rHu TNF-α促进人胚和小鼠胸腺细胞增殖作用的研究

本文观察了rHuTNF-α对ConA诱导的10～15日龄BALB/C乳鼠胸腺细胞、脾细胞以及PHA或TPA诱导的20～32周龄人胚胸腺细胞增殖的调节作用。结果表明:rHuTNF-a对上述增殖作用均有显著的促进作用,并且呈剂量依赖关系;rHuTNF-a对rHuIL-2促进ConA诱导的小鼠胸腺细胞和脾细胞的增殖反应有协同作用。此结果提示rHuTNF-a在促进丝裂原诱导的胸腺细胞增殖作用中无明显种属特异性,并且对于了解TNF-a在胸腺细胞发育中的作用以及在某些病毒性感染疾病患者血清中高水平的TNF-a活性与胸腺功能改变的关系方面均有一定的意义。     

四氧嘧啶糖尿病小鼠免疫状态及胰岛素免疫调节作用的研究

本文以四氧嘧啶糖尿病小鼠为模型,探讨了糖尿病小鼠在高血糖低胰岛素状态下对免疫器官、自然杀伤活性细胞、脾淋巴细胞增殖及IL-2产生的影响。结果表明,高血糖低胰岛素状态可致小鼠脾脏及胸腺明显萎缩,脾细胞总数减少(均P<0.01)。体内YAC-1细胞清除率降低,淋巴细胞对ConA的增殖反应及IL-2产生能力减弱。体外给予胰岛素可使病鼠淋巴细胞对ConA的增殖反应显著升高,IL-2合成增多,表明胰岛素具有重要的免疫调节作用。     

大肠癌模型动物脾细胞的IL-2诱生水平和NK细胞活性的动态观察

本文报道以二甲肼诱发的大肠癌小鼠为动物模型,于肿瘤生长的不同阶段,分别测定其脾细胞产生IL-2能力,对ConA的增殖反应及NK细胞活性。结果表明,荷瘤鼠脾细胞产生IL-2能力和对ConA的增殖反应均明显受到抑制,且随荷瘤期的延长其受抑制程度加剧,但荷瘤鼠的NK细胞活性变化与对照鼠无显著差异。     

盐酸小檗碱对小鼠脾细胞增殖和凋亡及分泌细胞因子的影响

目的 研究盐酸小檗碱(BBR)对小鼠脾细胞增殖与凋亡及细胞因子产生的影响.方法 采用无菌取BALB/c小鼠脾脏,制成脾细胞悬液,脾细胞预先用(1、2、4) μg/mL BBR处理60 min,加入刀豆蛋白(ConA)刺激脾细胞增殖,细胞培养至24、48、72 h时,用MTT方法检测脾细胞增殖情况;流式细胞术检测脾细胞培养不同时间的凋亡情况,用细胞因子ELISA检测试剂盒定量分析细胞上清液中TNF-α,IL-2和IFN-γ的浓度.结果 与对照组相比,在以上浓度范围内,BBR对ConA刺激下实验组小鼠脾细胞的增殖和TNF-α,IL-2,IFN-γ产生有明显的抑制作用(P＜0.05),且呈浓度及时间依赖性,但对小鼠脾细胞凋亡无明显影响(P>0.05).结论 BBR对小鼠脾细胞具有明显的免疫抑制作用,可作为潜在的免疫抑制药物.     

心房肽对自发性高血压大鼠免疫细胞增殖活性的影响

本文探讨了心房肽对免疫细胞增殖活性的影响。结果表明,心房肽可以直接促进大鼠胸腺细胞的增殖反应,亦可协同ConA促进脾细胞及T细胞的增殖反应,协同IL-2促进经ConA诱导的淋巴母细胞增殖;心房肽还可促进ConA诱导的大鼠脾细胞产生IL-2。但心房肽并不影响B细胞的增殖反应,也不影响巨噬细胞产生IL-1。同时发现,自发性高血压大鼠脾细胞和胸腺细胞对心房肽与ConA协同刺激的增殖反应性低下。     

