A Brucella ovis antigenic complex bearing poly-epsilon-caprolactone microparticles confer protection against experimental brucellosis in mice

A hot saline antigenic extract (HS) from Brucella ovis was encapsulated in poly-epsilon -caprolactone microparticles (PEC), and tested as a vaccine ag ainst B. ovis and B. abortus infections in mice. Subcutaneous but not oral administration in BALB/c mice of the HS-PEC induced high amounts of IFN-gam ma and IL-2 but low quantities of IL-4 suggesting a combined Th1/Th2 cellul ar immune response. The vaccine administered either subcutaneously or orall y protected mice against B. ovis infection. Such protection was similar to that provided by the reference living attenuated B. melitensis Rev. 1 vacci ne. By contrast, only the subcutaneous vaccination with HS-PEC was as effec tive as Rev. 1 in conferring protection against B. abortus infection. The u se of free HS or empty PEC microparticles did not produce any protective ef fect. (C) 2001 Elsevier Science Ltd. All rights reserved.