Human leukocyte antigen and donor-specific antibodies in liver transplantation

In this article,we comment on an article published in a recent issue of the World Journal of Gastroenterology.We specifically focus on the roles of human leukocyte antigen(HLA)and donor-specific antibodies(DSAs)in pediatric liver transpl-antation(LT),as well as the relationship between immune rejection after LT and DSA.Currently,LT remains the standard of care for pediatric patients with end-stage liver disease or severe acute liver failure.However,acute and chronic re-jection continues to be a significant cause of graft dysfunction and loss.HLA mismatch significantly reduces graft survival and increases the risk of acute rejection.Among them,D→R one-way mismatch at three loci was significantly related to graft-versus-host disease incidence after LT.The adverse impact of HLA-DSAs on LT recipients is already established.Therefore,the evaluation of HLA and DSA is crucial in pediatric LT.

New glucocerebrosidase antibodies can advance research in the field of neurodegenerative disorders

In medical research,there are times when the introduction of a new tool can launch scientific discovery in new directions.While antibody development may be considered mundane,in the field of glucocerebrosidase(GCase)research,the dearth of validated antibodies for different applications has impeded progress in studies of disease pathogenesis and therapeutic development.The recent introduction of new,rigorously evaluated antibodies can now propel research into the link between glucocerebrosidase and Parkinson’s disease(PD)as well as aspects of the pathobiology of Gaucher disease(Jong et al.,2024).

Expanding role of antibodies in kidney transplantation

The role of antibodies in kidney transplant(KT)has evolved significantly over the past few decades.This role of antibodies in KT is multifaceted,encompassing both the challenges they pose in terms of antibody-mediated rejection(AMR)and the opportunities for improving transplant outcomes through better detection,prevention,and treatment strategies.As our understanding of the immunological mechanisms continues to evolve,so too will the approaches to managing and harnessing the power of antibodies in KT,ultimately leading to improved patient and graft survival.This narrative review explores the multifaceted roles of antibodies in KT,including their involvement in rejection mechanisms,advancements in desensitization protocols,AMR treatments,and their potential role in monitoring and improving graft survival.

Serological surveillance for SARS-CoV-2 antibodies among students,faculty and staff within a large university system during the pandemic

BACKGROUND At the end of December 2019,the world faced severe acute respiratory syndrome-coronavirus 2(SARS-CoV-2),which led to the outbreak of coronavirus disease 2019(COVID-19),associated with respiratory issues.This virus has shown significant challenges,especially for senior citizens,patients with other underlying illnesses,or those with a sedentary lifestyle.Serological tests conducted early on have helped identify how the virus is transmitted and how to curb its spread.The study hypothesis was that the rapid serological test for SARS-CoV-2 antibodies could indicate the immunoreactive profile during the COVID-19 pandemic in a university population.AIM To conduct active surveillance for serological expression of anti-SARS-CoV-2 antibodies in individuals within a university setting during the COVID-19 pandemic.METHODS This sectional study by convenience sampling was conducted in a large university in Niteroi-RJ,Brazil,from March 2021 to July 2021.The study population consisted of students,faculty,and administrative staff employed by the university.A total of 3433 faculty members,60703 students,and 3812 administrative staff were invited to participate.Data were gathered through rapid serological tests to detect immunoglobulin(Ig)M and IgG against SARS-CoV-2.Theχ²or Fisher's exact test was used to conduct statistical analysis.A 0.20 significance level was adopted for variable selection in a multiple logistic regression model to evaluate associations.RESULTS A total of 1648 individuals were enrolled in the study.The proportion of COVID-19 positivity was 164/1648(9.8%).The adjusted logistic model indicate a positive association between the expression of IgM or IgG and age[odds ratio(OR)=1.16,95%CI:1.02-1.31](P<0.0024),individuals who had been in contact with a COVID-19-positive case(OR=3.49,95%CI:2.34-5.37)(P<0.001),those who had received the COVID-19 vaccine(OR=2.33,95%CI:1.61-3.35)(P<0.001)and social isolation(OR=0.59,95%CI:0.41-0.84)(P<0.004).The likelihood of showing a positive result increased by 16%with every ten-year increment.Conversely,adherence to social distancing measures decreased the likelihood by 41%.CONCLUSION These findings evidenced that the population became more exposed to the virus as individuals discontinued social distancing practices,thereby increasing the risk of infection for themselves.

