小鼠异种皮肤移植模型的建立及对免疫抑制药物的药效评价

目的建立小鼠异种皮肤移植模型,以期为免疫抑制药物提供研究模型。方法将C57BL/6小鼠耳部皮肤移植到BALB/c小鼠背部,同时设立同种移植对照(BALB/c小鼠耳部皮肤移植到BALB/c小鼠背部)。选用环孢素A作为抑制异种移植引起的免疫排斥反应的免疫抑制剂,利用该模型评价环孢素A免疫抑制效果。在移植和给药后,对移植排斥评分和移植皮肤的存活率进行统计。移植手术4 d和9 d后,ELISA法对血清中IL-4、IL-12和IFN-γ的水平进行测定。12 d后,计算胸腺和脾脏系数,对脾脏T细胞中CD4~+和CD8~+的比例进行分析,同时将移植皮肤进行病理观察。结果皮肤移植后,排斥评分逐渐增加,移植皮肤的存活率逐渐下降,有明显的水肿、炎症细胞浸润等炎症反应。环孢素A可明显降低移植排斥评分,提高移植皮肤的存活率,使小鼠胸腺和脾脏系数明显降低,高剂量可明显降低脾脏T细胞中CD4~+和CD8~+细胞的比例。同时,环孢素A处理可明显降低移植皮肤的炎症反应。结论小鼠经异种皮肤移植后会出现急性移植排斥反应,环孢素A可有效抑制移植排斥反应,并呈现出明显的剂量依赖性。     

体外阻断CD137-CD137L途径抑制移植物抗宿主病的免疫效应

目的探讨体外阻断活化的供鼠T淋巴细胞CD137-CD137L共刺激途径抑制供鼠淋巴细胞的免疫反应。方法应用雄性供鼠BALB/c脾淋巴细胞为反应细胞,雌性受鼠C57BL/6脾淋巴细胞为刺激细胞,进行混合淋巴细胞培养(MLC)。设单抗实验组(加抗CD137L单抗)和对照组(不加抗CD137L单抗),初次和再次MLC第1、3、5、7天采用流式细胞术检测CD3+CD4+T细胞、CD3+CD8+T细胞;RT-PCR法检测培养的细胞IL-2、IFN-γ、IL-4、IL-10的水平。结果实验组CD3+CD8+T细胞明显低于对照组(P<0.01);实验组IL-2、IFN-γ水平明显低于对照组(P<0.01);实验组IL-10表达明显高于对照组(P<0.01)。结论体外MLC中,应用抗CD137L单抗孵育供鼠脾T淋巴细胞主要抑制供鼠CD3+CD8+T细胞的增殖,抑制Ⅰ类细胞因子IFN-γ及IL-2的表达,促进Ⅱ类细胞因子IL-10的表达。     

剔除CCR5基因供者小鼠细胞加重急性移植物抗宿主疾病

目的评价供者CCR5在经过强化预处理的骨髓移植动物模型受者体内的作用,为今后的异基因造血干细胞移植的临床应用提供科学依据。方法经过致死剂量照射的BALB/C小鼠接受异基因C57BL/6小鼠骨髓移植。根据回输的细胞不同分为4组:B6CCR5KO组,受者接受C57BL/6CCR5-/-小鼠骨髓和脾脏细胞;B6WT组,受者接受野生型C57BL/6小鼠骨髓细胞;B6CCR5KOBMC组,受者只接受C57BL/6CCR5-/-小鼠骨髓细胞;B6WTBMC组,受者只接受野生型C57BL/6小鼠骨髓细胞。结果较之B6WT组,B6CCR5KO组小鼠以更快的速度死于急性GVHD;其受者体内的CD8+T细胞更大量的增殖;其T细胞恢复后产生更多的IFN-γ和TNF-α,并且由于其T细胞有丝分裂原刀豆素水平处于较高水平从而进一步促进T细胞增殖,提示CCR5的作用之一是下调参与排异反应的供者CD8+T细胞的增殖。组织学评价提示移植剔除CCR5基因受者细胞的小鼠肾脏出现了病理损伤并且肝脏存在更为严重的病理变化。结论剔除CCR5基因的异基因骨髓移植使GVHD发病率增加,供者CD8+T细胞在受者体内增殖增加以及肝肾损害加重,提示CCR5在异基因骨髓移植中起着重要作用。     

