Antibodies elicited by Newcastle disease virus-vectored H7N9 avian influenza vaccine are functional in activating the complement system

H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are protective and allow mass administration.Of note,these vaccines elicit undetectable H7N9-specific hemagglutination-inhibition(HI)but high IgG antibodies in chickens.However,the molecular basis and protective mechanism underlying this particular antibody immunity remain unclear.Herein,immunization with an NDV_(vec)H7N9 induced low anti-H7N9 HI and virus neutralization titers but high levels of hemagglutinin(HA)-binding IgG antibodies in chickens.Three residues(S150,G151 and S152)in HA of H7N9 virus were identified as the dominant epitopes recognized by the NDV_(vec)H7N9 immune serum.Passively transferred NDV_(vec)H7N9 immune serum conferred complete protection against H7N9 virus infection in chickens.The NDV_(vec)H7N9 immune serum can mediate a potent lysis of HA-expressing and H7N9 virus-infected cells and significantly suppress H7N9 virus infectivity.These activities of the serum were significantly impaired after heat-inactivation or treatment with complement inhibitor,suggesting the engagement of the complement system.Moreover,mutations in the 150-SGS-152 sites in HA resulted in significant reductions in cell lysis and virus neutralization mediated by the NDV_(vec)H7N9 immune serum,indicating the requirement of antibody-antigen binding for complement activity.Therefore,antibodies induced by the NDV_(vec)H7N9 can activate antibody-dependent complement-mediated lysis of H7N9 virus-infected cells and complement-mediated neutralization of H7N9 virus.Our findings unveiled a novel role of the complement in protection conferred by the NDV_(vec)H7N9,highlighting a potential benefit of engaging the complement system in H7N9 vaccine design.

Frequencies of the expression of main protein antigens from Helicobacter pylori isolates and production of specific serum antibodies in infected patients

AIM: To investigate the frequencies of the expression of main protein antigens of Helicobacter pylori (H py/ori) isolates, such as UreB, VacA, CagA1, HpaA, NapA, FlaA and FlaB and the production of specific antibodies in sera from H pylori-infected patients, and to understand the correlations among the different clinical types of chronic gastritis and peptic ulcer and the infection and virulence of H pylori. METHODS: H pylori strains in biopsy specimens from 157 patients with chronic gastritis and peptic ulcer were isolated and serum samples from the patients were also collected. The target recombinant proteins rUreB, rVacA, rCagAl, rHpaA, rNapA, rFlaA and rFlaB expressed by the prokaryotic expression systems constructed in our previous studies were collected through Ni-NTA affinity chromatography. Rabbit antisera against rUreB, rVacA, rCagAl, rHpaA, rNapA, rFlaA and rFlaB were prepared by using routine subcutaneous immunization. By using ultrasonic lysates of the isolates as coated antigens, and the self-prepared rabbit antisera as the first antibodies and commercial HRP-labeling sheep anti-rabbit IgG as the second antibody, expression frequencies of the seven antigens in the isolates were detected by ELISA. Another ELISA was established to detect antibodies against the seven antigens in sera of the patients by using the corresponding recombinant proteins as coated antigens, and the sera as the first antibody and HRP-labeling sheep anti-human IgG as the second antibody respectively. Correlations among the different clinical types of chronic gastritis and peptic ulcer and the infection and virulence of H pylori were statistically analysed. RESULTS: In the 125 isolates of H pylori, the positive rates of UreB, VacA, CagAl, HpaA, NapA, FlaA and FlaB were 100%, 65.6%, 92.8%, 100%, 93.6%, 100% and 99.2% respectively. In the 125 serum samples from the H pylori infected patients, the positive rates of antibodies against recombinant UreB, VacA, CagA1, HpaA, NapA, FIaA and FlaB were 100%, 42.4%, 89.6%, 81.6%, 93.6%, 98.4% and 92.8% respectively. H pylori strains were isolated from 79.6% (125/157) of the biopsy specimens, but no close correlations among the H pylori infection frequencies and different types of chronic gastritis and peptic ulcer could be found (P>0.05, x2 = 0.01-0.87). The VacA positive rate (82.40%) in the strains isolated from the specimens of patients with peptic ulcer and the anti-VacA positive rate (54.3%) in the sera from the patients were significantly higher than those (51.5%, 32.3%) from the patients with chronic gastritis (P<0.01, x2= 13.19; P<0.05, x2= 6.13). When analysis was performed in the different types of chronic gastritis, the VacA in the strains isolated from the specimems of patients with active gastritis showed a higher expression frequency (90.0%) than those from superficial (47.9%) and atrophic gastritis (30.0%) (P<0.05, x2 = 5.93; P<0.01,x2 = 7.50). While analysis was carried out in the strains isolated from the specimens with superficial (93.8%) and active gastritis (100%), NapA showed a higher expression frequency compared to that from atrophic gastritis (60.0%) (P<0.01, x2 = 8.88; P<0.05, X2=5.00). CONCLUSION: The types of chronic gastritis and peptic ulcer and their severity are not associated with H pylori infection frequency but closely related to the infection frequency of different virulent H pylori strains. The optimal antigens for developing vaccine and diagnostic kit are UreB, FlaA, HpaA, FlaB, NapA and CagAl, but not VacA.

