Figure 4. Cellular immune responses to Burkholderia pseudomallei, B. thailandensis, and BTCV by whole-blood stimulation assay using flow cytometry between melioidosis patients and healthy persons in B. pseudomallei–endemic areas, Thailand. Whole blood samples from 14 patients with acute melioidosis and 8 HH contacts were stimulated with culture-filtrate antigens of B. pseudomallei, B. thailandensis, BTCV, and SEB (positive control). Frequencies of CD4, CD8, and DN T cells; NK cells; and other cells within total IFN-γ–producing cells are shown. Medians were used to generate each vertical slice graph. BTCV, B. thailandensis CPS variant; CPS, capsular polysaccharide; DM, patients with diabetes mellitus; DN, double negative (CD4–CD8–); HH, healthy household contacts of melioidosis case-patients; IFN-γ, interferon-γ; SEB, Staphylococcus enterotoxin B.