Rapid and sensitive detection of Epstein-Barr virus antibodies in nasopharyngeal carcinoma by chemiluminescence strips based on iron-porphyrin single atom nanozyme

The correlation between Epstein-Barr virus(EBV)infection and nasopharyngeal carcinoma(NPC)risk has been extensively researched.The continual monitoring of EBV-IgAs provides a promising approach of NPC screening in its early stage.In this study,we successfully synthesized a single-atom nanozyme(SANzyme)through the application of iron-porphyrin based metal organic framework(MOF-FeP).The MOF-FeP possesses precisely-defined electronic and geometric structures that accurately mimic highly-evolved catalytic site of natural peroxidase.The peroxidase-like activity of MOF-FeP enables it to catalyze the chemiluminescence of luminol substrate.By integrating MOF-FeP into a traditional strip,we created a rapid and highly-sensitive evaluation tool for detecting EBV-IgAs.Importantly,the MOF-FeP strip enables the simultaneous detection of three EBV-IgAs,greatly improving the accuracy of EBV-associated NPC screening.The sensitivities of the MOF-FeP strip(75.56%–93.30%)surpass those of current enzyme-linked immunosorbent assay(ELISA)methods(64.44%–82.22%).This test takes only 16 min to perform as opposed to the customary 1–2 h required for standard ELISA.Additionally,the MOF-FeP strip is suitable for whole blood samples,thereby significantly simplifying the sample preparation and detection process.In conclusion,the MOF-FeP strip combines the simplicity of traditional strip with the high catalytic activity of SANzyme.Our innovative MOF-FeP strip offers a new point-of-care strategy for EBV-IgAs detection,which is expected to markedly facilitate early screening for EBV-associated diseases.

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.

Hepatitis B virus reactivation in patients treated with monoclonal antibodies

Hepatitis B virus(HBV)reactivation poses a significant clinical challenge,espe-cially in patients undergoing immunosuppressive therapies,including mono-clonal antibody treatments.This manuscript briefly explores the complex rela-tionship between monoclonal antibody therapy and HBV reactivation,drawing upon current literature and clinical case studies.It delves into the mechanisms underlying this phenomenon,highlighting the importance of risk assessment,monitoring,and prophylactic measures for patients at risk.The manuscript aims to enhance the understanding of HBV reactivation in the context of monoclonal antibody therapy,ultimately facilitating informed clinical decision-making and improved patient care.This paper will also briefly review the definition of HBV activation,assess the risks of reactivation,especially in patients treated with monoclonal antibodies,and consider management for patients with regard to screening,prophylaxis,and treatment.A better understanding of patients at risk can help clinicians provide optimum management to ensure successful patient outcomes and prevent morbidity.

Epstein-Barr Virus EA-IgA, VCA-IgA, and EBVNA-IgG Antibodies in a Population of Wuhan, China

The study investigated the distribution of Epstein-Barr virus(EBV)EA-IgA,VCAIgA,and EBVNA-IgG antibodies in a local population of Wuhan,China.Chemiluminescence immunoassay(CL1A)was used to detect EBV EA-IgA,VCA-IgA,and EBVNA-IgG antibodies in 972 subjects undergoing physical examination in Wuhan,and the results were analyzed.The detection rate of EBV was positively correlated with age.In the 972 cases,there was significant difference between different genders in the positive rate of VCA-IgA and EBVNA-IgG.Moreover,the positive rate of VCA-IgA and EBVNA-IgG was higher in men>60 years old than in those<60 but no significant differences were found in three antibodies among various age groups.Our results suggested that the EBV infection should be intensively monitored in elderly people in Wuhan.

