Antibody Titer of Newcastle Disease in Vaccinated and Non-vaccinated Local Chicken of Cambodia

The experiment was conducted at Veterinary Research Station of Faculty of Veterinary Medicine,Royal University of Agriculture.The experimental period lasted 60 days,starting from October 1st to November 30th 2022.CRD(Completely Randomized Design)was used with 2 treatments/groups,vaccination group and non-vaccination group“control”,and 6 replications.The vaccination groups received two times of vaccination by dropping into the ocular at 7 days and 21 days.Meanwhile,blood samples were collected 3 times to detect the antibody level of ND(Newcastle Disease)and contained 21 days old,35 days old and 49 days old chicks.The ELISA(Enzyme-Linked Immunosorbent Assay)was performed to detect the antibody of those 2 groups.The result of finding showed that the S/P(Sample to Positive)ratio of control at 21 days,was very low,even in 3rd quartile,which was below the threshold.However,the vaccination group was relatively high,even in 1st quartile,which was higher than the threshold.At 35 days,S/P ratio of control group was still very low,but a bit higher than at 21 days.Meanwhile,the vaccination group was still high,even in 1st quartile,and two-time higher than at 21 days,but an increasing number of samples developed less antibody than threshold,accounting for 12.22%.At 49 days,the control group was still very low,even in 3rd quartile,but a bit higher than at 21 days and 35 days,and was close to the threshold.The vaccination group was still relatively high,even in 1st quartile but lower than three times comparing to 35 days.However,in this age,the number of chickens that developed antibody seemed to be increased in the control group,vice versa for vaccination group.The average S/P ratio was different significant(p<0.001),where vaccination had higher S/P ratio than control.It was similar finding for log-titer,the vaccination had higher figure(p<0.001).The risk of infection of ND was higher in control group,but it will reduce by increasing the age of chicken,while vaccination group was decreased by increasing age,especially at 49 days and we need to consider another vaccination to get full protection.

Anti-pancreatic antibody in Turkish patients with inflammatory bowel disease and first-degree relatives

AIM: To identify the role of anti-pancreatic antibody (PAB) in the diagnosis of inflammatory bowel diseases (IBD) among Turkish patients, and its frequency in firstdegree relatives.METHODS: PAB and anti-Saccharomyces cerevisiae (ASCA) were examined in serum samples of 214 subjects including patients with Crohn's disease (CD, n = 64), ulcerative colitis (UC, n = 63), first-degree relatives of patients with CD (n = 25), first-degree relatives of patients with UC (n = 28),and a control group with gastrointestinal symptoms other than (IBD) (n = 34) by indirect immunofluorescence Positivity of PAB and ASCA was compared in terms of Vienna classification, disease activity and medications used.RESULTS: In terms of PAB positivity, no difference was found between patients with CD (14.1%) and UC (7.9%) however, significant difference was observed between patients with CD and subjects in the control group (P < 0.05). No difference was found between patients with CD and their relatives in terms of ASCA positivity, whereas a significant difference was found between other groups (P < 0.001). Compared to ASCA, the sensitivity of the PAB was 19% (7/37), its specificity was 93% (25/27), positive predictive value was 77% (7/9) and negative predictive value was 45% (25/55). ASCA was found with significantly higher prevalence in patients with CD activity index > 150 (P < 0.05).CONCLUSION: PAB is valuable in the diagnosis of IBD rather than CD, but cannot be used alone for diagnostic purposes. PAB is not superior to ASCA in CD diagnosis and in detecting CD among relatives of patients with CD.

