DENDRITIC CELLS OF THE ORAL-MUCOSA AND THE INDUCTION OF ORAL TOLERANCE - A LOCAL AFFAIR

The oral mucosa is an important site to induce immunological tolerance to protein antigens. Previously we have established that oral contact s to allergen can lead to systemic tolerance in both humans and experi mental animals. Because of the importance of tolerance induction as a possible way to modulate allergic reactivity, we wished to study the m echanisms involved in efficient tolerance induction via the oral mucos a. Dendritic Langerhans' cells in both skin and oral epithelium are th e first cells to encounter antigen. Therefore, possible functional dif ferences between Langerhans' cells from skin and oral mucosa were stud ied by migration and transfer experiments. It was found that dendritic cells derived from the oral mucosa were not able to transfer toleranc e, but that they acted as antigen-presenting cells in sensu stricto ir respective of the source and route of antigen administration.