With the development of bio-technological drugs, drug immunogenicity evaluation has become key factor of clarifying safety and efficacy of these drugs. It has become the focus to establish a stable and reliable evaluation system. Due to the advantages such as continuous real-time monitoring, surface plasmon resonance (SPR) technology has been widely used in bio-technological drugs immunogenicity assessments. Our study applied this technology to detect anti-drug antibody (ADA) of a recombinant human anti-rabies monoclonal antibody NM57 in the sera of 48 volunteers admitted in phase I clinical trials. This method could satisfy the basic requirements of detection of ADA.
Antibodies, Anti-Idiotypic ; analysis ; blood ; immunology ; Antibodies, Monoclonal ; analysis ; blood ; immunology ; Antibodies, Viral ; analysis ; blood ; immunology ; Humans ; Rabies virus ; immunology ; Recombinant Proteins ; analysis ; blood ; immunology ; Surface Plasmon Resonance

OBJECTIVETo learn the prevalence of infection of human and animals severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) in Yantai, Shandong province, and to analyze the pathogenic features of SFTSV as well as its relationship between human and animal hosts.

METHODSFrom April to November in 2011, 3 576 serum samples were collected from domesticated animals, including sheep, cattle, pigs, dogs, chickens, in Laizhou and Penglai areas where fever with thrombocytopenia syndrome frequently occurred among local residents. Total SFTSV antibodies and virus-specific nucleic acids of the serum were tested by ELISA and Real time RT-PCR, respectively. SFTSV infection on each animal was observed in different months. 2 590 human serum samples were also collected in Laizhou and Penglai areas, with IgG antibodies tested by ELISA. Virus was isolated with Vero cells from the serum which SFTSV viral nucleic acids were positive. S fragments were amplified by RT-PCR and sequenced, with homology analysis conducted on these sequences.

RESULTSThe overall positive rate of serum samples from animals on the total SFTSV antibodies was 40.24% (1 439/3 576) while the positive rate for specific nucleic acids was 4.56% (163/3 576). The positive rates for SFTSV antibodies were 62.78%, 52.97%, 45.56%, 28.73%, 1.45% and the positive rates for specific nucleic acids were 5.72%, 4.63%, 3.02%, 5.25% and 3.73%, in sheep, cattle, chickens, dogs, pigs, respectively. The antigens/antibodies for SFTSV in animals changed seasonally. The overall positive rate for SFTSV IgG antibody from 2 590 human samples was 5.41%. Thirteen virus strains were isolated from these serum samples (10 strains from human and 3 strains from animals). The nucleotide homology of 13S fragments' sequences ranged from 95.23% to 100.00% and the nucleotide homology with the isolates from other provinces were between 94.72% and 99.13%. The homology was considered to be high.

CONCLUSIONHigh prevalence of SFTSV infections occurred both in human and domestic animals in Yantai city. The nucleotide sequences of SFTSV were highly homologous among human and domestic animals. The findings suggested that domesticated animals might serve as SFTSV proliferation and the hosts for transmission thus should be attached great importance.

Animals ; Antibodies, Viral ; blood ; Bunyaviridae Infections ; epidemiology ; China ; epidemiology ; Humans ; Prevalence ; RNA, Viral ; blood ; Sequence Analysis, RNA

To establish an electrochemiluminescence immunoassay (ECLIA) for the detection of influenza virus B (Flu B), we biotinylated the Flu B monoclonal antibody (mAb),labeled the paired Ab with ruthenium and used the streptavidin-coated microparticles in this study. The ECL intensity was linear with the concentrations of antigen of Flu B in the range of 0.55 microg/mL to 17.5 microg/mL, with a detection limit of 0.55 microg/mL (S/N= 3). The precision,sensitivity and specificity were evaluated. The established ECLIA for Flu B antigen in this study was specific, sensitive and precise. It may provide a convenient and rapid technique for clinical detection of Flu B.
Antibodies, Viral ; analysis ; Electrochemical Techniques ; Immunoassay ; methods ; Influenza B virus ; isolation & purification ; Luminescence

