Fig. 5.

Antigen-presenting capacity of Mϕ-1 versus Mϕ-2. To determine the antigen-presenting capacity of Mϕ-1 and Mϕ-2, cells were pretreated (black bars) or not (gray bars) for 24 h with a (myco)bacterial stimulus before incubation with antigen and antigen-specific Th1 cells. Mo.DCs were included for control purposes. (A) In contrast to Mϕ-1 and mo.DCs, Mϕ-2 relatively poorly supported proliferation of the M. leprae-specific Th1 clone R2F10 toward protein or peptide antigen, which was reduced further after activation of Mϕ-2 by M. tuberculosis sonicate (myc). (B) Similar results were obtained when antigen-presenting cells were pretreated with LPS. (C) The antigen-presenting capacity of Mϕ-2 toward the influenza hemagglutinin-specific T cell clone HA1.7 was reduced also by mycobacterial stimulation in a dose-dependent fashion. (D) Protein or peptide antigen-specific IFN-γ secretion of R2F10 Th1 cells was supported by Mϕ-1, albeit less efficiently than by mo.DCs. IFN-γ secretion by R2F10 cells responding to Mϕ-2 was substantially lower and reduced further by mycobacterial activation of Mϕ-2. IFN-γ production is depicted as secreted protein in the pooled supernatant of triplicate cultures. Proliferation is depicted as the average incorporation of [³H]thymidine in triplicate cultures (cpm; + standard deviation). Experiments were repeated at least twice using independent donors to generate Mϕ and DCs.