Joaquin Cicotello, Camila Miotti, Guillermo Suarez Archilla, Ana Ines Molineri, Diego Aliprandi, Agostina Peña, Ivana Gabriela Reidel, Sonia Ricotti, María Virginia Zbrun, Lourdes Fraile Wirth, Marcelo Lisandro Signorini, Luis Fernando Calvinho, Carolina Melania Isabel Veaute, Cecilia María Camussone
The development of effective adjuvant systems remains a critical challenge in veterinary vaccine design, particularly for infectious diseases causing significant economic losses in dairy cattle. This study evaluated the immunological profile induced by a mixture of recombinant antigens, formulated with cationic liposomes containing different combinations of gemini lipopeptide AG2-C16, bovine-specific CpG oligodeoxynucleotide, and S. cerevisiae mannans, in dairy heifers. Thirty-five dairy heifers aged 8-10 months were randomly assigned to seven groups and immunized with recombinant Staphylococcus aureus antigens (α-toxin, β-toxin, clumping factor A, and fibronectin-binding protein A) formulated with different adjuvant combinations. Animals received two primary doses 21 days apart, followed by a booster dose 8 months later. Humoral immune responses were assessed through ELISA measuring specific immunoglobulin G (IgG), IgG1, and IgG2 levels, while cytokine production was evaluated via whole-blood assays. Results demonstrate that liposomal formulations combining AG2-C16, CpG-ODN, and mannans induce a significant immune response, in heifers, with IFN-γ production. These findings provide valuable insights for the development of new vaccine strategies in cattle.