32 Daverzhofen, Helen Maria Brandenburg, Lars-Ove Tauber, Simone 511001-5 ; 921210 Aachen German VI, 90 Seiten : Illustrationen The infection with S. pneumoniae leads to a meningitis infection. This is a potentially fatal disease. Nearly 50% of the survivors suffer after the acute pneumococcus infection from long term complications like cognitive impairment, neurological deficits and hearing loss. In this study we investigate the effect of the bioactive fragment Ac2-26 in correlation with an acute pneumococcus infection. The fragment Ac2-26 is part of the peptide Annexin A1 and is a ligand to the family of formyl peptide receptors (FRP). The focus of this study was the effect of the treatment with Ac2-26 regarding the outcome and the neurogenesis showed with a mouse model. For the long-term complications, we used the Morris Water Maze test (MWM). With this test we study the learning and orientation ability. The rate of neurogenesis we showed with immunohistochemistry. We used the antibodies for tyrosine receptor kinase B (TrkB), a receptor of brain derived neurotrophic factor (BDNF), bromdesoxyuridine (BrdU) and the neuronal nuclear antigen Neuronal nuclei (NeuN), to show the new mature neurons in the hippocampal region of the brain and Synaptophysin as an integral membrane glycoprotein for the presynaptic vesicle. In addition, we used the real-time polymerase chain reaction (qRT-PCR) to measure the expression of the mRNS of Synaptophysin. The results did not show a better performance in the MWM. Further only a little increase of the neurogenesis after the treatment with Ac2-26 could be shown. In addition, we showed a positive effect of the expression of Synaptophysin through the treatment with Ac2-26. Taken together the results show a positive effect of Ac2-26 to the inflammation reaction and the regeneration after the infection. The injection of Ac2-26 increased the number of new neurons and effects the synaptic functions positive. But it must be mentioned that the neurogenesis was stronger after the infection with S. pneumoniae than under the treatment with Ac2-26. So, it has been shown, that the treatment with Ac2-26 after the infection with S. pneumoniae is able to modulate the inflammatory response. Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2024 ; 2, ; PUB:(DE-HGF)11, ; Dissertation / PhD Thesis Dissertation Rheinisch-Westfälische Technische Hochschule Aachen 2024 2024 RWTH-2025-04986 2024 https://publications.rwth-aachen.de/record/1012417