SERO-EPIDEMIOLOGICAL STUDIES OF EPSTEIN-BARR VIRUS(EBV) INFECTION BY TESTING ANTIBODIES AGAINST EBV SPECIFIC DNASE(EDAb) AS A METHOD FOR EARLY DETECTION OF NASOPHARYNGEAL CARCINOMA(NPC)

In 1987, a mass survey of EDAb was carried out in Sihui county of Gunagdong Province (the highest incidence area of NPC in China) and the city of Guangzhou using the methods previously established by our lab. In order to study the correlation between EDAb level and NPC, the titre of DEAb and their distribution in sera from 430 patients with NPC and 5030 normal persons were detected. It was found that the AER (level of EDAb was represented by the anti enzyme rate) of NPC patients gave a negative skew distribution and the Md=65.3% while the natural population (30 59 years old) gave a serious positive skew distribution and the Md is 7.9%. According to the pattern of EDAb distribution curve of 430 NPC patients and 2060 natural population. AER≥30% was defined as a cut off point between EDAb positive and negative. Using this value we got a rate of 90.7% (390/430) positive diagnosis in NPC patients, while in natural population the positive rate was 3.3% (68/2060), and in the IgA/VCA positive (1:5) normal person the positive rate was 6.0% (41/681). As to the other tumors including head and neck tumors the positive rate was 3.4% (7/204), similar to the natural population. After a period of 62 months of follow up surveillance, 15 of 224 EDAb positive normal persons found in the mass survey were diagnosed as NPC by histopathological examination. While in 4806 EDAb negative normal person only one case NPC patient was found in this period. 60% of these patients were diag nosed in their early stage of NPC. From these patients it was found that EDAb could appear in the sera of the patients as early as 62 months before NPC was definitely diagnosed. 2 of these patients were shown IgA/VCA negative and EDAb positive in mass survey. This suggested that in some of the precancerous patients EDAb could appear earlier than IgA/VCA. The signifi cance of the sera EDAb positivity of normal person was discussed.

Disparities in the Levels of Whole-Blood Epstein-Barr Virus between the Cancer and Non-Cancer Populations in Zhejiang,China

Objective This study aimed to investigate the prevalence of Epstein-Barr virus(EBV)infection in patients with and without cancer.Methods A total of 26,648 participants who underwent whole-blood EBV DNA(WBEBV)assays between January 1,2020,and August 31,2023,were included.The chi-square test was used for categorical data analysis,and R software was used to analyze the differences in EBV DNA load levels and the diagnostic capabilities of WBEBV.Results Positive rates were 10.2%and 25.4%for healthy controls(HC)and patients,respectively.The positivity rate for EBV-associated neoplasms(EN)was the highest at 7.53%,followed by leukemia(Le)at 5.49%.The subgroup analysis showed that the positivity rate for abnormal proliferation or hyperplasia(APH)was 31.9%,followed by 30.5%for Le.The WBEBV of patients with transplants(TP),especially living-related transplants(LT),was the highest among all subgroups.WBEBV at diagnosis was used to differentiate between infectious mononucleosis(IM)and chronic active Epstein-Barr virus(CAEBV),with a sensitivity of 67.4%(95%confidence interval[CI]:57.6-75.8)and specificity of 72%(95%CI:63.3-79.3).We conclude that the prevalence of EBV infection is low in the healthy population in this region and that a high EBV load at baseline is more common in LT,IM,and Lymphocyte Leukemia(LL).Conclusion This study used a large-sample survey to characterize the prevalence of whole-blood EBV levels in various diseases,including the stages and subtypes.The EBV detection rate was higher in patients with malignant disease than in those with benign disease.Our study provides clinicians with baseline information regarding EBV-associated diseases.

Evaluating the role of interleukin-2 and interleukin-12 in pediatric patients with concurrent Mycoplasma pneumoniae and Epstein-Barr virus infections

