Reciprocal regulation of IL-6 and IL-12 production in splenocytes from WT mice. (Ai,Bi) Flow cytometric detection of intracellular IL-6 in adherent cell-depleted splenocytes cultured with PHA, PMA, LPS, CpG, and calcium ionophore in the absence (A) or presence (B) of murine rIL-12. Open profile is anti–IL-6 mAb staining; dark profile is isotypic control staining. (Aii-iv, Bii-iv) Dot-plots showing the results of double staining with CD19, CD11c, or CD4 and anti–IL-6 mAbs. Gate was set on CD19⁺, CD11c⁺, or CD4⁺ splenocytes, respectively. (C) Flow cytometric detection of intracellular IL-6 in gated CD11b⁺ macrophages cultured with LPS, CpG, PMA, and calcium ionophore in the presence (+IL-6) or absence (no IL-6) of murine rIL-6. (Ci) Dark profile is isotypic control staining, dashed profile is anti–IL-6 mAb staining in macrophages treated with IL-6, and open profile is anti–IL-6 mAb staining in macrophages cultured without IL-6. (Cii-iii) Dot-plots showing the results of double staining with CD11b and anti–IL-6 mAbs. Gate was set on CD11b⁺ cells.