@article{LangenhorstHaackGoebetal.2018,
  author    = {Langenhorst, Daniela and Haack, Stephanie and G{\"o}b, Selina and Uri, Anna and L{\"u}hder, Fred and Vanhove, Bernhard and H{\"u}nig, Thomas and Beyersdorf, Niklas},
  title     = {CD28 costimulation of T helper 1 cells enhances cytokine release in vivo},
  series = {Frontiers in Immunology},
  volume    = {9},
  journal   = {Frontiers in Immunology},
  number    = {1060},
  doi       = {10.3389/fimmu.2018.01060},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176726},
  year      = {2018},
  abstract  = {Compared to naive T cells, differentiated T cells are thought to be less dependent on CD28 costimulation for full activation. To revisit the role of CD28 costimulation in mouse T cell recall responses, we adoptively transferred in vitro generated OT-II T helper (Th) 1 cells into C57BL/6 mice (Thy1.2\(^{+}\)) and then either blocked CD28-ligand interactions with Fab fragments of the anti-CD28 monoclonal antibody (mAb) E18 or deleted CD28 expression using inducible CD28 knock-out OT-II mice as T cell donors. After injection of ovalbumin protein in adjuvant into the recipient mice we observed that systemic interferon (IFN)γ release strongly depended on CD28 costimulation of the Th1 cells, while secondary clonal expansion was not reduced in the absence of CD28 costimulation. For human memory CD4\(^{+}\) T cell responses we also noted that cytokine release was reduced upon inhibition of CD28 costimulation. Together, our data highlight the so far underestimated role of CD28 costimulation for the reactivation of fully differentiated CD4\(^{+}\) T cells.},
  language  = {en}
}
@article{DasariShopovaStroeetal.2018,
  author    = {Dasari, Prasad and Shopova, Iordana A. and Stroe, Maria and Wartenberg, Dirk and Martin-Dahse, Hans and Beyersdorf, Niklas and Hortschansky, Peter and Dietrich, Stefanie and Cseresny{\´e}s, Zolt{\´a}n and Figge, Marc Thilo and Westermann, Martin and Skerka, Christine and Brakhage, Axel A. and Zipfel, Peter F.},
  title     = {Aspf2 From Aspergillus fumigatus Recruits Human Immune Regulators for Immune Evasion and Cell Damage},
  series = {Frontiers in Immunology},
  volume    = {9},
  journal   = {Frontiers in Immunology},
  number    = {1635},
  issn      = {1664-3224},
  doi       = {10.3389/fimmu.2018.01635},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197013},
  year      = {2018},
  abstract  = {The opportunistic fungal pathogen Aspergillus fumigatus can cause life-threatening infections, particularly in immunocompromised patients. Most pathogenic microbes control host innate immune responses at the earliest time, already before infiltrating host immune cells arrive at the site of infection. Here, we identify Aspf2 as the first A. fumigatus Factor H-binding protein. Aspf2 recruits several human plasma regulators, Factor H, factor-H-like protein 1 (FHL-1), FHR1, and plasminogen. Factor H contacts Aspf2 via two regions located in SCRs6-7 and SCR20. FHL-1 binds via SCRs6-7, and FHR1 via SCRs3-5. Factor H and FHL-1 attached to Aspf2-maintained cofactor activity and assisted in C3b inactivation. A Δaspf2 knockout strain was generated which bound Factor H with 28\% and FHL-1 with 42\% lower intensity. In agreement with less immune regulator acquisition, when challenged with complement-active normal human serum, Δaspf2 conidia had substantially more C3b (>57\%) deposited on their surface. Consequently, Δaspf2 conidia were more efficiently phagocytosed (>20\%) and killed (44\%) by human neutrophils as wild-type conidia. Furthermore, Aspf2 recruited human plasminogen and, when activated by tissue-type plasminogen activator, newly generated plasmin cleaved the chromogenic substrate S2251 and degraded fibrinogen. Furthermore, plasmin attached to conidia damaged human lung epithelial cells, induced cell retraction, and caused matrix exposure. Thus, Aspf2 is a central immune evasion protein and plasminogen ligand of A. fumigatus. By blocking host innate immune attack and by disrupting human lung epithelial cell layers, Aspf2 assists in early steps of fungal infection and likely allows tissue penetration.},
  language  = {en}
}
@article{LangenhorstTabaresGuldeetal.2018,
  author    = {Langenhorst, Daniela and Tabares, Paula and Gulde, Tobias and Becklund, Bryan R. and Berr, Susanne and Surh, Charles D. and Beyersdorf, Niklas and H{\"u}nig, Thomas},
  title     = {Self-recognition sensitizes mouse and human regulatory T cells to low-dose CD28 superagonist stimulation},
  series = {Frontiers in Immunology},
  volume    = {8},
  journal   = {Frontiers in Immunology},
  number    = {1985},
  doi       = {10.3389/fimmu.2017.01985},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159387},
  year      = {2018},
  abstract  = {In rodents, low doses of CD28-specific superagonistic monoclonal antibodies (CD28 superagonists, CD28SA) selectively activate regulatory T cells (Treg). This observation has recently been extended to humans, suggesting an option for the treatment of autoimmune and inflammatory diseases. However, a mechanistic explanation for this phenomenon is still lacking. Given that CD28SA amplify T cell receptor (TCR) signals, we tested the hypothesis that the weak tonic TCR signals received by conventional CD4\(^{+}\) T cells (Tconv) in the absence of cognate antigen require more CD28 signaling input for full activation than the stronger TCR signals received by self-reactive Treg. We report that in vitro, the response of mouse Treg and Tconv to CD28SA strongly depends on MHC class II expression by antigen-presenting cells. To separate the effect of tonic TCR signals from self-peptide recognition, we compared the response of wild-type Treg and Tconv to low and high CD28SA doses upon transfer into wild-type or H-2M knockout mice, which lack a self-peptide repertoire. We found that the superior response of Treg to low CD28SA doses was lost in the absence of self-peptide presentation. We also tested if potentially pathogenic autoreactive Tconv would benefit from self-recognition-induced sensitivity to CD28SA stimulation by transferring TCR transgenic OVA-specific Tconv into OVA-expressing mice and found that low-dose CD28SA application inhibited, rather than supported, their expansion, presumably due to the massive concomitant activation of Treg. Finally, we report that also in the in vitro response of human peripheral blood mononuclear cells to CD28SA, HLA II blockade interferes with the expansion of Treg by low-dose CD28SA stimulation. These results provide a rational basis for the further development of low-dose CD28SA therapy for the improvement of Treg activity.},
  language  = {en}
}