Usharauli David
Department of Immunology, Institute of Medical Biotechnology, Chiaureli Str. #2, Tbilisi 0159 (formerly 380059), Georgia.
Med Hypotheses. 2005;64(1):112-3. doi: 10.1016/j.mehy.2004.02.061.
The role of dentritic cells in initiating the immune response has been well established. Recent studies point to an important role for DCs in the induction of peripheral tolerance as well. It was proposed that the role of DC in the immunity/tolerance decision could be associated simply with DC maturation states. However, it has been observed that immature DC do not process endocytosed antigens well to form MHC+peptide complexes and therefore self-specific T cells would not be able to recognize their ligands on immature DCs. Then how might immature DCs induce tolerance to self-antigens? Below it is discussed a new mechanism which might control whether the DCs behavior will be tolerogenic or immunogenic. The hypothesis proposed that DCs should have two maturation programs operating in absence/presence of Danger signals leading to mature-tolerogenic and mature-immunogenic phenotypes, respectively.
树突状细胞在启动免疫反应中的作用已得到充分证实。最近的研究还指出，树突状细胞在外周耐受诱导中也发挥着重要作用。有人提出，树突状细胞在免疫/耐受决定中的作用可能仅仅与树突状细胞的成熟状态有关。然而，已经观察到未成熟的树突状细胞不能很好地处理内吞的抗原以形成MHC +肽复合物，因此自身特异性T细胞将无法识别未成熟树突状细胞上的配体。那么未成熟的树突状细胞如何诱导对自身抗原的耐受呢？下面将讨论一种新机制，该机制可能控制树突状细胞的行为是产生耐受性还是免疫原性。该假说提出，树突状细胞应该有两个成熟程序，分别在有无危险信号的情况下运行，导致成熟的耐受性和成熟的免疫原性表型。