BACKGROUND Mycoplasma pneumoniae(MP)frequently causes respiratory infections in children,whereas Epstein-Barr virus(EBV)typically presents subclinical manifestations in immunocompetent pediatric populations.The incidence of MP and EBV coinfections is often overlooked clinically,with the contributory role of EBV in pulmonary infections alongside MP remaining unclear.AIM To evaluate the serum concentrations of interleukin-2(IL-2)and interleukin-12(IL-12)in pediatric patients with MP pneumonia co-infected with EBV and assess their prognostic implications.METHODS We retrospectively analyzed clinical data from patients diagnosed with MP and EBV co-infection,isolated MP infection,and a control group of healthy children,spanning from January 1,2018 to December 31,2021.Serum IL-2 and IL-12 levels were quantified using enzyme-linked immunosorbent assay.Logistic regression was employed to identify factors influencing poor prognosis,while receiver operating characteristic(ROC)curves evaluated the prognostic utility of serum IL-2 and IL-12 levels in co-infected patients.RESULTS The co-infection group exhibited elevated serum IL-2 and C-reactive protein(CRP)levels compared to both the MP-only and control groups,with a reverse trend observed for IL-12(P<0.05).In the poor prognosis cohort,elevated CRP and IL-2 levels,alongside prolonged fever duration,contrasted with reduced IL-12 levels(P<0.05).Logistic regression identified elevated IL-2 as an independent risk factor and high IL-12 as a protective factor for adverse outcomes(P<0.05).ROC analysis indicated that the area under the curves for IL-2,IL-12,and their combination in predicting poor prognosis were 0.815,0.895,and 0.915,respectively.CONCLUSION Elevated serum IL-2 and diminished IL-12 levels in pediatric patients with MP and EBV co-infection correlate with poorer prognosis,with combined IL-2 and IL-12 levels offering enhanced predictive accuracy.

N6-methyladenosine methylation regulates the tumor microenvironment of Epstein-Barr virus-associated gastric cancer

BACKGROUND N6-methyladenosine(m6A)methylation modification exists in Epstein-Barr virus(EBV)primary infection,latency,and lytic reactivation.It also modifies EBV latent genes and lytic genes.EBV-associated gastric cancer(EBVaGC)is a distinctive molecular subtype of GC.We hypothesized EBV and m6A methylation regulators interact with each other in EBVaGC to differentiate it from other types of GC.AIM To investigate the mechanisms of m6A methylation regulators in EBVaGC to determine the differentiating factors from other types of GC.METHODS First,The Cancer Gene Atlas and Gene Expression Omnibus databases were used to analyze the expression pattern of m6A methylation regulators between EBVaGC and EBV-negative GC(EBVnGC).Second,we identified Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)functional enrichment of m6A-related differentially expressed genes.We quantified the relative abundance of immune cells and inflammatory factors in the tumor microenvironment(TME).Finally,cell counting kit-8 cell proliferation test,transwell test,and flow cytometry were used to verify the effect of insulin-like growth factor binding protein 1(IGFBP1)in EBVaGC cell lines.RESULTS m6A methylation regulators were involved in the occurrence and development of EBVaGC.Compared with EBVnGC,the expression levels of m6A methylation regulators Wilms tumor 1-associated protein,RNA binding motif protein 15B,CBL proto-oncogene like 1,leucine rich pentatricopeptide repeat containing,heterogeneous nuclear ribonucleoprotein A2B1,IGFBP1,and insulin-like growth factor 2 binding protein 1 were significantly downregulated in EBVaGC(P<0.05).The overall survival rate of EBVaGC patients with a lower expression level of IGFBP1 was significantly higher(P=0.046).GO and KEGG functional enrichment analyses showed that the immunity pathways were significantly activated and rich in immune cell infiltration in EBVaGC.Compared with EBVnGC,the infiltration of activated CD4+T cells,activated CD8+T cells,monocytes,activated dendritic cells,and plasmacytoid dendritic cells were significantly upregulated in EBVaGC(P<0.001).In EBVaGC,the expression level of proinflammatory factors interleukin(IL)-17,IL-21,and interferon-γ and immunosuppressive factor IL-10 were significantly increased(P<0.05).In vitro experiments demonstrated that the expression level of IGFBP1 was significantly lower in an EBVaGC cell line(SNU719)than in an EBVnGC cell line(AGS)(P<0.05).IGFBP1 overexpression significantly attenuated proliferation and migration and promoted the apoptosis levels in SNU719.Interfering IGFBP1 significantly promoted proliferation and migration and attenuated the apoptosis levels in AGS.CONCLUSION m6A regulators could remodel the TME of EBVaGC,which is classified as an immune-inflamed phenotype and referred to as a“hot”tumor.Among these regulators,we demonstrated that IGFBP1 affected proliferation,migration,and apoptosis.