多房棘球绦虫重组Bb-EmⅡ/3-Em14-3-3疫苗诱导小鼠细胞因子变化的研究

目的:研究多房棘球绦虫重组Bb-EmⅡ/3-Em14-3-3疫苗对原头蚴攻击小鼠细胞因子变化的影响.方法:将重组Bb-EmⅡ/3-Em14-3-3疫苗分别通过皮下注射、肌肉注射、鼻腔黏膜接种和口服接种免疫BALB/c小鼠12周后, 用50个多房棘球绦虫原头蚴腹腔注射进行攻击, 攻击感染后18周剖杀小鼠, 取脾脏制备淋巴细胞悬液体外培养, 分别以多房棘球绦虫抗原(EmAg)、 刀豆素A(ConA)刺激诱生白细胞介素12(IL-12)、白细胞介素10(IL-10)和干扰素γ(IFN-γ);以脂多糖(LPS)刺激诱生肿瘤坏死因子α(TNF-α).常规ELISA测定脾细胞培养上清液中IL-12、 IL-10、 IFN-γ和TNF-α水平.结果:与对照组相比,疫苗免疫组IFN-γ、 IL-12、 TNF-α水平增加, IL-10水平降低, EmAg刺激组和ConA或LPS刺激组细胞因子水平明显高于相应的原液组.结论:多房棘球绦虫重组Bb-EmⅡ/3-Em14-3-3疫苗可诱导攻击感染小鼠产生Th1型细胞免疫应答, 增强宿主抗多房棘球绦虫感染的保护性免疫反应.     

白术多糖对小鼠淋巴细胞的免疫调节作用

目的:探讨白术多糖对小鼠脾淋巴细胞的免疫调节作用。方法:将白术多糖和ConA或LPS及小鼠脾淋巴细胞在体外共培养,MTT法检测淋巴细胞转化;ELISA法检测细胞培养上清中细胞因子(IL-2、IL-6、IL-10和TNF-α)和IgG含量;RT-qPCR法检测白术多糖联合ConA或LPS对转录因子T-bet、Gata3和NF-κB mRNA表达的影响;流式细胞术检测白术多糖联合LPS对CD3、CD4、CD8和CD19淋巴细胞亚群比例的影响。结果:白术多糖促进ConA诱导的脾脏T淋巴细胞转化、IL-2、IL-6、IL-10和TNF-α分泌和转录因子(T-bet和Gata3)mRNA表达,抑制LPS对脾脏B淋巴细胞的激活,减少TNF-α和IgG分泌,降低NF-κB mRNA表达水平,降低LPS诱导的CD3、CD4和CD8淋巴细胞亚群比例。结论:白术多糖可促进ConA诱导的淋巴细胞转化,但抑制LPS诱导的淋巴细胞转化。     

肾综合征出血热病毒(HFRSV)抗独特型抗体免疫调节初探

本文应用一株HFRSV抗独特型抗体(Ab_2)观察其对HFRSV感染BALB/c小鼠脾细胞体外增殖的影响,以及部分淋巴因子在其中的作用,旨在探讨抗独特型抗体对免疫应答的调节机理。从感染HFRSV小鼠脾细胞中分离制备单个核细胞悬液体外培养,加入不同剂量Ab_2,用~3H-TdR掺入法测定脾细胞增殖水平。结果Ab_2可明显抑制感染小鼠脾细胞在体外的增殖,并呈剂量依赖关系及具有独特型特异性。早期加入EL-4细胞上清或rHuIL-2可完全逆转此抑制作用,且具有剂量依赖和时间相关性。EL-4细胞上清含有IL-2和IL-6。对抗独特型抗体产生抑制作用的机制进行了讨论。     

雌二醇在体外对脾细胞和胸腺细胞增殖反应的影响

本文研究在体外细胞培养系统中直接加入雌二醇(E_2)对脾细胞和胸腺细胞的作用,发现高剂量(≥5μg/ml)的E_2可直接抑制脾细胞对ConA诱导的增殖反应;但在胸腺细胞的实验中,无论低或高剂量(10~(-2)ng/ml～20μg/ml)的E_2均未发现它对ConA诱导的增殖反应产生明显影响。表明E_2在体外对脾细胞和胸腺细胞的作用存在差异。     