猪急性腹泻综合征冠状病毒S蛋白多克隆抗体的制备及在检测该病毒感染中的应用

为制备猪急性腹泻综合征冠状病毒(SADS-CoV)纤突蛋白(S)的多克隆抗体(PAb),本研究经PCR扩增SADS-Co V S蛋白S1亚基C端结构域(S1-CTD)基因片段(384 bp),并将其克隆至原核表达载体p GEX-6p-1中,构建重组质粒p GEX-6p-1-S1-CTD,经双酶切和测序鉴定正确后,转化大肠杆菌BL21(DE3)感受态细胞,利用IPTG诱导表达,通过western blot鉴定重组S1-CTD蛋白(rS1-CTD)的表达及反应原性。结果显示,r S1-CTD以包涵体的形式表达,在40 ku处出现特异性条带。诱导表达后的r S1-CTD经不同浓度尿素重悬并超声离心,SDS-PAGE检测后切胶纯化,得到纯化的重组蛋白。利用BCA试剂盒测得蛋白的浓度为33μg/m L。将该重组蛋白乳化后经3次免疫新西兰大白兔,并在3免一周后采血,分离血清获得S1-CTD蛋白PAb。将SADS-Co V感染Vero E6细胞24 h后,以获得的兔PAb为一抗,分别采用western blot和间接免疫荧光试验(IFA)检测该PAb的反应原性。Western blot结果显示,在约250 ku处出现特异性条带,而阴性对照组无该条带;IFA结果显示,SADS-Co V感染的细胞中出现绿色荧光,而阴性对照细胞无绿色荧光。将SADS-Co V感染仔猪的回肠组织制备病理切片,以制备的PAb为一抗,通过免疫组织化学(IHC)检测SADS-Co V的抗原。结果显示,该组织切片中出现棕色阳性信号,而阴性对照仔猪回肠组织切片则无该棕色信号。表明该PAb可与感染SADS-Co V的仔猪回肠组织中的相应抗原发生特异性免疫反应。综上所述,本实验制备的S1-CTD蛋白PAb具有良好的反应原性和免疫原性,可以用于western blot、IFA、IHC检测体内外SADS-Co V的感染,为后续SADS-Co V检测方法的建立及S蛋白生物学功能的研究奠定基础。

Construction and selection of the natural immune Fab antibody phage display library from patients with colorectal cancer

AIM: To construct the natural immune Fab antibody phage display libraries of colorectal cancer and to select antibodies related with colorectal cancer. METHODS: Extract total RNA from tissue of local cancer metastasis lymph nodes of patients with colorectal cancer. RT-PCR was used to amplify the heavy chain Fd and light chain kappa and the amplification products were inserted successively into the vector pComb3 to construct the human libraries of Fab antibodies. They were then panned by phage display technology. By means of Dot immunoblotting and ELISA, the libraries were identified and the Fab phage antibodies binding with antigens of colorectal cancer were selected. RESULTS: The amplified fragments of Fd and kappa gained by RT-PCR were about 650 bp. Fd and kappa PCR products were subsequently inserted into the vector pComb3, resulting in a recombination rate of 40% and the volume of Fab phage display library reached 1.48 x 10(6).The libraries were enriched about 120-fold by 3 cycles of adsorption-elution-multiplication (panning). Dot immunoblotting showed Fab expressions on the phage libraries and ELISA showed 5 clones of Fab phage antibodies which had binding activities with antigens of colorectal cancer. CONCLUSION: The natural immune Fab antibody phage display libraries of colorectal cancer were constructed. They could be used to select the relative antibodies of colorectal cancer.

Phase I study of chimeric anti-CD20 monoclonal antibody in Chinese patients with CD20-positive non-Hodgkin＇s lymphoma

