Immunoreactivity of recombinant OMP28 of Brucella melitensis in mice

The present study was planned to construct the conjugate ofFc fragment of mice IgG with rOMP 28. The developed conjugate wasused to investigate the kinetics of humoral and cellular immuneresponse in comparison to its un conjugated and the rOMP 28 alone.Among all the groups, the group of mice immunized with CpG+ rOMP 28 induced highest level of humoral immune response andBrucella abortus S19 group conferred highest level of cellular response which was evidenced by high nitric oxide concentration and also by the clearance of virulent B. abortus 544 from the spleen after challenge.The conjugated group conferred low level of humoral responsewhen compared to the rOMP28 alone which may be due to theirreversible loss of Fc receptors on the macrophage plasma membraneand the involvement of inhibitory Fc¿IIR which is involved in theregulation of immune responses.The B. abortus S19 strain group induced a high level of protection when challenged with virulent B. abortus 544 which indicate whole cell organism composed of various components may be involved in the protection.