R848协同CD3抗体诱导C57BL/6小鼠脾脏淋巴细胞功能改变

目的观察并初步分析1-[4-amino-2-(ethoxymethyl)imidazo[4,5-c]quinolin-1-yl]-2-methylpropan-2-ol(R848)协同CD3抗体诱导C57BL/6小鼠脾脏中淋巴细胞发生的功能改变。方法分离正常C57BL/6小鼠脾脏的淋巴细胞,分别在anti-CD3、R848及anti-CD3+R848的作用下培养72 h。通过MTT法观察淋巴细胞的增殖情况;采用ELISA的方法检测脾脏淋巴细胞的IFN-γ和IL-4的产生情况;使用细胞内细胞因子染色的方法检测CD4+T和CD8+T细胞的IFN-γ和IL-4的产生情况;再用细胞表面分子染色的方法检测R848诱导不同淋巴细胞群活化的情况。结果单独使用R848对淋巴细胞的增殖作用不明显,但anti-CD3+R848可促进淋巴细胞的增殖;R848能辅助anti-CD3明显诱导脾CD4+T和CD8+T细胞分泌IFN-γ和IL-4;R848能够使淋巴细胞活化,且以B细胞亚群为主。结论 R848能够协助CD3抗体促进脾脏淋巴细胞的增殖,分泌IFN-γ和IL-4,其机制与R848能明显促进B淋巴细胞活化有关。     

Roles of gamma interferon and other cytokines in suppression of the spleen cell proliferative response to concanavalin A and toxoplasma antigen during acute toxoplasmosis.

Suppressed splenocyte proliferation in response to mitogen and toxoplasma lysate antigen (TLA) is observed in mice acutely infected with Toxoplasma gondii. Recently, we reported that NG-monomethyl-L-arginine (NMMA), an inhibitor of reactive nitrogen intermediate (RNI) production, partially restored proliferative responses of splenocytes from infected mice. In the present study we have examined the effect of NMMA on production of cytokines by splenocytes from mice acutely infected with T. gondii and assessed the role of gamma interferon (IFN-gamma) and interleukin-10 (IL-10) in the RNI-mediated suppression. Stimulation with concanavalin A (ConA) or TLA of splenocytes from CBA/Ca mice infected for 7 days resulted in increased production of IFN-gamma, IL-4, and IL-10 but reduced levels of IL-2 when compared with cultures of splenocytes from uninfected mice. Whereas addition of NMMA did not alter levels of cytokines produced by splenocytes from uninfected mice, splenocytes from infected mice stimulated with ConA produced significantly higher levels of IL-10 and reduced levels of IL-2 and IL-4. Addition of anti-IFN-gamma monoclonal antibodies to cultures of spleen cells from mice infected for 7 or 14 days remarkably decreased the levels of nitrite and resulted in a 47- and 4-fold increase in proliferation induced by stimulation with ConA or TLA, respectively. Anti-IL-10 did not reduce levels of nitrite produced in culture but did result in a fourfold increase in the proliferative response of splenocytes from mice infected for 14 days. In vivo administration of anti-IFN-gamma or anti-IL-10 monoclonal antibodies to infected mice partially restored ex vivo spleen cell proliferative responses by approximately 40 and 15%, respectively. Our data indicate that IFN-gamma is important in inducing the RNI-mediated immunosuppression, which, in turn, affects production of cytokines by splenocytes. Our data also demonstrate that IL-10 is involved in the suppression observed but that this activity is independent of RNI.     

Low-level dietary deoxynivalenol and acute exercise stress result in immunotoxicity in BALB/c mice

We hypothesized that acute exercise stress would exacerbate immunosuppressive effects of sub-acute exposure to dietary deoxynivalenol (DON). Male BALB/c mice were fed 0 or 2 mg DON/kg diet for 14 days, 12 animals per dose, and then exercised to fatigue on a treadmill. Mice were euthanized by decapitation, trunk blood and spleens were collected. Single-cell suspensions of splenocytes were used to quantify immune function by plaque hemolysis and conconavalin-A (ConA) stimulated lymphocyte proliferation assays. Serum corticosterone level was determined by enzyme immunoassay. Only the nonexercised DON-fed mice showed significant splenocyte proliferation suppression, 32.9 +/- 17.9% of nonexercised controls (p = 0.021). Exercised controls and DON-fed exercised animals showed splenocyte proliferation of 68-75% of nonexercised controls. Antibody response to a T-dependent antigen, sheep red blood cells, was significantly less for exercised DON-fed mice than in controls (p = 0.031). Serum corticosterone levels were significantly higher for both exercised groups compared to the unexercised groups (p < 0.001). IL-4 secretion from mitogen-stimulated splenocytes was elevated by DON alone (p < 0.05) while IL-2 was elevated by DON with exercise stress (p < 0.05). Our hypothesis was confirmed with respect to T-lymphocyte-dependent antibody production, but not for splenocyte proliferation. Exercise stress abrogated DON-mediated suppression of splenocyte proliferation, perhaps mediated by induction of elevated stress hormones counteracting cytokine expression alterations of DON.     

C57BL/6 mice are more susceptible to antigen-induced pulmonary eosinophilia than BALB/c mice, irrespective of systemic T helper 1/T helper 2 responses

Inflammatory response differences between C57BL/6 and BALB/c mice following ovalbumin (OVA) sensitization and a single challenge were investigated. Serum immunoglobulin (Ig)E and IgG1 levels were higher in C57BL/6 mice than in BALB/c mice. In contrast, IgG2a levels in C57BL/6 mice were lower than in BALB/c mice. Furthermore, the number of eosinophils infiltrating into lungs in C57BL/6 mice was significantly higher than in BALB/c mice after OVA challenge. The levels of the T helper 2 (Th2)-type cytokines interleukin (IL)-4 and IL-5, generated in challenged C57BL/6 lung tissue, were also higher than in BALB/c lung tissue. The participation of IL-4 and IL-5 in the induction of eosinophil infiltration into the lungs was confirmed in both strains of mice by injection of anti-IL-4 and anti-IL-5 monoclonal antibodies (mAbs). However, following OVA stimulation, in vitro IL-4 and IL-5 production in splenocyte cultures from C57BL/6 mice was lower than in splenocyte cultures from BALB/c mice. These results indicate that C57BL/6 mice induce Th2-type responses in the lungs, while BALB/c mice induce T helper 1 (Th1)-type responses in the lungs, despite considerable production of IL-4 and IL-5 from splenocytes. Therefore, local immune responses are more important in the induction of allergic inflammation in the lungs and are different from systemic immune responses, which are thought to depend on genetic background.     

The initial immune response during experimental cysticercosis is of the mixed Th1/Th2 type

The immunological events that occur during the initial stages of experimental cysticercosis are not known. The studies presented here examined the cytokines produced by peritoneal exudate cells (PECs), splenocytes and mesenteric lymph node (MLN) cells during the first week of infection with larval Taenia crassiceps in BALB/cJ mice. Proliferation assays determined that the earliest time when antigen-specific responses could be measured was 5 days post-infection. Concanavalin A (ConA) stimulation of host cells elicited an initial burst of IL-4 production at 24 h of infection and ConA-stimulated Th2-type cytokine production is predominant by 7 days post-infection. Thus, there are responses at day 1 of infection that seem to promote a Th2-type response. Stimulation of MLN cells, splenocytes and PECs with larval antigens supported previous reports of mixed Th1/Th2-type cytokine production with increases in interleukin (IL)-4, IL-10 and interferon (IFN)-gamma. Ex vivo IFN-gamma production by PECs from infected mice was increased at 3, 5 and 7 days post-infection, whereas at these times reduced ex vivo IL-10 production was observed. This ex vivo IFN-gamma response preceded an increasing IL-10 production by PECs between 3 and 7 days post-infection in parasite-specific and ConA-induced proliferation assays. Thus, infection with larval T. crassiceps results in an initial response mediated by IFN-gamma that is quickly followed by an increase in IL-10 production and subsequent reduction in the amount of IFN-gamma being produced.     

