Neospora caninum truncated recombinant proteins formulated with liposomes and CpG-ODNs triggered a humoral immune response in cattle after immunisation and challenge

Abortions caused by Neospora caninum are a serious problem in cattle production and require effective immunoprophylaxis. The objective of this work was to assess the humoral immune response four recombinant (r) N. antigens after immunisation challenge. MIC1 MIC3 proteins from micronemes, SRS2 surface tachyzoites, GRA7 dense granules were expressed as truncated Escherichia coli. Cationic liposomes (Lip) CpG oligodeoxynucleotides (CpG-ODNs) used adjuvant. Steers assigned three groups six steers each inoculated twice subcutaneously, 21 days apart. rP + Lip CpG-ODN group received rMIC1, rMIC3, rSRS2 rGRA7 formulated with adjuvant; adjuvant alone; PBS sterile phosphate-buffered saline. All subcutaneously challenged NC-1 strain 35 second dose immunisation. developed specific IgG, IgG1 IgG2 against After challenge, IgG rMIC1 rMIC3 detected all groups. remained high challenge group. Indirect ELISA anti-N. antibodies groups, highest level being vaccine using immunogenic enhanced vaccinated cattle.