BAZF is required for activation of naive CD4 T cells by TCR triggering.
BAZF, a member of the Bcl6 gene family, acts as a sequence-specific transcriptional repressor in association with Bcl6. However, the tissue expression pattern of BAZF differs from that of Bcl6, suggesting a Bcl6-independent function of BAZF. In order to examine the physiological function of BAZF, we generated BAZF-deficient mice and transgenic mice with BAZF-cDNA under the control of the lck proximal promoter (lck-BAZF). These mice were viable and no gross anatomical abnormalities were observed after birth. Since Bcl6 is a key molecule for the generation of memory T cells, we examined the function of T cells of these mice. We show here that cell proliferation of naive CD4 T cells, but not memory ones, of BAZF-deficient mice to anti-CD3 antibody stimulation was impaired. Conversely, cell proliferation of naive CD4 T cells, but not memory ones, of lck-BAZF mice was augmented. Since cell proliferation of naive CD4 T cells of lck-Bcl6 mice to anti-CD3 antibody stimulation was severely impaired, BAZF may attenuate the regulatory effect of Bcl6 on antigenic activation of naive CD4 T cells by Bcl6/BAZF heterodimer formation. These results suggest that BAZF is necessary for activation of naive T cells to antigenic stimulation.
Takamori
Mikio
M
Department of Developmental Genetics (H2), Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
Hatano
Masahiko
M
Arima
Masafumi
M
Sakamoto
Akemi
A
Fujimura
Lisa
L
Hartatik
Tety
T
Kuriyama
Takayuki
T
Tokuhisa
Takeshi
T
D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D005434:Flow Cytometry; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D012097:Repressor Proteins / Q000235:genetics / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
C113027:Bcl6b protein, mouse; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell; D012097:Repressor Proteins