类风湿性关节炎滑膜病变高频超声表现与Anti-ccp、ESR及CRP的相关性

目的分析类风湿性关节炎(RA)滑膜病变高频超声表现与抗环瓜氨酸肽抗体(Anti-CCP)、红细胞沉降率(ESR)和C反应蛋白(CRP)的相关性,以期为该疾病早期诊断及治疗方案的制定提供更为准确和科学的依据。方法选取2020年1月至2023年3月于大庆龙南医院风湿免疫科住院的治疗前RA患者65例(RA组),另选取同期于本院体检中心行体检的健康者55名(对照组)。比较两组高频超声表现、髌上囊液体厚度、滑膜厚度、滑膜动脉RI及实验室指标(Anti-ccp、ESR及CRP水平),RA组根据Anti-ccp、ESR及CRP阳性标准分为阳性、阴性组,比较Anti-ccp、ESR及CRP阳性及阴性组的髌上囊液体厚度、滑膜厚度、滑膜动脉RI。采用Pearson分析滑膜病变高频超声表现各指标与Anti-ccp、ESR及CRP的相关性。结果对照组膝积液少<4 mm;RA组80%膝积液>4 mm,多对称,尤见于内外侧隐窝。对照组滑膜难辨,RA组滑膜增厚、低回声、分界清、表面糙、见绒毛。彩超示RA组81.53%膝滑膜有明显血流信号,多为Ⅱ、Ⅲ级。RA组髌上囊液体厚度、滑膜厚度、Anti-ccp、ESR及CRP水平均高于对照组,滑膜动脉RI则低于对照组,差异有统计学意义(P<0.05);Anti-ccp、ESR及CRP阳性组髌上囊液体厚度、滑膜厚度水平均显著高于阴性组,滑膜动脉RI低于阴性组,差异有统计学意义(P<0.05)。髌上囊液体厚度、滑膜厚度与Anti-ccp、ESR及CRP水平均呈正相关(P<0.05);滑膜动脉RI与Anti-ccp、ESR及CRP水平均呈负相关(P<0.05)。结论高频超声可清晰观察RA患者的滑膜病变情况,且与Anti-ccp、ESR及CRP等实验室指标存在显著关联性,可为临床诊断RA滑膜病变患者提供有力的参考依据,利于制定更具针对性的治疗措施。

Monoclonal antibodies as therapeutic agents in oncology and antibody gene therapy

Antibodies as therapeutic agents are mostly used in oncology, as illustrated by their applications in lymphoma, breast cancer or colorectal cancer. This review provides a brief historical sketch of the development of monoclonal antibodies for cancer treatment and summarizes the most significant clinical data for the best-established reagents to date. It also discusses strategies to improve the anti-tumor efficacy of antibody therapy, including antibody gene therapy and exploitation of bone marrow derived primary mesenchymal stem cells as the antibody gene transporter.

Preparation of Polyclonal Antibodies Against Testis-specific Protease 50 and Characterization of Antibody Specificity

Testis-specific protease 50 （TSP50） is a testis-specific oncogene, which is abnormally activated in most tested patients with breast cancer. This property makes it an attractive molecular marker and a promising target for the diagnosis and therapy of breast cancer. In order to obtain the protective and specific polyclonal antibodies for further research, TSPS0 cDNA was amplified by RT-PCR from normal human testicular tissue, and inserted into eukaryotic expression vector PeDNA3.1. Rabbit anti-TSPS0 polyclonal antibodies were prepared by means of intramuscular injection of peDNA3.1-TSPS0 into the rabbits. Titem of the anti-sera were measured by ELISA and Western blotting with the E. coli cell lysate containing the induced GST-TSPS0 fusion protein as an antigen. In addition, we examined the expression of TSPS0 in both breast cancer cell line MCF-7 and breast cancer tissue by immunofluorescent and immunohistochemistry analysis.

