T cells require Foxo1 to populate the peripheral lymphoid organs.
Forkhead transcription factors play critical roles in leukocyte homeostasis. To study further the immunological functions of Foxo1, we generated mice that selectively lack Foxo1 in T cells (Foxo1(flox/flox) Lck.cre(+)conditional knockout mice (cKO)). Although thymocyte development appeared relatively normal, Foxo1 cKO mice harbored significantly increased percentages of mature single positive T cells in the thymus as compared with WT mice, yet possessed smaller lymph nodes and spleens that contained fewer T cells. Foxo1 cKO T cells were not more prone to apoptosis, but instead were characterized by a CD62L(lo) CCR7(lo) CD44(hi) surface phenotype, a poorly populated lymphoid compartment in the periphery, and were relatively refractory to TCR stimulation, all of which were associated with reduced expression of Sell, Klf2, Ccr7, and S1pr1. Thus, Foxo1 is critical for naïve T cells to populate the peripheral lymphoid organs by coordinating a molecular program that maintains homeostasis and regulates trafficking.
Gubbels Bupp
Melanie R
MR
Inflammation Discovery, Roche Palo Alto, Palo Alto, CA, USA.
Edwards
Bonnie
B
Guo
Caiying
C
Wei
Datsen
D
Chen
Gang
G
Wong
Brian
B
Masteller
Emma
E
Peng
Stanford L
SL
D000818:Animals; D017209:Apoptosis / Q000276:immunology; D049109:Cell Proliferation; D002634:Chemotaxis, Leukocyte / Q000276:immunology*; D005434:Flow Cytometry; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000276:immunology*; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; C467200:Foxo1 protein, mouse