Development of Type I diabetes results from an autoimmune attack of islet cell antigen specific T helper I (Th I) cells and scavenger macrophages directed towards β-cells f islets of Langerhans. Such an aggressive Th I response can be downregulated by other subsets of so-called regulatory or "suppressor" T-cells, amongst which are the Th 2 cells. In the BB rat model of Type I diabetes such regulatory T-cells reside in the RT6+T-cell pool, since transfer of such cells from diabetes-resistant rats (BB-DP rats) prevents the development of the disease. Dentric cells (CD), the antigen-presenting cells (APC) par excellence play a pivotal role in the initial triggering of islet-specific T-cells in the Type I diabetic process: [...],
Experimental and Clinical Endocrinology and Diabetes
Erasmus MC: University Medical Center Rotterdam

Delemarre, F., & Drexhage, H. (1997). Dendritic cells of the BB-DP rat are deficient accesssory cells, particularly for DC8+ and RT6+ T-cells (“suppressor cells”). Experimental and Clinical Endocrinology and Diabetes, 105, 5–6. doi:10.1055/s-0029-1211812