黏膜免疫壳聚糖-多胺转运蛋白D(PotD)DNA纳米微粒对小鼠鼻咽部肺炎链球菌定植的保护作用研究

Objective To prepare the chitosan-potD nanoparticles and to evaluate its protective efficacy against pneumococcal nasopharyngeal colonization. Methods potD gene was amplificated from pneumococcal genome and was inserted into pVAX1 expression vectors to construct pVAX1-potD recombinant plasmid which was then transfected into 293T cell using LipofectAMINE 2000 to analyze transient potD gene expression in vitro by RT-PCR and Western blot. Chitosan-potD nanoparticles were freshly prepared by coacervation methods at each time and the characterizations of the nanoparticles were then evaluated. BALB/c mice were immunized with chitosan-potD, naked potD DNA or pVAX1 for 4 times at two-week intervals. Anti-PotD IgG, IgG1 and IgG2a levels in serum and IgA levels in nasal washes, bronchoalveolar lavage fluids (BALF) and middle ear lavages(MEL) were detected by indirect enzyme-linked immunosorbent assay (ELISA). IL-17A, IL-4 and IFN-γ levels in splenocytes were determined by double sandwich ELISA. Mice were intrannsally challenged with Streptococcus pneumoniae ATCC6303, and Pneumococci were recovered from the nasopharyngeal niche at the fifth day after challenge. Results potD gene was successfully amplificated by PCR and the sequence was confimed to be consistent with that in the Genbank. The pVAX1-potD recombinant plasmid was successfully constructed and was expressed in eukaryocytes in vitro. The mean size and zeta potential of chitosan-potD nanoparticles was 430 nm and + 20.5 mv, respectively. Chitosan-potD nanoparticles were not digested by DNase Ⅰ , while naked potD DNA was completely digested. The levels of antibodies inculding IgG, IgG1, IgG2a, IgA and cytokines including IL-17A, IL-4 and IFN-γ were significantly higher in mice immunized with chitosan-potD nanoparticles than mice with naked potD or pVAX1 ( P <0.05) only. More importantly, much less Pneumococci were recovered from mice immunized with chitosan-potD nanoparticles than the other groups(P <0.05). Conclusion Chitosan-potD nanoparticles significantly enhanced the immunogenicity and protection efficacy of DNA vaccines by intranasal immunization and could be used as a potential mucosal vaccine to prevent pneumococcal infection.     

黏膜免疫壳聚糖-多胺转运蛋白D(PotD)DNA纳米微粒对小鼠鼻咽部肺炎链球菌定植的保护作用研究

Objective To prepare the chitosan-potD nanoparticles and to evaluate its protective efficacy against pneumococcal nasopharyngeal colonization. Methods potD gene was amplificated from pneumococcal genome and was inserted into pVAX1 expression vectors to construct pVAX1-potD recombinant plasmid which was then transfected into 293T cell using LipofectAMINE 2000 to analyze transient potD gene expression in vitro by RT-PCR and Western blot. Chitosan-potD nanoparticles were freshly prepared by coacervation methods at each time and the characterizations of the nanoparticles were then evaluated. BALB/c mice were immunized with chitosan-potD, naked potD DNA or pVAX1 for 4 times at two-week intervals. Anti-PotD IgG, IgG1 and IgG2a levels in serum and IgA levels in nasal washes, bronchoalveolar lavage fluids (BALF) and middle ear lavages(MEL) were detected by indirect enzyme-linked immunosorbent assay (ELISA). IL-17A, IL-4 and IFN-γ levels in splenocytes were determined by double sandwich ELISA. Mice were intrannsally challenged with Streptococcus pneumoniae ATCC6303, and Pneumococci were recovered from the nasopharyngeal niche at the fifth day after challenge. Results potD gene was successfully amplificated by PCR and the sequence was confimed to be consistent with that in the Genbank. The pVAX1-potD recombinant plasmid was successfully constructed and was expressed in eukaryocytes in vitro. The mean size and zeta potential of chitosan-potD nanoparticles was 430 nm and + 20.5 mv, respectively. Chitosan-potD nanoparticles were not digested by DNase Ⅰ , while naked potD DNA was completely digested. The levels of antibodies inculding IgG, IgG1, IgG2a, IgA and cytokines including IL-17A, IL-4 and IFN-γ were significantly higher in mice immunized with chitosan-potD nanoparticles than mice with naked potD or pVAX1 ( P <0.05) only. More importantly, much less Pneumococci were recovered from mice immunized with chitosan-potD nanoparticles than the other groups(P <0.05). Conclusion Chitosan-potD nanoparticles significantly enhanced the immunogenicity and protection efficacy of DNA vaccines by intranasal immunization and could be used as a potential mucosal vaccine to prevent pneumococcal infection.     

