不同病毒载量HBV感染者外周血T淋巴细胞亚群和转化生长因子β的变化及意义

目的通过检测不同病毒载量慢性乙型肝炎(CHB)患者和HBV携带者(ASC)外周血T淋巴细胞各亚群变化的规律,探讨T淋巴细胞与人转化生长因子(TGF)β、ALT及TBil相关性。方法选择2012年7月至2012年12月兰州市第二人民医院收治的175例HBV感染者作为研究对象,分为ASC组(112例)、CHB组(63例),以同期健康体检者84例作为对照组。运用流式细胞术检测3组血清中T淋巴细胞亚群水平,同时检测肝功能指标等。正态分布的计量资料多组间比较采用方差分析,偏态分布的计量资料组间比较采Kruskal-Wallis H秩和检验。结果与健康对照组相比,ASC和CHB组TGFβ表达水平显著升高(P均0.05),CD3+、CD4+T淋巴细胞百分数显著降低(P0.05或P0.01),CD4+与CD8+T淋巴细胞比值显著降低(P0.01),CD8+T淋巴细胞百分数显著升高(P0.05或P0.01)。ASC与CHB组HBeAg阳性组和HBeAg阴性组患者CD3+、CD4+T淋巴细胞百分数均降低,CD8+T淋巴细胞百分数升高,CD4+与CD8+T淋巴细胞百分数降低。结论 TGFβ可能参与了CHB的发病过程,其免疫抑制作用可能是通过对T淋巴细胞、抗原递呈细胞成熟分化的抑制等多个环节发挥作用。     

Designing the epitope flanking regions for optimal generation of CTL epitopes

The flanking amino acids that surround epitopes are critical for effective antigen processing and maintenance of epitope integrity. In the present study, the frequency and characteristics of each amino acid that flanked the peptides generated from the proteasomal degradation of three different subtypes of HIV-1 Gag-p24 were determined. Synthetic flanking regions were designed based on the highest and the lowest frequencies of amino acid with the ideal characteristics at positions upstream and downstream of the proteasomal cleavage site. Peptides were synthesized that contained known CD8+ CTL-epitopes from HIV-1 Gag, CMV pp65, and vaccinia proteins HRP-2, and C16, flanked by amino acid sequences specifically designed to either generate or inhibit the known CD8+ CTL-epitopes. As predicted, the known CD8+ CTL-epitopes were effectively generated from the peptides with synthetic flanking regions specifically designed to promote epitope generation in a proteasome-dependent manner. The majority of the proteasome-generated epitopes were cleaved immediately after the C-terminal amino acid of the specific CTL-epitope. The synthetic peptide sequences containing known CD8+ CTL-epitopes with the flanking regions that promote epitope generation were effectively processed and presented to epitope specific CD8+ T-cells resulting in the production of IFN-γ. These results highlight the importance of flanking regions in promoting efficient antigen processing and presentation. This concept can have important implications in vaccine design and development strategies.     

Effects of 1α, 25-dihydroxyvitamin D3 on memory CD4+ T cells of focal proliferative IgA nephropathy

