Deficient CD4+ CD25+ FOXP3+ T regulatory cells in acquired aplastic anemia.

Abstract

Regulatory T cells are believed to control the development and progression of autoimmunity by suppressing autoreactive T cells. Decreased numbers of CD4(+)CD25(+) FOXP3(+) T cells (Tregs) are associated with impaired immune homeostasis and development of autoimmune diseases. The transcription factors FOXP3 and NFAT1 have key roles in regulatory T-cell development and function. We show that Tregs are decreased at presentation in almost all patients with aplastic anemia; FOXP3 protein and mRNA levels also are significantly lower in patients with aplastic anemia and NFAT1 protein levels are decreased or absent. Transfection of FOXP3-deficient CD4(+)CD25(+) T cells from patients with a plasmid encoding wild-type NFAT1 resulted in increased FOXP3 expression in these cells. By NFAT1 knockdown in CD4(+)CD25(+) T cells, FOXP3 expression was decreased when NFAT1 expression was decreased. Our findings indicate that decreased NFAT1 could explain low FOXP3 expression and diminished Treg frequency in aplastic anemia. Treg defects are now implicated in autoimmune marrow failure.

• Authors: Elena E Solomou, Katayoun Rezvani, Stephan Mielke, Daniela Malide, Keyvan Keyvanfar, Valeria Visconte, Sachiko Kajigaya, A John Barrett, Neal S Young
• Journal: Blood (Blood) Vol. 110 Issue 5 Pg. 1603-6 (Sep 01 2007) ISSN: 0006-4971 [Print] United States
• PMID: 17463169 (Publication Type: Clinical Trial, Journal Article, Multicenter Study, Research Support, N.I.H., Intramural)

Chemical References

• FOXP3 protein, human
• Forkhead Transcription Factors
• NFATC Transcription Factors
• NFATC2 protein, human

Topics

• Adolescent
• Adult
• Anemia, Aplastic (genetics, immunology, metabolism, pathology)
• Autoimmune Diseases (genetics, immunology, metabolism, pathology)
• Autoimmunity (genetics)
• Cells, Cultured
• Female
• Forkhead Transcription Factors (biosynthesis, genetics, immunology)
• Gene Expression Regulation (immunology)
• Humans
• Male
• Middle Aged
• NFATC Transcription Factors (biosynthesis, genetics, immunology)
• T-Lymphocytes, Regulatory (immunology, metabolism, pathology)
• Transfection