Evidence of a pro-apoptotic effect of specific antibodies in a bovine macrophage model of infection with Mycobacterium avium subsp. paratuberculosis
Abstract
Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's disease (JD), a chronic granulomatous enteritis in ruminants. Understanding the protective immune response following infection is crucial to improve the diagnosis and the development of vaccines against this disease. The goal of this work was to assess whether specific antibodies were able to modulate the macrophage response to MAP infection by evaluating apoptosis and TNF-α secretion in an in vitro model. Sera from healthy (n=2), MAP-infected (n=3) and lipoarabinomannan (LAM)-immunized (n=3) bovines were evaluated. LAM was chosen as immunogen due to its relevant role in mycobacterial pathogenesis. We demonstrated by two different techniques (Acridine Orange/Ethidium Bromide microscopy and Annexin V/7-Amino-Actinomycin D flow cytometry) that the immune sera from both, MAP-infected and LAM-immunized bovines, significantly increased macrophage apoptosis in infected cultures. Comparable levels of apoptosis were detected when MAP was pre-incubated with purified specific antibodies instead of whole serum. Furthermore, this effect was accompanied by a significantly higher secretion of TNF-α. These results strongly suggest that specific antibodies ...Continue Reading
References
Citations
Related Concepts
Related Feeds
Apoptosis
Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis