藤黄微球菌Rpf结构域多肽诱导小鼠免疫应答的实验研究

目的:研究藤黄微球菌Rpf结构域多肽的免疫学特性.方法:用原核表达的藤黄微球菌Rpf结构域多肽免疫哌BALB/c小鼠3次,每次间隔2周.用ELISA法检测免疫小鼠血清中特异性抗体滴度.分离免疫小鼠的脾淋巴细胞,体外用抗原再刺激后,用MTT比色法检测免疫小鼠脾淋巴细胞的增值指数.ELISA方法检测淋巴淋巴细胞悬液中IFN-γ、IL-10和IL-12产生水平.另一部分免疫的小鼠经尾静脉感染MTB毒株H37Rv,4周后,计数脾脏细菌负荷数.结果:藤黄微球菌Rpf结构域多肽免疫小鼠血清特异性抗体滴度为1∶128 000,淋巴细胞增殖指数为(2.10±0.12),明显高于生理盐水对照组(0.90±0.21).ELISA方法检测Rpf结构域多肽免疫组IFN-γ,IL-10和IL-12水平为(1 126±36) ng/L,(368±13)ng/L和(289±14)ng/L,明显高于生理盐水对照组(P<0.01).与生理盐水免疫组(细菌负荷6.64±0.13)相比较,Rpf结构域多肽免疫的BALB/c小鼠,对攻击感染后抗MTB在脾脏中增殖有明显作用(细菌负荷为5.03±0.11,P<0.05).结论:藤黄微球菌Rpf结构域多肽有可能作为新型结核疫苗的候选组分.     

结核分枝杆菌ESAT6-CFP10融合蛋白诱导的小鼠免疫应答及其保护力

目的:研究结核分枝杆菌(MTB)ESAT6-CFP10融合蛋白诱导的小鼠体液和细胞免疫应答以及对MTB感染小鼠的保护能力。方法:用预先转移到硝酸纤维素膜条的ES-AT6-CFP10融合蛋白采用皮下包埋的方法免疫小鼠。用MTB培养上清滤液蛋白(CFP)作为抗原,用ELISA法测定免疫小鼠血清特异性抗体的滴度。末次免疫后,取部分免疫小鼠脾淋巴细胞,体外用ESAT6-CFP10融合蛋白刺激后,以MTT比色法检测淋巴细胞增殖反应,同时检测免疫小鼠IFN-γ和IL-2水平及脾细胞杀伤效应。另一部分免疫的BALB/c小鼠经尾静脉感染MTB毒株H37Rv,4周后计数脾脏中的细菌数。结果:ESAT6-CFP10融合蛋白免疫小鼠血清特异性抗体的滴度为1∶6400。淋巴细胞刺激增殖指数为1.90±0.15,明显高于生理盐水组(0.90±0.15);IFN-γ和IL-2的含量分别为1.792±19ng/L和0.211±11ng/L,显著高于生理盐水对照组,但不及BCG免疫组;同时融合蛋白诱导的脾细胞杀伤率为36%。与生理盐水免疫组(细菌负荷6.51±0.13)相比较,融和蛋白免疫的BALB/c小鼠,对攻击感染后MTB在脾脏中增殖有显著作用(细菌负荷为5.24±0.15,P<0.05),但与BCG免疫组相比脾脏中细菌负荷减少甚微。结论:ESAT6-CFP10融合蛋白可作为新型结核疫苗的候选组分。     

结核分枝杆菌MPT64重组母牛分枝杆菌免疫学特性

目的:研究结核分枝杆菌MPT64重组母牛分枝杆菌疫苗免疫学特性.方法:用分泌表达MPT64的重组母牛分枝杆菌疫苗免疫BALB/c小鼠,ELISA法检测免疫小鼠的特异性抗体滴度和抗体亚类.分离免疫小鼠脾淋巴细胞,检测淋巴细胞增殖、IFN-γ和IL-12产生水平、CD4+细胞和CD8+细胞数、脾淋巴细胞特异性CTL杀伤效应.毒株攻击后对脾脏细菌负荷计数.结果:MPT64重组母牛分枝杆菌疫苗免疫可诱导小鼠高水平的体液免疫应答,免疫小鼠脾淋巴增殖明显,IFN-γ和IL-12含量增加,CD4+和CD8+细胞百分比明显增加,CTL杀伤效应明显,对MTB H37Rv攻击后有一定的保护作用.结论:MPT64重组母牛分枝杆菌疫苗可诱导小鼠有效的体液和细胞免疫应答,有可能作为新型TB疫苗候选.     