肺炎支原体P1C-IL-2融合基因疫苗鼻饲对小鼠免疫效果的检测

目的 研究肺炎支原体(Mp) P1C-IL-2融合基因疫苗经鼻饲免疫小鼠后的免疫应答水平和免疫保护作用,了解IL-2对P1C核酸疫苗的免疫佐剂效应.方法 将构建的P1C-IL-2核酸疫苗鼻饲免疫BALB/c鼠,ELISA检测免疫小鼠血清IgG滴度、IgG亚类和支气管肺泡灌洗液中IgA及IFN-γ、IL-4的水平;建立小鼠Mp感染模型,观察Mp攻击后小鼠肺组织炎症情况和支气管肺泡灌洗液中Mp菌落数的变化.结果 P1C-IL-2双基因疫苗组小鼠血清中的总IgG、IgG1、IgG2a亚类和支气管肺泡灌洗液中IFN-γ和IL-4水平均较PIC疫苗组小鼠显著增高(P＜0.05),但两组支气管肺泡灌洗液IgA差异无显著性(P＞0.05).用Mp滴鼻感染免疫小鼠,第1、3、6天P1C-IL-2双基因融合疫苗组小鼠肺组织炎症病理评分显著高于P1C单基因疫苗免疫组小鼠,两组小鼠支气管肺泡灌洗液中的Mp菌落数差异无显著性(P＞0.05).结论 IL-2能显著增强PIC疫苗的免疫应答水平,但在感染早期也激发了较强的肺组织炎症.     

IL-2增强肺炎支原体P1C核酸疫苗的肌注免疫效果

目的:研究IL-2对肺炎支原体(Mycoplasma pneumoniae,Mp)P1C核酸疫苗经肌注免疫BALB/c小鼠后的免疫应答水平和免疫保护作用.方法:将P1C-IL-2核酸疫苗肌注免疫BALB/c鼠,ELISA检测疫苗免疫后56天小鼠血清IgG和IgG亚类、支气管灌洗液中SIgA、IFN-γ和IL-4的水平;用2×107 Mp菌落形成单位鼻饲感染BALB/c鼠,建立感染小鼠模型,病理切片检测Mp感染后小鼠肺部炎症病理改变;将系列10倍稀释的支气管灌洗液接种于SP4固体平板,并进行菌落计数.结果:P1C-IL-2核酸疫苗免疫组小鼠血清中的总IgG、IgG1、IgG2a、IFN-γ和IL-4水平均较P1C单基因疫苗组显著增高(P＜0.05),但两组支气管灌洗液中SIgA差异无显著性(P＞0.05).Mp感染后第1、3、6天P1C-IL-2双基因疫苗组小鼠肺组织病理评分(HPS)较P1C单基因疫苗免疫组显著增高,但支气管灌洗液中的Mp菌落数明显减少;第9天后两组HPS和Mp菌落数差异无显著性.结论:IL-2能显著增强P1C疫苗肌注的免疫保护作用和免疫应答水平,但同时在Mp感染早期激发了较重的肺组织炎症.     