Analysis of the Capacity to Produce IL-3 in Murine AIDS

Adult C57BL/6 mice infected with LP-BM5 murine leukaemia virus represent a model of murine AIDS (MAIDS). In this study we have analysed the capacity of CD4⁺ T cells from infected mice to produce IL-3 following stimulation with ConA for 24–72 h. In contrast to the position with IL-2, the production of which is markedly impaired during LP-BM5 infection, similar levels of IL-3 were measured in culture supernatants of splenocytes from infected and uninfected mice harvested at 24 h of stimulation. Forty eight and 72 h of ConA stimulation led to increasing levels of IL-3 being measured in cultures from uninfected mice, whilst in cultures from infected animals, IL-3 levels remained stagnant. Similar results were obtained 4, 8 and 13 weeks post-infection. In view of the fact that parallel experiments revealed markedly impaired proliferative responses to ConA during MAIDS, we conclude that IL-3 production is basically intact at the cellular level in T cells during MAIDS; but when in a situation requiring clonal expansion of the activated T cells, IL-3 production will be inhibited owing to the impaired capacity for proliferation.     

Deficit of interleukin 2 production associated with impaired T-cell proliferative responses in Mycobacterium lepraemurium infection.

C57BL/6 and BALB/c mice were infected intravenously with 10(7) Mycobacterium lepraemurium (MLM). At various times after infection, spleen cells were tested for their capacity to proliferate in vitro in response to concanavalin A (ConA) and to allogeneic cells. The generation of alloreactive cytotoxic T lymphocytes was also studied. The mitogen- and allogeneic-cell-induced blastogenesis of splenocytes from MLM-infected C57BL/6 and BALB/c mice was shown to be depressed during infection. The maximal decrease occurred 6 months after infection. Conversely, no reduction in the ability to generate alloreactive cytotoxic T lymphocytes was observed even after 6 months of infection. At the same time, interleukin 2 (IL2) activity generated by ConA stimulation of infected splenocytes was measured in both strains. IL2 activity in the ConA-stimulated culture supernatants was decreased as early as 1 month after MLM inoculation as compared with supernatants from age-matched control mice. Thus, IL2 production by infected-mouse spleen cells was shown to decline earlier than their proliferative responses to ConA and to allogeneic cells. ConA-induced T-cell blasts from infected mice showed a reduced ability to proliferate when incubated with an IL2-containing reference supernatant from ConA-stimulated normal spleen cells. These data suggest that a defect in IL2 production and utilization might contribute to the impairment of T cell-mediated immunity observed in MLM-infected mice.     

Beta-adrenoceptor-induced inhibition of rat splenocyte proliferation: cytokine gene transcription as the target of action

Recently, we have demonstrated that behavioral conditioning reduced splenocyte proliferation and IL-2 production in DA rats, and that these behaviorally conditioned immunosuppressive effects were completely abrogated by prior surgical denervation of the spleen. Since the splenic denervation significantly reduced catecholamine concentrations in the spleen, adrenergic mechanisms have been considered to play an important role in conditioned immunosuppression observed in this model. Thus, the current in vitro studies were designed to analyze the influence of adrenergic mechanisms on the proliferation of rat splenocytes, their IL-2 production, and IL-2 mRNA expression. The data demonstrate that beta-adrenoceptor agonist isoproterenol at concentrations of 10(-5) M diminished mitogen (ConA)-induced splenocyte proliferation by 75%, which was associated with a pronounced (50%) decrease in IL-2 production at both the protein and mRNA levels. The beta-adrenoceptor antagonist propranolol completely reversed the isoproterenol-mediated suppressive effects. Stimulation of splenocytes with the mitogen and either the alpha1-adrenoceptor agonist methoxamine or the alpha2-adrenoceptor agonist UK-14,304 did not affect splenocyte proliferation, IL-2 synthesis or IL-2 mRNA expression. These data demonstrate that catecholamines inhibit splenocyte proliferation and IL-2 production via a beta-adrenoceptor-induced regulation of IL-2 mRNA expression, indicating that beta-adrenoceptor mechanisms are responsible for behaviorally conditioned immunosuppression.