乙型肝炎疫苗联合B7-H1蛋白疫苗对HBV转基因小鼠抗HBsAg免疫应答的影响

目的:研究B7-H1蛋白疫苗对HBV转基因小鼠免疫应答的影响,探索治疗慢性乙型肝炎的新方法。方法:用不同剂量的乙型肝炎疫苗和B7-H1蛋白疫苗联合免疫HBV转基因小鼠,应用ELISA法检测转基因小鼠在不同时间点血清抗B7-H1抗体滴度,同时在免疫后第14周末处死小鼠取脾细胞,检测不同的免疫方法对小鼠脾细胞产生HBsAg特异性Th1类细胞因子(IFN-γ及IL-2)、对HBsAg特异性分泌IFN-γT细胞数量及对小鼠淋巴细胞增殖的影响。结果:成功完成小鼠的免疫计划,5周起血清中即能测到B7-H1抗体,同一时间点各组之间的抗体滴度值并无明显差异。加B7-H1蛋白免疫各组与相同剂量单用HBsAg蛋白免疫各组相比:IL-2均明显减低(P<0.05),分泌IFN-γT的T细胞数量下降,但脾淋巴细胞分泌IFN-γ的水平各组间无明显差异;MTT法测定的淋巴细胞增殖能力各组间也无明显变化。结论:B7-H1蛋白疫苗可诱导HBV转基因小鼠产生明显的抗B7-H1抗体应答,但不能增强抗HBsAg的免疫应答。较小剂量的HBsAg即可引起HBV转基因小鼠Th1类细胞因子(IFN-γ及IL-2)的分泌以及淋巴细胞增殖。     

Flt3L及CCL5对prime/boost免疫策略中抗原特异性免疫应答的增强及抗肿瘤作用

目的:研究Flt3L与CCL5作为联合佐剂在prime/boost免疫策略中对HBc抗原特异性免疫应答的增强及抗肿瘤作用.方法:将两种细胞因子质粒与携带HBc抗原的DNA疫苗经肌内注射法共免疫小鼠, 免疫3次后再用原核表达的HBc颗粒蛋白或HBc DNA疫苗加强, 观察对稳定表达HBcAg 的小鼠黑色素瘤细胞(B16-HBc)的生长抑制作用;并分别采用MTT法检测荷瘤小鼠脾淋巴细胞增殖、流式细胞术检测脾CD8 T淋巴细胞中IFN-γ表达、ELISA法检测脾淋巴细胞培养上清IL-2、IL-4含量及乳酸脱氢酶(LDH)释放法检测特异性CTL杀伤活性.结果:与对照组相比, 佐剂联合DNA疫苗免疫经蛋白加强组(DDP/Adj)显著抑制肿瘤生长;佐剂联合DNA疫苗免疫组(DDD/Adj)及DDP/Adj组均可促进特异性淋巴细胞增殖反应(P＜0.05), 且DDP/Adj 高于DDD/Adj组(P＜0.05);DDD/Adj 及DDP/Adj组小鼠脾脏CD8 T淋巴细胞中IFN-γ表达、IL-2 表达水平及CTL杀靶活性均高于对照组(P＜0.01或P＜0.05), IL-4 表达水平在各组无显著区别(P＞0.05).结论:在prime/boost免疫策略中, 采用Flt3L与CCL5两种细胞因子联合应用可显著促进荷瘤小鼠产生抗原特异性免疫应答及抗肿瘤作用.     