Objective： This study was designed to determine the safety, pharmacokinetics and biologic effects of a humanmouse chimeric anti-CD20 monoclonal antibody （SCT400） in Chinese padents with CD20-positive B-cell non- Hodgkin＇s lymphoma （CD20 B-cell NHL）. SCT400 has an identical amino acid sequence as rituximab, with the exception of one amino acid in the CH1 domain of the heavy chain, which is common in Asians. Methods： Fifteen patients with CD20＋ B-cell NHL received dose-escalating SCT400 infusions （250 mg/m2： n=3; 375 mg/m2： n=9; 500 mg/m2： n=3） once weekly for 4 consecutive weeks with a 24-week follow-up period. The data of all patients were collected for pharmacoklnetics and pharmacodynamics analyses. Results： No dose-limiting toxicities were observed. Most drug-related adverse events were grade 1 or 2. Two patients had grade 3 or 4 ncutropenia. Under premedication, the drug-related infusion reaction was mild. A rapid, profound and durable depletion of circulating B cells was observed in all dose groups without significant effects on T cell count, natural killer （NK） cell count or immunoglobulin levels. No patient developed anti- SCT400 antibodies during the course of the study. SCT400 serum half-life （Tin）, maximum concentration （Cmax and area under the curve （AUC） generally increased between the first and fourth infusions （P〈0.05）. At the 375 mg/m2 dose, the T1/2 was 122.5±46.7 h vs. 197.0,75.0 11, respectively, and the Cmax was 200.6±20.2 pg/mL vs. 339.1±71.0 ng/mL, respectively. From 250 mg/m2 to 500 mg/m2, the Cmax and AUC increased significantly in a dose-dependent manner （P〈0.05）. Patients with a high tumor burden had markedly lower serum SCT400 concenmations compared with those without or with a low tumor burden. Of the 9 assessable patients, 1 achieved complete response and 2 achieved partial responses. Conclusions; SCT400 is well-tolerated and has encouraging preliminary efficacy in Chinese patients with CD20＋ B-cell NHL.

Comparison ofβ-Amyloid Plaque Labeling Methods:Antibody Staining,Gallyas Silver Staining,and Thioflavin-S Staining

Objective To evaluate senile plaque formation and compare the sensitivity of three differentβ-amyloid(Aβ)labeling methods(antibody staining,Gallyas silver staining,and thioflavin-S staining)to detect Aβdeposition.Methods APPswe/PSEN1dE9 transgenic mice(APP/PS1)of different ages were used to examine spatiotemporal changes in Aβplaque deposition.Antibody staining,Gallyas silver staining,and thioflavin-S staining were used to detect Aβplaque deposition in the same brain region of adjacent slices from model mice,and the results were compared.Results With aging,Aβplaques first appeared in the cortex and then the deposition increased throughout the whole brain.Significantly greater plaque deposition was detected by 6E10 antibody than that analyzed with Gallyas silver staining or thioflavin-S staining(P<0.05).Plaque deposition did not show significant difference between the APP/PS1 mice brains assayed with Gallyas silver staining and ones with thioflavin-S staining(P=0.0033).Conclusions The APP/PS1 mouse model of Alzheimer’s disease could mimick the progress of Aβplaques occurred in patients with Alzheimer’s disease.Antibody detection of Aβdeposition may be more sensitive than chemical staining methods.

Clinical correlations of infliximab trough levels and antibodies to infliximab in South Korean patients with Crohn's disease

To investigate the clinical implications of infliximab trough levels (IFX-TLs) and antibodies to infliximab (ATI) levels in Crohn’s disease (CD) patients in Asian countries.METHODSIFX-TL and ATI level were measured using prospectively collected samples obtained with informed consent from CD patients being treated at Asan Medical Center, South Korea. We analyzed the correlations between IFX-TLs/ATI levels and the clinical activity of CD (quiescent vs active disease) based on the CD activity index, C-reactive protein level, and physician’s judgment of patients’ clinical status at enrollment. The impact of concomitant immunomodulators was also investigated.RESULTSThis study enrolled 138 patients with CD (84 with quiescent and 54 with active disease). In patients with quiescent and active diseases, the median IFX-TLs were 1.423 μg/mL and 0.163 μg/mL, respectively (P < 0.001) and the median ATI levels were 8.064 AU/mL and 11.209 AU/mL, respectively (P < 0.001). In the ATI-negative and -positive groups, the median IFX-TLs were 1.415 μg/mL and 0.141 μg/mL, respectively (P < 0.001). In patients with and without concomitant immunomodulator use, there were no differences in IFX-TLs (0.632 μg/mL and 1.150 μg/mL, respectively; P = 0.274) or ATI levels (8.655 AU/mL and 9.017 AU/mL, respectively; P = 0.083).CONCLUSIONIFX-TL/ATI levels were well correlated with the clinical activity in South Korean CD patients. Our findings support the usefulness of IFX-TLs/ATI levels in treating CD patients receiving IFX in clinical practice.