H pylori infection and systemic antibodies to CagA and heat shock protein 60 in patients with coronary heart disease

AIM: To determine the overall prevalence of H pylori and CagA positive H pylori infection and the prevalence of other bacterial and viral causes of chronic infection in patients with coronary heart disease (CHD), and the potential role of anti-heat-shock protein 60 (Hsp60) anti- body response to these proteins in increasing the risk of CHD development. METHODS: Eighty patients with CHD and 160 controls were employed. We also compared the levels of anti- heat-shock protein 60 (Hsp60) antibodies in the two groups. The H pylori infection and the CagA status were determined serologically, using commercially available enzyme-linked immunosorbent assays (ELISA), and a Western blotting method developed in our laboratory. Systemic antibodies to Hsp60 were determined by a sandwich ELISA, using a polyclonal antibody to Hsp60 to sensitise polystyrene plates and a commercially available human Hsp60 as an antigen. RESULTS: The overall prevalence of H pylori infec- tion was 78.7% (n = 63) in patients and 76.2% (n = 122) in controls (P = 0.07). Patients infected by CagA- positive (CagA+) H pylori strains were 71.4% (n = 45) vs 52.4% of infected controls (P = 0.030, OR = 2.27). Sys-temic levels of IgG to Hsp60 were increased in H pylori- negative patients compared with uninfected controls (P < 0.001) and CagA-positive infected patients compared with CagA-positive infected controls (P = 0.007). CONCLUSION: CagA positive H pylori infection may concur to the development of CHD; high levels of anti- Hsp60 antibodies may constitute a marker and/or a con- comitant pathogenic factor of the disease.

Cross-neutralizing Anti-hemagglutinin Antibodies Isolated from Patients Infected with Avian Influenza A(H5N1) Virus

Objective To recover broad-neutralizing monoclonal antibodies(Bn Abs)from avian influenza A(H5N1)virus infection cases and investigate their genetic and functional features.Methods We screened the Abs repertoires of expanded B cells circulating in the peripheral blood of H5N1 patients.The genetic basis,biological functions,and epitopes of the obtained Bn Abs were assessed and modeled.Results Two Bn Abs,2-12 D5,and 3-37 G7.1,were respectively obtained from two human H5N1 cases on days 12 and 21 after disease onset.Both Abs demonstrated cross-neutralizing and Ab-dependent cellular cytotoxicity(ADCC)activity.Albeit derived from distinct Ab lineages,i.e.,V^H1-69-D2-15-JH^4(2-12D5)and V^H1-2-D3-9-JH^5(3-32 G7.1),the Bn Abs were directed toward CR6261-like epitopes in the HA stem,and HA2 I45 in the hydrophobic pocket was the critical residue for their binding.Signature motifs for binding with the HA stem,namely,IFY in VH1-69-encoded Abs and LXYFXW in D3-9-encoded Abs,were also observed in 2-12D5 and 3-32 G7.1,respectively.Conclusions Cross-reactive B cells of different germline origins could be activated and re-circulated by avian influenza virus.The HA stem epitopes targeted by the Bn Abs,and the two Ab-encoding genes usage implied the VH1-69 and D3-9 are the ideal candidates triggered by influenza virus for vaccine development.