Epstein-Barr virus positive post-transplant lymphoproliferative disorder with significantly decreased T-cell chimerism early after transplantation:A case report

BACKGROUND Post-transplant lymphoproliferative disorder(PTLD)is a rare but highly fatal complication occurring after allogeneic hematopoietic cell transplantation(allo-HCT)or solid organ transplantation(SOT).Unlike SOT,PTLD after allo-HCT usually originates from the donor and is rarely accompanied by a loss of donor chimerism.CASE SUMMARY We report a case of Epstein-Barr virus positive PTLD manifesting as diffuse large B-cell lymphoma(DLBCL)with significantly decreased T-cell chimerism early after allo-HCT.A 30-year-old patient with acute myeloid leukemia underwent unrelated allo-HCT after first complete remission.Nearly 3 mo after transplantation,the patient developed cervical lymph node enlargement and gastric lesions,both of which were pathologically suggestive of DLBCL.Meanwhile,the patient experienced a significant and persistent decrease in T-cell chimerism.A partial remission was achieved after chemotherapy with single agent rituximab and subsequent R-CHOP combined chemotherapy.CONCLUSION The loss of T-cell chimerism and the concomitant T-cell insufficiency may be the cause of PTLD in this patient.

Research Advances in Infectious Mononucleosis Caused by Epstein-Barr Virus

Infectious mononucleosis (IM), primarily caused by the Epstein-Barr virus (EBV), manifests as the classic triad of fever, pharyngitis, and cervical lymphadenopathy. Severe cases may involve organ damage, most commonly affecting the liver. Diagnosis relies on a combination of clinical presentation and laboratory parameters, with commonly used indicators including EBV-specific antibodies, EBV-DNA load, and the ratio of atypical lymphocytes. Treatment primarily involves symptomatic supportive care, with a cautious approach to the routine use of antiviral medications. In recent years, significant research in traditional Chinese medicine has been conducted in China, showing promising advancements. This article provides a comprehensive review of EBV-induced infectious mononucleosis, offering insights for clinical diagnosis and treatment.

Application of high-titred IgY antibodies in orthopox virus diagnostics

Layer chickens were immunized with three species of inactivated orthopox virus （vaccinia virus, calpox virus and cowpox virus）. Antibodies （IgY） were purified from egg yolks by improved polyethylene glycol precipitation. The development of IgY directed against orthopox virus antigens was followed by immunofluorescence assay, plaque reduction neutraliztion test and immunoelectron microscopy. Cross-reactivity of two IgY antibodies with cells infected by the different strains of the pox viruses was also investigated by different methods （immunofluorescence assay, plaque reduction neutraliztion test and Western blot）. Even in very high dilutions in immunofluorescence assay （titres up to 1：10^6 and 1：10^5, respectively） and persisted on a plateau over 10 months after four booster injections, it was showed that anti-vaccinia virus IgY and anti-calpox virus IgY were positive. Neutralizing activity and ultra-structural detection of antigen with gold-labelled antibodies were respectively observed in plaque reduction neutralization test and immunoelectron microscopy. Western blot analysis revealed specific binding of IgY to virus proteins. Thus, there was cross-reactivity between different orthopox viruses. Finally, orthopox virns-specific IgY antibodies bounded magnetic beads （Dynabead） were used to concentration of orthopox viruses. This study suggests that anti-pox virus IgY could serve as a useful tool for orthopox viruses diagnosis.

