It takes guts for tolerance: the phenomenon of oral tolerance and the regulation of autoimmune response.
The intestinal tract is a peculiar environment due to its constant contact with the microbiota agents, food antigens and other molecules. Such exposure requires the establishment of important regulatory mechanisms in order to avoid inflammatory response and self aggression. In this context, the GALT plays a very relevant role due to the presence of several different cellular populations which are the main players in this phenomenon. Moreover, it was described a while ago that the oral ingestion of a given molecule is able to induce systemic tolerance to the same molecule when it is used as an immunogen by parenteral route, known as oral tolerance. This observation led researches to use these mechanisms to induce tolerance against cognate antigens of different autoimmune diseases. In this context, in this review we focused on several tolerance inducing mechanisms which are relevant not only for the maintenance of intestinal tract but also for the suppression of T effector cells, such as Th1, Th2 and the newly described Th17 cells. To name a few, CD103(+) dendritic cells, Tr1 cells derived IL-10 secretion, Foxp3 conversion and CD4(+)LAP(+) regulatory cells induction are among the recently described features of the tolerogenic environment of the intestinal tract.
Peron
Jean Pierre Schatzmann
JP
Laboratório de Imunologia Clínica, Instituto de Ciências Biomédicas IV, Universidade de São Paulo, SP, Brazil. jeanpierre@usp.br
de Oliveira
Ana Paula Ligeiro
AP
Rizzo
Luiz Vicente
LV
D000284:Administration, Oral; D000818:Animals; D000941:Antigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology* / Q000517:prevention & control; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007108:Immune Tolerance; D018928:Immunity, Mucosal; D007422:Intestines / Q000276:immunology* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
D000941:Antigens