肺炎链球菌溶血素黏膜免疫抗定植保护作用的研究

目的 原核表达ΔA146 Ply蛋白,评价ΔA146 Ply黏膜免疫对肺炎链球菌(Streptococcus pneumoniae,S.pn)在宿主鼻咽部定植的保护作用.方法 IPTG诱导、Ni-NTA树脂纯化获得纯化的ΔA146 Ply蛋白,经黏膜免疫BALB/C小鼠,制备其特异性抗血清;进行体内抗定植实验,观察小鼠...     

rIL-18对肺炎链球菌肺炎小鼠Th1/Th2免疫应答的影响

目的 研究重组白细胞介素18(rIL-18)对肺炎链球菌肺炎小鼠Th1/ Th2免疫应答的影响.方法 鼻腔接种肺炎链球菌建立小鼠肺炎链球菌肺炎模型,将Balb/c小鼠24只随机分为3组,分别为对照组,肺炎组和肺炎rIL-18干预组(n=8 ),RT-PCR法检测各组小鼠肺组织中IFN-γ、IL-4 mRNA 的表达,同时支气管肺泡灌洗液(BALB)进行活菌计数,有核细胞分类计数.结果 ①肺炎rIL-18干预组BA LF中性粒细胞和巨噬细胞计数显著高于肺炎组和对照组(P＜0.001);②肺炎rIL-18 干预组BALF活菌计数显著低于肺炎组(P＜0.001);③肺炎rIL-18干预组肺组织IFN- γ mRNA表达上调而IL-4 mRNA表达下调(P＜0.001).结论 在小鼠肺炎链球菌肺炎早期给予rIL-18可诱导IFN-γ的合成,促进Th1免疫应答,使Th1/ Th2免疫平衡向Th1免疫偏移、促进宿主对肺炎链球菌的防御.     

鸡IL-2、IL-1 8、IFN-γ cDNA和CpG DNA在减毒沙门菌运送H5亚型禽流感DNA疫苗中的佐剂作用

目的 探讨鸡IL-2、IL-18、IFN-γ cDNA和CpG DNA在减毒沙门菌运送H5亚型禽流感DNA疫苗中的佐剂作用。方法 将携带禽流感病毒（AIV）DNA疫苗的重组沙门菌SL7207（pVAX1-HA-IL2）、SL7207（pVAX1-HA—IL18）、SL7207（pVAXt—HA—IFN-γ）、SL7207（pVAX1—HA—CpG）、SL7207（pVAX1-HA）和SL7207（pVAX1）经口服和滴鼻途径首免1日龄商品代伊莎褐蛋鸡，测定免疫鸡的体液和黏膜免疫应答水平，并进行攻毒保护试验。结果 二免后3周，SL7207（pVAX1-HA—CpG）、SL7207（pVAX1-HA-IFN-γ）免疫组以及SL7207（pVAX1-HA）和SL7207（pVAX1-IFN-7）联合免疫组鸡产生了较高水平的特异性黏膜免疫应答（P〈0．05），但重组菌免疫鸡血清中抗AIV HI抗体水平与空载体组相比差异无统计学意义。SL7207（pVAX1-HA-CpG）、SL7207（pVAX1-HA—IFN-7）的免疫保护指数显著高于阴性对照组。结论 初步观察佐剂效应依次为：CpG〉IFN-7〉IL-18，IL-2未表现出佐剂效应。     

新生期肺炎链球菌肺炎对成年期肺组织免疫状态及气道高反应的影响

目的研究新生期肺炎链球菌(S.pneumoniae)肺炎对成年期肺组织免疫状态及气道高反应的影响。方法 Balb/c小鼠出生后第7天鼻腔滴注2×107CFU S.pneumoniae 5μl(肺炎链球菌肺炎组)或等量PBS(对照组),5周后用体积描计法检测小鼠肺功能,收集支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF),进行白细胞数及分类计数,ELISA法检测BALF中IL-4、IL-5、IL-10、IL-17A、IFN-γ及TGF-β水平,流式细胞术检测肺组织中的CD4+T细胞亚群Th1、Th2及Foxp3+Treg。结果新生期肺炎链球菌肺炎组小鼠成年后BALF中细胞总数、中性粒细胞、淋巴细胞及巨噬细胞水平显著高于对照组(P0.01)。BALF中IFN-γ、IL-10及TGF-β均显著低于对照组(P0.01),而IL-5、IL-17A显著高于对照组(P0.01);肺组织Th1、Foxp3+Treg显著低于对照组(P0.01);而Th2显著高于对照组(P0.05);Th1/Th2显著低于对照组(P0.01)。新生期肺炎链球菌肺炎小鼠成年后气道高反应显著高于对照组(P0.01)。结论新生期肺炎链球菌肺炎能影响肺组织免疫分化方向,促进成年后气道高反应的形成。     

