Constitutive Akt1 signals attenuate B-cell receptor signaling and proliferation, but enhance B-cell migration and effector function

Ligation of the BCR induces a complex signaling network that involves activation of Akt, a family of serine/threonine protein kinases associated with B-cell development, proliferation, and tumor formation. Here, we analyzed the effect of enhanced Akt1 signals on B-cell maturation and function. Unexp...

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Bibliographic Details
Main Authors: Pierau, Mandy (Author) , Marx, Alexander (Author)
Format: Article (Journal)
Language:English
Published: 18 December 2012
In: European journal of immunology
Year: 2012, Volume: 42, Issue: 12, Pages: 3381-3393
ISSN:1521-4141
DOI:10.1002/eji.201242397
Online Access:Verlag, Volltext: http://dx.doi.org/10.1002/eji.201242397
Verlag, Volltext: https://www.onlinelibrary.wiley.com/doi/abs/10.1002/eji.201242397
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Author Notes:Mandy Pierau, Shin-Young Na, Narasimhulu Simma, Theresa Lowinus, Alexander Marx, Burkhart Schraven and Ursula H. Bommhardt
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Summary:Ligation of the BCR induces a complex signaling network that involves activation of Akt, a family of serine/threonine protein kinases associated with B-cell development, proliferation, and tumor formation. Here, we analyzed the effect of enhanced Akt1 signals on B-cell maturation and function. Unexpectedly, we found that peripheral B cells overexpressing Akt1 were less responsive to BCR stimuli. This correlated with a decrease in Ca2+-mobilization and proliferation, in an impaired activation of Erk1/2 and mammalian target of rapamycin (mTOR) kinases and poor mobilization of NFATc1 and NF-κB/p65 factors. In contrast, activation of STAT5 and migration of B cells toward the chemokine SDF1α was found to be enhanced. Akt1 Tg mice showed an altered maturation of peritoneal and splenic B1 B cells and an enhanced production of IgG1 and IgG3 upon immunization with the T-cell independent Ag TNP-Ficoll. Furthermore, mice homo-zygous for Tg Akt1 showed a severe block in the maturation of B-cell precursors in BM and a strong enrichment of plasma cells in spleen. Altogether, our data reveal that enhanced Akt1 signals modify BCR signaling strength and, thereby, B-cell development and effector function.
Item Description:Gesehen am 05.11.2018
Physical Description:Online Resource
ISSN:1521-4141
DOI:10.1002/eji.201242397