Fig. 6.

IL-12, IL-1β and TNF-α are produced by type 1 myeloid DCs. a Flow cytometry was used to measure the expression of CD4, CD3, CD11c, CD123 and CD14 on purified CD4⁺ cells. From left to right: Debris was excluded according to size and granularity using gate (G) 1. Within the G1 population, CD3 and CD4 expression identified CD4⁺ αβ T-cells (CD3⁺CD4^high) and non-T-cells (CD3⁻CD4^low; G2). Within the G1+G2 non-T-cell population, CD11c and CD123 expression identified myeloid DC (mDC) and plasmacytoid DC (pDC) populations, both of which did not express CD14. Representative flow cytometric dot plots from one of two donors are shown. b CD4⁺ cells were cultured overnight with LPS/R848, heat-killed BCG, M. vaccae (Mv) and M. obuense (Mo). Untreated (un) cells were used as a negative control. IL-12, IL-1β and TNF-α expression was measured on gated T-cells (CD3⁺), mDCs (CD3⁻CD11c⁺) and pDCs (CD3⁻CD11c⁻CD123^high). Mean values for n = 3 are shown (except TNF-α, where n = 2). Error bars represent SD. * and ** indicate P values of <0.05 and <0.001, respectively, for statistical comparisons between treated and untreated conditions. c CD1c expression was analysed on gated mDCs as shown. d Top panels: CD1c⁺ cells were depleted from the CD4⁺ cell population. Representative data from one of three donors are shown. Bottom panels: γδ T-cells were co-cultured overnight with CD4⁺ cells or CD1c-depleted CD4⁺ cells in the absence or presence of BCG. Percentage of Vδ2⁺ cells expressing IFN-γ was measured