Cross-reactivity of anti-H pylori antibodies with membrane antigens of human erythrocytes

AIM： To investigate whether anti-H pylori antibodies have cross-reaction with antigens of erythrocyte membrane. METHODS： Blood samples were collected from 14 volunteers （8 positive and 6 negative for Hpylori detected by ^13C-urea breath test） of the general population. Erythrocyte membrane proteins of the subjects were examined by Western blot using anti-H pylori serum. The proteins related to the positive bands were identified by mass spectrum analysis. RESULTS： Anti-Hpylori antibodies had cross-reaction with the proteins of about 50 kDa of erythrocyte membranes in all samples independent of H pylori infection. One protein in the positive band was identified as Chain S, the crystal structure of the cytoplasmic domain of human erythrocyte Band-3 protein. CONCLUSION： Anti-HpyloH antibodies cross-react with some antigens of human erythrocyte membrane, which may provide a clue for the relationship between Hpylori infection and vascular disorders.

Preparation of Monoclonal Antibodies against Hemagglutinin of Avian Influenza Virus H9 Subtype by Plasmid Immunization

Avian influenza has caused enormous economic losses to poultry industry. To develop kits for rapid diagnosis of avian influenza virus （AIV） H9 subtype, 8-week-old Balb/c mice were administered with pcDNA3.1 （ ＋ ） carrying hemagglutinin （HA） gene of AIV H9 subtype. After cell fusion, one positive hybridoma cell strain was screened out by hemagglutination inhibition assay （ HI ）, and another positive hybddoma call strain was screened out by ELISA. After subcloning 3 times, the two cell strains could still secret antibodies against the HA of AIV H9 subtype. The mono- clonal antibodies did not react with Newcastle disease virus, AIV H5 subtype and duck adenovirus A. Their subtypes were IgG2b with kappa light chain. These two hybridoma cell strains may play an important role in rapid diagnosis and early-warning surveillance of AIV H9 subtype.

Maternal-derived antibodies hinder the antibody response to H9N2 AIV inactivated vaccine in the field

The H9N2 subtype avian influenza virus(AIV)inactivated vaccine has been used extensively in poultry farms,but it often fails to stimulate a sufficiently high immune response in poultry in the field,although it works well in laboratory experiments;hence,the virus still causes economic damage every year and poses a potential threat to public health.Based on surveillance data collected in the field,we found that broilers with high levels of maternal-derived antibodies(MDAs)against H9N2 virus did not produce high levels of antibodies after vaccination with a commercial H9N2 inactivated vaccine.In contrast,specific pathogen-free(SPF)chickens without MDAs responded efficiently to that vaccination.When MDAs were mimicked by administering passively transferred antibodies(PTAs)into SPF chickens in the laboratory,similar results were observed:H9N2-specific PTAs inhibited humoral immunity against the H9N2 inactivated vaccine,suggesting that H9N2-specific MDAs might hinder the generation of antibodies when H9N2 inactivated vaccine was used.After challenge with homologous H9N2 virus,the virus was detected in oropharyngeal swabs of the vaccinated and unvaccinated chickens with PTAs but not in the vaccinated chickens without PTAs,indicating that H9N2-specific MDAs were indeed one of the reasons for H9N2 inactivated vaccine failure in the field.When different titers of PTAs were used to mimic MDAs in SPF chickens,high(HI=12 log2)and medium(HI=log 9 log2)titers of PTAs reduced the generation of H9N2-specific antibodies after the first vaccination,but a booster dose would induce a high and faster humoral immune response even of PTA interference.This study strongly suggested that high or medium titers of MDAs might explain H9N2 inactivated vaccine failure in the field.

