Fig. 3.

The association between HbA1c and TNF-α expression was observed following stimulation in a TCR-specific manner. CD8⁺ T cells were stimulated for 18 h using either, influenza virus peptide pool (A), anti-CD3/anti-CD28 coated beads (B), or PMA/I (C). Results are presented as the frequency of CD8⁺ T cells expressing TNF-α, with background staining subtracted. Data points represent individual donors (left & middle: Beads and PMA/I n = 88, peptide pool n = 73 [Caucasian donors]) (right: age- and sex-matched donors [n = 11/group (A), n = 16/group (B)]. Statistical significance was determined using simple linear regression (left), multiple variable regression analysis, where input variables were age, sex, BMI, HbA1c and ethnicity (middle), or a Mann–Whitney test *P < 0.05 (right). A–C Donors without diabetes are represented by green triangles. Donors with diabetes are represented by blue circles