on the surface of various antigen presenting cells were peptide-pulsed and used to stimulate human CD8(+) T cells expressing the different TCR via lentiviral transduction. At intermediate peptide concentration we measured maximum cytokine/chemokine secretion, cytotoxicity, and Ca(2+) flux for CD8(+) T cells expressing TCR within a dissociation constant (K(D)) range of ～1-5 μM. Under these same conditions there was a gradual attenuation in activity for supraphysiologic affinity TCR with K(D) < ～1 μM, irrespective of CD8 co-engagement and of half-life (t(1/2) = ln 2/k(off)) values. With increased peptide concentration, however, the activity levels of CD8(+) T cells expressing supraphysiologic affinity TCR were gradually restored. Together our data support the productive hit rate model of T cell activation arguing that it is not the absolute number of TCR/pMHC complexes formed at equilibrium, but rather their productive turnover, that controls levels of biological activity. Our findings have important implications for various immunotherapies under development such as adoptive cell transfer of TCR-engineered CD8(+) T cells, as well as for peptide vaccination strategies.     

复合微生态制剂对断奶仔猪生产性能、粪便菌群及血液指标的影响

目的 探讨复合微生态制剂对断奶仔猪生长性能、粪便乳酸菌和大肠埃希菌数、血液红胞数以及血红蛋白含量及其对免疫水平的影响.方法 选择25日龄的断奶仔猪共108头,平均分为两组:Ⅰ组和Ⅱ组,每组3个重复,每个重复18只,Ⅰ组饲喂全价料+2.0‰复合微生态制剂;Ⅱ组为对照组,饲喂全价料,实验期为42 d.结果 至实验结束时,复合微生态制剂组的料重比显著低于对照组(P ＜0.05);14、28和42 d时复合微生态制剂组粪便中的大肠埃希菌数比对照组低7.94％,2.90％和4.89％,与对照组相比差异有统计学意义(P＜0.05);14d时,复合微生态制剂组粪便乳酸菌数与对照组相比差异有统计学意义(P＜0.05),28和42 d时,两组粪便乳酸菌数差异无统计学意义(P＞0.05).14、28和42 d时复合微生态制剂组血液中红细胞数和血红蛋白浓度均显著高于对照组.两组血清尿素氮水平差异无统计学意义(P＞0.05),复合微生态制剂组血清总蛋白和IgG的含量与对照组相比有升高的趋势,但差异无统计学意义(P＞0.05),复合微生态制剂组血清IgA和IgM的浓度显著高于对照组(P＜0.05).结论 复合微生态制剂可以显著降低断奶仔猪的料重比,降低粪便中大肠埃希菌数量,促进血液红细胞和血红蛋白的含量,提高断奶仔猪的免疫水平.     

Effects of dietary n-3 highly unsaturated fatty acids on growth, nonspecific immunity, expression of some immune related genes and disease resistance of large yellow croaker (Larmichthys crocea) following natural infestation of parasites (Cryptocaryon irritans)

The study was conducted to investigate the effects of dietary n-3 highly unsaturated fatty acid (n-3 HUFA) on growth, nonspecific immunity, expression of some immune related genes and disease resistance of juvenile large yellow croaker (Larmichthys crocea) following natural infestation of parasites (Cryptocaryon irritans). Six isoproteic and isolipidic diets were formulated with graded levels of n-3 HUFA ranging from 0.15% to 2.25% of the dry weight and the DHA/EPA was approximately fixed at 2.0. Each diet was randomly allocated to triplicate groups of fish in floating sea cages (1.0 × 1.0 × 1.5 m), and each cage was stocked with 60 fish (initial average weight 9.79 ± 0.6 g). Fish were fed twice daily (05:00 and 17:00) to apparent satiation for 58 days. Results showed that moderate n-3 HUFA level (0.98%) significantly enhanced growth compared with the control group (0.15% HUFA) (P < 0.05), while higher n-3 HUFA levels (1.37%, 1.79% and 2.25%) had detrimental effects on the growth though no significance was found (P > 0.05). Nitro blue tetrazolium (NBT) positive leucocytes percentage of head kidney and serum superoxide dismutase (SOD) activity increased with increasing n-3 HUFA from 0.15% to 0.60%, and decreased with further increase of n-3 HUFA from 0.60% to 2.25% (P < 0.05). Serum lysozyme activity increased significantly as n-3 HUFA increased from 0.15% to 1.37%, and then decreased with n-3 HUFA from 1.37% to 2.25% (P > 0.05). There were no significant differences in phagocytosis index (PI) of head kidney leucocytes among dietary treatments (P > 0.05). The hepatic mRNA expression of Toll-like receptor 22 (TLR22) and Myeloid differentiation factor 88 (MyD88) was significantly up-regulated in fish fed the diets with low or moderate levels, while in kidney this increment was only found at specific sampling time during the natural infestation of parasites. The 13 d cumulative mortality rate following natural infestation of parasites decreased with n-3 HUFA increased from 0.15% to 0.60% (P < 0.05), and significantly increased with n-3 HUFA from 0.60% to 2.25% (P < 0.05). Results of this study suggested that fish fed low or moderate dietary n-3 HUFA had higher growth, nonspecific immune responses, expression levels of some immune related genes and disease resistance of large yellow croaker following natural infestation of parasites and dietary n-3 HUFA may regulate fish immunity and disease resistance by altering the mRNA expression levels of TLR22 and MyD88.     