St udy on Hsp90 Expression in Different Tissues and Its Antibody in Serum of Chickens Infected with Marek's Diseases

To investigate the dynamic change of heat shock protein 90 （Hsp90） in the genesis and development of tumor, we successfully established tumor animal model using Marek’s disease and then determined the location of Hsp90 in the tumor tissue using immunohistochemistry method, the antibody titer level of Hsp90 in the serum and the expression level in the tissue using enzyme-linked immunosorbent assay （ELISA） method. Our result showed that Hsp90 location in the tumor tissue was signiifcantly associated with the tumor cell and most in the cytoplasm of the tumor cell, and Hsp90 expression level in the tissue and the antibody titer level in the serum was most signiifcantly increased with the development of tumor. This is the ifrst report to show the presence of Hsp90 in tumor tissues induced by the Marek’s disease, with its expression correlated to the tumoral grading. These data may also be valuable for developing new molecular anti-cancer therapies.

Serological profiling of Crohn’s disease and ulcerative colitis patients reveals anti-microbial antibody signatures

BACKGROUND The healthcare burden of inflammatory bowel disease(IBD)is rising globally and there are limited non-invasive biomarkers for accurate and early diagnosis.AIM To understand the important role that intestinal microbiota play in IBD pathogenesis and identify anti-microbial antibody signatures that benefit clinical management of IBD patients.METHODS We performed serological profiling of 100 Crohn’s disease(CD)patients,100 ulcerative colitis(UC)patients and 100 healthy controls against 1173 bacterial and 397 viral proteins from 50 bacteria and 33 viruses on protein microarrays.The study subjects were randomly divided into discovery(n=150)and validation(n=150)sets.Statistical analysis was performed using R packages.RESULTS Anti-bacterial antibody responses showed greater differential prevalence among the three subject groups than anti-viral antibody responses.We identified novel antibodies against the antigens of Bacteroidetes vulgatus(BVU_0562)and Streptococcus pneumoniae(SP_1992)showing higher prevalence in CD patients relative to healthy controls.We also identified antibodies against the antigen of Streptococcus pyogenes(SPy_2009)showing higher prevalence in healthy controls relative to UC patients.Using these novel antibodies,we built biomarker panels with area under the curve(AUC)of 0.81,0.87,and 0.82 distinguishing CD vs control,UC vs control,and CD vs UC,respectively.Subgroup analysis revealed that penetrating CD behavior,colonic CD location,CD patients with a history of surgery,and extensive UC exhibited highest antibody prevalence among all patients.We demonstrated that autoantibodies and anti-microbial antibodies in CD patients had minimal correlation.CONCLUSION We have identified antibody signatures for CD and UC using a comprehensive analysis of antimicrobial antibody response in IBD.These antibodies and the source microorganisms of their target antigens improve our understanding of the role of specific microorganisms in IBD pathogenesis and,after future validation,should aid early and accurate diagnosis of IBD.

Differentiation of Behcet's disease from inflammatory bowel diseases:Anti-saccharomyces cerevisiae antibody and anti-neutrophilic cytoplasmic antibody

The differential diagnosis of Behcet's disease(BD) from inflammatory bowel disease(IBD) is sometimes difficult and challenging.Hereby,we suggested the utility of anti-saccharomyces cerevisiae antibody(ASCA) and anti-neutrophilic cytoplasmic antibody(p-ANCA) in the differential diagnosis of BD from IBD.

