Immunoproteomics of extracellular proteins of theAeromonas hydrophilaChina vaccine strain J-1 reveal a highly immunoreactive outer membrane protein

Abstract

Aeromonas hydrophila is a gram-negative bacterium that can infect a variety of aquatic and terrestrial animals. It is essential to develop a vaccine to reduce the economic losses caused by this bacterium in aquaculture worldwide. Here, an immunoproteomic assay was used to identify the immunogenic extracellular proteins of the Chinese vaccine strain J-1. Ten unique immunogenic proteins were identified from the two-dimensional electrophoresis immunoblot profiles by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) or MALDI-TOF-TOF-MS. One protein of interest, Omp38, was detected by antisera on two-dimensional immunoblots, suggesting that it might be located both extracellularly and in the membrane. In exploring the potential of Omp38 as a vaccine candidate in fish, we found the omp38 gene to be prevalent by PCR among different (36/48) A. hydrophila isolates. The recombinant Omp38 induced a strong antibody response in rabbits, and the polyclonal antibody could recognize a band of approximately 38 kDa in the immunoblots of outer membrane protein extracts from most (24/40) of the A. hydrophila strains, including different predominant serotypes in China. These results indicated that the outer membrane antigen identified in this study could be developed as a vaccine candidate to induce protective immunity against A. hydrophila infection.

Identification of early diagnostic antigens from major excretory-secretory proteins of Trichinella spiralis muscle larvae using immunoproteomics

“…The ES proteins were precipitated using trichloroacetic acid (TCA) and acetone using a previously described method with some modifications [27]. The electrophoresis was performed as described previously [17,28].…”

Proteomic Analysis ofTrichinella spiralisMuscle Larval Excretory-Secretory Proteins Recognized by Early Infection Sera

“…The ES proteins were precipitated using trichloroacetic acid (TCA) and acetone as previously described method with some modifications [27]. Briefly, the sample was suspended in 10% TCA in acetone with 20 mM DTT for 2 h at −20°C.…”

Proteomic analysis of surface proteins of Trichinella spiralis muscle larvae by two-dimensional gel electrophoresis and mass spectrometry

“…The surface antigens were precipitated using trichloroacetic acid (TCA) and acetone as for the previously described method with some modifications [27]. Briefly, the sample was suspended in 10% TCA in acetone with 20 mM DTT at -20°C for 2 h. After centrifugation at 15,000 g at 4°C for 15 min, the pellet was resuspended in cold acetone containing 20 mM DTT and washed three times.…”