Mucosal vaccination shapes the expression of salivary antibodies and establishment of cd8+ T-cells

Background: Mucosal vaccination for preventing periodontitis shows promising results. However, various administration routes and adjuvants may have a substantial role in the efficacy of the vaccination. The aim of the study is to compare different modes of mucosal vaccination with whole-cell Porphyromonas gingivalis and to test the role of various adjuvants as potential modifiers of this process. Methods: Mucosal vaccine was administered through oral or nasal routes to BALB/C mice. The tested adjuvants included Escherichia coli cholera toxin, E. coli labile toxin (LT), and unmethylated CpG dinucleotide (CpG). Control mice were vaccinated subcutaneously. Saliva and serum were collected; anti-P. gingivalis salivary immunoglobulin A (IgA) and serum IgG were quantified. A quantitative enzyme-linked immunosorbent assay to measure anti-P. gingivalis IgA levels was established. In addition, cells were extracted from head and neck lymph nodes, and the relative CD8+ cells were quantified using flow cytometry. Results: All mucosal vaccination modes induced anti-P. gingivalis salivary IgA but not anti-P. gingivalis serum IgG. Subcutaneous vaccination induced both salivary IgA and serum IgG against P. gingivalis. Mucosal vaccination also induced greater establishment of CD8+ cells compared to the subcutaneous vaccination. Oral mucosal vaccinations with LT or CpG were the most efficient for salivary IgA expression and CD8 cell establishment in lymph nodes. Conclusions: Oral and nasal mucosal vaccination induced a local host response with little systemic effect. The use of CpG or LT as adjuvants with the oral mucosal vaccination was the most efficient vaccination mode in the present mouse model.