Morphologic and Functional Effects of Gamma Secretase Inhibition on Splenic Marginal Zone B Cells

Autor: Maria Cristina de Vera Mudry, Franziska Regenass-Lechner, Laurence Ozmen, Bernd Altmann, Matthias Festag, Thomas Singer, Lutz Müller, Helmut Jacobsen, Alexander Flohr
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: International Journal of Alzheimer's Disease, Vol 2012 (2012)
Druh dokumentu: article
ISSN: 2090-8024
2090-0252
DOI: 10.1155/2012/289412
Popis: The γ-secretase complex is a promising target in Alzheimer’s disease because of its role in the amyloidogenic processing of β-amyloid precursor protein. This enzyme also catalyzes the cleavage of Notch receptor, resulting in the nuclear translocation of intracellular Notch where it modulates gene transcription. Notch signaling is essential in cell fate decisions during embryogenesis, neuronal differentiation, hematopoiesis, and development of T and B cells, including splenic marginal zone (MZ) B cells. This B cell compartment participates in the early phases of the immune response to blood-borne bacteria and viruses. Chronic treatment with the oral γ-secretase inhibitor RO4929097 resulted in dose-dependent decreased cellularity (atrophy) of the MZ of rats and mice. Significant decreases in relative MZ B-cell numbers of RO4929097-treated animals were confirmed by flow cytometry. Numbers of MZ B cells reverted to normal after a sufficient RO4929097-free recovery period. Functional characterization of the immune response in relation to RO4929097-related MZ B cell decrease was assessed in mice vaccinated with inactivated vesicular stomatitis virus (VSV). Compared with the immunosuppressant cyclosporin A, RO4929097 caused only mild and reversible delayed early neutralizing IgM and IgG responses to VSV. Thus, the functional consequence of MZ B cell decrease on host defense is comparatively mild.
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