International Immunology Advance Access published online on March 15, 2007
International Immunology, doi:10.1093/intimm/dxm023
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dexamethasone-induced Ras-related protein 1 is a potential regulatory protein in B lymphocytes
Department of Neurology, University of Texas-Houston Medical School, 6431 Fannin Street, Suite 7.044, Houston, TX 77030, USA
Correspondence to: Correspondence to: J. W. Lindsey; E-mail: john.w.lindsey{at}uth.tmc.edu
Dexamethasone-induced Ras-related protein 1 (RASD1) is a protein of the Ras family which probably has a regulatory function. We demonstrate that Rasd1 mRNA is expressed in mouse lymph node cells in response to inhibitory stimuli. Rasd1 mRNA is present at very low levels in freshly isolated cells, but it is rapidly up-regulated in culture and is expressed at elevated levels in cells whose proliferation is blocked by exposure to homogenized brain tissue. The cells expressing Rasd1 mRNA are positive for MHC class II and B220 and negative for Thy-1. Expression of Rasd1 mRNA is very low in B cell-deficient mice. We conclude that Rasd1 mRNA is expressed by B lymphocytes derived from lymph node cells in response to inactivating or inhibitory stimuli. It may play a role in regulating B lymphocyte activity and proliferation.
Keywords: B cells, immune regulation, Ras proteins
Transmitting editor: L. Steinman
Received 6 December 2005, accepted 5 February 2007.