Avidin layer was bound on the substrate surface of Silicon wafer modified with aldehyde. The interaction between avidin and biotin was adopted for the immobilization of mouse monoclonal biotin-anti-M13 (antibody GP3)-labeled biotin. The surface was incubated in a solution containing phage M13KO7, which was trapped by the antibody GP3 with the interaction between phage M13KO7 and antibody GP3, resulting in a variation of layer thickness that was detected by imaging ellipsometry. The results showed a saturated layer of antibody GP3 with a thickness about 6.9 nm on the surface of the silicon wafer. The specific interaction between phage M13KO7 and antibody GP3 resulted in a variation of the layer thickness. The layer of phage M13KO7 bound with antibody GP3 was 17.5 nm in the concentration of 1.1 x 10(10) pfu/mL. Each variation of layer thickness corresponded to a concentration of phage M13KO7 in the range of 0.1 x 10(10) approximately 2.5 x 10(10) pfu/mL, with the sensitivity of 10(9) pfu/mL. Compared with other methods, the optical protein-chip requires only short measurement time, is label free, is a quantitative test, and can be visualized. This study could be significant on the investigation of interactions between the antibody and virus, and shows potential in the early diagnosis of virosis.
Animals ; Antibodies, Viral ; immunology ; Bacteriophage M13 ; immunology ; isolation & purification ; Mice ; Protein Array Analysis ; methods

Antibodies, Neutralizing ; Antibodies, Viral/isolation & purification* ; B-Lymphocytes/virology* ; COVID-19/virology* ; Humans ; Immunity/genetics* ; RNA, Viral/immunology* ; SARS-CoV-2/pathogenicity* ; Single-Cell Analysis

OBJECTIVETo develop the monoclonal antibody against N protein of SARS virus and study its applicability.

METHODSBALB/c mice were immunized with recombinant N protein. Spleen cells were collected and infused with SP2/0 cell. The infused cells were screened for anti-N protein antibody with ELISA. The positive cells were cloned and injected into abdominal cavity. The antibodies were purified from ascites. The affinities of those purified antibodies were analyzed with ELISA. The ELISA for detection of SARS virus antigen was developed by using antibody with the highest affinity. Its sensitivity and specificity were also evaluated primarily.

RESULTSEleven monoclonal cells secreting antibody have been developed. Three of the 11 purified monoclonal antibodies had very high affinity to N protein, while 4 purified McAbs showed very weak reaction to N protein, the affinities of remaining 4 McAbs were in between. The ELISA for detection of SARS virus antigen was developed with McAb 7. Its sensitivity was about 31 PFU/ml and had no cross reaction with other respiratory viruses.

CONCLUSIONThe monoclonal antibody has good specificity and may be used to detect SARS virus antigen. However, its sensitivity is to be evaluated further with clinical samples from SARS patients, especially at acute phase.

Animals ; Antibodies, Monoclonal ; biosynthesis ; Antibodies, Viral ; biosynthesis ; Antigens, Viral ; analysis ; Humans ; Hybridomas ; Mice ; Mice, Inbred BALB C ; Nucleocapsid Proteins ; immunology ; SARS Virus ; immunology ; Sensitivity and Specificity

OBJECTIVETo investigate hepatitis E virus (HEV) infection among pigs in Henan province.

METHODSA total of 623 swine sera, collected from 5 districts, were divided into two groups, under 3-month of age and over 3-month of age. They were tested for HEV antigen and antibody by using ELISAs, respectively. The sera positive for HEV antigen were tested for HEV RNA with RT-PCR. The positive products of RT-PCR were cloned and sequenced.

RESULTSThe positive rates of anti-HEV antibody of the groups under 3-month and over 3-month of age were 90.27% and 92.55%, respectively, without statistical difference, while those of HEV antigen were 15.93% and 5.69%, respectively, with significant difference. The positive rates of anti-HEV antibody and HEV antigen were significantly different among different districts. HEV RNA was detectable in 5 of 47 HEV antigen positive samples. The sequence analysis showed that in 4 of 5 specimens the sequence belonged to genotype 4 while in the remaining one the sequence was genotype 1.

CONCLUSIONThe prevalence rate of HEV infection in pigs was high in Henan province and the rate differed in different districts.

Animals ; Antibodies, Viral ; analysis ; immunology ; Antigens, Viral ; analysis ; immunology ; China ; Genotype ; Hepatitis E ; epidemiology ; immunology ; veterinary ; virology ; Hepatitis E virus ; genetics ; immunology ; isolation & purification ; Phylogeny ; RNA, Viral ; analysis ; genetics ; Sequence Analysis, DNA ; Swine ; virology ; Swine Diseases ; epidemiology ; immunology ; virology

OBJECTIVETo investigate the association of childhood hemophagocytic syndrome (HPS) with human parvovirus B19 (HPVB19) infection, and to analyze the clinical features of this disease.

METHODSELISA and quantitative real-time PCR were used to detect HPVB19-IgM, HPVB19-IgG and HPVB19-DNA in 65 children with HPS (HPS group) and 65 healthy children (control group). The HPS group was divided into HPVB19-infected (n=14) and non-infected (n=51) groups according to the detection results of HPVB19-DNA. The clinical data of two groups were compared.

