@article{RudelPrustySiegletal.2013,
  author    = {Rudel, Thomas and Prusty, Bhupesh K. and Siegl, Christine and Hauck, Petra and Hain, Johannes and Korhonen, Suvi J. and Hiltunen-Back, Eija and Poulakkainen, Mirja},
  title     = {Chlamydia trachomatis Infection Induces Replication of Latent HHV-6},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0061400},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96731},
  year      = {2013},
  abstract  = {Human herpesvirus-6 (HHV-6) exists in latent form either as a nuclear episome or integrated into human chromosomes in more than 90\% of healthy individuals without causing clinical symptoms. Immunosuppression and stress conditions can reactivate HHV-6 replication, associated with clinical complications and even death. We have previously shown that co-infection of Chlamydia trachomatis and HHV-6 promotes chlamydial persistence and increases viral uptake in an in vitro cell culture model. Here we investigated C. trachomatis-induced HHV-6 activation in cell lines and fresh blood samples from patients having Chromosomally integrated HHV-6 (CiHHV-6). We observed activation of latent HHV-6 DNA replication in CiHHV-6 cell lines and fresh blood cells without formation of viral particles. Interestingly, we detected HHV-6 DNA in blood as well as cervical swabs from C. trachomatis-infected women. Low virus titers correlated with high C. trachomatis load and vice versa, demonstrating a potentially significant interaction of these pathogens in blood cells and in the cervix of infected patients. Our data suggest a thus far underestimated interference of HHV-6 and C. trachomatis with a likely impact on the disease outcome as consequence of co-infection.},
  language  = {en}
}
@article{SieglPrustyKarunakaranetal.2014,
  author    = {Siegl, Christine and Prusty, Bhupesh K. and Karunakaran, Karthika and Wischhusen, J{\"o}rg and Rudel, Thomas},
  title     = {Tumor Suppressor p53 Alters Host Cell Metabolism to Limit Chlamydia trachomatis Infection},
  series = {Cell Reports},
  volume    = {9},
  journal   = {Cell Reports},
  number    = {3},
  issn      = {2211-1247},
  doi       = {10.1016/j.celrep.2014.10.004},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-118200},
  pages     = {918-929},
  year      = {2014},
  abstract  = {Obligate intracellular bacteria depend entirely on nutrients from the host cell for their reproduction. Here, we show that obligate intracellular Chlamydia downregulate the central tumor suppressor p53 in human cells. This reduction of p53 levels is mediated by the PI3K-Akt signaling pathway, activation of HDM2, and subsequent proteasomal degradation of p53. The stabilization of p53 in human cells severely impaired chlamydial development and caused the loss of infectious particle formation. DNA-damage-induced p53 interfered with chlamydial development through downregulation of the pentose phosphate pathway (PPP). Increased expression of the PPP key enzyme glucose-6-phosphate dehydrogenase rescued the inhibition of chlamydial growth induced by DNA damage or stabilized p53. Thus, downregulation of p53 is a key event in the chlamydial life cycle that reprograms the host cell to create a metabolic environment supportive of chlamydial growth.},
  language  = {en}
}
@article{SubbarayalKarunakaranWinkleretal.2015,
  author    = {Subbarayal, Prema and Karunakaran, Karthika and Winkler, Ann-Cathrin and Rother, Marion and Gonzalez, Erik and Meyer, Thomas F. and Rudel, Thomas},
  title     = {EphrinA2 Receptor (EphA2) Is an Invasion and Intracellular Signaling Receptor for Chlamydia trachomatis},
  series = {PLoS Pathogens},
  volume    = {11},
  journal   = {PLoS Pathogens},
  number    = {4},
  doi       = {10.1371/journal.ppat.1004846},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125566},
  pages     = {e1004846},
  year      = {2015},
  abstract  = {The obligate intracellular bacterium Chlamydia trachomatis invades into host cells to replicate inside a membrane-bound vacuole called inclusion. Multiple different host proteins are recruited to the inclusion and are functionally modulated to support chlamydial development. Invaded and replicating Chlamydia induces a long-lasting activation of the PI3 kinase signaling pathway that is required for efficient replication. We identified the cell surface tyrosine kinase EphrinA2 receptor (EphA2) as a chlamydial adherence and invasion receptor that induces PI3 kinase (PI3K) activation, promoting chlamydial replication. Interfering with binding of C. trachomatis serovar L2 (Ctr) to EphA2, downregulation of EphA2 expression or inhibition of EphA2 activity significantly reduced Ctr infection. Ctr interacts with and activates EphA2 on the cell surface resulting in Ctr and receptor internalization. During chlamydial replication, EphA2 remains active accumulating around the inclusion and interacts with the p85 regulatory subunit of PI3K to support the activation of the PI3K/Akt signaling pathway that is required for normal chlamydial development. Overexpression of full length EphA2, but not the mutant form lacking the intracellular cytoplasmic domain, enhanced PI3K activation and Ctr infection. Despite the depletion of EphA2 from the cell surface, Ctr infection induces upregulation of EphA2 through the activation of the ERK pathway, which keeps the infected cell in an apoptosis-resistant state. The significance of EphA2 as an entry and intracellular signaling receptor was also observed with the urogenital C. trachomatis-serovar D. Our findings provide the first evidence for a host cell surface receptor that is exploited for invasion as well as for receptor-mediated intracellular signaling to facilitate chlamydial replication. In addition, the engagement of a cell surface receptor at the inclusion membrane is a new mechanism by which Chlamydia subverts the host cell and induces apoptosis resistance.},
  language  = {en}
}