T Cell-Activated Signaling Pathways and Locally Produced Cytokines as Potential Targets in Celiac Disease

Celiac disease (CD) is an autoimmune disease induced by an autoimmune reaction to indigested gluten, which occurs in genetically predisposed population. The etiology of CD is linked to innate and adaptive immunity, mostly mediated by lymphocytes, especially T cells, infiltrating into the small intestinal wall. The subpopulations of T cells that infiltrate inflamed intestinal tissues comprise various CD4+ T cells and CD8+ T cells. The plethora of T cell subtypes activated in CD leads to simultaneous activation of different signaling cascades including GATA1, NF-kB, JAK or STAT5 the activity of which may be modified by diet or drugs. It was recently showed that food allergens may accelerate CD by altering the interaction between IL-15 and CD4+ T cells in the activation of CD8+ T cells. Increased levels of cytokines like IL-15 are considered to play a role in CD development. Furthermore it was showed that some drugs like tofacitinib or ruxolitinib may influence CD by blocking IL-15 signaling and CD8+ T cell activity. This mini-review will summarize the current knowledge on the role of CD4+ T cell and CD8+ T cell in clinical and experimental CD and will describe how T cell-activated signaling pathways and locally released proteins may be influenced by dietary factors and drugs used in CD treatment.