Bacterially produced human B7-1 protein encompassing its complete extracellular domain maintains its costimulatory activity in vitro

Ｏｂｊｅｃｔｉｖｅ　Ｔｏｉｎｖｅｓｔｉｇａｔｅｗｈｉｃｈｏｆｔｈｅｔｗｏｉｍｍｕｎｏｇｌｏｂｕｌｉｎ (Ｉｇ ) ｌｉｋｅｄｏｍａｉｎｓ ,ｉｍｍｕｎｏｇｌｏｂｕｌｉｎｖａｒｉａｂｌｅｒｅｇｉｏｎｈｏｍｏｌｏｇｏｕｓｄｏｍａｉｎＩｇＶ (ｈＢ7 1ＩｇＶ) ,ｏｒｉｍｍｕｎｏｇｌｏｂｕｌｉｎｃｏｎｓｔａｎｔｒｅｇｉｏｎｈｏｍｏｌｏｇｏｕｓｄｏｍａｉｎＩｇＣ (ｈＢ7 1ＩｇＣ)ｏｎｈｕｍａｎＢ7 1ｍｏｌｅｃｕｌｅｃｏｎｔａｉｎｔｈｅｒｅｃｅｐｔｏｒｂｉｎｄｉｎｇｓｉｔｅｓ ,ａｎｄｔｏｅｖａｌｕａｔｅｉｆｔｈｅＢ7 1ｍ…     

阻塞性睡眠呼吸暂停综合征患者T淋巴细胞亚群的变化

目的：探讨阻塞性睡眠呼吸道暂停综合征（ＯＳＡＳ）患者的血Ｔ淋巴细胞亚群（Ｔ－ＬＳ）的变化。方法：将经多导睡眠图检查确诊的ＯＳＡＳ患者按睡眠呼吸紊乱指数（ＡＨＩ）≤３０次／ｈ分为Ａ组（４４例）,ＡＨＩ〉３０次／ｈ分为Ｂ组（４７例）。正常对照组为Ｃ组（１０例）。测定３组患者血Ｔ－ＬＳ。结果：Ａ,Ｂ两组的ＣＤ＾＋２,ＣＤ＾＋４,ＣＤ＾＋８ ,ＣＤ＾＋４／ＣＤ＾＋８比较差异无显著性（Ｐ〉０．０５）。Ａ组,     

吸毒成瘾者免疫功能变化的研究

目的：测定吸毒者体液免疫和细胞免疫的各项指标,从而研究其免疫功能的改变。方法：取25例吸毒者及28例健康成人外周血,用ELISA法和免疫比浊法测其血清中抗体和补体;免疫荧光法和酶联免疫斑点法(ELISPOT)测其T细胞亚群和Th细胞亚群。结果：吸毒者IgG增高,C3下降,IgA、IgM和IgE与正常人无显著差异。吸毒者CD3、CD4^ 、CD4^ ／CD8^ 、Th1^ 和Th1／Th2低于正常人,而CD8^ 、CD20^ 和Th2与正常人相差不大。淋巴细胞转化试验吸毒者显著低于正常对照组。结论：吸毒者细胞免疫功能降低,而体液免疫变化不大。     

光化学诱导大鼠局灶脑缺血动物模型的建立及磁共振T2WI检测

目的检测光化学诱导大鼠局灶脑缺血后MRI改变。方法给大鼠尾静脉注射孟加拉玫瑰红,经颅骨用黄色激光连续光束照射,T2WI检测。结果1小时内即发现了缺血灶,图像清晰,部位明确。结论T2WI是一种确定脑缺血早期改变的敏感的检测方法。     

共表达HIV—1CN与IL—2基因产物免疫鼠T淋巴细胞亚群的研究

目的：研究细胞因子在机体免疫应答过程中的免疫佐剂效应。方法：以表达中国流行株ＨＩＶ－１ｇａｇ－ｇｐ１２０基因的核酸疫苗质粒ｐｃＤＮＡＧＰ及共表达中国流行株ＨＩＶ－ｌｇａｇ－ｇｐ１２０基因与ＩＩ－２基因的核酸疫苗质粒ｐＧＰＨ－２银川市Ｂａｌｂ／ｃ鼠,用流式细胞仪测定１００００个免疫鼠脾淋巴细胞中ＣＤ４＾＋,ＣＤ８Ｔ细胞数及ＣＤ４＾＋／ＣＤ８＾＋比值。结果：ｐＧＩＬ－２与ｐｃＤＮＡＧＰ比较,ｐＧＩＬ－２免疫鼠ＣＤ＾４和ＣＤ＾８Ｔ细胞数明显提高。结论：在机体的免疫应答过程中,细胞因子ＩＬ－２能很好地发挥免疫佐剂的作用。     

结核分枝杆菌DNA两种提取方法比较

目的 :比较能够满足内切酶分析的结核分枝杆菌染色体DNA提取的两种方法 ,并结合实验室条件加以改进。方法 :称取结核分枝杆菌培养物 ,灭活后以溶菌酶和蛋白酶K消化后 ,分别以CTAB/NaCl和酚 /氯仿 /异戊醇 (2 5∶2 4∶1)抽提 ,无水乙醇沉淀 ,紫外分光光度计测定DNA的含量。结果 :酚抽提法和CTAB抽提法提取的基因组DNA的得率分别为0 47± 0 0 71,0 41± 0 10 (‰ ,W/W )。A2 60 /A2 80 的值分别为 1 83± 0 12 ,1 89± 0 0 72。结论 :用CTAB/NaCl抽提结核分枝杆菌基因组DNA均能满足内切酶及杂交操作的要求 ,酚抽提法得率稍高 ,但无统计学意义。CTAB法污染少 ,省时省材 ,可代替酚抽提DNA。     