Sero-Prevalence of <i>H. pylori</i>Antibodies among Asymptomatic Rural Population in Bauchi State, Nigeria—A Preliminary Study

Helicobacter pylori infection is a major public health problem globally, with high prevalence in developing countries associated with poor sanitation, low standard of living, urban-rural disparity and increased gastrointestinal pathologies. This preliminary study determined the seroprevalence of H. pylori infection among asymptomatic rural population and association of sociodemographic variables on the result outcome. A total of 250 asymptomatic volunteered participants were screened for H. pylori antibodies, using rapid immunochromatographic strips. 44.8% (112/250) were seropositive, and showed increased prevalence with the age group, <15 years (8.0%), 18 - 39 years (23.5%) and 40 - 65 years (12.0%) with no significant difference. High prevalence among males, 88 (35.2) compared to 24 (9.6) females (p < 0.228). Significant association was observed with marital status, high prevalence among married participants 63 (25.0) followed by singles, 41 (16.4) (p < 0.010). Similarly, significant prevalence was observed among participants with non-formal education, 60 (24.0) followed by primary education, 21 (8.4) (p < 0.51). While non-salary earners accounted for 79 (31.6) (p < 0.244). The H. pylori seropositivity of 44.8% is relatively low in region with previous reports of high prevalence and predisposing risk factors. Further studies are needed to evaluate the effect of environmental and occupational risk factors for better epidemiological understanding of H. pylori infection and a template for intervention measures.

免疫性血小板输注无效患者HLA/HPA抗体特性分析及其对血小板输注效果的影响

目的 探讨免疫性血小板输注无效(PTR)患者HLA/HPA抗体特异性分布特征及其对血小板输注效果的影响。方法 本研究以86例免疫性PTR患者为研究对象,收集其性别、年龄、身高、体重、配血次数、疾病类型、输注前后血小板计数等临床资料,通过微珠法进行HLA特异性抗体的检测,并分析抗体特性对血小板输注效果的影响。结果 86例PTR患者中,单独HLA抗体、单独HPA抗体、HLA+HPA抗体阳性的患者分别为72例(83.72%)、8例(9.30%)、6例(6.98%)。HLA抗体在各位点中检出频率最高的抗体对应等位基因分别为A*25:01、B*15:12、C*02:02(和C*17:01),检出率分别为81.48%、87.04%、48.15%;而对应抗原表位出现频率最高的前三位为163LG、97V、71ATD,检出率分别为87.04%、77.78%、74.07%。仅存在HLA抗体的患者,输注交叉配型相合血小板的24 h血小板计数纠正增加指数(CCI)及输注有效情况均明显优于随机血小板(P<0.01)。在血小板交叉配型阴性结果的患者中,HLA抗体强度与交叉配型相合血小板的24 h CCI值及输注有效情况呈负相关关系,强度越高,输注效果越差(P<0.01)。HLA抗体强度为中、低等水平的患者,输注交叉配型相合血小板的24 h CCI值及输注有效情况均优于输注随机血小板(P<0.05)。结论 本研究所得到的PTR患者HLA/HPA抗体特性及其对血小板输注效果影响的结果,可为血小板库建立时供者的选择提供指导,同时对临床PTR患者的治疗方式选择有一定的参考价值。

自制肝素亲和柱分离纯化载脂蛋白H及其抗体制备与鉴定

目的:自制肝素-琼脂糖6B亲和柱提纯人血清载脂蛋白H(apoH),免疫制备多克隆抗体,为大量制备与进一步研究做准备。方法:利用间接还原胺化法制备亲和层析柱,并优化反应条件。运用高氯酸沉淀、离子交换及亲和层析从人血清中纯化抗原,制备兔源多克隆抗体。结果:自制亲和柱肝素结合量约5mg/g(介质体积)。纯化的抗原经SDS-PAGE鉴定分子量约50kD,无杂带;16种氨基酸组成分析结果与报道一致。多克隆抗体与购置的国外抗体一样,在进行ELISA与dot-ELISA时与小牛血清白蛋白有交叉反应;但在变性且还原的条件下,Western blot结果显示无交叉反应。结论:自制亲和柱成本低、亲和性好、肝素结合稳定,用之分离纯化得到了高纯度apoH;兔多克隆抗体用于检测血清中载脂蛋白H含量时需进一步纯化。