巨噬细胞源性趋化因子对NTHiP6蛋白疫苗免疫效果的影响

观察巨噬细胞源性趋化因子(MDC)佐剂对NTHiP6蛋白疫苗免疫效果的影响。将原核表达质粒PGEX-6P2/P6转入E.coli XL1-Blue,IPTG诱导P6蛋白的表达并进行纯化。将BALB/c小鼠随机分为A-D四组,分别为PBS对照组、MDC对照组、P6蛋白组、P6蛋白联合MDC组。分别于0、14、28d经黏膜免疫,末次免疫后14d,每组12只小鼠取血和肺泡灌洗液,ELISA检测血清中IgG抗体和肺泡灌洗液中IgA抗体水平。每组取3只小鼠,制备脾淋巴细胞,ELISA检测IL-4、IL-17和IFN-γ水平。用10LD50NTHi攻击每组剩余15只小鼠,观察免疫保护作用。在大肠杆菌中成功表达P6蛋白。第三次免疫后,D组诱导的IgG抗体、IgA抗体、IL-4、IL-17和IFN-γ水平显著高于其他各组(P0.05)。经NTHi攻击后,D组生存率达80%,与A组、B组相比差异有统计学意义(P0.05),但C组、D组之间无显著性差异(P0.05)。MDC作为佐剂可以使NTHiP6疫苗获得较好的免疫效果。     

幼年期肺炎链球菌肺炎对哮喘形成的影响

目的研究幼年期肺炎链球菌肺炎(S.pneumoniaepneumonia,S.pp)对成年期哮喘形成的影响。方法 3周龄雌性Balb/c小鼠随机分为对照组(control)、幼年期肺炎链球菌肺炎组(Inf S.pp)、哮喘组(OVA)、幼年期肺炎链球菌肺炎哮喘组(Inf S.pp+OVA)。3周龄雌性Balb/c小鼠鼻腔滴注2×106cfu/ml肺炎链球菌25μl建立肺炎链球菌肺炎模型,成年期用OVA致敏激发Balb/c小鼠建立哮喘模型,最后1次激发完成24 h内检测小鼠气道高反应性,HE染色制作肺组织病理切片,观察组织病理变化,检测支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中细胞总数、细胞分类计数及细胞因子水平,流式细胞术检测小鼠肺组织中CD4~+T细胞水平。结果幼年期肺炎链球菌肺炎哮喘组肺组织炎症细胞侵润、气道反应性、BALF细胞总数、嗜酸性粒细胞和中性粒细胞及细胞因子IL-5、IL-13、IL-17水平显著高于对照组(P0.05),IFN-γ、IL-10表达显著降低(P0.05),肺组织内Th2、Th17水平显著高于对照组(P0.05),Foxp3~+Treg水平显著降低(P0.01),Th1/Th2、Foxp3~+Treg/Th17比例明显降低(P0.01)。幼年期肺炎链球菌肺炎哮喘组肺组织炎症细胞侵润、气道高反应性、BALF细胞分类计数及炎性因子水平、肺组织CD4~+T细胞水平与哮喘组比较无统计学差异。结论幼年期肺炎链球菌肺炎对成年期哮喘形成无显著影响。     

Intranasal vaccination with chitosan-DNA nanoparticles expressing pneumococcal surface antigen a protects mice against nasopharyngeal colonization by Streptococcus pneumoniae

