@phdthesis{Eichler2005,
  author    = {Eichler, Lars},
  title     = {Effects of desialyation on TCR-cross-linking and antigen sensitivity of CD8 positive T lymphocytes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-19391},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2005},
  abstract  = {The featured experiments focus on changes in T cell membrane glycosylation as a possible means of controlling TCR cross-linking. Taking the long known fact that activated T cells show decreased levels of surface sialic acid as a starting point, differences in ligand binding and cellular reaction upon in vitro stimulation were investigated in na{\"i}ve, activated and enzymatically desialyated CD8+, 2C TCR transgenic mouse lymphocytes. To detect differences in ligand binding lymphocytes were incubated with various concentrations of fluorescently labeled, soluble MHC/Ig fusion proteins until equilibrium was reached. Without previous washing, cells were analyzed by flow cytometry, determined MCF values were normalized to the plateau and fit to a mathematical model of equilibrium binding of divalent ligands to monomorphic receptors (Perelson 1984). Parameters derived from the model fit of binding data show, that neuraminidase treatment of T cells was sufficient to mimic a partially activated phenotype, showing enhanced TCR cross-linking. Enhanced TCR cross-linking was found to be dependent on the presence of CD8, as neuraminidase treatment of DN cells lead to decreased cross-linking. To elucidate the physiological relevance of desialyation induced increases in TCR cross-linking early tyrosine phosphorylation events and proliferative response upon in vitro stimulation of T cells were investigated. Both were found enhanced in neuraminidase treated cells, as compared to native cells. In conclusion the featured experiments suggest a role of surface sialic acid in controlling TCR cross-linking on na{\"i}ve and activated T cells.},
  language  = {en}
}
@article{ProbstmeierBilzSchneiderSchaulies1994,
  author    = {Probstmeier, R. and Bilz, A. and Schneider-Schaulies, J{\"u}rger},
  title     = {Expression of the neural cell adhesion molecule and polysialic acid during early mouse embryogenesis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-54921},
  year      = {1994},
  abstract  = {The expression of the neural cell adhesion molccule (N-CAM) and a 2-8 linked polysialic acid (PSA), whieh is believed to be predominantly expressed on N-CAM, was investigated during early embryonie development ofthe mouse (embryonic days 7.5 to 10.0). By immunoeytoehemistry, in tissue sections, N-CAM and PSA were not detectable at embryonie day 7.5 but were expressed in the prominent body regions such as somites, unsegmented mesoderm, developing heart, and neuroectoderm at embryonie day 8.0 N-CAM and PSA immunoreaetivities were always predominantly associated with tbe plasma membrane. No tissue could be detected which was positive for PSA but negative for N-CAM. In Western blot analysis of whole embryos, by contrast, only the lightly sialylated and PSA-negative 180 and 140 kD isoforms of N-CAM werc present at embryonie day 8.0 and strong expression of PSA-bearing, heavily sialylated N-CAM was not detectable before embryonie day 10.0. In Western blot analysis of N-CAM immunoaffinity purifled from whole embryos and digested with neuraminidase as weil as in Northern blot analysis, the 120 kD isoform of N-CAM or its eorresponding mRN A were not expressed in detectable amounts during the time period investigated.},
  subject      = {Immunologie},
  language  = {en}
}
@article{RiveroAlhamaRibaKuetal.2021,
  author    = {Rivero, Olga and Alhama-Riba, Judit and Ku, Hsing-Ping and Fischer, Matthias and Ortega, Gabriela and {\´A}lmos, P{\´e}ter and Diouf, David and van den Hove, Daniel and Lesch, Klaus-Peter},
  title     = {Haploinsufficiency of the Attention-Deficit/Hyperactivity Disorder Risk Gene St3gal3 in Mice Causes Alterations in Cognition and Expression of Genes Involved in Myelination and Sialylation},
  series = {Frontiers in Genetics},
  volume    = {12},
  journal   = {Frontiers in Genetics},
  issn      = {1664-8021},
  doi       = {10.3389/fgene.2021.688488},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246855},
  year      = {2021},
  abstract  = {Genome wide association meta-analysis identified ST3GAL3, a gene encoding the beta-galactosidase-alpha-2,3-sialyltransferase-III, as a risk gene for attention-deficit/hyperactivity disorder (ADHD). Although loss-of-function mutations in ST3GAL3 are implicated in non-syndromic autosomal recessive intellectual disability (NSARID) and West syndrome, the impact of ST3GAL3 haploinsufficiency on brain function and the pathophysiology of neurodevelopmental disorders (NDDs), such as ADHD, is unknown. Since St3gal3 null mutant mice display severe developmental delay and neurological deficits, we investigated the effects of partial inactivation of St3gal3 in heterozygous (HET) knockout (St3gal3±) mice on behavior as well as expression of markers linked to myelination processes and sialylation pathways. Our results reveal that male St3gal3 HET mice display cognitive deficits, while female HET animals show increased activity, as well as increased cognitive control, compared to their wildtype littermates. In addition, we observed subtle alterations in the expression of several markers implicated in oligodendrogenesis, myelin formation, and protein sialylation as well as cell adhesion/synaptic target glycoproteins of ST3GAL3 in a brain region- and/or sex-specific manner. Taken together, our findings indicate that haploinsufficiency of ST3GAL3 results in a sex-dependent alteration of cognition, behavior and markers of brain plasticity.},
  language  = {en}
}