Detection of anti-preS1 antibodies for recovery of hepatitis B patients by immunoassay

AIM: To establish a convenient immunoassay method based on recombinant antigen preS1(21-119aa) to detect anti-preS1 antibodies and evaluate the clinical significance of antibodies in hepatitis B. METHODS: The expression plasmid pET-28a-preS1 was constructed, and a large quantity of preS1(21-119aa) fragment of the large HBsAg protein was obtained. The preS1 fragment purified by Ni(2+)-IDA affinity chromatography was used as coated antigen to establish the indirect ELISA based on streptavidin-biotin system for detection of the anti-preS1 antibodies in sera from HBV-infected patients. For follow-up study, serial sera were collected during the clinical course of 21 HBV-infected patients and anti-preS1 antibodies, preS1 antigen, HBV-DNA and other serological HBV markers were analyzed. RESULTS: preS1(21-119aa) fragment was highly expressed from the plasmid pET-28a-preS1 in a soluble form in E.Coli (30mg.L(-1)), and easily purified to high purity over 90% by one step of Ni(2+)-IDA-sepharose 6B affinity chromatography. The purity and antigenicity of the purified preS1(21-119aa) protein was determined by 150g.L(-1) SDS-PAGE, Western blot and a direct ELISA. Recombinant preS1(21-119aa) protein was successfully applied in the immunoassay which could sensitively detect the anti-preS1 antibodies in serum specimens of acute or chronic hepatitis B patients. Results showed that more than half of 19 acute hepatitis B patients produced anti-preS1 antibodies during recovery of the disease, however, the response was only found in a few of chronic patients. In the clinical follow-up study of 11 patients with anti-preS1 positive serological profile, HBsAg and HBV-DNA clearance occurred in 6 of 10 acute hepatitis B patients in 5-6 months, and seroconversion of HBeAg and disappearance of HBV-DNA occurred in 1 chronic patients treated with lavumidine, a antiviral agent. CONCLUSION: The high-purity preS1(21-119aa) coated antigen was successfully prepared by gene expression and affinity chromatography. Using this antigen, a conveniently detective system of anti-preS1 antibodies in sera was established. Preliminarily clinical trial the occurrence of anti-preS1 antibodies in acute hepatitis B patients suggests the clearance of HBV from serum in a short-term time, and anti-preS1 positive in chronic patients means health improvement or recovery from the disease.

Anti-Saccharomyces cerevisiae antibody titers are stable over time in Crohn's patients and are not inducible in murine models of colitis

AIM： To investigate ASCA production over time in CD and murine colitis in order to further our understanding of their etiology. MATERIALS AND METHODS： Sixty-six CD patients were compared to ulcerative colitis （UC） and irritable bowel syndrome patients with respect to ASCA production as measured by ELISA. ASCA IgG or IgA positivity as well as change in titers over a period of up to 3 years （△tgG/A） was correlated with clinical parameters such as CD activity index （CDM） and C-reactive protein levels （CRP）. Moreover, two murine models of colitis （DSS and IL-10 knock out） were compared to control animals with respect to ASCA titers after oral yeast exposure. RESULTS： ASCA IgG and IgA titers are stable over time in CD and non-CD patients. Fistular disease was associated with a higher rate of ASCA IgA positivity （P = 0.014）. Ileal disease was found to have a significant influence on the △tgG of ASCA （P = 0.032）. There was no correlation found between ASCA positivity or △tgG/A and clinical parameters of CD： CDAI and CRP. In mice, neither healthy animals nor animals with DSS-induced or spontaneous colitis exhibited a marked increase in ASCA titers after high-dose yeast exposure. On the other hand, mice immunized intraperitoneally with mannan plus adjuvant showed a marked and significant increase in ASCA titers compared to adjuvant-only immunized controls （P = 0.014）. CONCLUSION： The propensity to produce ASCA in a subgroup of CD patients is largely genetically predetermined as evidenced by their stability and lack of correlation with clinical disease activity parameters. Furthermore, in animal models of colitis, mere oral exposure of mice to yeast does not lead to the induction of marked ASCA titers irrespective of concomitant colonic inflammation. Hence, environment may play only a minor role in inducing ASCA.

