Limits...
A negative feedback loop mediated by the Bcl6-cullin 3 complex limits Tfh cell differentiation.

Mathew R, Mao AP, Chiang AH, Bertozzi-Villa C, Bunker JJ, Scanlon ST, McDonald BD, Constantinides MG, Hollister K, Singer JD, Dent AL, Dinner AR, Bendelac A - J. Exp. Med. (2014)

Bottom Line: Intriguingly, we found that Bcl6 was also highly and transiently expressed during the CD4(+)CD8(+) (double positive [DP]) stage of T cell development, in association with the E3 ligase cullin 3 (Cul3), a novel binding partner of Bcl6 which ubiquitinates histone proteins.Although they maintained an apparently normal phenotype after emigration, they expressed increased amounts of Batf and Bcl6 at basal state and produced explosive and prolonged Tfh responses upon subsequent antigen encounter.Ablation of Cul3 in mature CD4(+) splenocytes also resulted in dramatically exaggerated Tfh responses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Committee on Immunology, Department of Pathology, Howard Hughes Medical Institute, and Department of Chemistry, University of Chicago, Chicago, IL 60637Committee on Immunology, Department of Pathology, Howard Hughes Medical Institute, and Department of Chemistry, University of Chicago, Chicago, IL 60637Committee on Immunology, Department of Pathology, Howard Hughes Medical Institute, and Department of Chemistry, University of Chicago, Chicago, IL 60637.

Show MeSH

Related in: MedlinePlus

TCR- and SAP-dependent Tfh formation. (a) FACS analysis of splenic CD4+ T cells from 10-wk-old OTII Tg with intact or deleted Cul3 as indicated. CD4+ cells gated as TCR Tg+ or TCR Tg− were stained for ICOS and PD1 to measure the frequency of Tfh cells. Numbers represent mean ± SEM of five mice per group from two independent experiments. (b) FACS analysis of gated CD4+ splenocytes from 10–15-wk-old littermate (LM) controls, Sh2d1a (SAP)−/−, Cul3cKO, and Sh2d1a−/− Cul3cKO mice, stained for PD1 and CXCR5 (top) or PD1 and ICOS (bottom). (c) FACS analysis of the same spleens as in b, gated on B220+IgD− cells to identify GC B cells. Numbers represent the percentage (mean ± SEM) of five mice/group from three independent experiments in corresponding gates. For CD4+ T cells, GC-Tfh cells are identified as PD1hiICOShiCXCR5hi and pre-Tfh cells as intermediate for the same markers as shown.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4042651&req=5

fig2: TCR- and SAP-dependent Tfh formation. (a) FACS analysis of splenic CD4+ T cells from 10-wk-old OTII Tg with intact or deleted Cul3 as indicated. CD4+ cells gated as TCR Tg+ or TCR Tg− were stained for ICOS and PD1 to measure the frequency of Tfh cells. Numbers represent mean ± SEM of five mice per group from two independent experiments. (b) FACS analysis of gated CD4+ splenocytes from 10–15-wk-old littermate (LM) controls, Sh2d1a (SAP)−/−, Cul3cKO, and Sh2d1a−/− Cul3cKO mice, stained for PD1 and CXCR5 (top) or PD1 and ICOS (bottom). (c) FACS analysis of the same spleens as in b, gated on B220+IgD− cells to identify GC B cells. Numbers represent the percentage (mean ± SEM) of five mice/group from three independent experiments in corresponding gates. For CD4+ T cells, GC-Tfh cells are identified as PD1hiICOShiCXCR5hi and pre-Tfh cells as intermediate for the same markers as shown.

Mentions: To test whether the Tfh expansion was dependent on antigen stimulation, we crossed the Cul3cKO mice to OTII TCR transgenic (Tg) mice. As shown in Fig. 2 a, a Tfh expansion still occurred in TCR Tg mice, but it was strictly restricted to the cells that expressed endogenous TCRs (Vα2loVβ5lo), whereas the cells expressing high levels of Tg Vα2 and Vβ5 were not involved. Thus, Tfh expansion depended on TCR specificity.


