The Rac2 guanosine triphosphatase regulates B lymphocyte antigen receptor responses and chemotaxis and is required for establishment of B-1a and marginal zone B lymphocytes.

Abstract

We have defined roles for the hemopoietic-specific Rho guanosine triphosphatase, Rac2, in B lymphocyte development and function through examination of rac2(-/-) mice. Rac2-deficient mice displayed peripheral blood B lymphocytosis and marked reductions in peritoneal cavity B-1a lymphocytes, marginal zone B lymphocytes, and IgM-secreting plasma cells as well as reduced concentrations of serum IgM and IgA. The rac2(-/-) B lymphocytes exhibited reduced calcium flux following coligation of B cell AgR and CD19 and reduced chemotaxis in chemokine gradients. T cell-independent responses to DNP-dextran were of reduced magnitude, but normal kinetics, in rac2(-/-) mice, while T-dependent responses to nitrophenyl-keyhole limpet hemocyanin were subtly abnormal. Rac2 is therefore an essential element in regulating B lymphocyte functions and maintaining B lymphocyte populations in vivo.

• Authors: Ben A Croker, David M Tarlinton, Leonie A Cluse, Alana J Tuxen, Amanda Light, Feng-Chun Yang, David A Williams, Andrew W Roberts
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 168 Issue 7 Pg. 3376-86 (Apr 01 2002) ISSN: 0022-1767 [Print] United States
• PMID: 11907095 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 4-hydroxy-3-nitrophenylacetyl-keyhole limpet hemocyanin
• Actins
• Antigens, CD19
• Antigens, T-Independent
• Chemokines
• Haptens
• Immunoglobulin A
• Immunoglobulin G
• Immunoglobulin M
• Ligands
• Receptors, Antigen, B-Cell
• Hemocyanins
• rac GTP-Binding Proteins
• Calcium

Topics

• Actins (antagonists & inhibitors, metabolism)
• Animals
• Antibody-Producing Cells (pathology)
• Antigens, CD19 (immunology, metabolism)
• Antigens, T-Independent (pharmacology)
• B-Lymphocyte Subsets (immunology, metabolism, pathology)
• Calcium (antagonists & inhibitors, metabolism)
• Cell Differentiation (genetics, immunology)
• Cell Migration Inhibition
• Chemokines (pharmacology)
• Chemotaxis, Leukocyte (immunology)
• Down-Regulation (genetics, immunology)
• Haptens
• Hemocyanins (pharmacology)
• Immunoglobulin A (blood)
• Immunoglobulin G (biosynthesis, blood)
• Immunoglobulin M (blood)
• Ligands
• Lymphocyte Activation (genetics)
• Lymphopenia (genetics, immunology, pathology)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Receptors, Antigen, B-Cell (metabolism, physiology)
• Up-Regulation (genetics, immunology)
• rac GTP-Binding Proteins (deficiency, genetics, physiology)
• RAC2 GTP-Binding Protein