Preparation and application of monoclonal antibodies against hepatitis C virus nonstructural proteins

AIM To prepare hybridoma cell lines which secrete anti HCV recombinant NS3 and NS5 proteins′ monoclonal antibodies, and to evaluate their usage in the study of the distribution of HCV NS3 and NS5 antigen in liver tissues. METHODS The hybridoma cell lines were raised using the spleen cells of BALB/C mouse immunized with recombinant NS3 and NS5 proteins according to the conventional protocols. The antibody secreting cells were screened using solid phase ELISA and cloned by limited dilution method. In order to determine the specificity of these hybridoma cell lines, the culture supernatant of these cells was western blot assayed with expression and nonexpresion E. coli and ELISA with other antigens, including HCV core and NS3 and HBsAg. Immunohistochemistry of 51 cases paraffin embedded liver tissues was performed to determine the distribution of HCV NS5 antigen as well as NS3 antigen in liver tissues. RESULTS Eight hybridoma cell lines secreting monoclonal antibodies against HCV NS3 and NS5 proteins were raised. They are named 2B6, 2F3, 3D8, 3D9, 8B2, 6F11, 4C6 and 7D9. Among them only 2B6 against NS3 protein can react with the polypipetides of C7 that is another recombinant polypipetides of NS3 gene. Others have no reaction with HCV core and HBsAg of HBV, and there is no cross reaction between NS3Ag and anti NS5Ag McAb and between NS5Ag and anti NS3 McAb. The immunohistochemistry results indicate that no HCV antigen was detected in the specimens of HBV infection in 20 cases. In 31 HCV infected specimens the positive rate of NS3Ag and NS5Ag are 51 6% (16/31) and 54 9% (17/31), respectively. There were six pure HCV infected specimens in these 31 specimens and half of them were HCV NS3Ag and NS5Ag positive. In the co infection of HBV and HCV group the positive rate of NS3Ag and NS5Ag were 52% (13/25) and 56% (14/25), respectively, almost the same with that of pure HCV infected group. The positive rates of HCV antigens were 70 6% (12/17) and 76 5% (13/17) in CAC patients. CONCLUSION The monoclonal antibodies we prepared are specific to the recombinant HCV NS3 and NS5 proteins and can be used in the clinical immunohistochemistry diagnosis.

Development and detection application of monoclonal antibodies against Zucchini yellow mosaic virus

Aphid-borne Zucchini yellow mosaic virus （ZYMV） is one of the most economically important viruses of cucurbitaceous plants. To survey and control this virus, it is necessary to develop an efficient detection technique. Using purified ZYMV virion and the conventional hybridoma technology, three hybridoma cell lines （16A11, 5A7 and 3B8） secreting monoclonal antibodies （MAbs） against ZYMV Zhejiang isolate were obtained. The working titers of the ascitic fluids secreted by the three hybridoma cell lines were up to 10^-7 by indirect enzyme-linked immunosorbent assay （ELISA）. All MAbs were isotyped as IgG1, kappa light chain. Western blot analysis indicated that the MAb 3B8 could specifically react with the coat protein of ZYMV while MAbs 5A7 and 16A11 reacted strongly with a protein of approximately 51 kDa from the ZYMV-infected leaf tissues. According to this molecular weight, we consider this reactive protein As likely to be the HC-Pro protein. Using these three MAbs, we have now developed five detection assays, i.e., antigen-coated-plate ELISA （ACP-ELISA）, dot-ELISA, tissue blot-ELISA, double-antibody sandwich ELISA （DAS-ELISA）, and immunocapture-RT-PCR （IC-RT-PCR）, for the sensitive, specific, and easy detection of ZYMV. The sensitivity test revealed that ZYMV could be readily detected respectively by ACP-ELISA, dot-ELISA, DAS-ELISA and IC-RT-PCR in 1：163840, 1：2560, 1：327680 and 1：1 310720 （w/v, g mL-1） diluted crude extracts from the ZYMV-infected plants. We demonstrated in this study that the dot-ELISA could also be used to detect ZYMV in individual viruliferous aphids. A total of 275 cucurbitaceous plant samples collected from the Zhejiang, Jiangsu, Shandong and Hainan provinces, China, were screened for the presence of ZYMV with the described assays. Our results showed that 163 of the 275 samples （59%） were infected with ZYMV. This finding indicates that ZYMV As now widely present in cucurbitaceous crops in China. RT-PCR followed by DNA sequencing and sequence analyses confirmed the accuracy of the five assays. We consider that these detection assays can significantly benefit the control of ZYMV in China.

