title: 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 could limit the impact of MAP on the apoptosis of bovine cells. This work would contribute to elucidate the role of the specific antibody response in bovine JD and its prevention.
authors.affiliation: Cátedra de Inmunología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280 C1427CWO, Buenos Aires, Argentina.
authors.forename: Ana
authors.initials: A
authors.lastname: Jolly
authors.affiliation: Cátedra de Inmunología-Instituto de Estudios de la Inmunidad Humoral (IDEHU), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires-CONICET, Junín 956 C1113AAD, Buenos Aires, Argentina.
authors.forename: Silvina
authors.initials: S
authors.lastname: Lompardía
authors.affiliation: Cátedra de Inmunología-Instituto de Estudios de la Inmunidad Humoral (IDEHU), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires-CONICET, Junín 956 C1113AAD, Buenos Aires, Argentina.
authors.forename: Silvia E
authors.initials: SE
authors.lastname: Hajos
authors.affiliation: Cátedra de Inmunología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280 C1427CWO, Buenos Aires, Argentina. Electronic address: smundo@fvet.uba.ar.
authors.forename: Silvia L
authors.initials: SL
authors.lastname: Mundo
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D017209:Apoptosis; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology; D002461:Cell Line, Transformed; D004195:Disease Models, Animal; D005260:Female; D008264:Macrophages / Q000276:immunology*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D010283:Paratuberculosis / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000907:Antibodies, Bacterial; D014409:Tumor Necrosis Factor-alpha
keywords: Antibodies; Apoptosis; Bovine macrophages; Johne's disease; Lipoarabinomannan; Mycobacterium avium subspecies paratuberculosis