Antigen discovery: A postgenomic approach to paratuberculosis diagnosis

Abstract

Paratuberculosis is a chronic enteritis caused in domestic and wild ruminant species by Mycobacterium avium subsp. paratuberculosis (MAP) that is responsible for major economic losses to the agricultural industry. To date, no satisfactory therapeutic, vaccine, or diagnostic tools are available, globally impairing all control programs. In this study, we have undertaken a large-scale postgenomic analysis of MAP proteins, to identify specific antigens that could potentially improve the diagnosis of paratuberculosis. Two complementary approaches were implemented, the first one consisting in the systematic proteomic identification of proteins present in MAP culture filtrates (CFs), followed by the selection of MAP-specific proteins by BLAST query on available mycobacterial genomes. The resulting database represents the first established secretome of MAP and a useful source of potentially specific antigens. The second approach consisted in the immunoproteomic analysis of both MAP extracts and CFs, using sera from MAP-infected and uninfected cattle. Combining results obtained with both approaches resulted in the identification of 25 candidate diagnostic antigens. Five of these were tested in an ELISA assay for their diagnostic potential, on a limited panel of field sera, and the combination of three of them competed in performance with available commercial assays, reaching a test sensitivity of 94.74% and specificity of 97.92%.

The genome of cyprinid herpesvirus 3 encodes 40 proteins incorporated in mature virions

“…4. The gel slides were washed separately and digested with modified sequencing-grade trypsin (Promega), and the resulting peptides were extracted as described elsewhere (Leroy et al, 2007). The peptides were analysed by nanoLC-MS/MS as described previously (Mastroleo et al, 2009).…”

Diva technology: indispensable tool for the control of Johne’s disease

“…MAP 2677c Glyoxylase Tested for antigenicity by Roupie et al (2012) 27. MAP 3199 -Tested for antigenicity by Leroy et al (2007) 28.…”

Enzyme-Linked Immunospot: An Alternative Method for the Detection of Interferon Gamma in Johne's Disease

“…The use of crude antigens has been identified as a problem for the immunological diagnosis of JD in many studies. 1,[7][8][9]23,24,43 There is a need for defined specific antigens that could enable extension of the assay to identify animals likely to be immune and those with a latent infection that will eventually succumb to disease. It may enable identification of sheep that go on to develop a specific lesion type.…”