Figure 3.

CD14⁺ DCs but not LCs or dermal CD1a⁺ DCs polarize CD4⁺ T cells into Tfh cells

(A) Experimental protocol. Allogeneic naïve CD4⁺ T cells were cultured for 7 days with sorted purified mDC subsets. Activated CD4⁺ T cells (FSC^highCD11c^-CD4⁺ T cells) were sorted and cultured with naïve B cells that were preactivated with CpG and anti-IgM. After 14 days, Ig levels were measured by ELISA.

(B) Ig production by naïve B cells cocultured with CD4⁺ T cells primed with distinct skin mDC subsets. Naïve B cells were cultured with indicated number of CD4⁺ T cells stimulated by each skin mDC subset.

(C) Ig production assay with in vitro-generated mDC subsets.

(D-E) Production of CXCL13 by CD4⁺ T cells primed by skin mDC subsets (D) or in vitro-generated mDC subsets (E). Primed CD4⁺ T cells (day 7) were restimulated overnight with CD3/CD28 mAbs before CXCL13 was measured.