不可分型流感嗜血杆菌P6 DNA疫苗与蛋白疫苗序贯免疫效应研究

观察不可分型流感嗜血杆菌P6DNA疫苗初免蛋白疫苗加强免疫方式的免疫效果。大量扩增pcDNA3-P6。将65只BALB/c小鼠随机分PBS对照组、pcDNA3.1对照组、pcDNA3.1-P6组、P6蛋白组、pcDNA3.1-P6/P6蛋白组,分别于0、14、28d免疫。质粒每次每只接种100μg,蛋白每次每只接种10μg。末次免疫后14d,每组取10只小鼠取血,ELISA检测血清中特异性IgG抗体滴度。每组取3只小鼠处死,制备脾淋巴细胞,ELISA检测IL-4和IFN-γ水平,CCK-8法检测脾淋巴细胞增殖指数。用15LD50NTHi攻击每组剩余10只小鼠,观察免疫保护作用。结果:pcDNA3.1-P6/P6蛋白组小鼠的脾淋巴增殖指数和IFN-γ水平明显高于质粒组和蛋白组(P0.05)。pcDNA3.1-P6/P6蛋白组小鼠IgG抗体滴度、IL-4水平和动物生存率明显高于质粒组(P0.05)但和蛋白组相比无明显差异(P0.05)。因此pcDNA3.1-P6初免P6蛋白加强免疫的方式可以提高疫苗的免疫效果。     

小鼠接种HBV疫苗引起的特异性细胞免疫反应

目的：研究小鼠免疫接种基因重组乙型肝炎表面抗原疫苗(rHBs)产生的特异性细胞免疫反应。 方法： 40只BALB/c小鼠随机分为0.65、1.25、2.5、5 μg 4组，腹腔分别接种0.65、1.25、2.5、5 μg的rHBs 1次或2次。初次免疫后4周或加强免疫后2周分离小鼠脾T淋巴细胞；分别进行以下实验：实验组用rHBs(10 mg/L)刺激脾T淋巴细胞，对照组用PBS代替rHBs刺激脾T淋巴细胞；3 d后用［3H］掺入法检测脾T淋巴细胞特异性增殖反应，以［3H］掺入的同位素counts·min-1值及刺激指数(SI, 实验组counts·min-1值/对照组counts·min-1值)表示。同时用ELISA方法检测培养液中白细胞介素-2(IL-2)及γ-干扰素(IFN-γ)的浓度。 结果：只接受单次免疫的0.65、1.25、2.5、5 μg组小鼠脾T淋巴细胞特异性增殖反应SI分别为1.55、1.93、2.41、2.811；小鼠脾T淋巴细胞释放的IL-2分别为(5.48±8.88)、(9.28±6.98)、(28.53±14.32)、(64.69±20.88)ng/L，释放的IFN-γ分别为(8.22±8.61)、(9.89±9.34)、(20.27±15.50)、(30.77±22.12)ng/L。接受加强免疫的0.65、1.25、2.5、5 μg组小鼠脾T淋巴细胞特异性增殖反应SI分别为1.61、2.05、3.74、3.62；小鼠脾T淋巴细胞释放的IL-2分别为(5.75±5.04)、(102.53±67.52)、(177.13±91.12)、(332.10±124.31)ng/L，释放的γ-干扰素分别为(3.63±4.42)、(28.33±13.04)、(59.66±25.75)、(80.73±19.30)ng/L。 结论： 小鼠接种rHBs后, 脾T淋巴细胞产生特异性增殖反应，并特异性分泌IL-2、γ-干扰素，反应强度与是否加强免疫及接种的剂量密切相关。     

体外CD134L单抗或CTLA4Ig对狼疮样BXSB小鼠脾细胞分泌IL-6、IFN-γ及自身抗体的影响

目的:探讨体外CD134L单抗或CTLA4Ig对狼疮样BXSB小鼠脾细胞分泌IL-6、IFN-γ及自身抗体的影响。方法:采用未经治疗的狼疮样BXSB小鼠模型,应用CD134L单抗和/或CTLA4Ig体外特异性阻断CD134-CD134L或B7-CD28通路后,用MTT法测定分裂原刀豆蛋白A(ConA)诱导的脾淋巴细胞增殖反应和用ELISA方法测定ConA诱导的脾细胞培养上清液中IL-6、IFN-γ和抗ds-DNA抗体的表达水平,并与经中药狼疮方或强的松治疗的狼疮样BXSB小鼠模型进行比较。结果: (1)在单纯培养或经ConA刺激后培养,相比于正常对照鼠,狼疮样小鼠脾淋巴细胞都表现有增殖反应性的显著增高,IFN-γ、 IL-6蛋白量的增高和抗ds-DNA抗体的过度分泌。(2)经强的松或中药狼疮方体内治疗后,狼疮样小鼠脾淋巴细胞体外培养的增殖反应性及IFN-γ、IL-6的分泌都受到明显抑制,抗ds-DNA抗体的产生也明显减少。(3)体外单独应用CD134L单抗或 CTLA4Ig特异性阻断CD134-CD134L或B7-CD28共刺激信号通路,同样可以显著抑制体外培养的狼疮样小鼠脾淋巴细胞的增殖反应及IFN-γ、IL-6的分泌,并可明显减少抗ds-DNA抗体的产生,但它们的抑制作用比强的松、中药狼疮方体内治疗狼疮样小鼠时所表现出的类似效应要弱。(4)联合CD134L单抗和CTLA4Ig,则治疗作用显著提高,其抑制脾淋巴细胞的增殖反应及 IFN-γ、IL-6的分泌,抗ds-DNA抗体产生的作用都优于中药狼疮方的体内治疗效果,而与强的松的体内治疗效应相当。结论: CD134-CD134L可以提供独立的、非B7-CD28依赖的,另一种驱动抗原特异性T细胞增殖的协同刺激通路。同时阻断B7与 CD28、CD134L与CD134间的相互作用,使自身反应性T淋巴细胞的活化和增殖受到快速而最大限度的抑制,对治疗SLE等自身免疫性疾病可能是一种较理想的免疫干预模式。     

Cpn0308真核表达载体的构建及对小鼠免疫功能的影响

目的:构建Cpn0308重组质粒pcDNA3.1/His A-Cpn0308,将重组质粒腹腔注射小鼠后观察小鼠免疫反应变化,以期为进一步研究Cpn0308免疫保护性奠定基础。方法:构建pcDNA3.1/His A-Cpn0308,并用菌落PCR、双酶切、序列测定等多种技术确定其正确性;将重组质粒转染HeLa细胞,间接免疫荧光法检测细胞内蛋白表达情况;重组质粒免疫BALB/c小鼠,一定时间后Western blot检测血清Cpn0308抗体特异性,间接ELISA法检测小鼠血清中Cpn0308 IgG抗体水平、ELISA试剂盒检测血清中细胞因子。结果:pcDNA3.1/His A-Cpn0308重组质粒构建成功且序列正确;重组质粒转染的HeLa细胞胞浆观察到黄绿色荧光,对照组无荧光;重组质粒组血清抗体A450x±s为0.343±0.024,pcDNA3.1/His A质粒组为0.174±0.018,PBS组为0.156±0.023,WB结果显示重组质粒组小鼠血清稀释800倍后仍有特异性目的条带出现,对照组不出现;重组质粒组小鼠IFN-γ浓度均值为264 ng/L,IL-4浓度均值为22 ng/L,pcDNA3.1/His A质粒组为:IFN-γ120 ng/L,IL-4 10 ng/L,PBS组为:IFN-γ99 ng/L,IL-4 9 ng/L。重组质粒组IgG抗体水平和细胞因子水平明显升高,与对照组相比有统计学差异。结论:pcDNA3.1/His A-Cpn0308真核表达重组质粒构建成功,且能够在真核细胞中表达目的蛋白;重组质粒对小鼠进行免疫后,提高了小鼠血清IgG抗体水平和细胞因子水平,为进一步研究Cpn DNA疫苗以及研究该蛋白的生物学功能提供实验基础。     