MICA基因多态性及其与免疫性疾病相关性的研究进展

<正>人类主要组织相容性复合体(major histocompatibility complex,MHC)基因分为三类,MHCⅠ类,Ⅱ类,Ⅲ类。MHC I类(HLA-A,B,C)和MHCⅡ类(HLA-DR,DP,DQ)基因编码人类白细胞抗原(human leukocyte antigen,HLA)分子,通过识别和递呈抗原肽,分别激活CD4+T细胞或CD8+T细胞,从而达到免疫监视及免疫激活的目的。然而1994年Bahram等学     

移植肾急性排斥组织中C4d CD3 CD4 CD8 CD138表达的初步研究

目的分析探讨移植肾急性排斥组织中C4d、CD3、CD4、CD8、CD138的表达。方法收集我院2010年3月至2013年10月经病理学确认为急性排斥反应移植肾穿刺标本136例,依据Banff 2007标准将研究对象分为5组,利用免疫组织化学染色计数测定各组C4d、CD3、CD4、CD8、CD138阳性表达情况并计算CD4/CD8值。结果急性抗体介导性排斥反应组C4d染色均为阳性,急性T细胞介导性排斥反应组C4d染色均为阴性;CD3、CD4、CD8阳性细胞数及CD4+/CD8+值急性T细胞介导性排斥反应组高于急性抗体介导性排斥反应组,差异有统计学意义(P<0.01),急性T细胞性排斥Ⅰ、Ⅱ级组高于疑为急性T细胞介导性排斥组,差异有统计学意义(P<0.01),急性T细胞性排斥Ⅱ级组高于急性T细胞性排斥Ⅰ级组,差异具有统计学意义(P<0.05),急性抗体介导性排斥反应Ⅰ级组与急性抗体介导性排斥反应Ⅱ级组差异无统计学意义(P>0.05);CD138阳性细胞急性抗体介导性排斥反应组大于急性T细胞介导性排斥反应组,差异有统计学意义(P<0.01),急性抗体介导性排斥反应Ⅱ级组高于急性抗体介导性排斥反应Ⅰ级组,差异具有统计学意义(P<0.05),急性T细胞介导性排斥反应3组比较,差异无统计学意义(P>0.05)。结论 C4d的表达和CD3、CD4、CD8、CD138阳性细胞数以及CD4+/CD8+值与肾移植急性排斥反应的类型及反应程度密切相关,检测C4d、CD3、CD4、CD8、CD138在移植肾急性排斥组织中表达情况,对于探讨移植肾早期急性排斥反应发生具有重要意义。     

CCK-8对LPS作用下巨噬细胞B7.1和B7.2表达及其协同刺激功能的影响

目的探讨八肽胆囊收缩素(CCK-8)对LPS活化的巨噬细胞B7.1和B7.2表达及其协同刺激功能的影响。方法用CCK-8(10-12~10-6)mol.L-1和(或)脂多糖(LPS)孵育小鼠腹腔巨噬细胞,采用流式细胞术分析细胞表面B7.1和B7.2含量的变化,用免疫磁珠从小鼠脾细胞分离CD4+T细胞,按4∶1数量比与腹腔巨噬细胞[预先用LPS、CCK-8和(或)抗B7.1抗体、抗B7.2抗体、CCK1R拮抗剂CR1409、CCK2R拮抗剂CR2945孵育24h]共同体外培养,同时加入ConA5mg.L-1,采用3H参入法测定CD4+T细胞增殖反映巨噬细胞的协同刺激活性。结果CCK-8可以下调LPS诱导的巨噬细胞的B7.1和B7.2表达,抑制LPS活化的巨噬细胞的协同刺激活性。CCK-8的作用呈剂量依赖性,最大效应剂量在(10-7~10-9)mol.L-1之间。CR1409及CR2945均能逆转CCK-8的上述作用,且CR1409的作用较CR2945更明显。抗B7.1抗体和抗B7.2抗体可减轻LPS活化的巨噬细胞协同刺激活性。结论CCK-8通过下调LPS诱导的巨噬细胞B7.1和B7.2表达而抑制其协同刺激活性,该作用由CCK1R及CCK2R介导,其中CCK1R起主要介导作用。     