Objective To explore the effects of 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] on memory CD4+ T cells of focal proliferative IgA nephropathy (IgAN）patients. Methods (1) Total of twenty incipient focal proliferative IgAN patients (Lee classification: Ⅲ level) were chosen as IgAN group and 20 healthy volunteers were chosen as healthy control group. The level of serum 1,25(OH)2D3 was measured by radioimmunoassay (RIA). Peripheral blood mononuclear cells (PBMCs) were separated by the method of Ficoll density gradient centrifugation and were stimulated with anti-CD3/anti-CD28 in the absence or presence of various concentrations of 1,25(OH)2D3, Dexamethasone(DEX) and 1,25(OH)2D3 and DEX combined. PBMCs were cultured for 72 hours and the levels of IFN-γ, IL-4, IL-17A, Foxp3 were measured by flow cytometry(FCM), standing for the levels of Th1, Th2, Th17, Treg. (2) IgAN group was divided into two subgroups (proteinuria＜1 g/24 h subgroup, proteinuria≥1 g/24 h subgroup), then the serum levels of 1,25(OH)2D3, IFN-γ, IL-4, IL-17A, Foxp3 were compared. Results Compared with healthy control group, serum 1,25(OH)2D3 level of IgAN group was significantly lower (P＜0.05). Serum 1,25(OH)2D3 level in proteinuria≥1 g/24 h subgroup was significantly lower than proteinuria＜1 g/24 h subgroup and healthy control group (P＜0.05). The level in proteinuria＜1 g/24 h subgroup was lower than healthy control group, but the difference was not statistically significant (P＞0.05). (2) The levels of IFN-γ and IL-17A and the ratios of IFN-γ/IL-4, IL-17A/Foxp3 in IgAN group increased significantly compared with healthy control group (all P＜0.05), and the level of Foxp3 decreased significantly (P＜0.05). The level of IL-4 also increased, but the difference was not statistically significant (P＞0.05). The levels of IFN-γ and IL-17A and the ratio of IL-17A/Foxp3 in proteinuria≥1 g/24 h subgroup increased significantly, and the level of Foxp3 decreased significantly, compared with urinary protein＜1 g/24 h subgroup and healthy control group (P＜0.05). The ratio of IFN-γ/IL-4 in proteinuria≥1 g/24 h subgroup and proteinuria＜1 g/24 h subgroup all increased, compared with healthy control group, and the ratio in proteinuria≥1 g/24 h subgroup increased significantly (P＜0.05). There was no significant difference in the level of IL-4 among all groups. (3) After treatment with 1,25(OH)2D3, the levels of IFN-γ and IL-17A and the ratios of IFN-γ/IL-4 and IL-17A/Foxp3 decreased significantly, and the level of Foxp3 increased significantly (P＜0.05), and these effects were more obvious as the increase of the drug concentration. The level of IL-4 did not change significantly. The combination of 1,25(OH)2D3 and DEX had a synergistic inhibition on the production of IFN-γ, IL-4, IL-17A, and the ratios of IFN-γ/IL-4 and IL-17A/Foxp3, and had a synergistic promotion on the production of Foxp3. Conclusions There is a certain extent of vitamin D deficiency in focal proliferative IgAN patients, which may be associated with the severity of proteinuria. The disorder of immunomodulatory effects of memory CD4+ T cell might exist in the patients of focal proliferative IgAN. 1α,25-dihydroxyvitamin D3 might have beneficial effects on the immunoregulation of memory CD4+T cells of focal proliferative IgAN patients.     

恩替卡韦对慢性乙型肝炎患者细胞免疫功能的影响

目的 探讨慢性乙型肝炎患者接受恩替卡韦抗病毒治疗前后细胞免疫学功能的变化.方法 纳入对象为慢性乙型肝炎患者（CHB）50例,分为治疗组30例,对照组20例,治疗组接受恩替卡韦抗病毒治疗12个月,对照组未接受核苷类似物或干扰素抗病毒治疗.通过流式细胞术动态分析两组患者外周T细胞亚群和CD4＋ CD25＋ Foxp3＋调节性T细胞的表型和频率变化.结果 接受恩替卡韦治疗的患者,与治疗前比较,治疗后3个月、6个月和12个月其CD4 T细胞、CD4/CD8逐渐增高和CD4＋ CD25＋ Foxp3＋调节性T细胞比例逐渐显著性降低,差异有统计学意义（P＜0.05）;而对照组观察前后差异无统计学意义（P＞0.05）.治疗组治疗后12个月,其调节性T细胞的下降幅度与血清HBV DNA的下降水平呈显著正相关（r=0.65,P＜0.01）.结论 恩替卡韦在有效抗病毒治疗同时具有改善患者的细胞免疫功能.     

Foxp3调节性T细胞在感染免疫中的作用

Foxp3调节性T细胞是具有免疫抑制功能的CD4+T淋巴细胞的一个亚群,在自身免疫性疾病、器官移植免疫耐受、抗肿瘤免疫及过敏性疾病中均发挥重要作用.近年研究发现,调节性T细胞在一些病原体感染过程中扩增并聚集到感染部位,通过细胞直接接触或分泌抑制性细胞因子如,白细胞介素10、转化生长因子β等,限制效应细胞免疫应答,从而减轻机体免疫反应过程对宿主的病理性损伤,同时也可减弱机体清除病原微生物的能力,导致感染持续存在.     

