Anti-Aspergillus CD4⁺ T cells respond on stimulation with antigen extracts of A fumigatus, A flavus, A niger, and P chrysogenum, but not on stimulation with A alternata and C albicans. IFN-γ staining of anti-Aspergillus CD4⁺ lymphocytes from 1 donor on stimulation with antigen extracts of A fumigatus (A), A flavus (B), A niger (C), A alternata (D), P chrysogenum (E), and C albicans (F).