细胞因子对小鼠肺癌细胞MHC Ⅰ类分子和共刺激分子的调节作用

目的观察T细胞活化因子对小鼠肺癌细胞表达MHCⅠ类分子和共刺激分子的调节作用,探讨细胞因子增强特异性抗肿瘤应答的免疫效果。方法用rhIL-2和IFN-γ分别活化对数生长期的小鼠lewis肺癌3LL细胞48h,FACS检测细胞因子活化前后3LL细胞表达MHCⅠ类分子(H-2)和共刺激分子(CD80)的荧光强度。结果3LL细胞低表达H-2和CD80,经rhIL-2和IFN-γ活化48h后,3LL表达H-2和CD80的荧光强度明显增强,rhIL-2的活化的两种分子荧光强度高于IFN-γ。结论rhIL-2和IFN-γ能上调小鼠lewis肺癌3LL细胞表面MHCⅠ类分子和共刺激分子的表达,增强体内特异性抗肿瘤免疫应答。     

免疫抑制剂对糖尿病小鼠胰岛细胞移植长期存活效果的研究

目的观察胰岛细胞移植后应用免疫抑制剂对胰岛组织长期存活的影响。方法对Wistar大鼠胰腺进行灌注,分离和纯化胰腺的胰岛细胞;将纯化的胰岛移植入C57BL/6糖尿病小鼠肾包膜下,分组对移植后的小鼠进行不同免疫抑制剂(他克莫司、雷帕霉素、抗白介素-2R抗体)不同方案联合治疗,比较各个方案组与对照组(不同任何免疫抑制剂)的差异性。并对术后移植物存活时间、糖耐量试验以及外周血CD4+、CD8+T细胞亚群和IL-2含量进行分析和比较。对移植部位进行组织学切片,分析胰岛周围单核细胞现象。结果单纯移植组在无任何免疫抑制剂的情况下,异种胰岛一般在术后10天左右丧失功能,外周血中CD4+T细胞亚群明显高于使用免疫抑制剂组(P<0.05),而CD8+T细胞亚群没有明显变化(P>0.05),IL-2含量各组无明显差异(P>0.05)。各实验组1周后血糖浓度变化与对照组比较均有显著性差异(P<0.05)。应用T+R+A组,移植受体存活时间最长平均为161.4±40.4天。结论他克莫司、雷帕霉素及抗白介素-2R抗体联合用药,能够不同程度的提高胰岛细胞移植后糖尿病小鼠的存活时间。     

穿心莲二萜类化合物对B16细胞致敏小鼠CTL杀伤活性的影响

目的研究穿心莲二萜类化合物(DAP)对B16细胞致敏小鼠脾脏CTL杀伤活性的影响。方法将♂BALB/c小鼠分为对照组、致敏组、50mg·kg-1及150mg·kg-1DAP给药组,制备小鼠脾脏淋巴细胞悬液,流式细胞术分析T淋巴细胞亚群,乳酸脱氢酶(LDH)法和DiO/PI双染色法分别测定CTL杀伤活性。结果50mg·kg-1及150mg·kg-1DAP口服给药可以增加B16细胞致敏小鼠脾脏淋巴细胞中T细胞及CD8+T细胞比例,降低T细胞中CD4+/CD8+比值并增强CTL对B16细胞的杀伤活性。结论DAP可增加B16细胞致敏小鼠脾脏T细胞比例及提高CTL杀伤活性。     

