Tae-Sung Jung

Evaluation of non-specific immune components from the skin mucus of olive flounder (Paralichthys olivaceus).

The innate immune system, particularly the external body surface, plays a frontier role in protecting fish under intensive aquaculture and at prolonged low temperatures from relevant infections due to inadequate adaptive immune responses. In the present study we aimed to understand the mucosal immunity of an economically important mariculture fish, olive flounder (Paralichthys olivaceus) by evaluating the immune components from its skin mucus. The activities of lysozyme (233.33+/-171.82 units mg(-1)), trypsin-like protease (42.84+/-1.249 units mg(-1)), alkaline phosphatase (0.376+/-0.005 units mg(-1)) and esterase (0.170+/-0.006 units mg(-1)) were detected in the skin mucus. Transferrin was identified by MALDI-TOF/MS analysis. ELISA and immunoblot assays using anti-flounder IgM monoclonal antibody showed the presence of a significant level (1.80+/-0.001, n=3) of monomer immunoglobulin M (IgM) with approximate molecular weight of 160 and 25 kDa under non-denaturing and denaturing states, respectively. Skin mucus showed strong antibacterial activity against tested fish pathogenic bacteria. In addition, skin mucus successfully agglutinated (HA titre 2(8)), but completely failed to haemolyse, rabbit erythrocytes. In conclusion, the major immune components of the skin mucus, identified in the present study, are possibly involved in the broad spectrum non-specific immunity of olive flounder.

Production of monoclonal antibodies against serum immunoglobulins of black rockfish (Sebastes schlegeli Higendorf).

The present study was undertaken to produce monoclonal antibodies (MAbs) against immunoglobulin (Ig) purified from black rockfish (Sebastes schlegeli Higendorf) serum using protein A, mannan binding protein, and goat IgG affinity columns. These three different ligands were found to possess high affinity for black rockfish serum Ig. All of the Igs purified eluted at only 0.46 M NaCl concentration in anion exchange column chromatography and consisted of two bands at 70 kDa and 25 kDa in SDS-PAGE; they also had similar antigenicity for MAbs to Ig heavy chain in immunoblot assays. Therefore, black rockfish Ig is believed to exist as a single isotype within serum. The MAbs produced against Ig heavy chain reacted specifically with spots distributed over the pI range from 4.8 to 5.6 with a molecular weight of 70 kDa on two dimensional gel electrophoresis immunoblot profiles.

Development of competitive ELISA for neosporosis by employing immunoproteomics

In this study, proteomics was used to explore the antigenic proteins that are involved in cross-reactivity during serodiagnosis between Neospora caninum (N. caninum) and Toxoplasma gondii (T. gondii). Competitive enzyme-linked immunosorbent assay (C-ELISA) developed by proteomics shed a new light on the infection of N. caninum. Cross-reactivity of antigenic proteins between N. caninum and T. gondii tachyzoites was explored by using the conventional sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) (1-DE) and two-dimensional gel electrophoresis (2-DE) immunoblot. The proteins were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The protein expression patterns in the immunoblot profiles of N. caninum were similar to bovine, chicken, and rabbit anti-N. caninum serum, but they were not similar to rabbit anti-T. gondii serum. Band at 79 kDa, HSP70, and actin on immunoblot profiles reacted, in general, with bovine, chicken, and rabbit anti-N. caninum serum and also with rabbit anti-T. gondii serum, respectively. Whereas the band at 144 kDa, and NCDG-1 were detected on bovine, chicken, and rabbit anti-N. caninum immunoblot profiles, they were not observed on rabbit anti-T. gondii immunoblot profile. These specific antigenic proteins were recorded as species-specific proteins of N. caninum against T. gondii. Based on the proteome analysis, C-ELISA was developed to screen the cattle infected with N. caninum by using N. caninum tachyzoite lysate as a coating antigen and chicken anti-N. caninum immunoglobulin (Ig)Y as a competitor. C-ELISA was able to detect the antibody of N. caninum without cross-reactivity with T. gondii. Furthermore, it achieved a fine diagnostic performance in the cases of 162 bovine sera.