Immune responses and protection induced by mucosal and systemic immunisation with recombinant measles nucleoprotein in a mouse model of measles virus-induced encephalitis

In this study the immunogenicity of recombinant nucleoprotein (Np) administered intranasally or intraperitoneally, and its ability to support a systemic protective anti-virus antibody response was examined, in a mouse model of measles virus (MV)-induced encephalitis. Although both intranasal and intraperitoneal routes of immunisation resulted in priming Np-and MV-specific T-cell responses, the intraperitoneal route was shown to prime for a predominantly IgG2a serum anti-MV antibody response of high avidity, which confered complete protection following intracranial challenge with a neuroadapted strain of MV. On the other hand, intranasal priming resulted in a mixed IgG1, IgG2a serum anti-MV antibody response of low avidity, and only 43% of immunised mice survived following intracranial challenge with the neuroadapted strain of MV.