A negative feedback loop mediated by the Bcl6-cullin 3 complex limits Tfh cell differentiation.

Mathew R, Mao AP, Chiang AH, Bertozzi-Villa C, Bunker JJ, Scanlon ST, McDonald BD, Constantinides MG, Hollister K, Singer JD, Dent AL, Dinner AR, Bendelac A - J. Exp. Med. (2014)

TCR- and SAP-dependent Tfh formation. (a) FACS analysis of splenic CD4+ T cells from 10-wk-old OTII Tg with intact or deleted Cul3 as indicated. CD4+ cells gated as TCR Tg+ or TCR Tg− were stained for ICOS and PD1 to measure the frequency of Tfh cells. Numbers represent mean ± SEM of five mice per group from two independent experiments. (b) FACS analysis of gated CD4+ splenocytes from 10–15-wk-old littermate (LM) controls, Sh2d1a (SAP)−/−, Cul3cKO, and Sh2d1a−/− Cul3cKO mice, stained for PD1 and CXCR5 (top) or PD1 and ICOS (bottom). (c) FACS analysis of the same spleens as in b, gated on B220+IgD− cells to identify GC B cells. Numbers represent the percentage (mean ± SEM) of five mice/group from three independent experiments in corresponding gates. For CD4+ T cells, GC-Tfh cells are identified as PD1hiICOShiCXCR5hi and pre-Tfh cells as intermediate for the same markers as shown.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4042651&req=5

fig2: TCR- and SAP-dependent Tfh formation. (a) FACS analysis of splenic CD4+ T cells from 10-wk-old OTII Tg with intact or deleted Cul3 as indicated. CD4+ cells gated as TCR Tg+ or TCR Tg− were stained for ICOS and PD1 to measure the frequency of Tfh cells. Numbers represent mean ± SEM of five mice per group from two independent experiments. (b) FACS analysis of gated CD4+ splenocytes from 10–15-wk-old littermate (LM) controls, Sh2d1a (SAP)−/−, Cul3cKO, and Sh2d1a−/− Cul3cKO mice, stained for PD1 and CXCR5 (top) or PD1 and ICOS (bottom). (c) FACS analysis of the same spleens as in b, gated on B220+IgD− cells to identify GC B cells. Numbers represent the percentage (mean ± SEM) of five mice/group from three independent experiments in corresponding gates. For CD4+ T cells, GC-Tfh cells are identified as PD1hiICOShiCXCR5hi and pre-Tfh cells as intermediate for the same markers as shown.
Mentions: To test whether the Tfh expansion was dependent on antigen stimulation, we crossed the Cul3cKO mice to OTII TCR transgenic (Tg) mice. As shown in Fig. 2 a, a Tfh expansion still occurred in TCR Tg mice, but it was strictly restricted to the cells that expressed endogenous TCRs (Vα2loVβ5lo), whereas the cells expressing high levels of Tg Vα2 and Vβ5 were not involved. Thus, Tfh expansion depended on TCR specificity.

Bottom Line: Intriguingly, we found that Bcl6 was also highly and transiently expressed during the CD4(+)CD8(+) (double positive [DP]) stage of T cell development, in association with the E3 ligase cullin 3 (Cul3), a novel binding partner of Bcl6 which ubiquitinates histone proteins.Although they maintained an apparently normal phenotype after emigration, they expressed increased amounts of Batf and Bcl6 at basal state and produced explosive and prolonged Tfh responses upon subsequent antigen encounter.Ablation of Cul3 in mature CD4(+) splenocytes also resulted in dramatically exaggerated Tfh responses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Committee on Immunology, Department of Pathology, Howard Hughes Medical Institute, and Department of Chemistry, University of Chicago, Chicago, IL 60637Committee on Immunology, Department of Pathology, Howard Hughes Medical Institute, and Department of Chemistry, University of Chicago, Chicago, IL 60637Committee on Immunology, Department of Pathology, Howard Hughes Medical Institute, and Department of Chemistry, University of Chicago, Chicago, IL 60637.

Show MeSH
Related in: MedlinePlus