Neosporacaninum: Application of apical membrane antigen 1 encapsulated in the oligomannose-coated liposomes for reduction of offspring mortality from infection in BALB/c mice

Abstract

Liposomes coated with neoglycolipids constructed with mannopentaose and dipalmitoylphosphatidylethanolamine (M3–DPPE), referred to as M3–DPPE liposomes, have been shown to induce cellular immunity against antigens encapsulated therein. To evaluate whether these M3–DPPE liposomes have an adjuvant capacity against Neospora caninum infection, a novel immunization method utilizing soluble N. caninum apical membrane antigen 1 (NcAMA1) encapsulated in the M3–DPPE liposomes (M3–NcAMA1) was employed. The results revealed that a significant amount of interferon (IFN)-γ production was detected in culture supernatants of NcAMA1 protein- or N. caninum lysate-stimulated spleen cells obtained from the mice one week after the third immunization with M3–NcAMA1. The parasite burden in the dams’ brain tissue was decreased and the survival rate of offspring increased significantly in M3–NcAMA1-immunized mice. Thus, a parasite-specific Th1 immune response was successfully induced in the pregnant mice immunized with M3–NcAMA1, and an effective reduction of offspring mortality from N. caninum infection was triggered.