Effects of p300/CBP on histone acetylation of Foxp3 gene in children with Kawasaki disease / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the effects of p300/CBP on histone acetylation of Foxp3 gene and its roles in the immunological pathogenesis of Kawasaki disease (KD).Methods Forty-six children with KD and twenty-eight age-matched health children were consented to participate in this study.Co-immunoprecipitation and real-time PCR were performed to detect Foxp3-associated acetylation levels of histone H4 and binding abilities of p300, CBP, pSmad3 (phosphorylated mothers against decapentaplegic homolog 3) and NF-AT (nuclear factor of activated T cells) with Foxp3 gene in CD4+ T cells.The percentages of CD4+CD25high Foxp3+ cells (Treg) and the expression of Foxp3, CTLA4 (cytotoxic T-lymphocyte-associated protein 4), p300, CBP, TGF-βRⅡ (transforming growth factor β receptor Ⅱ) and pLAT1 at protein level were analyzed by flow cytometry.Quantitative real-time PCR was used to measure the expression of Foxp3, IL-10, TGF-β, TGF-βRⅠ, Egr-1 (early growth response protein 1), RARα (retinoic acid receptor α) and PLCγ1 (phospholipase C-γ1) in Treg cells at mRNA level.Plasma concentrations of TGF-β and retinol acid (RA) were measured by enzyme-linked immunosorbent assay.Results (1) The percentages of Treg cells, levels of Foxp3 and molecules associated with suppressive function of Treg cells (TGF-β, IL-10 and CTLA4), acetylation levels of histone H4 associated with promoter, conserved non-coding DNA sequence 1 (CNS1) and CNS2 of Foxp3 gene decreased remarkably during acute KD (P0.05).(2) The levels of p300 and CBP in Treg cells and their binding abilities with Foxp3 gene were down-regulated significantly during acute KD (P0.05).Conclusion Hypoacetylation of histone H4 associated with Foxp3 gene caused by insufficient expression of p300/CBP and their impaired binding abilities might be involved with immune dysfunction in KD.IVIG therapy regulates the expression of p300/CBP and their binding abilities with Foxp3 gene through up-regulating TGF-β signal.