抗-H抗体引起血型鉴定困难3例报告

抗 H抗体属于IgM型冷抗体 ,临床鉴定血型时 ,常可引起正反定型不符 ,造成定型困难。在反定型鉴定血型时发现的抗 H抗体中 ,3例患者经血型血清学检测 ,抗体在 37℃、室温、4℃均有活性 ,分析抗体性质为IgM ,提示紧急时刻给AB型患者输血 ,不能盲目输注O型红细胞 ,最好输注同型血。如果没有同型时 ,需输O型红细胞 ,先用盐水离心法配血 ,主侧配血相合时方可发出 ,再用不完全法检测。防止患者有抗 H抗体存在 ,引起输血不良反应。

抗肿瘤血管三结构域单链抗体V_H/L的构建与表达

以本室研制的一株抗肿瘤血管单克隆抗体AA98为基础 ,采用PCR扩增抗体AA98基因的重链可变区(VH)和轻链 (L) ,以重链恒定区 1(CH1) 5′端 12个氨基酸的序列作为连接肽 ,并将连接肽中的Lys突变为Ser,构建VH 连接肽 L三结构域单链抗体。重组VH/L单链抗体在大肠杆菌中得到了高效表达 ,其表达量占菌体总蛋白质的 2 0 %。表达的蛋白质在菌内形成包含体 ,经凝胶过滤法复性 ,获得了有抗原结合活性的VH/L。该三结构域单链抗体的成功构建和复性 ,为重组抗体片段的研制提供了借鉴。

基于Arah6的花生间接竞争ELISA检测方法的建立

建立了基于花生主要过敏原蛋白Arah6的间接竞争酶联免疫检测法,实现了对食物中花生的定量检测。利用花生过敏原Arah6纯品免疫新西兰大白兔,制得兔抗Arah6的多克隆抗体,以Arah6纯品作为包被抗原、自制抗体为一抗、辣根过氧化物酶标记的羊抗兔IgG为二抗,确定了包被抗原质量浓度为1μg/mL,一抗最佳稀释度为1:50000,酶标二抗稀释度为1:5000。此检测方法对Arah6的定量检测范围为16.5～10000ng/mL(折合成含花生的含量,约为165ng/mL～100μg/mL),抑制方程为抑制率I=21.418lgC-6.0633(C为Arah6的质量浓度,单位ng/mL),IC50为414.6ng/mL,相关系数R2=0.9989。该检测方法灵敏度高,检测范围广,适用于食品中花生现场快速检测。

抗CEA嵌合抗体在CHO细胞中的高效表达

目的为了在CHO-dhfr 细胞中高效表达有活性的抗人CEA鼠-人嵌合抗体。方法构建抗CEA嵌合抗体的真核高效表达载体,转染CHO-dhfr-细胞,通过加入 MTX进行基因扩增表达,获得高产细胞株。采用Western bolt、ELISA 、体内放射免疫实验等方法鉴定所表达的嵌合抗体的生物学特性。结果获得产量可达60 μg/ml的细胞株。Western blot、 ELISA、体内放射免疫实验证明所表达的嵌合抗体的确含人抗体的恒定区,并特异地与 CEA结合。结论成功地在真核细胞CHO-dh fr-中高效表达了抗CEA嵌合抗体,并具有良好的生物活性。

