Fig 2. T-cell Responses to Heat killed B. pseudomallei (Fig 2A) to control antigens (Fig 2B) and by cell phenotype (Fig 2C).

Peripheral blood mononuclear cells (PBMC) from patients with acute melioidosis (Melioid Cohort Wk0) and 12 (Wk12) and 52 (Wk 52) weeks later were tested alongside PBMC from diabetic outpatients (Diabetes) and healthy endemic seronegative control subjects (Healthy). Cells were stimulated with heat-inactivated B. pseudomallei (Fig 2A), a control antigen T-cell epitope pool or media only (Fig 2B) for 18 hours and IFN-γ secreting cells counted and expressed as spot forming cells per million PBMC (SFC/10⁶ PBMC). To characterise the cell phenotype producing IFN-γ, PBMC were incubated with whole B. pseudomallei for 18 hours and stained for intracellular IFN-γ versus immune cell surface markers (PCP-anti-CD3, FITC-anti-CD4, APCH7-anti-CD8, PE-anti-CD56 and V450-CD14, Fig 2C). Horizontal lines represent medians, ***P<0.001, **P<0.01, *P<0.05, ns = not significant, testing by Kruskal-Wallis with Dunn’s correction for multiple testing.