Streptococcus pneumoniae is a respiratory pathogen, and mucosal immune response plays a significant role in the defense against pneumococcal infections. Thus, intranasal vaccination may be an alternative approach to current immunization strategies, and effective delivery systems to mucosal organism are necessary. In this study, BALB/c mice were immunized intranasally with chitosan-DNA nanoparticles expressing pneumococcal surface antigen A (PsaA). Compared to levels in mice immunized with naked DNA or chitosan-pVAX1, anti-PsaA IgG antibody in serum and anti-IgA antibody in mucosal lavages were elevated significantly in mice immunized with chitosan-psaA. The balanced IgG1/IgG2a antibody ratio in serum, enhanced gamma interferon (IFN-γ) and IL-17A levels in spleen lymphocytes, and mucosal washes of mice immunized with chitosan-psaA suggested that cellular immune responses were induced. Furthermore, significantly fewer pneumococci were recovered from the nasopharynx of mice immunized with chitosan-psaA than for the control group following intranasal challenge with ATCC 6303 (serotype 3). These results demonstrated that mucosal immunization with chitosan-psaA may successfully generate mucosal and systemic immune responses and prevent pneumococcal nasopharyngeal colonization. Hence, a chitosan-DNA nanoparticle vaccine expressing pneumococcal major immunodominant antigens after intranasal administration could be developed to prevent pneumococcal infections.     

Intra-peritoneal and intra-rectal immunogenicity induced by rotavirus virus like particles 2/6/7 in mice

We previously developed virus like particles of rotavirus (RV) with VP2, VP6, and VP7 proteins (VLP2/6/7) using stable High-five cell line. To evaluate the immunogenicity of our construct, we assessed the humoral and cytokine responses induced by VLP2/6/7 in BALB/c mice immunized intra-peritoneally and intra-rectally. Enzyme-linked immunosorbent assay (ELISA) and Relative quantitative (RQ) Real-time PCR were used to evaluate the antibody (IgG and IgA) levels in serum and mRNA levels of IL-6, IL-10 and IFN-γ in spleen cells, respectively. Our results showed that VLP2/6/7 is capable of intra-peritoneal (I.P.) and intra-rectal (I.R.) induction of serum IgG and IgA responses. IgA was detected in fecal samples of immunization groups by I.P. and I.R. routes. Interestingly, I.R. route induced higher IgA titer compared with I.P. route which was statistically significant. Moreover, mRNA levels of IL-6 and IFN-γ were significantly elevated in mice immunized intra-peritoneally with VLP2/6/7 compared to control group. As such, the mean change was 7.4 (P < 0.05) and 14.8 (P < 0.001) for IFN-γ and IL-6, respectively. Likewise, the same pattern was found when mice were immunized intra-rectally. Although elevated, the difference in the mean change for IL-10 was not statistically significant when compared to control group. Our findings indicated that VLPs constructed via a stable insect cell line are able to induce both humoral and cellular responses, a similar pattern as observed after immunization with live RVs.     

Experimental autoimmune thyroiditis (EAT) in mice lacking the IFN-γ receptor gene

To investigate the role of interferon-γ (IFN-γ) in experimental autoimmune thyroidits (EAT), H-2k mice with a disrupted IFN-γ receptor (IFN-γ R) gene were immunized with porcine thyroglobulin (pTg). We observed that EAT occurred on day 19 and remitted on day 35 in IFN-γ R- deficient (IFN-γR0/0) mice, whereas in wild-type mice, EAT occurred on day 21 and remitted on day 42 – 49. Moreover, EAT in the mutant mice was attenuated and accompanied by diminished Tg-specific cytotoxic and proliferative responses and decreased titers of anti-Tg antibodies, notably of the IgG2a and IgG2b isotypes. In contrast, Tg-specific IgG1 was increased in the IFN-γ R0/0 mice. In supernatants from T cells further stimulated in vitro by Tg, IFN-γ levels were higher in IFN-γ R0/0 than in wild-type mice throughout the course of the dis ease, whereas interleukin-10 was transiently increased prior to EAT onset in both groups of mice. Finally, using IFN-γ R0/0 mice, we demonstrate that induction of EAT does not require an intact IFN-γ system, while progression to full-blown disease depends on the action of IFN-γ.     

