Antibodies Induced by Lipoarabinomannan in Bovines: Characterization and Effects on the Interaction betweenMycobacterium aviumSubsp.paratuberculosisand MacrophagesIn Vitro

Abstract

Lipoarabinomannan (LAM) is a major glycolipidic antigen on the mycobacterial envelope. The aim of this study was to characterize the humoral immune response induced by immunization with a LAM extract in bovines and to evaluate the role of the generated antibodies in the in vitro infection of macrophages with Mycobacterium avium subsp. paratuberculosis (MAP). Sera from fourteen calves immunized with LAM extract or PBS emulsified in Freund's Incomplete Adjuvant and from five paratuberculosis-infected bovines were studied. LAM-immunized calves developed specific antibodies with IgG1 as the predominant isotype. Serum immunoglobulins were isolated and their effect was examined in MAP ingestion and viability assays using a bovine macrophage cell line. Our results show that the antibodies generated by LAM immunization significantly increase MAP ingestion and reduce its intracellular viability, suggesting an active role in this model.

Paratuberculose em ruminantes no Brasil

“…Além disso, deve-se considerar as possibilidades de reações cruzadas com outros agentes como Escherichia coli (Gilot & Missone 1994apud Gomes et al 2002, Mycobacterium spp, Corynebacterium pseudotuberculosis e Nocardia spp (Yakes et al 2008, Behr & Collins 2010, devido à presença de determinantes antigênicos comuns entre os gêneros. Componentes da parede celular especialmente as glicoproteínas e lipoarabinomannan (LAM) têm sido es-tudados e utilizados como antígenos para aumentar a especificidade do teste ELISA, assim como para a elaboração de vacinas contra a paratuberculose, devido ao seu papel no processo patogênico (Stevenson & Sharp 1997, Jolly et al 2011.…”

Antemortem and postmortem examinations of the cattle calf naturally infected withMycobacterium aviumsubsp.paratuberculosis

“…CMI-based diagnostics test mostly employed in JD diagnosis because IFN-γ is considered as the essential cytokines that play an important role in achieving protective immunity against mycobacterial infection [34,35]. Even though humoral immune response against mycobacterial infection has been considered nonproductive, the active role of B-cells and antibodies in mycobacterial infection was proven in the last decade [36][37][38][39]. Thus, in the present case study, both CMI and humoral response assays were adopted; moreover, in JD, it is proven that antibody response appears late in infections and prominent during subclinical and clinical stage.…”

Fasciola hepatica — the pilot study of in vitro assessing immune response against native and recombinant antigens of the fluke

“…Fh-ES impairs the activation of dendritic cells (DC) induced by TLR ligands (Falcón et al 2010), but the lack of a change of IL-4 and IFN-γ or TNF-α during our experiments might be caused by a non-physiological behavior of BOMAC cells, due to an absence of response observed to LPS. However, this question is still to be solved since BOMAC cells retain properties of ingestion of opsonised bacteria (Jolly et al 2011) which indicates their phagocytic character. Bone marrow derived mouse dendritic cells do not change secretion of IL-6, 10, 12p70, TNF-α upon stimulation with Fh-ES, but they release significant lower amounts of those cytokines upon stimulation with LPS and Fh-ES than stimulated with LPS only (Falcón et al 2010).…”