@article{BoeckelKarstenGoepeletal.2023,
  author    = {Boeckel, Hannah and Karsten, Christian M. and G{\"o}pel, Wolfgang and Herting, Egbert and Rupp, Jan and H{\"a}rtel, Christoph and Hartz, Annika},
  title     = {Increased expression of anaphylatoxin C5a-receptor-1 in neutrophils and natural killer cells of preterm infants},
  series = {International Journal of Molecular Sciences},
  volume    = {24},
  journal   = {International Journal of Molecular Sciences},
  number    = {12},
  issn      = {1422-0067},
  doi       = {10.3390/ijms241210321},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-321196},
  year      = {2023},
  abstract  = {Preterm infants are susceptible to infection and their defense against pathogens relies largely on innate immunity. The role of the complement system for the immunological vulnerability of preterm infants is less understood. Anaphylatoxin C5a and its receptors C5aR1 and -2 are known to be involved in sepsis pathogenesis, with C5aR1 mainly exerting pro-inflammatory effects. Our explorative study aimed to determine age-dependent changes in the expression of C5aR1 and C5aR2 in neonatal immune cell subsets. Via flow cytometry, we analyzed the expression pattern of C5a receptors on immune cells isolated from peripheral blood of preterm infants (n = 32) compared to those of their mothers (n = 25). Term infants and healthy adults served as controls. Preterm infants had a higher intracellular expression of C5aR1 on neutrophils than control individuals. We also found a higher expression of C5aR1 on NK cells, particularly on the cytotoxic CD56\(^{dim}\) subset and the CD56\(^-\) subset. Immune phenotyping of other leukocyte subpopulations revealed no gestational-age-related differences for the expression of and C5aR2. Elevated expression of C5aR1 on neutrophils and NK cells in preterm infants may contribute to the phenomenon of "immunoparalysis" caused by complement activation or to sustained hyper-inflammatory states. Further functional analyses are needed to elucidate the underlying mechanisms.},
  language  = {en}
}
@phdthesis{Krenz2023,
  author    = {Krenz, Bastian},
  title     = {The immune-evasive potential of MYC in pancreatic ductal adenocarcinoma},
  doi       = {10.25972/OPUS-32590},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325903},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Pancreatic ductal adenocarcinoma (PDAC) is predominantly driven by mutations in KRAS and TP53. However, PDAC tumors display deregulated levels of MYC and are a paradigm example for MYC-driven and -addicted tumors. For many years MYC was described as a transcription factor that regulates a pleiotropic number of genes to drive proliferation. Recent work sheds a different light on MYC biology. First, changes in gene expression that come along with the activation of MYC are mild and MYC seems to act more as a factor that reduces stress and increases resilience towards challenges during transcription. Second, MYC is a strong driver of immune evasion in different entities. In this study we depleted MYC in murine PDAC cells and revealed the immune dependent regression of tumors in an orthotope transplant model, as well as the activation of the innate immune system using global expression analysis, immunoblotting and fCLIP. These experiments revealed that endogenous double-stranded RNA is binding as a viral mimicry to Toll-like receptor 3, causing activation of TBK1 and downstream activation of a proimmunogenic transcription program. The regression of tumors upon depletion of MYC is dependent on this pathway since the knockout of TBK1 prevents regression of tumors after depletion of MYC. We can summarize this study in three main findings: First, the dominant and most important function of MYC in tumors is not to drive proliferation but to promote immune evasion and prevent immune-dependent regression of tumors. Second, cells monitor defects or delay in splicing and RNA processing and activate the immune system to clear cells that face problems with co-transcriptional processing. Third, MYC suppresses the activation of the cell-intrinsic innate immune system and shields highly proliferating cells from the recognition by the immune system. To translate this into a therapeutically approach, we replaced the shRNA mediated depletion of MYC by treatment with cardiac glycosides. Upon treatment with cardiac glycosides tumor cells reduce uptake of nutrients, causing a downregulation of MYC translation, inhibition of proliferation, glycolysis and lactate secretion. Lactate is a major reason for immune evasion in solid tumors since it dampens, amongst others, cytotoxic T cells and promotes regulatory T cells. Treatment of mice with cardiac glycosides causes a complete and immune-dependent remission of PDAC tumors in vivo, pointing out that cardiac glycosides have strong proimmunogenic, anti-cancer effects. More detailed analyses will be needed to dissect the full mechanism how cardiac glycosides act on MYC translation and immune evasion in PDAC tumors.},
  subject      = {Bauchspeicheldr{\"u}senkrebs},
  language  = {en}
}