壳聚糖介导增强幽门螺杆菌Lpp20 DNA疫苗黏膜免疫效果的研究

目的 探讨壳聚糖包裹DNA疫苗黏膜免疫效果.方法 采用复凝聚法制备载幽门螺杆菌脂蛋白 Lpp20基因的壳聚糖(CS)纳米粒(NPs),并对CS/DNA纳米粒的特质进行研究;用载基因壳聚糖纳米粒黏膜免疫(滴鼻和口服)小鼠,检测免疫小鼠的细胞和体液免疫水平.结果 裸质粒pcDNA3.1(+)/Lpp20与CS/DNA NPs通过黏膜免疫均能诱导小鼠产生有效的免疫应答.CS/DNANPs滴鼻和口服免疫组诱导的抗体明显升高,与裸质粒组相比有明显差异(P＜0.05),同时CS/DNANPs滴鼻和口服免疫组小鼠脾淋巴细胞经特异性抗原刺激后,刺激指数及培养上清中IFN-γ和IL-4含量明显高于裸质粒组、壳聚糖组和PBS组,且滴鼻免疫组高于口服组.结论 壳聚糖纳米粒能增强pcDNA3.1(+)/Lpp20核酸疫苗的黏膜免疫(滴鼻和口服免疫)效果;载Lpp20基因壳聚糖纳米粒滴鼻免疫比口服免疫能诱导更强的细胞和体液免疫应答.

Abstract：

Objective To investigate the immune response of mucosal immunization of new chitosan(CS) nanoparticles coating DNA vaccine. Methods The chitosan nanoparticles containing plasmid DNA encoding H. pylori lipoprotein Lpp20 gene were prepared using a complex coacervation method and then its speciality were analyzed. We then administered the naked plasmid DNA and chitosan-DNA nanoparticles to 6-week-old female BALB/c mice by intranasal or oral mucosal routes to observe the humoral and cellular immune responses. Results Naked plasmid pcDNA3.1 ( + )/Lpp20 and chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles both induced effective immune response in mice through mucosal vaccination. Specific IgG and sIgA antibodies of chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles groups were higher than that of naked pcDNA3.1 ( + )/Lpp20 group. The concentration of cytokines IFN-γ and IL-4 in cultural supernatant of T lymphocytes from chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles immunized mice increased greatly than that of control groups. After stimulated by corresponding antigen, the stimulation index of intranasal or oral delivery of chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles group was significantly higher than that of pcDNA3.1( + )/Lpp20 group, CS group and PBS control group. Moreover, systemic and mucosal immune responses in mice induced by intranasal immunization were stronger than that of oral immunization. Conclusion Chitosan nanoparticles enhanced the immune response of pcDNA3.1 ( + )/Lpp20 DNA vaccine by intranasal or oral administration in BALB/c mice. Compared to oral administration, intranasal delivery of chitosan-pcDNA3.1 ( + )/Lpp20 DNA nanoparticles could induce stronger cellular and humoral immune responses in BALB/c mice.     

Mucosal Immunization with PsaA Protein,Using Chitosan as a Delivery System,Increases Protection Against Acute Otitis Media and Invasive Infection by Streptococcus pneumoniae

As infection with Streptococcus pneumoniae (mainly via the mucosal route) is a leading cause of acute otitis media, sinus and bacterial pneumonia, the mucosal immunity plays an important role in the prevention of pneumococcal diseases. Therefore, intranasal vaccination may be an effective immunization strategy, but requires appropriate mucosal vaccine delivery systems. In this work, chitosan was used as a mucosal delivery system to form chitosan–PsaA nanoparticles based on ionotropic gelation methods and used to immunize BALB/c mice intranasally. Compared to mice immunized with naked PsaA, levels of IFN‐γ, IL‐17A and IL‐4 in spleen lymphocytes, the systemic (IgG in serum) and mucosal (IgA in mucosal lavage) specific antibodies were enhanced significantly in mice inoculated with chitosan–PsaA. Furthermore, increased protection against acute otitis media following middle ear challenge with pneumococcus serotype 14, and improved survival following intraperitoneal challenge with pneumococcus serotype 3 or serotype 14, was found in the mice immunized with chitosan–PsaA nanoparticles. Thus, intranasal immunization with chitosan–PsaA can successfully induce mucosal and systemic immune responses and increase protection against pneumococcal acute otitis media and invasive infections. Hence, intranasal immunization with PsaA protein, based on chitosan as a delivery system, is an efficient immunization strategy for preventing pneumococcal infections.     

