Human T-cell responses to Aspergillus fumigatus: In healthy individuals and patients with Aspergillus-related disease

The T-cell mediated immune response to Aspergillus fumigatus was studied in healthy individuals and in several patient groups. In peripheral blood of healthy individuals low frequencies of Aspergillus-specific CD4+ T-cells with a Thelper 1 profile were present. In patients with invasive aspergillosis after allogeneic stem cell transplantation Aspergillus-specific T-cells with a Thelper 1 phenotype increased in peripheral blood at the moment of improvement of aspergillus lesions. On the other hand, in patients with allergic bronchopulmonary aspergillosis Aspergillus-specific T-cells with a Thelper 2 phenotype were present, these were directed both to the classical described Aspergillus allergens Aspf1, Aspf2, Aspf3 and Aspf4, as well as to other Aspergillus antigens Crf1 and Catalase1. In COPD patients lung-derived Aspergillus-specific T-cells were characterized and showed a Thelper17 phenotype, in contrast to the Thelper1 phenotype that was present in peripheral blood. Finally, the interplay between different immune cells was studied in an in vitro model. CD4+ T-cells improved the phagocytosis capacity of neutrophil granulocytes, but not of monocytes.