TY - JOUR U1 - Wissenschaftlicher Artikel A1 - Bonifacius, Agnes A1 - Goldmann, Oliver A1 - Floess, Stefan A1 - Holtfreter, Silva A1 - Robert, Philippe A. A1 - Nordengrün, Maria A1 - Kruse, Friederike A1 - Lochner, Matthias A1 - Falk, Christine S. A1 - Schmitz, Ingo A1 - Bröker, Barbara M. A1 - Medina, Eva A1 - Huehn, Jochen T1 - Staphylococcus aureus Alpha-Toxin Limits Type 1 While Fostering Type 3 Immune Responses JF - Frontiers in Immunology N2 - Staphylococcus aureus can cause life-threatening diseases, and hospital- as well as community-associated antibiotic-resistant strains are an emerging global public health problem. Therefore, prophylactic vaccines or immune-based therapies are considered as alternative treatment opportunities. To develop such novel treatment approaches, a better understanding of the bacterial virulence and immune evasion mechanisms and their potential effects on immune-based therapies is essential. One important staphylococcal virulence factor is alpha-toxin, which is able to disrupt the epithelial barrier in order to establish infection. In addition, alpha-toxin has been reported to modulate other cell types including immune cells. Since CD4+ T cell-mediated immunity is required for protection against S. aureus infection, we were interested in the ability of alpha-toxin to directly modulate CD4+ T cells. To address this, murine naïve CD4+ T cells were differentiated in vitro into effector T cell subsets in the presence of alpha-toxin. Interestingly, alpha-toxin induced death of Th1-polarized cells, while cells polarized under Th17 conditions showed a high resistance toward increasing concentrations of this toxin. These effects could neither be explained by differential expression of the cellular alpha-toxin receptor ADAM10 nor by differential activation of caspases, but might result from an increased susceptibility of Th1 cells toward Ca2+-mediated activation-induced cell death. In accordance with the in vitro findings, an alpha-toxin-dependent decrease of Th1 and concomitant increase of Th17 cells was observed in vivo during S. aureus bacteremia. Interestingly, corresponding subsets of innate lymphoid cells and γδ T cells were similarly affected, suggesting a more general effect of alpha-toxin on the modulation of type 1 and type 3 immune responses. In conclusion, we have identified a novel alpha-toxin-dependent immunomodulatory strategy of S. aureus, which can directly act on CD4+ T cells and might be exploited for the development of novel immune-based therapeutic approaches to treat infections with antibiotic-resistant S. aureus strains. KW - - KW - CD4 KW - alpha-toxin KW - innate lymphoid cells KW - γδ T cells Y1 - 2020 UN - https://nbn-resolving.org/urn:nbn:de:gbv:9-opus-38973 SN - 1664-3224 SS - 1664-3224 U6 - https://doi.org/10.3389/fimmu.2020.01579 DO - https://doi.org/10.3389/fimmu.2020.01579 VL - 11 PB - Frontiers Media S.A. ER -