INDUCTION OF ANTIGEN-SPECIFIC ANTIBODY-SECRETING CELLS IN THE NASAL-MUCOSA BY INTRANASAL IMMUNIZATION OF BALB C MICE/

Recent studies have demonstrated that antigen-specific IgA immune resp onses in nasal cavity are induced by intranasal immunization with seve ral antigens. However, the precise mechanisms regulating such immune r esponses are unclear. In the present study, mice were immunized intran asally with horseradish peroxidase (HRP) plus cholera toxin into the r ight nostril, and HRP-specific ISA immune responses were investigated. After the immunization, an enzyme-linked immunospot assay showed an i ncreased number of anti-HRP IgA cells in the nasal mucosa. Histochemic al staining demonstrated the presence of anti-HRP antibody-secreting c ells, mainly in the nasal subepithelial layer, Interestingly, these ce lls were induced predominantly on the right nostril, where intranasal immunization was performed. These findings suggest that antigen-specif ic IgA antibodies in the nasal secretions were produced locally from a ntibody-secreting cells in the nasal mucosa and that IgA immune respon ses in the nose were compartmentalized. Furthermore, lectin histochemi stry showed an accumulation of peanut agglutinin-positive cells in the nasal-associated lymphoreticular tissue, suggesting the development o f germinal centers in the immunized animals.