Antigen-specific cytokine and antibody isotype profiles induced by mucosaland systemic immunization with recombinant adenoviruses

We investigated antigen-specific antibody and T-cell responses in mice immu nized with human adenovirus type 5 (HAd5) vectors expressing either the aut hentic or truncated form of glycoprotein D (gD and tgD, respectively) of bo vine herpesvirus type 1 (BHV-1). We also tested whether different routes of immunization influenced the level and type of immunity, Immunization intra nasally (i.n.) stimulated higher levels of gD-specific IgA in the lung and nasal washes and induced a higher frequency of gD-specific antibody secreti ng cells (CSs) in the lung than did immunization subcutaneously (s.c.). In addition, immunization i.n. stimulated go-specific systemic antibody respon ses of a higher IgG1/IgG2a ratio and lower numbers of gD-specific interfero n (IFN)-gamma SCs in the spleen than did immunization s.c. HAd5-specific re sponses also depended on the route of immunization and were characterized b y lower IFN-gamma interleukin (IL)-4 ratios than go-specific responses. Imm unization with the tgD-expressing vector induced generally lower antibody a nd cytokine responses than the gD-expressing vector, sigher numbers of anti gen-specific IgA SCs in the lung as measured by enzyme-linked immunospot (E LISPOT) assay correlated with higher levels of IgA in the respiratory tract as measured by enzyme-linked immunosorbent (ELISA) assay, although there w as no such correlation for IgG responses of any isotype. In conclusion, the route of immunization and form of antigen had an impact on the level and t ype of immune responses induced by adenovirus vectors.