Evaluating the Immunogenicity of recombinant VP1 protein from the foot-and-mouth disease virus encapsulated in nanoliposome in guinea pig animal model.

Foot-and-mouth disease (FMD) is considered as contagious in livestock, which is caused by the Picornavridae virus family known as FMD virus (FMDV). In the present study, the VP1 gene from FMDV (O strain) was expressed and purified. In addition, nanoliposomes were utilized as an adjuvant. After formulating the nanoliposomes with DMPC, DMPG, and cholesterol, the recombinant VP1 protein was encapsulated in the nanoliposomes. Further, the intended nanoliposomes in the sizes of 400 and 200 nm, nanoliposome-inactivated FMDV, Freund's adjuvant-inactivated FMDV, and Freund's adjuvant-recombinant VP1 mixtures, and PBS buffer (negative control) were injected to six groups of five guinea pigs. Furthermore, the guinea pig serums were analyzed through using ELISA and serum neutralization tests after four boosting vaccinations. Based on the results, the immunogenicity of the 200 nm-nanoliposomes encapsulating recombinant VP1 protein was more than that of 400 nm-ones so that 200 nm-nanoliposomes could trigger the immune response against FMDV in guinea pigs.

Comparison of Gold Nanoparticle Conjugated Secondary Antibody with Non-Gold Secondary Antibody in an ELISA Kit Model.

In this study, gold nanoparticles (AuNPs) were used as carriers of the signaling anti-chicken antibody peroxidase in comparison with anti-chicken antibody peroxidase without gold nanoparticle in a commercial avian influenza kit. AuNPs enhanced the absorbance and shortened the assay time. AuNPs act as a carrier of many enzymes and multiply the effect of enzyme when reacting with substrate. They amplify optical signal, while keeping low background signals.

Evaluation of immunogenicity of purified cell wall-associated 34 kDa antigen of Mycobacterium avium subsp. paratuberculosis infection.

The 34 kDa cell wall protein of Mycobacterium avium subsp. paratuberculosis (MAP) has been suggested as a major species-specific immunodominant antigen in Johne's disease. However to date, there has not been a purified 34 kDa protein isolated from bacterial lysates used in immunogenicity analysis. Therefore we attempted to assess the immunogenicity properties of the purified cell wall 34 kDa protein for the first time, and compare the results with previous studies. We used an ELISA test for evaluation of the immunogenicity of this 34 kDa antigen against MAP infection. All serum samples from cattle confirmed to be infected with MAP were positive and those from healthy cattle were negative with the present antigen in ELISA tests. The sensitivity and specificity of 34 kDa antigen were then evaluated in comparison with a standard commercial kit and whole cell wall extracts. The results indicated that the pure 34 kDa antigen specific to MAP with high specificity and sensitivity has a strong potential for use in serodiagnosis assays and screening of Johne's disease.

Differentiating pestes des petits ruminants and rinderpest viruses by a novel monoclonal antibody.

Peste des petits ruminant (PPR) is an acute, febrile, viral disease of small ruminants with great economic importance. PPR and rinderpest (RP) viruses are antigenically related and need to be differentiated serologically. The use of monoclonal antibodies (MAbs) in ELISA for specific diagnostics and separation of PPR and RPV is important. For this purpose, six Balb/c mice were immunized with inactivated antigen from the Nijeria strain. Fusion cloning was performed 3 months later by directly using cloning plates, selecting the hybridoma colonies at an early stage with an inverted microscope, and transferring the colonies into 96-well plates with a micropipette. From 300 wells, nearly 56 hybridoma clones were found, from which, after testing in ELISA, 11 with higher titer were selected. Among these, only two clones were placed for limiting dilution (1H1, 6A12). Only one clone (6A12L1F12) had no cross-reactivity with RP, reacted with the N protein, and was of IgG2 isotype.

Development of a sandwich enzyme-linked immunosorbent assay (ELISA) for determining of bovine serum albumin (BSA) in trivalent measles-mump-rubella (MMR) vaccines.

A sandwich enzyme-linked immunosorbent assay (ELISA), using polyclonal antibody, was developed and compared with the commercial kit for detecting and estimating of BSA content in Measles-Mump-Rubella (MMR) vaccine samples in detection limit of nanogram level. The test depends on the capturing and detecting of BSA antigen by the polyclonal antibody. Initially, a detection range of 0-64 ng/ml was established, could be used for estimation of BSA content according to WHO requirement (50 ng/ml) in MMR vaccines. Comparative analysis of the test results for 85 MMR vaccine samples obtained with the commercial kit gave a sensitivity of 58.8% and a specificity of 97%. A high correlation (r = 0.94) was observed between BSA sandwich ELISA and commercial kit for BSA content in MMR samples. However, variations in values also were observed for the two assays. These variations may have been due to difference of upper limit of detection range of BSA content in commercial kit (32 ng/ml) and new sandwich ELISA (64 ng/ml) as well as the use of a different polyclonal antibody. In concerning the cutoff value for the WHO requirement and employment of standard solution of 64 ng/ml in developing assay, it would be adequate to use this test for assessing BSA content in viral vaccines same as MMR vaccines.