First Author | Lee K | Year | 2013 |
Journal | Blood | Volume | 122 |
Issue | 14 | Pages | 2369-79 |
PubMed ID | 23958952 | Mgi Jnum | J:203260 |
Mgi Id | MGI:5525925 | Doi | 10.1182/blood-2013-01-477505 |
Citation | Lee K, et al. (2013) Requirement for Rictor in homeostasis and function of mature B lymphoid cells. Blood 122(14):2369-79 |
abstractText | The mammalian target of rapamycin (mTOR), an essential serine/threonine kinase, functions in biochemically distinct multiprotein complexes, but little is known about roles of the complexes in B cells. The acutely rapamycin-sensitive mTOR complex 1 (mTORC1) is defined by a core subunit Raptor, whereas mTORC2 lacks Raptor and, instead, has Rictor and SIN1 as distinct essential components. We now show that homeostasis and function of B cells require Rictor. Conditional deletion of Rictor before lymphoid specification impaired generation of mature follicular, marginal zone, and B1a B lymphocytes. Induced inactivation in adult mice caused cell-autonomous defects in B lymphoid homeostasis and antibody responses in vivo, along with affecting plasma cells in bone marrow. Survival of B lymphocytes depended on Rictor, which was vital for normal induction of prosurvival genes, suppression of proapoptotic genes, nuclear factor kappaB induction after B-cell receptor stimulation, and B-cell activating factor-induced nuclear factor kappaB2/p52 generation. Collectively, the findings provide evidence that mTOR signaling affects survival and proliferation of mature B lymphocytes, and establish Rictor as an important signal relay in B-cell homeostasis, fate, and functions. |