ISOTYPES CHARACTERIZATION OF THE MAP-SPECIFIC EARLY IMMUNE RESPONSE IN EXPERIMENTALLY INFECTED CALVES BY IMMUNOBLOT

FERNÁNDEZ B.; COLAVECCHIA S.; A JOLLY; FERNANDO PAOLICCHI; MUNDO SL.

Riviera Maya.

Simposio; 14th International Colloquium on Paratuberculosis.; 2018

International Colloquium on Paratuberculosis.

The understanding of the immune response in paratuberculosis (caused by Mycobacterium avium subsp.paratuberculosis (Map) is still limited by a lack of tools to diagnose Map soon after infection occurs.The aim of this work was to characterize the early humoral immune response induced after experimental infectionof calves.Holstein calves (6-7 weeks old) were experimentally infected per os with 250 mg of total wet weight live Mapbelonging to two Argentinean isolated strains. The groups were: Map strain A infected (MA; n=3), Map strain Cinfected (MC; n=2) and mock infected (MI; n=3). Specific IgG, IgG1 and IgG2 in sera, against sonicated Map (ATCC19698) were analyzed by immunoblot prior-infection(0) and 150 days post-infection (dpi).IgG reactivity to antigens of lower molecular weight than 50kDa was detected in sera of all infected calves at 150dpi. Two wide bands (~35-47kDa and ~21-30kDa) were detected in sera of MC group when total IgG was evaluated.IgG1 showed no or a weak reactivity in all calves. Meanwhile, immunereactivity by igG2 resulted in heterogeneousband patterns (