多房棘球绦虫ELP重组蛋白疫苗免疫Balb/c小鼠引起的免疫应答

目的：观察多房棘球绦虫ELP重组蛋白疫苗免疫Balb／c小鼠引起的体液和细胞免疫应答。方法：在成功构建多房棘球绦虫elp基因原核表达载体(pQ-ELP)的基础上，以亲和层析法纯化重组蛋白，SDS-PAGE鉴定，Bradford法进行定量。用ELP重组蛋白(A组)及ELP重组蛋白加弗氏佐剂(B组)免疫Balb／c小鼠(10只／组)，以生理盐水(NS组)作对照。ELISA方法检测免疫后不同时间产生的特异性IgG1，IgG2a和IgG2b水平。双抗体夹心ELISA试剂盒检测免疫鼠脾脏单个核细胞(PMNC)在受到特异抗原刺激后，产生IL-4、IL-12和IFN-γ的能力，^3H-TdR掺入法检测脾淋巴细胞的增殖能力。结果：本研究成功获得高纯度重组蛋白ELP。首次免疫后2周，A、B组小鼠均产生了大量的特异IgGl抗体，B组还产生了少量的特异IgG2b抗体。除B组小鼠脾PMNC产生了微量IFN-γ外，A组、NS组IFN-γ及各组IL-4和IL-12均未检出。A、B组小鼠脾淋巴细胞增殖能力增高，其淋巴细胞CPM值分别为NS组的2．8和10．8倍，受到多房棘球绦虫抗原或刀豆素刺激时，A、B组淋巴细胞增殖更明显。结论：多房棘球绦虫ELP重组蛋白疫苗可引起很强的体液免疫应答和微弱的细胞免疫应答，如与弗氏佐剂联合应用引起的细胞免疫应答会进一步提高。     

Decreased severity of myelin oligodendrocyte glycoprotein peptide 33 - 35-induced experimental autoimmune encephalomyelitis in mice with a disrupted TCR delta chain gene

Immunization of C57BL / 6 mice with myelin oligodendrocyte glycoprotein (MOG) peptide (p) 35 - 55 induces chronic experimental autoimmune encephalomyelitis (EAE). The role of gamma delta T cells in the regulation of EAE is unclear. We investigated gamma delta T cells in C57BL / 6 wild-type mice and C57BL / mice with a disrupted TCRdelta chain gene (delta(- / -) mice) using MOG p35 - 55. We found significantly less disease in delta(- / -) mice immunized with MOG / complete Freund's adjuvant (mean maximal EAE score 4.3 +/- 0.8 in wild-type vs. 2.3 +/- 0.5 in delta(- / -) mice). Transfer of wild-type spleen cells restored the ability of delta(- / -) mice to develop equally severe EAE as wild-type mice. In addition to IFN-gamma, IL-2, IL-5 and IL-10 was decreased in delta(- / -) mice. Decreased immune responses were also seen in delta(- / -) animals immunized with OVA peptide or protein and in concanavalin A-stimulated splenocytes from delta(- / -) mice. Enriched dendritic cells from delta(- / -) mice secreted significantly less TNF-alpha in response to lipopolysaccharide stimulation. Furthermore, when EAE was induced by adoptive transfer of an anti-MOG p35 - 55 alpha beta T cell line, there was a striking reduction of disease incidence (0 %) and severity in delta(- / -) as compared to wild-type mice (83 % incidence). delta(- / -) mice showed no cellular infiltration in the spinal cord whereas wild-type animals had infiltration of macrophages, B cells, alpha beta- and gamma delta T cells. In adoptive transfer EAE, there was reduced IL-2 and IFN-gamma secretion in delta(- / -) mice. These results demonstrate an impaired immune response in the delta(- / -) mouse that is associated with a defect in developing both actively induced and adoptively transferred EAE.     

日本血吸虫rGST-Sj32蛋白免疫小鼠感染前后细胞因子水平的变化

目的 :为进一步探讨rGST Sj32保护性免疫机制。 方法 :用rGST Sj32加弗氏完全佐剂 (FCA)皮下免疫BALB/c小鼠。于免疫前 ,攻击感染前 (第 3次免疫后 2wk)以及攻击感染后10d、30d及 4 5d ,各剖杀免疫组与对照组小鼠 5只 ,取脾细胞培养 ,对体外培养的脾细胞诱生的细胞因子进行分析。结果 :用rSj32刺激体外培养的小鼠脾细胞时 ,第 3次免疫后2wk(即攻击感染前 )剖杀小鼠的脾细胞分泌IL 4、IL 5和IFN γ的水平与佐剂对照组相比较 ,均有不同程度的升高 ,分别为 ( 10 .2 1± 3.6 5 )ng/L (P >0 .0 5 )、( 19.89± 9.5 7)ng/L (P >0 .0 5 )、( 5 .0 9± 2 .5 1) μg/L (P <0 .0 1)。攻击感染后10d、30d及 4 5d ,对照组与免疫组IFN γ的水平未见升高 ;对照组IL 4和IL 5的水平随着感染时间的延长明显升高 ,免疫组升高不如对照组明显。结论 :rGST Sj32疫苗免疫BALB/c小鼠后 ,可诱导以Th1类细胞因子为主的免疫应答 ;而攻击性感染则诱导以Th2型细胞因子为主的免疫应答     