Newcastle disease virus-based MERS-CoV candidate vaccine elicits high-level and lasting neutralizing antibodies in Bactrian camels

Middle East respiratory syndrome coronavirus （MERS-CoV）, a member of the Coronavifidae family, is the causative pathogen for MERS that is characterized by high fever, pneumonia, acute respiratory distress syndrome （ARDS）, as well as extrapul- monary manifestations. Currently, there are no approved treatment regimens or vaccines for MERS. Here~ we generated recombinant nonvirulent Newcastle disease virus （NDV） LaSota strain expressing MERS-CoV S protein （designated as rLa- MERS-S）, and evaluated its immunogenicity in mice and Bactrian camels. The results revealed that rLa-MERS-S showed similar growth properties to those of LaSota in embryonated chicken eggs, while animal immunization studies showed that rLa-MERS-S induced MERS-CoV neutralizing antibodies in mice and camels. Our findings suggest that recombinant rLa- MERS-S may be a potential MERS-CoV veterinary vaccine candidate for camels and other animals affected by MERS.

Monoclonal Antibodies Against the Whitefly-Transmitted Tomato Yellow Leaf Curl Virus and Their Application in Virus Detection

Tomato yellow leaf curl virus（TYLCV）is a species of the family Geminiviridae,causing serious yield losses in tomato production.The coat protein（CP）gene of TYLCV isolate SH2 was expressed in Escherichia coli BL21（DE3）using pET-32a as the expression vector.The recombinant protein was purified through Ni＋-NTA affinity column and used to immunize BALB/c mice.Three hybridoma cell lines（2B2,2E3 and 3E10）secreting monoclonal antibodies（MAbs）against TYLCV CP were obtained by fusing mouse myeloma cells（Sp 2/0）with spleen cells from the immunized BALB/c mouse.The titers of ascitic fluids of three MAbs ranged from 10-6 to 10-7 in indirect-ELISA.Isotypes and subclasses of all the MAbs belonged to IgG1,κ light chain.Triple antibody sandwich enzyme-linked immunosorbent assay（TAS-ELISA）showed that the MAb 3E10 could react with five begomoviruses infecting tomato,while the other two（2B2 and 2E3）mainly reacted with TYLCV.TAS-ELISA was set up using the MAb 3E10,and the established method could successfully detect virus in plant sap at 1：2 560（w/v,g mL-1）.Detection of field samples showed that begomoviruses were common in tomato crops in Zhejiang Province,China.

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.

Neutralizing antibodies in hepatitis C virus infection

Hepatitis C virus (HCV) is a major cause of hepatitis world-wide. The majority of infected individuals develop chronic hepatitis which can then progress to liver cirrhosis and hepatocellular carcinoma. Spontaneous viral clearance occurs in about 20%-30% of acutely infected individuals and results in resolution of infection without sequaelae. Both viral and host factors appear to play an important role for resolution of acute infection. A large body of evidence suggests that a strong, multispecific and long-lasting cellular immune response appears to be important for control of viral infection in acute hepatitis C. Due too the lack of convenient neutralization assays, the impact of neutralizing responses for control of viral infection had been less defined. In recent years, the development of robust tissue culture model systems for HCV entry and infection has finally allowed study of antibody-mediated neutralization and to gain further insights into viral targets of host neutralizing responses. In addition, detailed analysis of antibody-mediated neutralization in individual patients as well as cohorts with well defined viral isolates has enabled the study of neutralizing responses in the course of HCV infection and characterization of the impact of neutralizing antibodiesfor control of viral infection. This review will summarize recent progress in the understanding of the molecular mechanisms of antibody-mediated neutralization and its impact for HCV pathogenesis.

