The immunomodulatory effect of antimicrobial peptide HPA3P restricts Brucella abortus 544 infection in BALB/c mice.

•HPA3P did not cause any cytotoxicity or bactericidal effect to B. abortus.•HPA3P inhibited bacterial internalization and reduced intracellular growth within macrophages.•Mice treated with HPA3P demonstrated a significant log reduction and spleen weight reduction compared to the nanocarrier control.•Significant increases in key cytokines IFN-γ and TNF were observed in HPA3P treated mice.•Histopathological analysis suggests reduced bacterial granuloma in the liver and spleens of HPA3P treated group compared to nanocarrier group.