Characterization of the Early Antibody Response in Bovine Tuberculosis: MPB83 is an Early Target with Diagnostic Potential

Abstract

A 26-kDa antigen has been shown to be a dominant antibody target in Mycobacterium bovis-infected cattle. In this study, that antigen was used as an immunogen to raise a panel of mouse monoclonal antibodies. The majority of those bound to native protein with a molecular mass of 26 kDa and to recombinant MPB83, strongly suggesting that MPB83 is an important B-cell antigenic target in bovine tuberculosis. In order to provide assessment of the potential of measuring antibody responses to the native protein, one monoclonal antibody, 1F11, was incorporated into an enzyme-linked immunosorbant assay format to trap antigen from a crude bacterial extract. Despite some disadvantages of this format, serum samples from cattle which had been infected experimentally with M. bovis, and from tuberculin skin-test-negative and -positive field cattle were tested for the presence of antibodies. Data from the skin-test-negative cattle allowed an arbitrary cut-off value to be established and, under these conditions, test sensitivity and specificity were estimated at 37.5 and 89%, respectively. These results indicate potential for MPB83 in the development of assays for serological diagnosis of bovine tuberculosis.

Diagnosis of bovine tuberculosis: review of main techniques

“…Most of these antigens have achieved a sensitivity and specificity of around 90%, and their recommendations are based on the existence of anergic animals, as well as increased antibody titres in more advanced stages of the disease (Faye et al, 2011;McNair et al, 2001;Welsh et al, 2005).…”

Association of Tuberculin-Boosted Antibody Responses with Pathology and Cell-Mediated Immunity in Cattle Vaccinated with Mycobacterium bovis BCG and Infected with M. bovis

“…In particular, the mycobacterial antigens MPB70 and MPM83 have been identified as serodominant antigens (7,8,17,19,22). However, precise correlates of protection and disease severity in cattle (and in other systems) are not well defined.…”

A multidisciplinary approach to diagnose naturally occurring bovine tuberculosis in Brazil

“…or 21p.i. The two antigens used as ELISA reagents in our study are capable of stimulating B-lymphocytes in the early phases of tuberculosis (McNair et al 2001) In addition, both of these antigens are components of bovine PPD and their presence could lead to a booster effect (Stevens et al 1998). This effect could be most intense when an animal is really infected, or herd is located in an endemic area.…”

“…MPB70 and MPB83 have been used independently or in association with other important antigens, such as EAST-6 and CFP-10, for diagnosis purposes (Aagard et al 2006). The MPB70 and MPB83 proteins are identified as early B-cell targets in M. bovis infection and could detect antibodies in experimentally infected cattle seven (MPB70) to 18 (MPB83) weeks before a positive tuberculin response could be measured (McNair et al 2001, Lin et al 2007). In addition, selection of highly specific antigens could help to eliminate cross-reactions between other species of mycobacteria, such as M. avium paratuberculosis and M. kansassii (El-Zaatari et al 1995, Olsen et al 2001, Water et al 2006, Marassi et al 2009a).…”