Differential expression and function of phosphodiesterase 4 (PDE4) subtypes in human primary CD4+ T cells:: Predominant role of PDE4D
Differential expression and function of phosphodiesterase 4 (PDE4) subtypes in human primary CD4+ T cells:: Predominant role of PDE4D
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DOI：
10.4049/jimmunol.178.8.4820
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发表时间：
2007-04-15
影响因子：
4.4
通讯作者：
Zitt, Christof
中科院分区：
文献类型：
--
作者：
Peter, Daniel;Jin, S. L. Catherine;Zitt, Christof
4型磷酸二酯酶（PDE 4）通过减弱cAMP的负约束而在TCR信号传导中是关键调节剂。在这项研究中，我们发现抗CD 3/CD 28刺激人原代CD 4（+）T细胞以特异性和时间依赖性方式增加PDE 4亚型PDE 4A、PDE 4 B和PDE 4D的表达。PDE 4A和PDE 4D的mRNA和酶活性在5 d内上调，PDE 4 B的mRNA和酶活性在24 h后达到最高水平。诱导被证明是独立的不同的刺激条件，是类似的幼稚和记忆T细胞亚群。为了阐明单个PDE 4亚型对T细胞功能的功能影响，我们使用PDE 4亚型特异性短干扰RNA（siRNA）。PDE 4 B或PDE 4D的敲低在刺激后24小时（最大IL-2浓度的时间点）抑制IL-2释放，其程度与用panPDE 4抑制剂RP 73401（吡拉米司特）观察到的相似。IFN-γ或IL-5的大量仅在稍后的时间点测量。72小时后测量，靶向PDE 4D的ARNA对这些细胞因子表现出显着的抑制作用。然而，当PDE 4 siRNA组合应用时，所有细胞因子的抑制最有效。虽然PDE 4抑制对T细胞增殖的影响很小，但单独的PDE 4D靶向siRNA与panPDE 4抑制剂一样有效，而PDE 4A或PDE 4 B siRNA几乎没有影响。总之，个体PDE 4亚型在传播各种T细胞功能中具有总体非冗余但互补的时间依赖性作用，并且PDE 4D是可能发挥主导作用的形式。
Type 4 phosphodiesterases (PDE4) are critical regulators in TCR signaling by attenuating the negative constraint of cAMP. In this study, we show that anti-CD3/CD28 stimulation of human primary CD4(+) T cells increases the expression of the PDE4 subtypes PDE4A, PDE4B, and PDE4D in a specific and time-dependent manner. PDE4A and PDE4D mRNAs as well as enzyme activities were up-regulated within 5 days, PDE4B showed a transient up-regulation with highest levels after 24 h. The induction was shown to be independent of different stimulation conditions and was similar in naive and memory T cell subpopulations. To elucidate the functional impact of individual PDE4 subtypes on T cell function, we,used PDE4 subtype-specific short-interfering RNAs (siRNAs). Knockdown of either PDE4B or PDE4D inhibited IL-2 release 24 h after stimulation (time point of maximal IL-2 concentrations) to an extent similar to that observed with the panPDE4 inhibitor RP73401 (piclamilast). Substantial amounts of IFN-gamma or IL-5 were measured only at later time points. ARNA targeting PDE4D showed a predominant inhibitory effect on these cytokines measured after 72 h. However, the inhibition of all cytokines was most effective when PDE4 siRNAs were applied in combination. Although the effect of PDE4 inhibition on T cell proliferation is small, the PDE4D-targeting siRNA alone was as effective as the panPDE4 inhibitor, whereas PDE4A or PDE4B siRNAs had hardly an effect. In summary, individual PDE4 subtypes have overall nonredundant, but complementary, time-dependent roles in propagating various T cell functions and PDE4D is the form likely playing a predominant role.