Molecular characterization of three L-type lectin genes from channel catfish, Ictalurus punctatus and their responses to Edwardsiella ictaluri challenge

L-type lectins have a leguminous lectin domain and can bind to high-mannose type oligosaccharides. In the secretory pathway, L-type lectins play crucial roles in selective protein trafficking, sorting and targeting. Three L-type lectins were cloned in the channel catfish, Ictalurus punctatus, the 53 kDa endoplasmic reticulum ER-Golgi intermediate compartment protein (ERGIC-53), the vesicular integral protein of 36 kDa (VIP36) and VIP36-like. Phylogenetic analysis indicated that the catfish genes are orthologous to their counterparts in other species. Southern blot analysis demonstrated that all three L-type lectin genes are likely single-copy genes in the catfish genome. Analysis of expression in healthy tissues using quantitative real time RT-PCR indicated that all three genes are expressed widely in all tested tissues, but with strong tissue preference of expression: ERGIC-53 was found to be abundantly expressed in the liver, VIP36 was found to be abundantly expressed in the head-kidney, whereas VIP36-like was found to be abundantly expressed in the brain. Upon infection with Edwardsiella ictaluri, expressions of the three genes all had significant up-regulation in the head-kidney, but had distinct expression patterns: ERGIC-53 was gradually induced with the highest expression 7 days after challenge in the head-kidney, but was down-regulated in the liver, spleen, and brain. VIP36 was highly induced in the head-kidney, and 3 days after challenge in the brain, but was not up-regulated in any other tissues or timepoints after challenge. Expression levels of the catfish VIP36-like gene appeared to also respond to infection, albeit with differing patterns among the tested tissues. Taken together, our results indicate that all three L-type lectin genes may be involved in the immune responses of catfish after infection with E. ictaluri.     

肿瘤免疫逃逸与T淋巴细胞关系的研究进展

阐明肿瘤免疫逃逸是防止肿瘤发生、诊断肿瘤发展以及治愈肿瘤的关键。肿瘤逃避免疫监视(immunosurveillance)已知与宿主免疫低下、T细胞无能,和肿瘤抗原缺失和调变、肿瘤漏逸、缺乏共刺激通路信号等相关,总结了近期研究进展,围绕肿瘤和T淋巴细胞相互关系,从T细胞对肿瘤识别和耐受、肿瘤下调识别分子导致活化T细胞丧失识别能力、肿瘤抵抗凋亡助其逃逸免疫、肿瘤通过抑制性受体和分子诱导T细胞无能耐受和凋亡、肿瘤细胞攻击T细胞逃避免疫、和肿瘤依赖Treg和MDSC抑制免疫等方面总结了理解思路,对肿瘤免疫消除(elimination)、免疫相持(equilibrium)和免疫逃逸(escape)三个阶段对抗T细胞免疫监视的机理提供参考,对肿瘤治疗具有重要意义。     

刺参酸性粘多糖对诱发性肝癌大鼠的干预作用及免疫功能的影响*

目的:通过建立诱发性大鼠肝癌动物模型,研究用刺参酸性粘多糖(SJAMP)对大鼠诱发性肝癌的干预作用及免疫功能的影响。方法:将雄性Wistar大鼠50只随机均分为5个组,正常对照组、模型组和3个SJAMP干预组(A组,B组和C组),模型组和SJAMP干预组灌胃0.2%DEN生理盐水溶液以诱发肝癌,同时SJAMP干预组按照不同剂量(0.175μg/g,0.35μg/g,0.7μg/g)给予SJAMP,至16周处死大鼠,取血,无菌取脾、胸腺,计算脾指数、胸腺指数。比较各组>3mm和>5mm的结节数以及最大结节的体积,计算肿瘤抑制率。贴壁法纯化巨噬细胞,用中性红吞噬实验检测巨噬细胞吞噬功能,MTT法检测巨噬细胞杀伤功能。结果:SJAMP干预组>3mm和>5mm的结节数明显少于模型组,最大结节的平均体积明显小于模型组(P<0.05);与模型组相比,SJAMP干预组脾指数和胸腺指数明显升高(P<0.05),SJAMP干预组巨噬细胞吞噬能力和杀伤功能显著提高(P<0.05)。结论:刺参酸性粘多糖对大鼠诱发性肝癌有明显的抑制作用;其机制可能是通过刺激免疫器官生长,增强机体的细胞免疫能力来实现的。     

转移性肾癌细胞因子疗法的研究进展

转移性肾癌(mRCC)对放疗、化疗均不敏感,虽然靶向治疗为转移性肾癌的治疗提供了新的治疗方案,但免疫疗法一直作为治疗转移性肾癌的基础疗法。在过去的20年中,研究者也一直在研究新的免疫疗法,研究方向趋向于研究各种细胞因子,其中最主要的有IFN-α和IL-2两种,二者可以明显提高患者的生存时间。但是转移性肾癌的细胞因子疗法仍需进一步优化,本文总结了使用细胞因子治疗转移性肾癌的Ⅲ期临床试验,以期为转移性肾癌细胞因子疗法的合理选择提供参考。     

口服卡介菌诱导免疫耐受的CD4+CD25+调节性T 细胞机制研究

目的:研究口服卡介菌诱导免疫耐受对CD4+CD25+调节性T细胞的影响。方法:采用口服MPB制备EAE大鼠模型,随机分为BCG组(0.5mg/kg)和EAE模型组(PBS),每组各15只,连续经口灌服给药14d,同时选取15只健康大鼠作为对照组。分别于免疫后15d、27d流式细胞术检测外周血、胸腺及脾脏中CD4+CD25+T淋巴细胞百分率,ELISA检测血清IL-6、TGF-β、IgE、IgG含量。结果:与EAE模型组相比,免疫后BCG组大鼠外周血、胸腺及脾脏中CD4+CD25+T淋巴细胞百分率增加,血清IL-6、TGF-β含量上升,血清IgE、IgG抗体水平下降。结论:口服BCG通过上调淋巴器官中CD4+CD25+T淋巴细胞比例,抑制效应性T细胞活性,发挥免疫耐受作用。