Differential expression of constitutive and inducible proteasome subunits in human monocyte-derived DC differentiated in the presence of IFN-alpha or IL-4.
Several studies strongly suggest that DC differentiated in vitro in the presence of type I IFN acquire more potent immune stimulatory properties, compared with DC differentiated in vitro with IL-4. However, little is known about the molecular mechanisms underlying this phenomenon. To address this question, we compared the Ag-processing machinery (APM) profile in human DC grown in the presence of IFN-alpha ((IFN)DC) or IL-4 ((IL-4)DC). Using a panel of APM component-specific mAb in Western blot experiments, we found that (IFN)DC preferentially express inducible proteasome subunits (LMP2, LMP7, and MECL1) both at immature and mature stages. In contrast, immature (IL-4)DC co-express both constitutive (beta1, beta2, and beta5) and inducible subunits, as shown by Western blotting analysis. In addition, immature (IFN)DC express higher levels of TAP1, TAP2, calnexin, calreticulin, tapasin, and HLA class I molecules than (IL-4)DC. The different proteasome profiles of (IFN)DC and (IL-4)DC were associated with a greater ability of (IFN)DC to present an immunodominant epitope that requires LMP7 expression for its processing. In general, these data show the impact of cytokines on APM component expression and hence the Ag-processing ability of DC.
Tosello
Valeria
V
Department of Oncology and Surgical Sciences, Oncology Section, University of Padova, Padova, Italy.
Zamarchi
Rita
R
Merlo
Anna
A
Gorza
Margherita
M
Piovan
Erich
E
Mandruzzato
Susanna
S
Bronte
Vincenzo
V
Wang
Xinhui
X
Ferrone
Soldano
S
Amadori
Alberto
A
Zanovello
Paola
P
D018528:ATP-Binding Cassette Transporters / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology*; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology; D016898:Interferon-alpha / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D052139:Intracellular Calcium-Sensing Proteins / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000201:enzymology* / Q000276:immunology; D009097:Multienzyme Complexes / Q000096:biosynthesis* / Q000187:drug effects; D046988:Proteasome Endopeptidase Complex / Q000096:biosynthesis* / Q000187:drug effects
D018528:ATP-Binding Cassette Transporters; D000939:Epitopes; D007155:Immunologic Factors; D016898:Interferon-alpha; D052139:Intracellular Calcium-Sensing Proteins; D026901:Membrane Transport Proteins; D009097:Multienzyme Complexes; C107762:tapasin; D015847:Interleukin-4; C077436:LMP7 protein; D046988:Proteasome Endopeptidase Complex