Protection against Infectious Bronchitis Virus, a Corona Virus Infection, Using Ostrich Antibodies

In chickens, infectious bronchitis (IB) is a major respiratory disease. The respiratory system is the primary multiplication site of IB virus (IBV), a coronavirus, after which the virus is distributed to other organs. Poultry farms sustain considerable economic damage due to IB outbreaks in flocks, since IB causes a severe reduction in weight gain in chicks. In the present study, we produced the ostrich IgY against IBV by immunizing female ostriches with the IB viral antigens. The resultant purified IgY showed a strong neutralizing activity against IBV infection of cultured primary chick kidney cells. The infectivity of IBV was markedly inhibited in the trachea of chicks when ostrich IgY was injected intra-muscularly into newly hatched chicks prior to viral inhalation challenge at two weeks of age. Furthermore, the infection was strongly blocked in the tracheae when IgY was injected into chicks at one day and one week of age, with viral inhalation performed at three weeks of age. These findings suggest that the injection of ostrich IgY can help protect young chicks from IBV infections. In south Asian and African countries, broiler chicks are sent to poultry market around 30 days of age, so it is important to prevent IB outbreaks in very young flocks. We strongly believe that ostrich IgY will be a powerful weapon against IB infection in poultry farms on a wide scale and also hope that these findings will aid in the development of antibody vaccines for new type corona viruses, SARS-CoV and MERS-CoV.

Generation and application of two monoclonal antibodies targeting conserved linear epitopes in the NP protein of influenza A virus

Monoclonal antibodies(mAbs) are widely used in virus research and disease diagnosis. The nucleoprotein(NP) of influenza A virus(IAV) plays important roles in multiple stages of the virus life cycle. Therefore, generating conserved mAbs against NP and characterizing their properties will provide useful tools for IAV research. In this study, two mAbs against the NP protein, 10 E9 and 3 F3, were generated with recombinant truncated NP proteins(NP-1 and NP-2) as immunogens. The heavy-chain subclass of both 10 E9 and 3 F3 was determined to be IgG2α, and the light-chain type was κ. Truncation and site-specific mutation analyses showed that the epitopes of mAbs 10 E9 and 3 F3 were located in the N terminal 84–89 amino acids and the C terminal 320–324 amino acids of the NP protein, respectively. We found that mAbs 10 E9 and 3 F3 reacted well with the NP protein of H1–H15 subtypes of IAV. Both 10 E9 and 3 F3 can be used in immunoprecipitation assay, and 10 E9 was also successfully applied in confocal microscopy. Furthermore, we found that the 10 E9-recognized _(84) SAGKDP_(89) epitope and 3 F3-recognized 320 ENPAH324 epitope were highly conserved in NP among all avian and human IAVs. Thus, the two mAbs we developed could be used as powerful tools in the development of diagnostic methods of IAV, and also surely promote the basic research in understanding the replication mechanisms of IAV.

Monoclonal antibodies:Principles and applications of immmunodiagnosis and immunotherapy for hepatitis C virus

Hepatitis C virus(HCV) is a major health problem worldwide. Early detection of the infection will help better management of the infected cases. The monoclonal antibodies(m Ab) of mice are predominantly used for the immunodiagnosis of several viral,bacterial,and parasitic antigens. Serological detection of HCV antigens and antibodies provide simple and rapid methods of detection but lack sensitivity specially in the window phase between the infection and antibody development. Human mA b are used in the immunotherapy of several blood malignancies,such as lymphoma and leukemia,as well as for autoimmune diseases. In this review article,we will discuss methods of mouse and human monoclonal antibody production. We will demonstrate the role of mouse mA b in the detection of HCV antigens as rapid and sensitive immunodiagnostic assays for the detection of HCV,which is a major health problem throughout the world,particularly in Egypt. We will discuss the value of HCV-neutralizing antibodies and their roles in the immunotherapy of HCV infections and in HCV vaccine development. We will also discuss the different mechanisms by which the virus escape the effect of neutralizing mA b. Finally,we will discuss available and new trends to produce antibodies,such as egg yolk-based antibodies(Ig Y),production in transgenic plants,and the synthetic antibody mimics approach.