雷公藤甲素对类风湿性关节炎患者外周血T细胞的免疫抑制作用

目的:研究雷公藤甲素对类风湿性关节炎(RA)患者外周血T细胞免疫功能的抑制作用。方法:在RA患者外周血T细胞中加入T细胞多克隆刺激剂(0.2μg/ml)以活化淋巴细胞并分泌细胞因子。实验分为空白对照(常规培养液)组、抗人CD3抗体(anti-CD3)刺激(0.2μg/ml)组、雷公藤甲素(anti-CD3 0.2μg/ml+雷公藤甲素1 mmol/ml)组。采用密度梯度离心法分离RA患者的外周血单核细胞(PBMCs),加入雷公藤甲素,以酶联免疫吸附(ELISA)法检测细胞γ干扰素(IFN-γ)含量,流式细胞仪检测分泌IFN-γ、白细胞介素(IL)-2、IL-4与T细胞活化分子CD69和CD25的CD4+、CD8+T细胞百分比。结果:与anti-CD3刺激组比较,雷公藤甲素组PBMCs中IFN-γ含量减少,分泌IFN-γ、IL-2、IL-4的CD4+、CD8+T细胞百分比降低,分泌CD69和CD25的CD4+、CD8+T细胞百分比降低,差异均有统计学意义(P<0.01)。结论:雷公藤甲素可能通过抑制T细胞活化和细胞因子分泌来发挥免疫抑制作用,从而发挥对RA的临床治疗作用。     

T lymphocytes are direct,aryl hydrocarbon receptor (AhR)-dependent targets of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD): AhR expression in both CD4+ and CD8+ T cells is necessary for full suppression of a cytotoxic T lymphocyte response by TCDD

The cellular basis for the potent suppression of T cell-mediated immune responses in mice following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is not fully understood. Although activation of the aryl hydrocarbon receptor (AhR) is required, the specific AhR+ cells that transduce the suppression have been difficult to identify in vivo. The recent availability of AhR-/- mutant mice has provided a resource for novel approaches to investigate the direct targets of TCDD. In our studies, we used an in vivo acute graft versus host (GVH) model of T cell immunity to address the direct AhR-dependent effects of TCDD on T cells. In this model, T cells from C57B1/6 mice are injected into C57B1/6 x DBA/2 F1 host mice. The injected T cells recognize the MHC disparity of the host cells, resulting in the generation of an antihost cytotoxic T lymphocyte (CTL) response. By comparing the ability of TCDD to suppress the CTL response of T cells obtained from AhR+/+ and AhR-/- C57B1/6 mice, the need for AhR expression in T cells themselves could be assessed. The results of these studies showed that the CTL response of T cells from AhR+/+ mice was highly suppressed when the F1 host mice were treated with 15 microg/kg TCDD. TCDD treatment also protected the F1 host mice from the loss of body weight that accompanies the induction of the GVH response. In contrast, when grafted T cells were derived from AhR-/- mice, there was no suppression of the CTL response by TCDD, and the host animals lost significant body weight. Furthermore, when T cells from AhR+/+ and AhR-/- mice were separated into CD4+ and CD8+ subsets and recombined using one subset from each donor prior to injection into the F1 host, suppression of the CTL response by TCDD was still apparent, but the degree of suppression was significantly reduced when either subset was AhR-/-. These results indicate that direct AhR-dependent effects of TCDD occur in both CD4+ and CD8+ T cell subsets and both T cell subsets contribute to the full suppression of the CTL response by TCDD.     

Effects of subchronic inhalation exposure to ethyl tertiary butyl ether on splenocytes in mice

