Fig 3. Ex vivo interferon-gamma ELISPOT responses by survival.

Peripheral blood mononuclear cells (PBMC) from patients with acute melioidosis at study entry (Week 0) were stimulated with heat-inactivated B. pseudomallei (Bp), or a control antigen panel for 18 hours and IFN-γ secreting cells counted and expressed as spot forming cells per million (SFC/10⁶) PBMC. Responses were compared for survivors and those who died (Fig 3A). 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 and APCH7-anti-CD8, Fig 3B). Horizontal lines represent medians, ***P<0.001, **P<0.01, *P<0.05, ns = not significant, by logistic regression adjusted for age, diabetes status, renal disease and neutrophil count for responses in Fig 3A and by Mann-Whitney test for Fig 3B.