应用H-Y单克隆抗体鉴定小鼠和家兔胚胎性别

以C57BL/6雄性小鼠的脾细胞免疫同系雌性小鼠,选择免疫应答反应较好的雌性小鼠4只,取其脾细胞与SP2/0骨髓瘤细胞进行融合,融合后的杂交瘤细胞经过3次克隆,筛选出了2株能够分泌H-Y抗体的杂交瘤细胞系HYA1和HYA2,其分泌的相应抗体分别命名为HYa1和HYa2。琼脂双扩散试验表明,HYa1和HYa2分别属于IgM和IgG亚类。胚胎间接免疫荧光分析及胚胎细胞毒试验证明,H-Y单克隆抗体能与雄性胚胎表面的H-Y抗原结合,在有补体存在时,能够溶解雄性胚胎。在胚胎免疫荧光分析中,共分析了438枚8细胞期至桑椹期小鼠胚胎,其中特异性荧光胚胎和无特异性荧光胚胎分别占50.5％(219枚)和47.3％(207枚),不易分辨胚胎占2.7％(12枚)。在86枚家兔胚胎中,特异性荧光胚胎和无特异性荧光胚胎分别占48.8％(42枚)和45.3％(39枚),不易分辨胚胎占5.8％(5枚)。小鼠胚胎移植后,接受发特异性荧光胚胎的一组母鼠生了22只小鼠,其雌性率和雄性率分别为18.2％(4只)和81.8％(18只)。而移植无特异性荧光胚胎的一组母鼠生了19只小鼠,其雌性率和雄性率分别为89.5％(17只)和10.5％(2只)。

抗牛H-Y抗原单克隆抗体的研制试验

Ｈ－Ｙ抗原是位于Ｙ染色体上的基因位点所编码的细胞膜抗原，能直接或间接地诱导原始性腺分化为睾丸。以牛睾丸组织匀浆作为抗原，免疫ＢＡＬＢ／Ｃ小鼠，用杂交瘤细胞技术制备的单克隆抗体６Ｆ、７Ｈ与部分牛精子呈阳性反应。

实验小鼠H-2抗原单克隆抗体的效价研究

目的 研究实验小鼠H - 2抗原单克隆抗体在初建时和经冷冻保存后的效价变化规律 ,为长期保存小鼠H - 2抗原单抗及规模性推广这一遗传监测方法奠定技术基础。方法 制备 6种抗小鼠H 2抗原的单克隆抗体 ,将具备一定抗体效价 (16 0倍以上 )的细胞株保存在 - 196℃的液氮中 ,数月后将复苏后的部分细胞株培养 4 8h后 ,取其上清液用微量细胞毒试验法测定抗体的效价 ,并与其原有效价进行比较。结果 单抗初建时效价达到 16 0倍以上的细胞株占总株数的 37%～ 5 3% ,H 2K抗体复苏后效价持平的细胞株占 13% ,效价下降的为 74 % ,效价上升的是 13% ;H 2D抗体效价持平的细胞株占 5 3% ,下降的为 31% ,上升的是 16 %。复苏后的抗体效价大部分与原效价持平或略有下降 ,个别的会有所提高。结论 单克隆抗体的效价略低于同种单价特异性抗血清 ;能否使冻存后的抗体保持原有的效价是抗体能否大量生产并推广的关键 ;要长期保存和生产H 2抗原单抗 ,应加强克隆和检测工作 ,建立稳定的制备、保存和检测系统 。

维持性血液透析患者血清抗-PF4/H抗体阳性率、危险因素及与血栓栓塞发病率的相关性

目的探讨维持性血液透析患者抗-PF4/H抗体的阳性率,分析影响抗体的危险因素及其与血栓栓塞事件的相关性。方法招募解放军总医院血液净化中心157例患者,分别设计横断面和队列研究,利用统计学方法分析抗-PF4/H抗体水平的影响因素及其与血栓栓塞事件的关系。结果 40.8%(64/157)的患者表现为抗-PF4/H抗体阳性;血清抗体阳性组与抗体阴性组患者既往血栓栓塞事件、抗凝剂类型、每周透析总时间和透析龄等因素差异具有统计学意义(P<0.05);抗体阳性患者血栓栓塞事件发生率高于阴性患者(P<0.05),抗-PF4/H抗体对血栓栓塞的危险度RR=2.349。服用阿司匹林或氯吡格雷的抗体阳性患者血栓栓塞发病率低于未服用抗血小板药物的透析患者。结论本组维持性血液透析患者抗-PF4/H抗体阳性率为40.8%,影响该抗体水平的危险因素包括既往血栓栓塞事件、抗凝剂类型、每周透析总时间和透析龄等。该抗体可以作为血栓栓塞事件的标志物,抗血小板药物对预防抗体阳性患者血栓栓塞事件效果显著。