Ethyl tertiary-butyl ether (ETBE) is a motor fuel oxygenate used in reformulated gasoline. The current use of ETBE in gasoline or petrol is modest but increasing. To investigate the effects of ETBE on splenocytes, mice were exposed to 0 (control), 500 ppm, 1750 ppm, or 5000 ppm of ETBE by inhalation for 6 h/day for 5 days/wk over a 6- or 13-week period. Splenocytes were harvested from the control and exposed mice, and the following cell phenotypes were quantified by flow cytometry: (1) B cells (PerCP-Cy5.5-CD45R/B220), (2) T cells (PerCP-Cy5-CD3e), (3) T cell subsets (FITC-CD4 and PE-CD8a), (4) natural killer (NK) cells (PE-NK1.1), and (5) macrophages (FITC-CD11b). Body weight and the weight of the spleen were also examined. ETBE-exposure did not affect the weight of the spleen or body weight, while it transiently increased the number of RBC and the Hb concentration. The numbers of splenic CD3+, CD4+, and CD8+ T cells, the percentage of CD4+ T cells and the CD4+/CD8+ T cell ratio in the ETBE-exposed groups were significantly decreased in a dose-dependent manner. However, ETBE exposure did not affect the numbers of splenic NK cells, B cells, or macrophages or the total number of splenocytes. The above findings indicate that ETBE selectively affects the number of splenic T cells in mice.     

Role of Fas apoptosis and MHC genes in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced immunotoxicity of T cells

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is well known for its immunotoxic effects particularly on the thymus as well as on T and B lymphocyte functions. Previous studies have suggested that TCDD may induce apoptosis in thymocytes although its demonstration in vivo has met with limited success. TCDD has also been shown to alter the major histocompatiblity complex- (MHC) encoded molecules, however, its role in immunotoxicity is not clear. In the current study, we investigated the role of Fas (CD95), an important molecule involved in the induction of apoptosis, on TCDD-mediated immunotoxicity using mice bearing homozygous lpr mutation which leads to failure of expression of Fas. When TCDD was administered orally at 0, 0.1, 1.0, or 5.0 μg/kg body weight for 11 days, it was found to be less toxic to the thymocytes from C57BL/6 lpr/lpr mice (Ah-responsive, Fas⁻) when compared to C57BL/6 +/+ mice (Ah-responsive, Fas⁺). Similar results were obtained when peripheral T cell responsiveness to antigenic challenge with conalbumin was studied in these mice. When mice that differed only at the MHC were compared for immunotoxic effects of TCDD, it was noted that B10.D2 (Ah-responsive, H-2^d) were more sensitive to TCDD-mediated thymic atrophy and peripheral T cell dysfunction when compared to B10 mice (Ah-responsive, H-2^b). In all TCDD-sensitive strains tested, the thymic atrophy was accompanied by a uniform depletion of all four subset of T cells (CD4⁺, CD4⁺CD8⁺ , CD4⁻CD8⁻, and CD8⁺) and the percentage of these subsets was not altered. Furthermore, in these strains, TCDD suppressed the antigen-specific peripheral T cell responsiveness but not the responsiveness of naive resting T cells to polyclonal mitogens. Lastly, using cell-mixing experiments, it was demonstrated that TCDD directly affected the T cells responding to conalbumin but not the antigen presenting cells (APCs). Together, our studies demonstrate that although Ah locus plays the primary role, determining the toxicity of TCDD on the T cells, there are secondary factors such as expression of Fas or the Abbreviations: Ah, aryl hydrocarbon; APC, antigen presenting cell; ConA, concanavalin A; FITC, fluorescein isothiocyanate; LN, lymph node; mAb, monoclonal antibody; MHC, major histocompatability complex; PE, phycoerythrin; PHA, phytohemagglutinin; TCDD, 2,3,7,8-tetrachlorodibenzo-p-dioxin; TCR, T cell receptor; TNF, tumor necrosis factor.     

白芍总甙调节小鼠免疫功能的机理

用单克隆抗体间接免疫荧光法观察白芍总甙(TGP)调节小鼠免疫功能的部分机理。TGP(5 mg/kg·d~(-1)×8d,ip)拮抗环磷酰胺(Cy)所致小鼠DTH反应增高,与其使L3T4~+/Lyt-2~+细胞比值降低有关;TGP(5mg/kg·d~(-1)×5d,ip)拮抗Cy所致小鼠DTH反应低下及脾细胞抗SRBC溶血素的减少,与其使该比值增高有关。提示TGP对小鼠免疫功能的调节作用与其调节Th/Ts细胞比值有关。     

Acute immunotoxicity of p-chloronitrobenzene in mice: II. Effect of p-chloronitrobenzene on the immunophenotype of murine splenocytes determined by flow cytometry.

