Characterization and functional evaluation of bovine antibody response against Mycobacterium avium subsp. paratuberculosis.

MUNDO, S; JOLLY, A; FERNÁNDEZ, B.; BASS, L; COLAVECCHIA, S

Viña del Mar

Congreso; IX Latin American Congress of Immunology; 2009

Asociación Latino Americana de Inmunología

Paratuberculosis (Mycobacterium avium subsp. paratuberculosis, Map) is a chronic granulomatous enteritis disease affecting ruminants. Generally, antibody (Ab) response against mycobacterial infections has been considered non protective. However, this afirmation is nowadays under review. Our aim was to characterize bovine Abs induced by natural infection or vaccination with Map membrane-antigens and their function in vitro. Thirty-three bovines were clasified as naturally infected (I), vaccinated with Map (Mv), p-34 (p34v) or LAM (Lv) and healthy controls (HC). Ab titres and isotype profile were assessed by ELISA. The effect of purified Abs on macrophage-Map (m-M) interaction in vitro was evaluated by association, NF-kB traslocation and bacteria intracellular survival assays. Results were analized using ANOVA. Our results showed the predominance of IgG1 and IgG3 in all groups. The m-M association increased when Map was treated with Abs from I, Mv, p34v and Lv compared with HC (p< 0.05). Macrophage NF-κB activation was improved with I and p-34v Abs. Also, Lv Abs could reduce Map intracellular survival in this model (survival % of 171.7 ± 68.3 and 76.0 ± 6.7 for HC and Lv respectively). These results demonstrate that Abs directed to Map-membrane might modified paratuberculosis course. This knowledge could contribute to subunit vaccine design.