Essential pathogenic role of endogenous IL-18 in murine diabetes induced by multiple low doses of streptozotocin. Prevention of hyperglycemia and insulitis by a recombinant IL-18-binding protein: Fc construct

IL-18 is a cytokine structurally and functionally related to IL-1 that, in synergy with IL-12, stimulates the synthesis of IFN-gamma from T lymphocytes and natural killer cells. Because IFN-gamma plays a key pathogenic role in the development of murine immunoinflammatory diabetes induced by multiple low doses of streptozotocin (STZ) we investigated the effect of negating the actions of endogenous IL-18 in this model by administering recombinant IL-18-binding protein:Fc (IL-18 bp:Fc). C57BL/6 mice were injected once daily with 40 mg/kg STZ for 5 consecutive days, day 0 being the first day of STZ challenge. Relative to control animals treated in parallel with either PBS or human IgG, mice treated from day -3 to day 7 with daily doses of 150 microg of IL-18 bp:Fc exhibited lower incidence of diabetes and milder insulitis. In contrast, mice that were treated with IL-18 bp:Fc from day 7 to day 14 exhibited clinical and histological signs of STZ-induced diabetes similar to those of control mice treated with IgG. The protective effect of IL-18 bp:Fc was accompanied by modified ex vivo immune responses, in that spleen cells and peritoneal macrophages contained fewer IFN-gamma secreting cells and released lower amounts of nitrite (an index of nitric oxide production) and IL-1beta. We conclude that intact IL-18 function is essential for the full diabetogenic effect of low dose STZ in C57BL/6 mice.     

Less inhibition of interferon-gamma to organism growth in host cells may contribute to the high susceptibility of C3H mice to Chlamydia trachomatis lung infection

T-helper-1-like cytokine response and cell-mediated immunity have been shown to be critical in host resistance to Chlamydia trachomatis infection. Using a murine pneumonia model, we compared the susceptibility of C3H/HeN (C3H) and C57BL/6 mice to C. trachomatis mouse pneumonitis (MoPn) infection. C3H mice exhibited significantly higher mortality, greater organism growth and much more severe pathological changes in the lung compared with C57BL/6 mice. However, the pattern of adaptive immune responses including organism-specific delayed-type hypersensitivity, antibody responses and cytokine [interferon-gamma (IFN-gamma), interleukin-12 (IL-12), IL-4, IL-10 and tumour necrosis factor alpha] production by spleen and local draining lymph node cells in these two strains of mice appeared comparable during the process of infection. Interestingly, MoPn growth in the cultured ex vivo macrophages from C3H mice was found to be significantly less inhibited by the exogenous IFN-gamma present in the culture compared to C57BL/6 mice. The lower inhibition of MoPn growth in C3H mice was associated with significantly lower nitric oxide production by the infected macrophages following IFN-gamma stimulation. The data suggest that the cellular events downstream of cytokine production in chlamydia host cells may be important in determining the different susceptibility of hosts to chlamydial infection.     

Reciprocal immunomodulatory effects of gamma interferon and interleukin-4 on filaria-induced airway hyperresponsiveness

Tropical pulmonary eosinophilia (TPE) is a severe asthmatic syndrome of lymphatic filariasis, in which an allergic response is induced to microfilariae (Mf) in the lungs. Previously, in a murine model for TPE, we have demonstrated that recombinant interleukin-12 (IL-12) suppresses pulmonary eosinophilia and airway hyperresponsiveness (AHR) by modulating the T helper (Th) response in the lungs from Th2- to Th1-like, with elevated gamma-interferon (IFN-gamma) production and decreased IL-4 and IL-5 production. The present study examined the immunomodulatory roles of IL-4 and IFN-gamma in filaria-induced AHR and pulmonary inflammation using mice genetically deficient in these cytokines. C57BL/6, IL-4 gene knockout (IL-4(-/-)), and IFN-gamma(-/-) mice were first immunized with soluble Brugia malayi antigens and then inoculated intravenously with 200,000 live Mf. Compared with C57BL/6 mice, IL-4(-/-) mice exhibited significantly reduced AHR, whereas IFN-gamma(-/-) mice had increased AHR. Histopathologically, each mouse strain showed increased cellular infiltration into the lung parenchyma and bronchoalveolar space compared with na?ve animals. However, consistent with changes in AHR, IL-4(-/-) mice had less inflammation than C57BL/6 mice, whereas IFN-gamma(-/-) mice had exacerbated pulmonary inflammation with the loss of pulmonary architecture. Systemically, IL-4(-/-) mice produced significantly higher IFN-gamma levels compared with C57BL/6 mice, whereas IFN-gamma(-/-) mice produced significantly higher IL-4 levels. These data indicate that IL-4 is required for the induction of filaria-induced AHR, whereas IFN-gamma suppresses AHR.     

Deficiency of CD26 results in a change of cytokine and immunoglobulin secretion after stimulation by pokeweed mitogen

To investigate the role of CD26 in the immune system, CD26 gene knockout mice with C57BL/6 background were used to study the immune response after stimulation with PWM. CD26(-/-) mice display an apparently normal phenotype. However, in their spleen lymphocyte population the percentage of CD4(+) T cells is lower, and that of NK cells is higher, than that in CD26(+/+) mice. In their peripheral blood, CD26(-/-) mice present a conspicuously decreased proportion of CD4(+) NKT lymphocytes. In vitro, the PWM-stimulated IL-4 production was decreased by 60-80% in the supernatants of spleen lymphocytes of CD26(-/-) mice compared to that of CD26(+/+) mice, whereas levels of IL-10 and IFN-gamma were increased. No significant differences were found in the production of IL-2, IL-5, IL-6 and IL-13 between knockout and wild-type mice. After immunization of mice with PWM in vivo, serum levels of total IgG, IgG1, IgG2a and IgE were markedly lower in CD26(-/-) mice than those in CD26(+/+) mice, while no difference was found in IgM production. Further analysis of cytokine levels in vivo revealed a reduced IL-4, IL-2 and delayed IFN-gamma production in sera of CD26(-/-) mice upon immunization with PWM. These results indicate that CD26 contributes to the regulation of development, maturation and migration of CD4(+) T, NK and NKT cells, cytokine secretion, T cell-dependent antibody production and immunoglobulin isotype switching of B cells.     

Effects of interleukin-4 deprivation and treatment on resistance to Trypanosoma cruzi

Trypanosoma cruzi (Y strain)-infected interleukin-4(-/-) (IL-4(-/-)) mice of strains 129/J, BALB/c, and C57BL/6 showed no significant difference in parasitemia levels or end point mortality rates compared to wild-type (WT) mice. Higher production of gamma interferon (IFN-gamma) by parasite antigen (Ag)-stimulated splenocytes was observed only for C57BL/6 IL-4(-/-) mice. Treatment of 129/J WT mice with recombinant IL-4 (rIL-4), rIL-10, anti-IL-4, and/or anti-IL-10 monoclonal antibodies (MAbs) did not modify parasitism. However, WT mice treated with rIL-4 and rIL-10 had markedly increased parasitism and suppressed IFN-gamma synthesis by spleen cells stimulated with parasite Ag, concanavalin A, or anti-CD3. Addition of anti-IL-4 MAbs to splenocyte cultures from infected WT 129/J, BALB/c, or C57BL/6 mice failed to modify IFN-gamma synthesis levels; in contrast, IL-10 neutralization increased IFN-gamma production and addition of rIL-4 and/or rIL-10 diminished IFN-gamma synthesis. We conclude that endogenous IL-4 is not a major determinant of susceptibility to Y strain T. cruzi infection but that IL-4 can, in association with IL-10, modulate IFN-gamma production and resistance.