Screening for celiac disease in Down's syndrome patients revealed cases of subtotal villous atrophy without typical for celiac disease HLA-DQ and tissue transglutaminase antibodies

A1M： To investigate the prevalence of celiac disease （CD） as well as CD marker antibodies and susceptibility HLA-DQ haplotypes in 134 karyotyped Down＇s syndrome （DS） patients. METHODS： Immunoglobulin A （IgA） and G （IgG） type anti-gliadin antibodies （AGA）, IgA type anti-tissue transglutaminase （tTG） antibodies （anti-tTG） with antigen of guinea pig and human source were determined by enzyme-linked immunosorbent assay and endomysium antibodies （EHA） by indirect immunofiuoresence test. HLA-DQA1＊0501/DQB1＊0201 （DQ2） was revealed by polymerase chain reaction. Celiac disease was diagnosed by revised ESPGHAN criteria. RESULTS： 41% of DS patients had AGA, 6.0% IgA anti-tTG with guinea pig antigen, and 3.0 % [gA EMA （all positive for anti-tTG with human tTG）. Subtotal villous atrophy was found in 5 out of 9 DS patients who had agreed to small bowel biopsy. One of them had DQA1＊0S01/DQB1＊0201 and anti-tTG and EMA i.e. typical for CD markers （this case also fulfilled the ESPGHAN diagnostic criteria）, but other four lacked these markers. Three non-biopsied DS patients had also most probably CD because DQA1＊0S01/DQB1＊0201 and IgA anti-tTG （EMA） were detected. Thus, the prevalence of CD among our DS patients population is 3.0 % （95 % of confidence interval [CI]： 0.1-5.9 %）. CONCLUSION： We confirm the increased frequency of CD among DS patients. In addition, we have revealed a subgroup of patients with subtotal villous atrophy but without characteristic for CD immunological and genetic markers. Whether these cases represent CD （with atypical immunopathogenesis） or some other immune enteropathy, requires further investigations.

Construction of human Fab library and screening of a single-domain antibody of amyloid-beta 42 oligomers

Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli- gomers and constructed a have human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe- cifically recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked im- munosorbent assay demonstrated this antibody bound specifically to human amyloid-beta 42 tetramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc- cessfully constructed a human phage display library and screened a single-domain antibody that specifically recognized amyloid-beta 42 oligomers.

Partial overlap of anti-mycobacterial,and anti-Saccharomyces cerevisiae mannan antibodies in Crohn's disease

AIM： To test whether humoral immune reaction against mycobacteria may play a role in anti- Saccharomyces cerevisiae antibodies （ASCA） generation in Crohn＇s disease （CD） and/or whether it correlates with clinical subtypes. METHODS： The dominant ASCA epitope was detected by Galanthus nivalis lectin （GNL）-binding assay. ASCA and IgG against mycobacterial lysates （M avium, M smegmatis, M chelonae, M bovis BCG M avium ssp. paratuberculosis （MAP）] or purified lipoarabinomannans （LAM） were detected by ELISA. ASCA and anti-mycobacterial antibodies were affinity purified to assess cross-reactivities. Anti-mycobacterial IgG were induced by BCG-infection of mice. RESULTS： GNL bound to different extents to mycobacterial lysates, abundantly to purified mannosecapped （Man） LAM from M tuberculosis, but not to uncapped LAM from M srnegrnatis. Fifteen to 45% of CD patients but only 0%-6% of controls were seropositive against different mycobacterial antigens. Anti-mycobacterial IgG correlated with ASCA （r = 0.37-0.64; P = 0.003-P 〈 0.001）. ASCA-positivity and deficiency for mannan-binding lectin synergistically associated with anti-mycobacterial IgG. In some patients, anti-mycobacterial antibodies represent crossreactive ASCA. Vice-versa, the predominant fraction of ASCA did not cross-react with mycobacteria. Finally, fistulizing disease associated with antibodies against M avium, M smegmatis and MAP （P = 0.024, 0.004 and 0.045, respectively）. CONCLUSION： Similar to ASCA, seroreactivity against mycobacteria may define CD patients with complicated disease and a predisposition for immune responses against ubiquitous antigens. While in some patients anti-mycobacterial antibodies strongly cross-react with yeast mannan; these cross-reactive antibodies only represent a minor fraction of total ASCA. Thus, mycobacterial infection unlikely plays a role in ASCA induction.