Fcgr2b基因及H-2复合体对SLE模型小鼠IgG抗体产生的调节作用

目的:分析Fcgr2b基因对SLE小鼠血清总IgG抗体产生的影响;Fcgr2b基因单独及Fcgr2b基因与H-2复合体共同作用对SLE小鼠血清IgG抗DNA抗体产生的调控。方法:建立(NZB×NZW)F1×NZW回交小鼠模型,用特异性荧光抗体染色,流式细胞术检测及PCR技术进行基因分型,以ELISA法测定血清总IgG及抗DNA抗体水平进行分析比较。采用扩增片段长度多态性(AmpFLP)分析NZB,NZW小鼠Fcgr2b基因启动子区是否有多态性。结果:(NZB×NZW)F1×NZW回交小鼠Fc-gr2b基因B/W型组血清总IgG水平明显高于W/W型组(P<0.0001)。Fcgr2b基因独作用时,回交小鼠Fcgr2b基因B/W型组与W/W型组间血清IgG抗DNA抗体水平差异不显著(P>0.05)。Fcgr2b基因与H-2复合体共同作用时,H-2复合体为d/z型时,无论Fcgr2b基因是B/W型或W/W型,其血清IgG抗DNA抗体水平明显高于含H-2复合体Z/Z型组(P<0.01);H-2复合体为d/z型时,含Fcgr2b基因B/W型组血清IgG抗DNA抗体水平明显高于W/W型组(P<0.01)。NZB小鼠Fcgr2b基因启动子区扩增片段长度短于非自身免疫病小鼠NZW,C57BL/6及BALB/c小鼠,提示可能存在碱基缺失。结论:血清总IgG水平由Fcgr2b基因调控;IgG抗DNA抗体产生主要由H-2复合体调控,Fcgr2b基因单独作用对该抗体产生的影响不明显,但与H-2复合体具有协同作用。

牛幽门螺杆菌抗体中和菌体蛋白对Hela细胞的生长抑制作用

目的:研究Hpylori菌体蛋白对Hela细胞增殖的影响及牛抗Hpylori抗体对Hpylori菌体蛋白的中和作用.方法:Hpylori超声全菌抗原接种奶牛,按多克隆抗体制备常规,腋下皮下接种,全程免疫后每1-2mo加强1次,琼脂双向扩散至1:32时可采集牛血制备抗血清,同期收集牛常乳.抗血清及牛乳低温保存备用.经500、330、330g/L饱和硫酸铵粗提后,沉淀用生理盐水溶解,对生理盐水透析24h,上DEAE-32柱,收集高峰蛋白,经SDS-PAGE鉴定后分装,-20℃保存,通过Hela生长曲线确定Hela细胞的接种密度.建立SS1及NCTC11637对Hela细胞生长增殖功能的抑制作用的MTT分析方法,以牛抗HpyloriIgG分别与SS1及NCTC11637共育2h后各自对Hela增殖功能的抑制率变化来评价牛抗HpyloriIgG对SS1及NCTC11637菌体蛋白的中和作用.结果:细胞毒模型发现SS1与NCTC11637均能浓度依赖性地抑制Hela细胞增殖(SS1:r=0.9594;NCTC11637:r=0.9371),Hela细胞圆缩、边界突显,胞质内可见较多颗粒,折光性差,至高浓度抗原孔,Hela多见碎片,或明显皱缩.但对于相同的细胞毒效应SS1所需浓度高于NCTC11637;中和模型发现牛特异性IgG可分别中和SS1及NCTC11637的细胞毒作用,且具有剂量-反应关系(SS1:r=-0.9936;NCTC11637:r=-0.9627).结论:牛抗Hpylori抗体能够剂量依赖地中和Hpylori对Hela细胞生长增殖的抑制作用.