重症肌无力患者外周血CD4+T细胞OX40的表达及作用机制研究

目的 分析重症肌无力(MG)患者外周血CD4+T细胞协同刺激分子OX40表达及其对FoxP3+CD4+CD25+调节性T细胞(Treg)的调控作用,初步探讨OX40在MG免疫学发病中的作用机制.方法 以流式细胞技术检测42例MG患者及38名健康对照的外周血OX40+CD4+T细胞、FoxP3+CD4+CD25+Treg表达水平,比较OX40表达在MG患者不同临床疾病状态、Osserman分型、临床绝对评分、胸腺病理类型等情况下的差异,并分析OX40对FoxP3+CD4+CD25+Treg细胞的影响.结果 (1) MG患者外周血OX40+CD4+T细胞占淋巴细胞百分比高于健康对照组(P<0.01).(2)MG患者OX40+CD4+T细胞百分比在发作或加重期高于缓解期(P＜0.05);在临床绝对评分呈中、重度患者OX40+CD4+T细胞百分比高于轻度患者(均P＜0.05);Osserman Ⅱ、Ⅳ型患者OX40+CD4+T细胞百分比高于Ⅰ型患者(均P＜0.05);胸腺增生及胸腺瘤患者OX40+CD4+T细胞百分比高于胸腺正常患者(P＜0.05,P＜0.01).(3)MG患者外周血OX40+CD4+T细胞百分比与FoxP3+CD4+CD25+Treg细胞百分比呈负相关(r=-0.843,P=0.01).结论 协同刺激分子OX40参与MG发病,可能通过抑制FoxP3+CD4+CD25+Treg细胞生成发挥作用.     

老年湿疹患者T辅助细胞相关细胞因子水平分析

目的 研究老年湿疹患者Th1/Th2细胞因子的血清水平与湿疹的发展及其临床表现的相关性. 方法 应用酶联免疫吸附法(ELISA)测定50例老年湿疹患者(≥60岁)白介素(IL)-2、4、10、12和肿瘤坏死因子(TNF-α)的血清水平并与34例健康老年人(对照组)进行比较;比较急性和慢性,或泛发性和局限性湿疹上述细胞因子的水平差异. 结果 老年湿疹组IL-2 [(16.03±0.47)比(15.72±0.33) μg/L]、IL-4 [(14.04±0.56)比(13.56±0.16)μg/L]、IL-10[(33.01±5.40)比(29.49±1.07) μg/L]、IL-12 [(39.32±3.54)比(37.93±1.17) μg/L]和TNF-α [(27.33±0.72)比(26.38±0.48) μg/L]水平均高于对照组(t/t'=3.55,5.74,4.4 9,2.58,6.69,均P＜0.05).急性湿疹组血清细胞因子水平均高于对照组(t/t'=3.59,6.44,4.68,3.35,2.00,均P＜0.05);慢性湿疹组中IL-2、IL-4、IL-10和TNF-α的血清水平高于对照组(t'=2.46,5.50,3.83,3.10,均P＜0.05),而IL-12水平与对照组的差异无统计学意义(t'=1.77,P＞0.05);急性与慢性湿疹患者血清细胞因子的水平差异无统计学意义(P＞0.05).泛发性与局限性湿疹患者血清IL-2、II4、IL-10和IL-12、TNF-α的水平差异无统计学意义(t=0.18,5.74,4.49,0.91,0.25,1.11,均P＞0.05). 结论细胞因子IL-2、IL-4、IL-10、Th1/Th2和TNF-α可能与老年人湿疹发生相关,不同临床类型的老年湿疹患者可能并无特定的Th1/Th2细胞因子变化模式.     