RESULTSThe positive rate of HPVB19-IgM in the HPS group (26%, 17/65) was significantly higher than that in the control group (9%, 6/65) (P=0.011), and there was no significant difference in the positive rate of HPVB19-IgG between the HPS (38%, 25/65) and control groups (29%, 19/65) (P=0.266). The infection rate of HPVB19 in the HPS group (22%, 14/65) was significantly higher than that in the control group (3%, 2/65) (P=0.001). Compared with the non-infected group, the HPVB19-infected group had significantly lower platelet count and hemoglobin level on admission, significantly more severe liver function damage, a significantly earlier onset time, and a significantly longer course of disease (P<0.05).

CONCLUSIONSThe pathogenesis of HPS may be associated with HPVBl9 infection. HPVBl9-infected children with HPS have more acute onset, more severe clinical manifestations, and a longer disease duration.

Adolescent ; Antibodies, Viral ; analysis ; Child ; Child, Preschool ; DNA, Viral ; analysis ; Female ; Humans ; Infant ; Lymphohistiocytosis, Hemophagocytic ; etiology ; Male ; Parvoviridae Infections ; complications ; Parvovirus B19, Human

OBJECTIVETo better understand the duplication of hepatitis B virus (HBV) in order to improve clinical diagnoses and treatments via quantitative measurement of HBV-DNA and comparison of correlation of HBV-DNA with HBeAg and anti-HBe.

METHODSFor 883 hepatitis B patients with positive HBsAg, HBV-DNA was measured by COBAS AMPLICOR HBV MONITOR reagent and COBAS AMPLICOR quantitative PCR instrument. Microparticle enzyme immunoassay analysis (MEIA) was then carried out with fully automatic enzyme immunoassay analysis instrument made by Abbott Axsym from the U.S. to measure HBeAg and anti-HBe. Correlation was analysed by SPSS.

RESULTS(1)Positive correlation between 690 HBV-DNA positive and HBeAg positive with r= 0. 505 (P< 0.01) was found with mean values as:HBV-DNA:7.12 x 10(12) copies/ml;HBeAg:218.31 S/CO. HBV-DNA:10(4) copies/ml, HBeAg: 104 S/CO; HBV-DNA: 10(5)-10(8) copies/ml, HBeAg: 112 S/CO; HBV-DNA: 10(9)-10(15) copies/ml, HBeAg: 252 S/CO. (2) No correlation was found between 193 HBV-DNA and anti-HBe + with r= -0.052(P= 0.477> 0.05) with Mean: HBV-DNA: 8.0x 10(10) copies/ml anti-HBe: 0.18 S/CO.

CONCLUSIONHBV-DNA and HBeAg appeared to have had linear correlation, showing that HBeAg> 100 S/CO,HBV-DNA> 10(4) copies/ml and hepatitis B virus were reproduced. However, HBV-DNA did not show linear correlation with anti-HBe as HBeAg negative and anti-HBe positive, the level of hepatitis B viral replication decrease slightly. But the virus load is still high. Infectivity can not neglect.

Antibodies, Viral ; analysis ; Carrier State ; DNA, Viral ; analysis ; Hepatitis B ; diagnosis ; genetics ; immunology ; Hepatitis B e Antigens ; analysis ; Hepatitis B virus ; genetics ; immunology ; Humans ; Immunoenzyme Techniques ; Polymerase Chain Reaction ; Viral Load ; Virus Replication

OBJECTIVETo prepare monoclonal antibodies specific for M1 protein of H5N1 subtype human influenza virus, this work may provide new tool in rapid diagnosis and study of type A influenza virus.

METHODSBALB/c mice were immunized with purified recombinant H5N1 (A/Anhui/1/2005)/M1 protein expressed in E. coli. Spleen cells of the immunized mice were fused with sp2/0 cells to produce hybridoma cell lines. ELISA was performed to identify the monoclonal antibody against M1 protein of H5N1. Immunofluorescence assay (IFA) were applied to identify the specificity of these antibodies.

RESULTSThree hybridoma cell lines steadily secreting anti-H5N1/M1 McAb were obtained, and their cross reactivity was confirmed by cross-reaction test and IFA.

CONCLUSIONMonoclonal antibodies immunized with H5N1 subtype influenza virus M1 protein are cross-reactive, which can be used to detect different subtype of influenze virus type A.

Animals ; Antibodies, Monoclonal ; analysis ; immunology ; Antibodies, Viral ; analysis ; immunology ; Cell Line ; Cross Reactions ; Dogs ; Humans ; Influenza A Virus, H5N1 Subtype ; genetics ; immunology ; Influenza, Human ; immunology ; virology ; Mice ; Mice, Inbred BALB C ; Viral Matrix Proteins ; genetics ; immunology