Elicitation of Th1/Th2 related responses in mice by chitosan nanoparticles loaded with Brucella abortus malate dehydrogenase,outer membrane proteins 10 and 19

Brucella spp. is the causative agent of brucellosis, one of the worldwide diseases. The pathogen infects humans and animals mainly through the digestive or respiratory tract. Therefore, induction of mucosal immunity is required as the first line of defense. In this study, three Brucella abortus recombinant proteins, malate dehydrogenase (rMdh), outer membrane proteins (rOmp) 10 and 19 were loaded in mucoadhesive chitosan nanoparticles (CNs) and induction of mucosal and systemic immunity were investigated after intranasal immunization of BALB/c mice. These antigens were also coimmunized as cocktail (rCocktail) to evaluate multiple antigen specific vaccine candidates. At 6-weeks post-immunization (wpi), antigen specific total IgG was increased in all of the immunized groups, predominantly IgG1. In addition, spleenocyte from rMdh-, rOmp19-, and rCocktail-immunized groups significantly produced IFN-γ and IL-4 suggesting the induction of a mixed Th1-Th2 response. For mucosal immunity, anti-Mdh IgA from nasal washes and fecal excretions, and anti-Omps IgA from sera, nasal washes, genital secretions and fecal excretions were significantly increased in single antigen immunized groups. In the rCocktail-immunized group, anti-Mdh IgA were significantly increased while anti-Omps IgA was not. Collectively, this study indicates that comprise of B. abortus antigen-loaded CNs elicited the antigen-specific IgA with a Th2-polarized immune responses and combination of the highly immunogenic antigens elicited IgG specific to each type of antigen.     

Immunomodulation of ALT-2 and TLR may collude in antigen specific T cell hyporesponsiveness: Proposed mechanism for elevated IL-10 levels in Balb/C mice

ALT-2, a novel antigen belonging to the chromadorea ALT-2 family of the filarial nematode is proved to clear filarial parasites in Jirds. In order to increase the protection efficacy by stimulating the cell mediated immunity, MPLA a detoxified derivative of LPS known to induce the cellular response, was used in this study as an adjuvant on mice models. ALT-2+MPLA formulation elicited a high titer of total IgG antibody, with profoundly increased levels of IgG2b. Reduced splenocyte proliferation was observed in immunized group when compared to control groups which could be attributed to many in vivo factors. The levels of IFN-γ were high in unstimulated MPLA group compared to ALT-2 stimulated MPLA group, suggesting that the ALT-2 antigen suppressed the IFN-γ levels. A high level of IL-10 was induced by the ALT-2+MPLA formulation, which inhibited the production of Th2 cytokines (IL-4, IL-5) and also reduced the Th1 cytokine (IFN-γ, IL-2) levels which are not in vogue with the classical MPLA adjuvant formulation. We propose a mechanism for this immunomodulation which involves a diminished expression of TLR-4, by which the filarial parasites have evolved to evade host immune mechanism.     

