Lymphocyte Development Group paper

Runx transcription factors help dictate the fate of T cellsas they become CD4⁺ or CD8⁺ T cells in the thymus, and Th1 orTh17 cells in the periphery. Now, according to Bruno et al.,Runx proteins also guide regulatory T (T reg) cell fate.

Runx proteins have been shown to bind to the canonical T regcell transcription factor Foxp3. Together, the two regulate(and primarily inhibit) the expression of target genes, suchas the Th17-promoting transcription factor Ror-γt. Now Brunoand colleagues reveal that Runx proteins also help induce andmaintain Foxp3 expression in mature CD4⁺ T cells.

Inducible T reg cells relied on Runx proteins to express Foxp3.Blocking the proteins reduced the number of these cells, andablating an indispensable subunit of Runx protein complexes,Cbfb, diminished Foxp3 expression in natural T reg cells. Runxproteins bound directly to the Foxp3 promoter in T reg cells,but not in naive CD4⁺ T cells because of locus inaccessibility.

Another group recently reported that Runx/Cbfb complexes controlthe expression of Foxp3 in natural T reg cells in vivo. WithoutCbfb, mice were susceptible to autoimmune disease. However,this study did not investigate a role for Runx proteins in Treg cell induction.

(Maxmen (2009) Runx: T reg cell keeper and creator. J. Exp. Med. doi:10.1084/jem.20611iti4)

This piece appears on the JEM website here
Lymphocyte Development Group paper

Runx transcription factors help dictate the fate of T cellsas they become CD4⁺ or CD8⁺ T cells in the thymus, and Th1 orTh17 cells in the periphery. Now, according to Bruno et al.,Runx proteins also guide regulatory T (T reg) cell fate.

Runx proteins have been shown to bind to the canonical T regcell transcription factor Foxp3. Together, the two regulate(and primarily inhibit) the expression of target genes, suchas the Th17-promoting transcription factor Ror-γt. Now Brunoand colleagues reveal that Runx proteins also help induce andmaintain Foxp3 expression in mature CD4⁺ T cells.

Inducible T reg cells relied on Runx proteins to express Foxp3.Blocking the proteins reduced the number of these cells, andablating an indispensable subunit of Runx protein complexes,Cbfb, diminished Foxp3 expression in natural T reg cells. Runxproteins bound directly to the Foxp3 promoter in T reg cells,but not in naive CD4⁺ T cells because of locus inaccessibility.

Another group recently reported that Runx/Cbfb complexes controlthe expression of Foxp3 in natural T reg cells in vivo. WithoutCbfb, mice were susceptible to autoimmune disease. However,this study did not investigate a role for Runx proteins in Treg cell induction.

(Maxmen (2009) Runx: T reg cell keeper and creator. J. Exp. Med. doi:10.1084/jem.20611iti4)

This piece appears on the JEM website here