The influence of different immunization pathways on the immunological response in the oral mucosa.

In order to study a possible difference in the induction of local immunological responses in the oral mucosa after different immunization pathways, Wistar rats were immunized with ovalbumin by different routes, (i) via the submandibular lymph nodes, (ii) via the Peyer's patches and (iii) via the hindpad. The local reaction after antigen challenge was compared with the systemic humoral response. To study the local reaction, the homologous antigen was injected in the oral mucosa. This resulted in a delayed type hypersensitivity reaction, being the same in extent and character for all immunization pathways. The humoral response was evaluated by serum antibody production (antiovalbumine IgG). It was shown that the antibody production obtained by immunization via the Peyer's patches was significantly smaller than that in the rats immunized via other pathways. The conclusion was that the induction of a local cellular reaction was independent of the antigen pathway, whereas serum antibody production depended on the route, i.e. antigen administration via the submandibular lymph nodes and the hindpad was significantly higher than via the Peyer's patches. The possible consequences of the findings are discussed together with their relevance to immunopathological reactions in the oral cavity.