壳聚糖TGF-β1纳米质粒构建及对卵清蛋白肠道过敏小鼠免疫调节效果

探索体内给予TGF-β质粒是否有利于诱导过敏小鼠肠道TGF-β表达;同时,分别采用质粒常规肌肉给药和壳聚糖纳米口服给药途径,比较OVA过敏小鼠肠道过敏炎症的缓解状况,了解TGF-β质粒经壳聚糖微粒口服给药是否优于常规肌肉给药,更利于食物过敏治疗。构建pBudCE4.1/TGF-β1真核表达重组质粒并制备壳聚糖-DNA纳米颗粒。建立BALB/c小鼠OVA肠道过敏模型,并随机将其分为口服壳聚糖/pBudCE4.1/TGF-β1质粒(Chit)组、口服pBudCE4.1/TGF-β1裸质粒对照(Nak)组、肌肉注射pBudCE4.1/TGF-β1裸质粒对照(Nak-im)组、口服pBudCE4.1/TGF-β1空质粒对照(Pla)组、激发(Cha)组、生理盐水对照(Ns)组。以实时荧光定量RT-PCR测定小肠组织中TGF-β1、IFN-γ、IL-4 mRNA表达,ELISA法测定小鼠小肠黏液中总IgA、OVA特异性IgA、外周血清OVA特异性IgE含量,组织荧光法测定小肠剩余组织胺含量。六组小鼠中,Ns组小鼠小肠组织TGF-β1和IFN-γmRNA表达、小肠剩余组织胺、小肠黏液中总IgA、OVA特异性IgA含量最高(P<0.01),小肠组织IL-4 mRNA、外周血清OVA特异性IgE含量最低(P<0.01);Nak-im、Chi组小鼠小肠组织TGF-β1和IFN-γmRNA表达、小肠剩余组织胺、小肠黏液中总IgA、OVA特异性IgA含量较Cha、Nak、Pla三组升高(P<0.01),且Chi组较Nak-im组高(P<0.01);Nak-im、Chi组小鼠小肠组织IL-4 mRNA表达、外周血OVA特异性IgE含量较Cha、Nak、Pla三组降低(P<0.01),且Chi组较Nak-im组低(P<0.01)。pBudCE4.1/TGF-β1质粒经常规肌肉或壳聚糖纳米微粒口服形式给药,均可促进过敏小鼠肠道TGF-β1表达,缓解肠道炎症,且以壳聚糖口服给药途径优于肌肉给药途径。进行壳聚糖为载体的基因转运研究可望提高TGF-β1治疗食物过敏的效果。     

CCK-8对KLH免疫小鼠脾细胞Th1/Th2平衡的影响

目的： 探讨八肽胆囊收缩素（CCK-8）对Th1/Th2平衡的调节作用。方法: 给予BALB/c小鼠钥孔戚血蓝蛋白（KLH）免疫同时体内给予不同剂量的CCK-8,酶联免疫吸附试验(ELISA)检测其脾细胞培养上清中Th1型细胞因子γ-干扰素(IFN-γ)、白细胞介素-2（IL-2）和Th2型细胞因子白细胞介素-4（IL-4）、白细胞介素-5（IL-5）水平,逆转录聚合酶链式反应(RT-PCR)法检测脾细胞中IFN-γ、IL-2、IL-4、IL-5 mRNA表达;ELISA法检测血清中Th1型抗KLH抗体IgG2a和Th2型抗KLH抗体IgG1水平。结果: ①KLH免疫使小鼠脾细胞分泌Th1/Th2型细胞因子水平明显增高,mRNA表达增高,KLH免疫同时给予CCK-8可使脾细胞培养上清中IFN-γ、IL-2含量进一步增加和IFN-γ、IL-2mRNA表达增高,而使IL-4、IL-5含量降低,IL-4、IL-5 mRNA表达减低和降低IL-4/IFN-γ比值。②KLH免疫小鼠血清中IgG2a、IgG1发生不同程度增高,CCK-8可使其血清中IgG1水平减低而使IgG2a水平增高。结论: CCK-8可促进KLH免疫小鼠体内Th1反应,使Th2优势反应向Th1方向转变。     

Immunomodulatory potentials of the water-soluble yam (Dioscorea opposita Thunb) polysaccharides for the normal and cyclophosphamide-suppressed mice

Immunomodulatory potentials of water-soluble yam (Dioscorea opposita Thunb) polysaccharides (WYPs) for the normal and immuno-suppressed mice were described in this study. For the normal mice, the WYPs at 500?mg?kg^?1 elevated spleen and thymus indices by 22–42%; promoted macrophages' phagocytosis; lymphocytes' proliferation and natural killer (NK) cell activity by 18–53%; enhanced IL-2 and IFN-γ levels in the splenocytes by 42–45%; raised IL-1β, IL-6, TNF-α, iNOS and lysozyme levels in the macrophages by 40–219%; and increased serum IgM, IgA and IgG levels by 44–51%. The WYPs could restore and improve immune status of the cyclophosphamide-treated mice, as they at 500?mg?kg^?1 elevated spleen and thymus indices by 85–172%; promoted macrophages' phagocytosis, lymphocytes' proliferation and NK cell activity by 24–98%; enhanced IL-2 and IFN-γ levels in the splenocytes by 44–109% or IL-1β, IL-6, TNF-α, iNOS and lysozyme levels in the macrophages by 53–287%; and increased the three immunoglobulins by 24–69%.