To evaluate the immunotoxicity of p-chloronitrobenzene (p-CNB), we investigated its effect on the immunophenotype of murine splenocytes. BDF1 male mice were randomly divided into exposed and control groups: the exposed group received p-CNB at 300 mg/kg dissolved in olive oil, while the control group received only olive oil, by a single intraperitoneal (i.p.) or subcutaneous (s.c.) injection. On days 3, 5, 7, and 10 after the injection, splenocytes were harvested from both groups, and the following cell phenotypes were quantified by flow cytometry: (1) B cells (CD45R/B220); (2) T cells (CD3e); (3) T-cell subsets (CD4 and CD8a); (4) natural killer (NK) cells (NK-1.1); (5) macrophages (CD11b; Mac-1); (6) nucleated erythrocytes (Ter-119); and (7) dead cells with propidium iodide (PI). The percentages and numbers of B, T, subsets of T (CD4 and CD8), and NK cells in the exposed mice significantly decreased as compared with the respective control. On the other hand, macrophages (Mac-1+ cells), nucleated erythrocytes (Ter-119+ cells), and dead cells in the exposed mice markedly increased as compared with the respective control after i.p. injection of p-CNB. The above findings indicate that p-CNB has an immunotoxic effect on mice.     

肺肿瘤小鼠MDSC、 Treg 及传统T 细胞变化研究

摘要： 目的 探讨肺肿瘤小鼠骨髓源性抑制细胞 （MDSC）、 调节性 T 细胞 （Treg） 和传统 T 细胞的变化及机制。方法 采用配对设计将 20 只 C57BL/6 小鼠随机均分为 Lewis 肺癌细胞注射组 （LLC 组） 和正常对照组 （NC 组）, LLC 组采用皮下注射 LLC 细胞 100 μL （1×106 ） 制备肺肿瘤小鼠模型, 对照组注射等量生理盐水。待肿瘤形成后取小鼠脾细胞, 采用流式细胞仪检测肺肿瘤小鼠 MDSC、 Treg 及 CD4+ 和 CD8+ T 细胞比例和数量变化, 膜联蛋白-V （Annexin-Ⅴ）染色检测 CD4+ 和 CD8+ T 细胞凋亡变化, 5-溴脱氧尿嘧啶核苷 （BrdU） 染色检测 CD4+ 和 CD8+ T 细胞增殖变化。结果 与 NC 组相比, LLC 组脾脏 MDSC 比例和数量明显增加, CD4+ Foxp3+ Treg 所占 CD4+ T 细胞比例和数量明显增加,而 CD4+ 和 CD8+ T 细胞所占脾细胞比例和数量明显降低 （均 P < 0.05）。与 NC 组相比, LLC 组 CD4+ 和 CD8+ T 细胞增殖明显降低, 同时 CD8+ T 细胞凋亡明显增加 （P < 0.05）。结论 MDSC 和 Treg 细胞在肺肿瘤小鼠数量增加, 同时, MDSC 和Treg 抑制 CD4+ 和CD8+ T 细胞增殖, 并促进 CD8+ T 细胞凋亡。     

Effects of a Low Dose of T-2 Toxin on the Percentage of T and B Lymphocytes and Cytokine Secretion in the Porcine Ileal Wall

Plant materials used in the production of pig feed are frequently contaminated with mycotoxins. T-2 toxin is a secondary metabolite of selected Fusarium species, and it can exert a harmful influence on living organisms. Most mycotoxins enter the body via the gastrointestinal tract, and they can modulate the gut-associated lymphoid tissue (GALT) function. However, little is known about the influence of low T-2 toxin doses on GALT. Therefore, the aim of this study was to evaluate the effect of T-2 toxin administered at 50% of the lowest-observed-adverse-effect level (LOAEL) on the percentage of CD2+ T cells, CD4+ T helper cells, CD8+ cytotoxic T cells, CD4+CD8+ double-positive T cells, TCRγδ+ cells, CD5+CD8- B1 cells, and CD21+ B2 cells, and the secretion of proinflammatory (IFN-γ, IL-1β, IL-2, IL-12/23p40, IL-17A), anti-inflammatory, and regulatory (IL-4, IL-10, TGF-β) cytokines in the porcine ileal wall. The results of the study revealed that T-2 toxin disrupts the development of tolerance to food antigens by enhancing the secretion of proinflammatory and regulatory cytokines and decreasing the production of anti-inflammatory TGF-β. T-2 toxin triggered the cellular response, which was manifested by an increase in the percentage of CD8+ T cells and a decrease in the percentage of B2 and Tγδ lymphocytes.     