Antibody research targeting Cathepsin S for cancer therapy

Cathepsin S is a cysteine protease highly expressed in many type of cancers including colorectal, prostate, breast, and glioblastoma’s. It is involved in tumor progression through extracellular matrix remodeling. In recent years, antibody research specifically targeting Cathepsin S to block/inhibit tumorigenic effects were generated some positive preclinical data. This antagonistic antibody was demonstrating efficacy in multiple in vitro/in vivo cancer models both as a monotherapy and in combination with approved agents. This mini-review provides an overview of therapeutic antibody targeting Cathepsin S strategies in the last half decade, focusing on the rationale of cell-surface Cathepsin S targeted and their potential clinical application.

Aβ28-Induced Specific and Effective Serum Antibodies Against Aβ42

Though phase I clinical trial of immunotherapy for Alzheimer＇s disease（AD） with inoculated Aβ42 in humans had been proven to be effective,phase II immunotherapy trial was discontinued in 2002 because a few patients developed significant inflammatory reactions caused by C-terminal domain of Aβ42.The aim of the study was to investigate the levels and the abilities of antibodies induced by C-terminal truncated Aβ species to inhibit Aβ42 aggregation and cytotoxity in vitro.46-week-old male BALB/c mice,Aβ42 and Aβ28/Aβ35/Aβ42 with a C-terminal eight-histidine tag（Aβ28H8,Aβ35H8,and Aβ42H8） were applied in the present study.The mice were randomly divided into 5 groups（n=8）,control mice immunized with the normal saline,Aβ42-immunized mice and Aβ42H-/Aβ35H-/Aβ28H-immunized mice.All the serum antibodies were evaluated by measuring their abilities to inhibit Aβ42 aggregation and cytotoxity in vitro.Each mouse was vaccinated with purified Aβ peptide emulsified with Freund＇s adjuvant（volume ratio 1：1）.Titers,concentrations and isotypes of serum antibodies against Aβ42 were measured by indirect ELISA.Effects of serum antibodies on Aβ42 aggregation and disassembly of Aβ42 fibrils in vitro were observed by electron microscopy.Effects of serum antibodies on Aβ42 cytotoxicity were determined by MTT assay.Aβ42 or Aβ28 could induce higher anti-Aβ42 antibody titer（1：6400） than Aβ35（1：3200）.Significantly,Aβ28 induced more IgG1 and IgG2b isotype antibodies and less IgG2b isotype antibody than other Aβ species though all the induced serum antibodies could inhibit Aβ42 aggregation or fibrillogenesis,could induce the disassembly of Aβ42 aggregates,and neutralized or inhibited the cytotoxicity of Aβ42 in vitro.C-Terminal truncated Aβ28 could induce the same effective but safer serum antibodies against Aβ42 than full length Aβ42 by eliciting more Th2-type immune responses.

Anti-microbial antibodies in celiac disease:Trick or treat?

AIM： To determine the prevalence of a new set ot anti-glycan and anti-outer membrane protein （anti- OMP） antibodies in a Hungarian cohort of adult Celiac disease （CD） patients. METHODS： 190 consecutive CD patients [M/F： 71/119, age：39.9 （SD：14.1） years], 100 healthy, and 48 gastrointestinal controls were tested for glycan anti-Saccharomyces cerevisiae （gASCA）, anti-laminaribioside （ALCA）, anti-chitobioside, anti-mannobioside, anti-OMP antibodies and major NOD2/CARD15 mutations. Thirty out of 82 CD patients enrolled at the time of diagnosis were re-evaluated for the same antibodies after longstanding gluten-free diet （GFD）. RESULTS： 65.9% of the CD patients were positive for at least one of the tested antibodies at the time of the diagnosis. Except anti-OMP and ALCA, antimicrobial antibodies were exclusively seen in untreated CD; however, the overall sensitivity was low. Any glycan positivity （LR＋： 3.13; 95% CI： 2.08-4.73） was associated with an increased likelihood ratio for diagnosing CD. Significant correlation was found between the levels of anti-glycan and anti-endomysial or anti-transglutaminase antibodies. Anti-glycan positivity was lost after longstanding GFD. Anti-glycan antibody titers were associated with symptoms at presentation, but not the presence of NOD2/CARD15 mutations. Patients with severe malabsorption more frequently had multiple antibodies at diagnosis （P = 0.019）. CONCLUSION： The presence of anti-glycan antibodies in CD seems to be secondary to the impaired small bowel mucosa which can lead to increased antigen presentation. Furthermore, anti-glycan positivity may be considered an additional marker of CD and dietary adherence.