类风湿关节炎合并骨关节炎病人血清anti-Sa、anti-CCP水平与骨关节损伤、全身炎症反应的相关性分析

目的:分析类风湿关节炎(RA)病人血清anti-Sa、anti-CCP抗体水平与其骨关节损伤、全身炎症反应的相关性。方法:选择RA合并骨关节损伤病人108例,根据血清anti-Sa、anti-CCP抗体水平分别列入高anti-Sa组和低anti-Sa组、高anti-CCP组和低anti-CCP组。比较各组病人WOMAC骨性关节炎指数、lysholms膝关节功能评分值,血清白细胞介素(IL)-1β、IL-6、IL-27、肿瘤坏死因子α(TNF-α)水平。采用Pearson检验评估有关指标的相关性。结果:高anti-Sa组、高anti-CCP组病人的WOMAC骨性关节炎指数明显高于低anti-Sa组(P<0.01),lysholms膝关节功能评分明显低于低anti-Sa组(P<0.01);血清中IL-1β、IL-6、IL-27、TNF-α的水平明显高于低anti-CCP组(P<0.01)。RA病人血清anti-Sa、anti-CCP抗体水平与骨关节损伤、全身炎症反应严重程度呈正相关关系(P<0.05~P<0.01),与lysholms膝关节功能评分呈负相关关系(P<0.01)。结论:RA病人血清中anti-Sa、anti-CCP抗体水平显著升高与关节损伤及全身炎症反应有一定的相关性,可作为临床判断病情活动性与骨关节损伤的参考指标。

PRODUCTION AND APPLICATION OF MONOCLONAL ANTIBODY TO POLYAMINE (PREPARATION AND CHARACTERISTICS OF MONOCLONAL ANTIBODIES AGAINST SPERMIDINE)

A monoclonal antibody was first prepared by fusion of mouse myeloma cells (SP2/0-Ag-14) with spleen cells isolated from male BALB/ c mice immunized with spermidine-bovine serum albumin conjugate (SPD- BSA). The hybridoma cell line producing antibody specific for spermidine was cultured in vitro and after i. p. into mice, the ascitic fluid gave suitably high dilution titres (1: 106) by enzyme immunoassay. This monoclonal antibody is of IgG1 class and the bimolecular compleex with molecular weight of 52KD and 27 KD. The monoclonal antibody was clearly specific to spermidine comparing with spermine or putriscine. Monclonal antibody may prove to be useful in the rapid diagnosis and evaluation of patients with cancer.

ISOLATION OF ENDOTOXIN-SPECIFIC ANTIBODIES BY SELECTION OF AN SINGLE CHAIN PHAGE ANTIBODY LIBRARY

Objective: To isolate murine anti endotoxin single chain phage antibody from a constructed library. Methods: Total RNA was firstly extracted from murine splenic cells and mRNA was reverse-transcribed into cDNA. Then the designed primers were used to amplify the variable region genes of the heavy and light chain (VH, VL) with polymerase chain reaction. The linker was used to assemble the VH and VL into ScFv, and the NotI and SfiI restriction enzymes were used to digest the ScFv in order to ligate into the pCANTAB5E phagemid vector that was already digested with the same restriction enzymes. The ligated vector was then introduced into competent E.coli TG1 cells to construct a single-chain phage antibody library. After rescued with M13KO7 helper phage, recombinant phages displaying ScFv fragments were harvested from the supernatant and selected with endotoxin. The enriched positive clones were reinfected into TG1 cells. Finally, 190 clones were randomly selected to detect the anti endotoxin antibody with indirect ELISA. Results: The titer of anti endotoxin in murine sera was 1:12,800. The concentration of total RNA was 12.38 μg/ml. 1.9×107 clones were obtained after transformed into TG1. 3×104 colonies were gotten after one round panning. Two positive colonies were confirmed with indirect ELISA among 190 randomly selected colonies. Conclusion: A 1.9×107 murine anti endotoxin single chain phage antibody library was successfully constructed. Two anti endotoxin antibodies were obtained from the library.