STAT5基因沉默对支气管哮喘小鼠T细胞增殖的影响

目的 探讨STAT5a/b基因沉默对支气管哮喘(简称哮喘)小鼠T细胞增殖功能的影响.方法 将20只雌性BALB/c小鼠按随机数字法分为正常组和哮喘组,哮喘组按处理因素不同分别分为空白对照组、STAT5a沉默组、STAF5b沉默组及错义链对照组,采用免疫磁珠法筛选出正常及哮喘模型小鼠的脾脏T细胞,利用RNA干扰(RNAi)沉默T细胞内STAT5a/b基因.荧光定量PCR检测STAT5a/b基因沉默前后STAT5a/b的mRNA表达变化;蛋白免疫印迹法检测STAT5a/b基因沉默前后的蛋白含量的变化;CCK-8检测T细胞RNA干扰前后增殖率的变化;流式技术检测T细胞RNA干扰前后细胞增殖周期及早期凋亡率的变化.结果 (1)哮喘小鼠气道病理结果显示明显炎症改变.(2)哮喘组小鼠脾脏淋巴细胞STAT5a/b mRNA表达量较正常组小鼠明显增高(T值分别为11.71、33.04,均P＜0.05).(3)与空白对照组比较:特异性siRNA转染哮喘小鼠T细胞后,STAT5a和STAT5b沉默组的mRNA表达明显降低(T值分别为35.014、14.553,均P＜0.01);STAT5a和STAT5b沉默组蛋白表达也明显降低(T值分别为- 10.958、- 14.706,均P＜0.01);STAT5a和STAT5b沉默组T细胞增殖率明显降低(T值分别为8.692、10.540,均P＜0.01);STAT5a和STAT5b沉默组增殖期T细胞均明显降低(T值分别为-6.975、-5.567,均P＜0.05);STAT5a和STAT5b沉默组T细胞凋亡率明显升高(T值分别为-6.404、-6.038,均P＜0.05).结论 RNA干扰能特异性降低哮喘小鼠STAT5 a/b表达,抑制T细胞的增殖并促进T细胞凋亡.     

特异性细胞因子对T辅助17细胞和T调节性细胞表达的调节作用

目的 探讨多种细胞因子包括转化生长因子β(TGF-β)、白细胞介素6(IL-6)、白细胞介素2(IL-2)对CD+4T淋巴细胞的分化调节作用.方法 将人外周血T淋巴细胞、鼠脾脏T淋巴细胞在不同的刺激条件下进行体外培养,采用流式细胞仪分析活化T淋巴细胞中CD+4IL-17+T辅助17细胞(Th17细胞)、C+4IL-17+T淋巴细胞、CD+4CD+25FOXP+3T调节性细胞(Treg细胞)的表达情况.结果 鼠脾脏T淋巴细胞培养液中有TGF-β存在时可促进Treg细胞、rh17细胞和CD+8;IL-17+T淋巴细胞分化,表达水平分别为(7.8±2.2)%、(12.6±3.1)%、(10.1±2.6)%.无细胞因子培养的同类细胞为实验对照组,表达水平分别为(4.8±0.6)%、(1.7±0.5)%、(1.0±0.4)%,差异均有统计学意义(q=4.09、8.80、9.61,P<0.05或P<0.01).TGF-β与IL-6细胞因子共同存在时可促进Th17和CD+8IL-17+T淋巴细胞分化,表达水平分别为(17.8±5.3)%、(15.0±4.2)%,而分化受抑制的Treg细胞的表达水平为(4.I±1.2)%,与TGF-β组同类细胞表达水平比较差异均有统计学意义(q=5.03、5.17、5.04,P均<0.01).在TGF-β刺激的T淋巴细胞中加入IL-2细胞因子可使Th17细胞、CD+8;IL-17+T淋巴细胞表达减少,同时伴有Treg细胞表达量的增加;在加入抗IL-2后结果相反,即Th17细胞、CD+8IL-17+T淋巴细胞表达水平增加,Treg细胞表达水平减少.人外周血T淋巴细胞上Th17、CD+8IL-17+、Treg细胞表达水平变化趋势与鼠脾脏淋巴细胞相似.结论 不同细胞因子对于调控Th17细胞和Treg细胞之间的平衡起着十分重要的作用.