Immunoproteomic identification of immunodominant antigens independent of the time of infection in Brucella abortus 2308-challenged cattle.

Jin Ju Lee,Dae Geun Kim,Han Sang Yoo,Alisha Wehdnesday Bernardo Reyes,Hannah Leah Simborio,Wongi Min,Huynh Tan Hop,Suk Chan Jung,Moon Her,Suk Kim

doi:10.1186/s13567-015-0147-6

Abstract

Brucellosis is a vital zoonotic disease caused by Brucella, which infects a wide range of animals and humans. Accurate diagnosis and reliable vaccination can control brucellosis in domestic animals. This study examined novel immunogenic proteins that can be used to detect Brucella abortus infection or as an effective subcellular vaccine. In an immunoproteomic assay, 55 immunodominant proteins from B. abortus 544 were observed using two dimensional electrophoresis (2DE) and immunoblot profiles with antisera from B. abortus-infected cattle at the early (week 3), middle (week 7), and late (week 10) periods, after excluding protein spots reacting with antisera from Yersinia enterocolitica O:9-infected and non-infected cattle. Twenty-three selected immunodominant proteins whose spots were observed at all three infection periods were identified using MALDI-MS/MS. Most of these proteins identified by immunoblot and mass spectrometry were determined by their subcellular localization and predicted function. We suggest that the detection of prominent immunogenic proteins during the infection period can support the development of advanced diagnostic methods with high specificity and accuracy; subsidiarily, these proteins can provide supporting data to aid in developing novel vaccine candidates.

Highlights

Brucella spp. are the etiological agents for brucellosis, a debilitating and chronic disease infecting a variety of domestic animals and humans
All animals were seronegative for brucellosis before immune challenge, as assessed by the standard tube agglutination test (STAT) and Rose Bengal test (RBT), which are internationally accepted serological tests for bovine brucellosis described by the OIE [5]
Immunogenic proteins in B. abortus at different infection periods and comparison with cross-reacting bacteria By immunoblotting the diverse B. abortus proteins detected on 2DE gels, 134, 110, and 106 proteins were recognized using positive antisera from B. abortus-infected cattle at 3, 7, and 10 weeks of infection, respectively (Figures 1B-D)

Summary

Introduction

Brucella spp. are the etiological agents for brucellosis, a debilitating and chronic disease infecting a variety of domestic animals and humans. Brucellosis is characterized by abortion and sterility in livestock as well as undulant fever, arthritis and neurological disorders in humans [1]. Definitive diagnosis is commonly performed by isolation and identification of the causative organism(s), but because the isolation is time-consuming and dangerous, serological analysis is widely preferred [2]. Several specific serological tests have been developed for the definitive diagnosis of brucellosis, and these tests have been upgraded repeatedly to obtain reliable data [3]. A large number of tests still rely on presumptive evidence of Several immunogenic proteins of B. abortus have been identified [10], but the antigens that are immunogenic at different stages of the infection have not been defined.

Methods

Results

Conclusion