Table 1.

T cell receptor (TCR) signals influencing T cell subset differentiation and Teff function in type 1 diabetes (T1D).

T cell subset	TCR Signal  Strength	Co-stimulatory   Molecule	Cytokine Environment	Transcription  Factor	Teff Cytokine	Teff Function
Th1/Tc1	Strong	CD28	IL-2, IL-12	T-bet	IFNγ	Involved in the defense against intracellular pathogens by lysing infected cells and inducing immune effector activation. Critical phenotype for the induction of T1D.
Th17	Moderate	–	IL-1β, IL-6, IL-21, IL-23, TGF-β	RORγt	IL-17A-E, IL-21, IL-22	Provide defense against extracellular pathogens by recruiting neutrophils and macrophages. Highly proinflammatory. Linked to T1D development.
Tfh	Strong	ICOS	IL-6, IL-21	Bcl-6	IL-4, IL-21	Support B cell activation and Ig affinity maturation in germinal centers. Tfh signatures are observed in both mouse and human T1D.
Treg –Thymic/ Adaptive	Strong/ Weak	CD28	IL-2, TGF-β	Foxp3	IL-10, IL-35, TGF-β	Dampen T cell responses and prevent autoimmunity via contact dependent and independent mechanisms. Loss of function associated with T1D progression.
Tr1	Weak	Inhibitory Receptors	IL-27, TGF-β	Variable Foxp3 expression	IL-10
iTreg	Weak	CD28	IL-2, TGF-β	Foxp3	IL-10, IL35, TGF-β