Figure 5: Circulating anti-IL-2-specific B and T lymphocytes in T1D patients.

(a) (Left) Relative frequency and (right) absolute numbers of antigen-specific IgG memory B cells across four T1D patients. Error bars represent s.d., P-values calculated using an unpaired t-test. (b) IL-2-specific heavy and light chain V gene segment usage, CDR3 amino acid sequences, and rhIL-2 solution equilibrium titration (SET) affinity for recombinant IgG obtained from a single T1D patient, (c) IFN-γ production by peripheral blood mononuclear cells (PBMCs) from healthy donors (HD) (n=14, closed circles) or T1D patients (n=13, open circles) quantified by ELISPOT after stimulation with rhIL-2 (Proleukin, Pro) or Pro peptides (10 μM per each), intracellular IA-2, adenovirus lysate (AdV), or PHA. The number of IFN-γ spot-forming cells (SFC)/10⁶ PBMCs is depicted, the dashed line indicates the positive cut-off threshold, and the grey shaded area shows undetectable responses (that is, identical to spontaneous background responses; see material and methods for threshold determination). The percent of positive T1D (top number) and HD (bottom number) is indicated for each condition, with antigens yielding responses significantly different between HD and T1D patients in bold (P<0.03 using the Fisher exact test).