Single-cell fate mapping reveals widespread clonal ignorance of low-affinity T cells exposed to systemic infection

T cell ignorance is a specific form of immunological tolerance. It describes the maintenance of naivety in antigen-specific T cells in vivo despite the presence of their target antigen. It is thought to mainly play a role during the steady state, when self-antigens are presented in absence of costimulatory signals and at low density or to T cells of low affinity. In how far antigen-specific T cells can also remain clonally ignorant to foreign antigens, presented in the inflammatory context of systemic infection, remains unclear. Using single-cell in vivo fate mapping and high throughput flow cytometric enrichment, we find that high-affinity antigen-specific CD8⁺ T cells are efficiently recruited upon systemic infection. In contrast, most low-affinity antigen-specific T cells ignore the priming antigen and persist in the naïve state while remaining fully responsive to subsequent immunization with a high-affinity ligand. These data establish the widespread clonal ignorance of low-affinity T cells as a major factor shaping the composition of antigen-specific CD8⁺ T cell responses to systemic infection.     

Clonal composition and persistence of antigen-specific circulating T follicular helper cells

T follicular helper (T_FH) cells play an essential role in promoting B cell responses and antibody affinity maturation in germinal centers (GC). A subset of memory CD4⁺ T cells expressing the chemokine receptor CXCR5 has been described in human blood as phenotypically and clonally related to GC T_FH cells. However, the antigen specificity and relationship of these circulating T_FH (cT_FH) cells with other memory CD4⁺ T cells remain poorly defined. Combining antigenic stimulation and T cell receptor (TCR) Vβ sequencing, we found T cells specific to tetanus toxoid (TT), influenza vaccine (Flu), or Candida albicans (C.alb) in both cT_FH and non-cT_FH subsets, although with different frequencies and effector functions. Interestingly, cT_FH and non-cT_FH cells specific for C.alb or TT had a largely overlapping TCR Vβ repertoire while the repertoire of Flu-specific cT_FH and non-cT_FH cells was distinct. Furthermore, Flu-specific but not C.alb-specific PD-1⁺ cT_FH cells had a “GC T_FH-like” phenotype, with overexpression of IL21, CXCL13, and BCL6. Longitudinal analysis of serial blood donations showed that Flu-specific cT_FH and non-cT_FH cells persisted as stable repertoires for years. Collectively, our study provides insights on the relationship of cT_FH with non-cT_FH cells and on the heterogeneity and persistence of antigen-specific human cT_FH cells.     

Enolase 1 of Candida albicans binds human CD4+ T cells and modulates naïve and memory responses

To obtain a better understanding of the biology behind life-threatening fungal infections caused by Candida albicans, we recently conducted an in silico screening for fungal and host protein interaction partners. We report here that the extracellular domain of human CD4 binds to the moonlighting protein enolase 1 (Eno1) of C. albicans as predicted bioinformatically. By using different anti-CD4 monoclonal antibodies, we determined that C. albicans Eno1 (CaEno1) primarily binds to the extracellular domain 3 of CD4. Functionally, we observed that CaEno1 binding to CD4 activated lymphocyte-specific protein tyrosine kinase (LCK), which was also the case for anti-CD4 monoclonal antibodies tested in parallel. CaEno1 binding to naïve human CD4⁺ T cells skewed cytokine secretion toward a Th2 profile indicative of poor fungal control. Moreover, CaEno1 inhibited human memory CD4⁺ T-cell recall responses. Therapeutically, CD4⁺ T cells transduced with a p41/Crf1-specific T-cell receptor developed for adoptive T-cell therapy were not inhibited by CaEno1 in vitro. Together, the interaction of human CD4⁺ T cells with CaEno1 modulated host CD4⁺ T-cell responses in favor of the fungus. Thus, CaEno1 mediates not only immune evasion through its interference with complement regulators but also through the direct modulation of CD4⁺ T-cell responses.     

Mechanistic insight of interleukin-9 induced osteoclastogenesis

Interleukin (IL)-9 is an emerging player in the pathogenesis of various chronic inflammatory diseases including bone disorders like rheumatoid arthritis (RA) and psoriatic arthritis. Recently, IL-9 was shown to enhance the osteoclast formation and their function in RA. However, the mechanisms by which IL-9 influences osteoclastogenesis are not known. Therefore, in this study we aimed to unravel the direct and indirect ways by which IL-9 can influence osteoclast formation. We used mouse bone marrow precursor cells for checking the effect of IL-9 on osteoclast differentiation and its function. Next, IL-9 induced signalling pathway were checked in the process of osteoclastogenesis. T cells play an important role in enhancing osteoclastogenesis in inflammatory conditions. We used splenic T cells to understand the impact of IL-9 on the functions of T effector (Teff) and regulatory T (Treg) cells. Furthermore, the effect of IL-9 mediated modulation of the T cell response on osteoclasts was checked using a coculture model of T cells with osteoclast precursors. We showed that IL-9 enhanced osteoclast formation and its function. We found that IL-9 activates STAT3, P38 MAPK, ERK1/2, NFκB and we hypothesize that it mediates the effect on osteoclastogenesis by accelerating mitochondrial biogenesis. Additionally, IL-9 was observed to facilitate the functions of pro-osteoclastogenic IL-17 producing T cells, but inhibits the function of anti-osteoclastogenic Treg cells. Our observations suggest that IL-9 can influence osteoclastogenesis directly by modulating the signalling cascade in the precursor cells; indirectly by enhancing IL-17 producing T cells and by reducing the functions of Treg cells.