Open AccessCorrelation of dendritic cell maturation and the formation of aggregates of poly-ubiquitinated proteins in the cytosol
Author(s) -
Melanie Faßbender,
Sylvia Herter,
Rafaela Holtappels,
Hansjörg Schild
Publication year - 2008
Publication title -
medical microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.954
H-Index - 61
eISSN - 1432-1831
pISSN - 0300-8584
DOI - 10.1007/s00430-008-0091-4
Subject(s) - microbiology and biotechnology , antigen processing , antigen presentation , antigen , dendritic cell , biology , antigen presenting cell , endocytosis , cytosol , cross presentation , ctl* , immune system , t cell , chemistry , cell , cd8 , immunology , biochemistry , enzyme
Dendritic cells (DCs) are the most powerful antigen presenting cells (APCs) in the immune system. Therefore, they are able to take up antigen by phagocytosis, macropinocytosis or endocytosis, process it in the cytosol and present it to naive T cells. It is known that presentation of the immunodominant influenza virus nucleoprotein-derived CTL epitope is delayed in bone marrow-derived DCs (BMDCs) compared to non-professional APCs. This delay coincided with the formation of transient aggregations of ubiquitinated proteins (DALIS, dendritic cell aggresome-like induced structures), which contain probably defective ribosomal products (DRiPs). DRiPs appear in the cytosol of maturing DCs and macrophages. Normally, DRiPs are degraded rapidly by proteasomes. However, their storage in DALIS delays their degradation. So, it is hypothesized that DALIS can function as antigen depots allowing DCs to coordinate maturation and antigen presentation during their migration to the lymph nodes. Upon inhibition of several pathways among the in signal transduction pathways of DCs, like the phosphatidylinositol 3-kinase (PI3-K) or the mammalian target of Rapamycin (mTOR), the cells show a rendered maturation profile. The formation of DALIS is inhibited in these cells which can be expected to influence antigen processing and presentation.