Immunological function in mice lacking the Rac-related GTPase RhoG.
RhoG is a low-molecular-weight GTPase highly expressed in lymphocytes that activates gene transcription and promotes cytoskeletal reorganization in vitro. To study the in vivo function of RhoG, we generated mice homozygous for a targeted disruption of the RhoG gene. Despite the absence of RhoG, the development of B and T lymphocytes was unaffected. However, there was an increase in the level of serum immunoglobulin G1 (IgG1) and IgG2b as well as a mild increase of the humoral immune response to thymus-dependent antigens. In addition, B- and T-cell proliferation in response to antigen receptor cross-linking was slightly increased. Although RhoG deficiency produces a mild phenotype, our experiments suggest that RhoG may contribute to the negative regulation of immune responses. The lack of a strong phenotype could indicate a functional redundancy of RhoG with other Rac proteins in lymphocytes.
Vigorito
Elena
E
Laboratory of Lymphocyte Signaling and Development, Molecular Immunology Programme, The Babraham Institute, Babraham, Cambridge CB2 4AT, UK. elena.vigorito@bbsrc.ac.uk
Bell
Sarah
S
Hebeis
Barbara J
BJ
Reynolds
Helen
H
McAdam
Simon
S
Emson
Piers C
PC
McKenzie
Andrew
A
Turner
Martin
M
D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D017209:Apoptosis / Q000528:radiation effects; D001402:B-Lymphocytes / Q000166:cytology / Q000201:enzymology / Q000276:immunology; D002454:Cell Differentiation; D016207:Cytokines / Q000096:biosynthesis; D020558:GTP Phosphohydrolases / Q000172:deficiency* / Q000235:genetics / Q000276:immunology*; D005720:Gamma Rays; D007074:Immunoglobulin G / Q000097:blood; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009420:Nervous System / Q000033:anatomy & histology / Q000201:enzymology; D010641:Phenotype; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000201:enzymology / Q000276:immunology / Q000528:radiation effects; D020741:rho GTP-Binding Proteins
D000941:Antigens; D016207:Cytokines; D007074:Immunoglobulin G; D011947:Receptors, Antigen, B-Cell; D011948:Receptors, Antigen, T-Cell; C489577:Rhog protein, mouse; D020558:GTP Phosphohydrolases; D020741:rho GTP-Binding Proteins