Fig. 1

Pancreatic draining lymph nodes (PLNs) integrate signal inputs from various sources and undergo substantial immune remodeling to elicit anti-islet response. Pancreas derived autoantigens (soluble or presented by APCs), viral infections, gut microbiota components and circulating lymphocytes get access into PLNs, leading to and/or boosting the imbalance of Treg/Teff. The primed autoreactive T cells then serve as the major PLN outputs that infiltrate the pancreas and are responsible for T1D initiation. APC antigen-presenting cell, Treg regulatory T cell, Teff effector T cell