H4-IC31® boost BCG-primed immune responses and memory.

<p>Mice that received BCG were immunized at week 0 and the H4-IC31® and BCG/H4-IC31® groups were subsequently immunized with H4 in IC31® at 19 and 22 weeks after initiating the experiment (A). The amount of IFNγ produced by splenocytes and PBMCs (pooled from five mice per group) in response to Ag85B and TB10.4 stimulation was evaluated by ELISA. The responses were evaluated two weeks after the first H4-IC31® immunization (B), and memory responses were evaluated six weeks after the second immunization in PBMCs pooled from n = 15 mice per group (C). Bars represent means and standard deviations of triplicate 72 hour culture-supernatants. Stimulation with media alone as well as ESAT-6 as a negative control antigen resulted in IFNγ secretion below 300 pg/ml (data not shown). This experiment was repeated once with similar results.