Blockade of Rho-associated kinase prevents inhibition of axon regeneration of peripheral nerves induced by anti-ganglioside antibodies

Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrèsyndrome,mostly related to halted axon regeneration.Cross-linking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon regeneration.These effects involve the activation of the small GTPase Rho A/ROCK signaling pathways,which negatively modulate growth cone cytoskeleton,similarly to well stablished inhibitors of axon regeneration described so far.The aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632,a selective pharmacological inhibitor of ROCK,in a mouse model of axon regeneration of peripheral nerves,where the passive immunization with a monoclonal antibody targeting gangliosides GD1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated fibers.Our results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of Y-27632.Treatment with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-GD1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous sensitivity.In contrast,the same dose showed toxic effects on the regeneration of myelinated fibers.Interestingly,scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-GD1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only Y-27632.Overall,these findings confirm the in vivo participation of Rho A/ROCK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-GD1a/GT1b monoclonal antibody.Our findings open the possibility of therapeutic pharmacological intervention targeting Rho A/Rock pathway in immune neuropathies associated with the presence of anti-ganglioside antibodies and delayed or incomplete clinical recovery after injury in the peripheral nervous system.

Analysis of Specific Th1/Th2 Helper Cell Responses and IgG Subtype Antibodies in Anti-CD4 Monoclonal Antibody Treated Mice with Autoimmune Cardiomyopathy

The cytokine repertoire of ADP/ATP carrier-specific humoral immune responses and the cytokine-dependent anti-ADP/ATP carrier antibody IgG subclasses were examined in a cohort of ADP/ATP carrier-immunized BALB/c mice treated with anti-CD4 monoclonal antibody. Eighteen male BALB/c mice （6–8 weeks old） were randomized into 3 groups： dilated cardiomyopathy （DCM） group, DCM-tolerance （Tol） group and control group. The mice in DCM group were immunized with the peptides derived from human ADP/ATP carrier protein for 6 months and mice in the control group were sham-immunized, while the mice in DCM-Tol group were immunized with ADP/ATP carrier protein and anti-CD4 McAb simultaneously. Serum autoantibody against ADP/ATP carrier and IgG subclasses were measured by ELISA, intracellular cytokines IFN-γ and IL-4 of Th cells were moni- tored with flow cytometry, and splenic T cell cytokines IFN-γ, IL-2, IL-4 and IL-6 were detected by using real-time fluorescent quantitative PCR. The results showed that the autoantibody against ADP/ATP carrier was found in all mice in DCM group, and the antibody level, serum IgG1 and IgG2a subclasses, cytokines in T cells and Th cells were all elevated in DCM group, as compared with those in control group （P〈0.01）. On the other hand, in DCM-Tol group, the autoantibody level and contents of all the cytokines were significantly different from those in DCM group （P〈0.01）, and were close to those in control group. And the levels of IgG1, IgG2a, IgG2b and IgG3 were influenced, to varying degrees, by anti-CD4 McAb as compared with those in DCM group. All these four types of IgG subclasses were substantially decreased in DCM-Tol group as compared with DCM group. It is concluded that the treatment with anti-CD4 McAb could prevent the activation of T cells, reverse the abnormal secretion of cytokines and the imbalance between Th1/Th2 cell subsets and abnormal production of autoantibody against ADP/ATP carrier, and eventually avoid myocardial injuries.

GENE ENGINEERING EB VIRUS MEMBRANE ANTIGEN IN DETECTION OF MA-IgA ANTIBODY(COMPARISON WITH VCA-IgA AND EA-IgA ANTIBODIES)

With gene engineering EB virus membrane antigen as the diagnostic antigen, indirect immunofluo-rescence (IF) assay was used to detect IgA antibody against EB virus membrane antigen (MA-IgA) in sera from 202 nasopharyngeal carcinoma (NPC) patients and 315 controls (normal and patients with other tumors). MA-IgA antibody was positive in 96.8% of the pretreatment NPC patients with a GMT of 1:36.3. MA-IgA detection by this method was more sensitive than EA-IgA detection by IE. In contrast, patients with tumors other than NPC were negative for MA-IgA antibody. 9.1% of VCA-IgA positive persons were MA-IgA positive with a GMT of less than 1:5. No MA-IgA positive was found in VCA-IgA negatives. The results indicated that this method was relatively specific. In the treatment group, the positive rate and GMT of MA-IgA antibody declined with increase in survival time and the decline was faster than VCA-IgA. When recurrence or distant metastasis developed, similar to VCA-IgA and EA-IgA antibodies, the positive rate and GMT of MA-IgA antibody increased to its pretreatment level. Therefore, MA-IgA detection might be valuable in the early diagnosis and monitor of NPC.

