Aspergillus fumigatus Crf1 protein mediates cross-protection to C albicans. Mice were vaccinated intranasally with resting A fumigatus conidia 14 days before infection or with purified Crf1 protein and murine CpG oligodeoxynucleotide 1862 14, 7, and 3 days before intragastric infection with C albicans. Note the reduced fungal growth, inflammatory cell recruitment (A, insets), and acanthosis in mice vaccinated with A fumigatus conidia or Crf1 protein as opposed to control mice shown in Figure 5C. Panel B shows the increase in protective T_H1 and regulatory T-cell transcription factors and cytokine levels in vaccinated mice with A fumigatus conidia or the Crf1 protein, whereas the levels of T_H2 transcription factors and cytokines remain unchanged. Shown are fungal growth (CFUs/organ, mean ± SE), stomach histology, differential cell counts in cytospin preparations from stomachs, and transcription factor and cytokine mRNA expression in CD4⁺ T cells from mesenteric lymph nodes a week after infection with C albicans. Shown are the results of one representative experiment of 3 independent experiments (for in vivo data) or pooled from 3 experiments (for in vitro assays). Bars represent SE. Photographs were taken using a high-resolution Olympus BX51 microscope, using Olympus Cell P 3.3 software. P, vaccinated vs unvaccinated animals. (C) Proliferation of purified CD4⁺ spleen cells from untreated mice or animals vaccinated with A fumigatus or C albicans in response to control DCs, anti-CD3ϵ antibody, heat-inactivated A fumigatus or C albicans, or A fumigatus Crf1 p41 and p22 peptides. The data are expressed as mean counts per minute ± SE of triplicate cultures. P, stimulated vs control DCs.