| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
,
Departments of
*
Medicine and
Microbiology, University of Alabama, Birmingham, AL 35294; and
Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294
CD19 plays a critical role in regulating B cell responses to Ag. We have studied the mechanism by which coligation of CD19 and the B cell Ag receptor, membrane Ig (mIg), augments signal transduction, including synergistic enhancement of release of intracellular Ca2+ and extracellular signal-regulated protein kinase 2 (ERK2) activation, in Daudi human B lymphoblastoid cells. The pathway leading to ERK2 activation was further dissected to determine how signals derived from CD19 and mIgM interact. The best-defined pathway, known to be activated by mIgM, consists of the sequential activation of the mitogen-activated protein kinase (MAPK) cascade that includes Ras, Raf, MAPK kinase 1 (MEK1), and ERK2. Ligation of CD19 alone had little effect on these. CD19-mIgM coligation did not increase activation of Ras or Raf beyond that induced by ligation of mIgM alone. In contrast, coligation resulted in synergistic activation of MEK1. Furthermore, synergistic activation of ERK2 occurred in the absence of changes in intracellular Ca2+, and was not blocked by inhibition of protein kinase C activity and represents a separate pathway by which CD19 regulates B cell function. Thus, the CD19-dependent signal after CD19-mIgM coligation converges with that generated by mIgM at MEK1. The intermediate kinases in the MAPK cascade leading to ERK2 integrate signals from lymphocyte coreceptors.
This article has been cited by other articles:
|
|
 |
|
  Y. Iwata, A. Yoshizaki, K. Komura, K. Shimizu, F. Ogawa, T. Hara, E. Muroi, S. Bae, M. Takenaka, T. Yukami, et al. CD19, a Response Regulator of B Lymphocytes, Regulates Wound Healing through Hyaluronan-Induced TLR4 Signaling Am. J. Pathol., August 1, 2009; 175(2): 649 - 660. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Mizuno and T. L. Rothstein B Cell Receptor (BCR) Cross-Talk: CD40 Engagement Enhances BCR-Induced ERK Activation J. Immunol., March 15, 2005; 174(6): 3369 - 3376. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C.-M. Leu, R. S. Davis, L. A. Gartland, W. D. Fine, and M. D. Cooper FcRH1: an activation coreceptor on human B cells Blood, February 1, 2005; 105(3): 1121 - 1126. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Keren, E. Diamant, O. Ostrovsky, E. Bengal, and D. Melamed Modification of Ligand-independent B Cell Receptor Tonic Signals Activates Receptor Editing in Immature B Lymphocytes J. Biol. Chem., April 2, 2004; 279(14): 13418 - 13424. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Mathas, A. Rickers, K. Bommert, B. Dörken, and M. Y. Mapara Anti-CD20- and B-cell Receptor-mediated Apoptosis: Evidence for Shared Intracellular Signaling Pathways Cancer Res., December 1, 2000; 60(24): 7170 - 7176. [Abstract] [Full Text]
|
|
|
|
|
|
S. R. Brooks, X. Li, E. J. Volanakis, and R. H. Carter Systematic Analysis of the Role of CD19 Cytoplasmic Tyrosines in Enhancement of Activation in Daudi Human B Cells: Clustering of Phospholipase C and Vav and of Grb2 and Sos with Different CD19 Tyrosines J. Immunol., March 15, 2000; 164(6): 3123 - 3131. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Fujimoto, J. C. Poe, P. J. Jansen, S. Sato, and T. F. Tedder CD19 Amplifies B Lymphocyte Signal Transduction by Regulating Src-Family Protein Tyrosine Kinase Activation J. Immunol., June 15, 1999; 162(12): 7088 - 7094. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Fujimoto, J. C. Poe, M. Hasegawa, and T. F. Tedder CD19 Amplification of B Lymphocyte Ca2+ Responses. A ROLE FOR Lyn SEQUESTRATION IN EXTINGUISHING NEGATIVE REGULATION J. Biol. Chem., November 21, 2001; 276(48): 44820 - 44827. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
