[Show abstract][Hide abstract] ABSTRACT: Abstract Two monoclonal antibodies (MAbs) against chicken secretory immunoglobulin A (SIgA) were generated and their binding specificities were characterized by enzyme-linked immunosorbent assay (ELISA), SDS-PAGE, and Western blotting. Analysis revealed that the subtypes of two MAbs were both IgG2b, with the light chain belonging to the kappa configuration. The affinity constant (K(aff)) of the two MAbs was 5.0 x 10(10) M(-1) and 9.7 x 10(9) M(-1), respectively. The MAbs are directed against the heavy chain domains of chicken SigA, and no cross-reactivities to IgG were observed. These results indicate that the MAbs are specific for SIgA and may be a useful tool for investigating issues regarding mucosal immunity and in the development of a good diagnostic kit for detection of specific IgA in chicken.
No preview · Article · Nov 2008 · Hybridoma (2005)
[Show abstract][Hide abstract] ABSTRACT: Infectious bronchitis (IB) is one of the major diseases in poultry flocks all over the world caused by infectious bronchitis virus (IBV). In the study, the complete genome sequence of strain A2 was sequenced and analyzed, which was a predominant IBV strain in China. The results indicated that there were mutations, insertions, and deletions distributed in the whole genome. The A2 virus had the highest identity to S14 and BJ in terms of full genome, whereas had a further distance to Massachusetts strains. Phylogenetic analysis showed that A2 isolate clustered together with most Chinese strains. The results of this study suggest that strain A2 may play an important role in IBV's evolution and A2-like IBVs are predominant strains in China.
[Show abstract][Hide abstract] ABSTRACT: A hybridoma cell line 1G4A7 secreting monoclonal antibody (McAb) specific to hemagglutinin of avian paramyxovirus type 2 (APMV-2) was developed by fusing the spleen cells of APMV-2 immunized BAlb/c mice with SP2/0 myeloma cells. The immunoglobulin subclass of 1G4A7 was IgG1 with light chain kappa and the affinity constant against APMV-2 was 1.02 X 10(10). Identified by HI and indirect ELISA, the McAb titers in ascities were 10 log 2 and 1 : 10(6) respectively. The McAb did not cross react with the common avian viruses, showing good specificity. There existed obvious differences in antigenitic relationship among APMV-2 viruses analyzed by HI and indirect ELISA using McAb 1G4A7.
No preview · Article · Jul 2008 · Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui]
[Show abstract][Hide abstract] ABSTRACT: We report the prevalent status of avian paramyxovirus serotype 2 (APMV-2) in China. Between 2003 and 2005, 9156 sera in total were collected and screened for APMV-2 antibodies by using the hemagglutination inhibition assay. The averaged seropositivity ofAPMV-2 for chickens, ducks, peacocks, ostriches, and partridges was 42.9%, 25.1%, 45.8%, 47.6%, and 80.0%, respectively. The results of this survey indicate that the distribution of APMV-2 is very widespread in China and that more attention should be paid to the influence of APMV-2 on poultry production.
[Show abstract][Hide abstract] ABSTRACT: Diethylstilbestrol (DES) is a synthetic estrogen that has ever been used worldwide. Polyclonal antibodies (PAbs) were used in immunoassay for detection of DES residues in environmental and agricultural samples in previous paper. In this paper, an indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed based on monoclonal antibody (MAb) for the determination of diethylstilbestrol. Mono-o-carboxypropyldiethylstilbestrol (DES-CP) and mono-o-carboxymethyldiethylstilbestrol (DES-CME) were synthesized to be haptens. DES-CP was coupled to bovine serum albumin (BSA) to be an immunogen in BALB/c female mouse for MAb production. The MAb was characterized for specificity and affinity to DES in icELISA. Under the optimum condition, the icELISA showed an IC50 of 9.8 ng/mL, the limit of detection (IC20) of 2.3 ng/mL and a working range of 2–42 ng/mL. Hexestrol and dienestrol exhibited cross-reactivity values were 44% and 27%, respectively. Cross-reactivity of natural estrogen 17β-estradiol was less than 0.1%. The influences of some factors such as salt concentration, pH and organic solvent concentration on the assay were evaluated. The concentrations of DES in the fortified water samples determined by the assay were correlated well with the fortification levels. The results were confirmed with analysis by HPLC.
No preview · Article · Dec 2006 · Chinese Journal of Chemistry
[Show abstract][Hide abstract] ABSTRACT: Four Yucaipa-like viruses of avian paramyxovirus serotype 2 (APMV-2) were isolated in China from the imported Gouldian Finch (Chloebia gouldiae) and broilers in 1998-2002, and were named F4, F6, F8, and NK, respectively. Examined under electron microscope, the isolates were found to be round in shape and varying in size. The results of the hemagglutination inhibition test and indirect enzyme-linked immunosorbent assay (using monoclonal antibodies) showed some differences between the isolates and the reference strain Yucaipa. The isolates derived from chickens had a closer relationship to Yucaipa virus than did those of finches. Sequence comparison of the fusion gene and the haemagglutinin-neuraminidase gene showed similar results, although the variations were lesser among APMV-2 viruses in nucleotide and amino acid sequence. By sequence comparison, it was also revealed that at the molecular level the four virus strains belong to APMV-2, and that two of the strains were isolated from the same group of imported Gouldian Finches.
[Show abstract][Hide abstract] ABSTRACT: Paramyxovirus might adopt a molecular mechanism of membrane fusion similar to that of other class I viruses in which the heptad repeat (HR) regions of fusion protein (F) HR1 and HR2 form a six-helix bundle structure inducing membrane fusion. In this study, we examined the structure and function of HR1 and HR2 from the avian paramyxovirus-2 (APMV-2) F protein. The study showed that APMV-2 HR1 and HR2 formed a stable six-helix bundle. Only a soluble APMV-2 HR2 peptide showed potent and specific virus-cell fusion inhibition activity. Cross-inhibiting activity with APMV-1 (Newcastle disease virus, NDV) was not found. A possible mechanism of membrane fusion inhibition by the paramyxovirus HR2 peptide is discussed.
Full-text · Article · May 2005 · Archives of Biochemistry and Biophysics