DeFillipo Anna M, Dai Jie, Li Zihai
Center for Immunotherapy of Cancer and Infectious Diseases, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-1601, USA.
Mol Immunol. 2004 Jul;41(8):785-92. doi: 10.1016/j.molimm.2004.04.016.
The transition of dendritic cells (DCs) from immature to mature states is critical for the optimal priming of the adaptive immune response. This highly regulated process is accompanied by structural and functional alterations of DCs, including rapid and dramatic redistributions of MHC class I and class II molecules to cell surfaces, nuclear translocation of NF-kappaB,and transient appearance of dendritic cell aggresome-like induced structures (DALIS) in the cytosol. We have previously found that DCs can be matured by a non-inflammatory stress stimulation, i.e., heat shock. In this study, we examined if thermomanipulation could induce DALIS formation. We found that heat shock of DCs, but not of other cell types, led to the appearance of aggresome-like structures that were structurally indistinguishable from DALIS induced by lipopolysaccharide (LPS). Furthermore, the induction of DALIS in DCs by heat, but not by LPS, correlated with the increased ability of DCs to cross-present exogenous antigens to MHC I. Since the canonical biochemical response to heat shock is the induction of heat shock proteins (HSP) by heat shock factors (Hsf), we studied the contribution of both HSP and Hsf in heat shock-mediated DALIS formation using gene knockout mice. We demonstrated that neither inducible HSP70 nor the major mammalian heat shock transcription factor Hsf1 was involved in the formation of DALIS. Our results highlighted the important roles of heat shock in modulating the function of DCs, and they further suggested that heat-mediated immune regulation can be uncoupled from heat shock response.
树突状细胞(DCs)从不成熟状态向成熟状态的转变对于适应性免疫反应的最佳启动至关重要。这个高度调控的过程伴随着DCs的结构和功能改变,包括MHC I类和II类分子迅速且显著地重新分布到细胞表面、NF-κB的核转位以及细胞溶质中树突状细胞聚集体样诱导结构(DALIS)的短暂出现。我们之前发现DCs可以通过非炎性应激刺激即热休克而成熟。在本研究中,我们检测了热调控是否能诱导DALIS形成。我们发现DCs的热休克而非其他细胞类型的热休克导致了聚集体样结构的出现,这些结构在结构上与脂多糖(LPS)诱导的DALIS无法区分。此外,热而非LPS诱导DCs中DALIS的形成与DCs将外源性抗原交叉呈递给MHC I的能力增强相关。由于对热休克的典型生化反应是热休克因子(Hsf)诱导热休克蛋白(HSP),我们使用基因敲除小鼠研究了HSP和Hsf在热休克介导的DALIS形成中的作用。我们证明诱导型HSP70和主要的哺乳动物热休克转录因子Hsf1均不参与DALIS的形成。我们的结果突出了热休克在调节DCs功能中的重要作用,并且进一步表明热介导的免疫调节可以与热休克反应解耦联。