Preparation and application of polyclonal antibodies against KSHV v-cyclin

We prepared rabbit polyclonal antibodies against Kaposi＇s sarcoma-associated herpesvirus （KSHV）-encoded v- cyclin （ORF 72） and detected the natural viral protein using these polyclonal antibodies. Three antigenic polypep- tides of v-cyclin were designed and synthesized. A fragment of the v-cyclin gene was cloned into a eukaryotic expression vector pEF-MCS-Flag-IRES/Puro to construct a recombinant vector, pEF v-cyclin. Then, pEF v-cyclin was transfected into 293T and EA.hy926 cells to obtain v-cyclin-Flag fusion proteins. Six New Zealand white rabbits were immunized with KLH-conjugated peptides to generate polyclonal antibodies against v-cyclin. The polyclonal antibodies were then characterized by ELISA and Western blotting assays. Finally, the polyclonal anti- bodies against v-cyclin were used to detect natural viral protein expressed in BCBL-1, BC-3, and JSC-1 cells. The results showed that using the Flag antibody, v-cyclin-Flag fusion protein was detected in 293T and EA.hy926 cells transfected with pEF-v-cyclin. Furthermore, ELISA showed that the titer of the induced polyclonal rabbit anti-v- cyclin antibodies was higher than 1：8,000. In Western blotting assays, the antibodies reacted specifically with the v-cyclin-Flag fusion protein as well as the natural viral protein. The recombinant expression vector pEF-v-cyclin was constructed successfully, and the polyclonal antibodies prepared can be used for various biological tests in- cluding ELISA and Western blotting assays.

Expression of secreted human single-chain fragment variable antibody against human amyloid beta peptide in Pichia pastoris

BACKGROUND：Studies have shown that monoclonal or polyclonal antibody injections of amyloid β peptide are effective in removing amyloid β peptide overload in the brain. OBJECTIVE： Based on successful screening of a human single-chain fragment variable antibody specific to amyloidβpeptide, this paper aimed to express recombinant human single-chain variable antibody against amyloid β peptide. DESIGN, TIME AND SETTING： A single sample experiment was performed at the Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Hospital （Beijing, China） from January to July 2006. MATERIALS： Human single-chain fragment variable antibody gene against amyloid β peptide was screened from a human phage-display antibody library. METHODS： Human single-chain fragment variable antibody gene was mutated to eliminate a BamHI restriction site and cloned into a T easy plasmid for pT-scFvAβ construction, which was identified by PCR amplification and endonuclease digestion. Plasmid pT-scFvAβ was cut by EcoRI and NotI endonucleases, and the antibody gene was cloned into pPIC9K plasmid to construct pPIC9K-scFvAβ expression vector, which was confirmed by gene sequencing. Linearized pPIC9K-scFvAβ was used to transform a Pichia pastoris GS115 cell line, and the recombinant was induced by 0.5% methanol to express human single-chain fragment variable antibody specific to amyloid β peptide. MAIN OUTCOME MEASURES： Protein electrophoresis was used to identify PCR products, gene sequencing was used to verify the pPIC9K-scFvA sequence, and SDS-PAGE was used to detect recombinant expression of human single-chain fragment variable antibody specific to amyloid β peptide in Pichia pastoris. RESULTS： Gene sequencing confirmed pPIC9K-scFvAβ orientation. Recombinants were obtained by linearized pPIC9K-scFvAβ transformation. After induction with 0.5% methanol, the recombinant yeast cells secreted proteins of 33-ku size. CONCLUSION： The expression vector pPIC9K-scFvAβ was successfully constructed. Human single-chain fragment variable antibody specific to amyloid β peptide was recombinantly expressed in Pichia pastoris.