Isolation of Goose-origin scFv Antibodies Against Goose Parvovirus from Bacterial Display Antibody Libraries

Goose parvovirus(GPV)can cause a highly contagious and fatal gosling plague(GP)disease in goslings and muscoy ducklings.Here,three goose-origin neutralizing single chain variable fragment(scFv)antibodies against GPV SYG-61 were isolated.The genes of scFv antibodies were derived from goslings immunized with GPV SYG-61,and scFvs were subcloned into a pBSD vector for the construction of pBSD-scFv libraries.The pBSD-scFv libraries were screened following three rounds using VP2(protective antigen of GPV)as the bait by flow cytometry(FCM).After screening,the 15 clones with high mean fluorescence intensity(MFI)were isolated and sequenced.These 15 scFvs were expressed by pET-28a(+)in E.coli.The specificity and affinity of the 15 purified scFvs were successfully confirmed by ELISA.In the preliminary neutralization experiment on primary goose embryo fibroblast(GEF)in vitro,three of the 15 purified scFvs(named scFv-10,scFv-11 and scFv-50)showed significant neutralizing capacities.The study generated the first goose-origin neutralizing scFv against GPV and laid the foundation for the appearance of full-length goose-origin neutralizing monoclonal antibody against GPV.

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.

Autoantibodies related to ataxia and other central nervous system manifestations of gluten enteropathy

Gluten ataxia and other central nervous system disorders could be linked to gluten enteropathy and related autoantibodies.In this narrative review,we focus on the various neuro-logical manifestations in patients with gluten sensitivity/celiac disease,immunological and autoimmune mechanisms of ataxia in connection to gluten sensitivity and the autoantibodies that could be used as a biomarker for diagnosing and following.We focused on the anti-gliadin antibodies,antibodies to different isoforms of tissue transglutaminase(TG)(anti-TG2,3,and 6 antibodies),anti-glycine receptor antibodies,anti-glutamine acid decarboxylase antibodies,anti-deamidated gliadin peptides antibodies,etc.Most studies found a higher prevalence of these antibodies in patients with gluten sensitivity and neurological dysfunction,presented as different neurological disorders.We also discuss the role of a gluten-free diet on the clinical improvement of patients and also on imaging of these disorders.

Atypical Guillain-Barrésyndrome with positive anti-sulfatide,anti-GT1b,and anti-GT1a antibodies:A case report

BACKGROUND The role of diverse antibodies in mediating peripheral nerve injury in Guillain-Barrésyndrome(GBS)is becoming clearer,but positivity for multiple antibodies in one case is uncommon.To our knowledge,this is the first case involving GBS with positive anti-sulfatide,anti-GT1a,and anti-GT1b antibodies.CASE SUMMARY A 20-year-old female patient was admitted to the hospital due to weakness of limbs for 5 d,and deterioration of the weakness and muscle aches for 1 d.The patient's limbs were weak,but the tendon reflexes in the part of the limbs were normal.There was no comorbid peripheral nociception or deep sensory dysfunction.She was diagnosed with GBS and was discharged after receiving intravenous human immunoglobulin pulse therapy.CONCLUSION In this article,the clinical manifestations,neurophysiological examination,and auxiliary examination findings of a GBS patient positive for multiple antibodies were analyzed to improve the identification of the disease by clinical physicians at an early stage.

Anti-PD1 antibody and not anti-LAG-3 antibody improves the antitumor effect of photodynamic therapy for treating metastatic breast cancer