Glycidol modulation of the immune responses in female B6C3F1 mice

The immunotoxic potential of glycidol was evaluated in female B6C3F1 mice using a battery of functional assays and three host resistance models. Glycidol was administered to the animals by oral gavage as a solution in sterile distilled water daily for 14 days at doses of 25, 125 and 250 mg/kg. In tier I, we observed that glycidol exposure produced a dose-related decrease in splenocyte IgM antibody-forming cell response to sheep red blood cells (sRBC); the spleen natural killer (NK) cell activity was also decreased. A decrease in B cell proliferative responses to anti-IgM F(ab')2 and/or interleukin-4 (IL-4) was observed while the splenocyte proliferative responses to T cell mitogen ConA and B cell mitogen LPS were not affected. The splenocyte proliferative response to allogeneic cells as evaluated in the mixed leukocyte reaction (MLR) to DBA/2 spleen cells was not affected. In tier II, we found that exposure to glycidol decreased the number and percentage of B cells and the absolute number of CD4+ T cells in the spleen while the number of total T cells, CD8+ T cells and CD4+CD8+ T cells was not affected. The cytotoxic T lymphocyte (CTL) response to mitomycin C-treated P815 mastocytoma was not affected; the cytotoxic activity of peritoneal macrophages was not suppressed. Moreover, the host resistance to Listeria monocytogenes was not affected although a slight increase in host resistance to Streptococcus pneumoniae was observed. However, exposure to glycidol decreased host resistance to the B16F10 melanoma tumor model with the maximal tumor formation in lung observed in the high dose group. Overall, these dada support the finding that glycidol is an immunosuppressive agent in female B6C3F1 mice.     

CYP2E1-dependent and leptin-mediated hepatic CD57 expression on CD8 + T cells aid progression of environment-linked nonalcoholic steatohepatitis

Environmental toxins induce a novel CYP2E1/leptin signaling axis in liver. This in turn activates a poorly characterized innate immune response that contributes to nonalcoholic steatohepatitis (NASH) progression. To identify the relevant subsets of T-lymphocytes in CYP2E1-dependent, environment-linked NASH, we utilized a model of diet induced obese (DIO) mice that are chronically exposed to bromodichloromethane. Mice deficient in CYP2E1, leptin (ob/ob mice), or both T and B cells (Pfp/Rag2 double knockout (KO) mice) were used to delineate the role of each of these factors in metabolic oxidative stress-induced T cell activation. Results revealed that elevated levels of lipid peroxidation, tyrosyl radical formation, mitochondrial tyrosine nitration and hepatic leptin as a consequence of metabolic oxidative stress caused increased levels of hepatic CD57, a marker of peripheral blood lymphocytes including NKT cells. CD8 + CD57 + cytotoxic T cells but not CD4 + CD57 + cells were significantly decreased in mice lacking CYP2E1 and leptin. There was a significant increase in the levels of T cell cytokines IL-2, IL-1β, and IFN-γ in bromodichloromethane exposed DIO mice but not in mice that lacked CYP2E1, leptin or T and B cells. Apoptosis as evidenced by TUNEL assay and levels of cleaved caspase-3 was significantly lower in leptin and Pfp/Rag2 KO mice and highly correlated with protection from NASH. The results described above suggest that higher levels of oxidative stress-induced leptin mediated CD8 + CD57 + T cells play an important role in the development of NASH. It also provides a novel insight of immune dysregulation and may be a key biomarker in NASH.