Photodynamic therapy(PDT)has limited effects in treating metastatic breast cancer.Immune checkpoints can deplete the function of immune cells;however,the expression of immune checkpoints after PDT is unclear.This study investigates whether the limited e±cacy of PDT is due to upregulated immune checkpoints and tries to combine the PDT and immune checkpoint inhibitor to observe the e±cacy.A metastatic breast cancer model was treated by PDT mediated by hematoporphyrin derivatives(HpD-PDT).The anti-tumor effect of HpD-PDT was observed,as well as CD4þT,CD8þT and calreticulin(CRT)by immunohistochemistry and immunofluorescence.Immune checkpoints on T cells were analyzed byflow cytometry after HpD-PDT.When combining PDT with immune checkpoint inhibitors,the antitumor effect and immune effect were assessed.For HpD-PDT at 100 mW/cm2 and 40,60 and 80 J/cm2,primary tumors were suppressed and CD4þT,CD8þT and CRT were elevated;however,distant tumors couldn't be inhibited and survival could not be prolonged.Immune checkpoints on T cells,especially PD1 and LAG-3 after HpD-PDT,were upregulated,which may explain the reason for the limited HpD-PDT effect.After PDT combined with anti-PD1 antibody,but not with anti-LAG-3 antibody,both the primary and distant tumors were signi-cantly inhibited and the survival time was prolonged,additionally,CD4þT,CD8þT,IFN-þCD4þT and TNF-þCD4þT cells were signi-cantly increased compared with HpD-PDT.HpD-PDT could not combat metastatic breast cancer.PD1 and LAG-3 were upregulated after HpD-PDT.Anti-PD1 antibody,but not anti-LAG-3 antibody,could augment the antitumor effect of HpD-PDT for treating metastatic breast cancer.

A nanobody-based blocking enzyme-linked immunosorbent assay for detecting antibodies against pseudorabies virus glycoprotein E

Pseudorabies(PR)is an acute infectious disease of pigs caused by the PR virus(PRV)and results in great economic losses to the pig industry worldwide.PRV glycoprotein E(gE)-based enzyme-linked immunosorbent assay(ELISA)has been used to distinguish gE-deleted vaccine-immunized pigs from wild-type virus-infected pigs to eradicate PR in some countries.Nanobody has the advantages of small size and easy genetic engineering and has been a promising diagnostic reagent.However,there were few reports about developing nanobody-based ELISA for detecting anti-PRV-gE antibodies.In the present study,the recombinant PRV-gE was expressed with a bacterial system and used to immunize the Bactrian camel.Then,two nanobodies against PRV-gE were screened from the immunized camel by phage display technique.Subsequently,two nanobody-HRP fusion proteins were expressed with HEK293T cells.The PRV-gE-Nb36-HRP fusion protein was selected as the probe for developing the blocking ELISA(bELISA)to detect anti-PRV-gE antibodies.Through optimizing the conditions of bELISA,the amount of coated antigen was 200 ng per well,and dilutions of the fusion protein and tested pig sera were separately 1:320 and 1:5.The cut-off value of bELISA was 24.20%,and the sensitivity and specificity were 96.43 and 92.63%,respectively.By detecting 233 clinical pig sera with the developed bELISA and a commercial kit,the results showed that the coincidence rate of two assays was 93.99%.Additionallly,epitope mapping showed that PRV-gE-Nb36 recognized a conserved conformational epitope in different reference PRV strains.Simple,great stability and low-cost nanobody-based bELISA for detecting anti-PRV-gE antibodies were developed.The bELISA could be used for monitoring and eradicating PR.

THE USE OF ANTI-HUMAN GLIOMA MONOCLONAL ANTIBODIES FOR TARGETING CHEMOTHERAPY OF BRAIN GLIOMAS(PREPARATION AND CYTOTOXIC PROPERTIES OF ANTIBODY-ADRIAMYCIN IMMUNOCONJUGATES)

Immunoconjugates are antibody-drug hybrid molecules which combine the exquisite selectivity or monoclonal antibodies with the potent toxicity of anticancer agents. A monoclonal antibody SZ39 against human brain gliomas was used as a drug carrier. Adriamycin (ADR) was bound covalently to SZ39 to form a SZ39-ADR conjugate. The cytotoxic activity of the SZ39-ADR conjugate was tested in vitro and demonstrated potent and specific killing of cells derived from a human malignant glioma. 50% inhibitory concentration (IC50) for SZ39-ADR to 'target' cells was 8.14×10-9 M. An index of specificity between 'target' and 'non-target' cells was calculated to be 88-fold. These data suggest that the SZ39-ADR may use as a potent and cell type-specific agent and is a likely candidate for the targeting chemotherapy of malignant gliotnas.