Identification of proteases employed by dendritic cells in the processing of protein purified derivative (PPD)

  • Dendritic cells (DC) are known to present exogenous protein Ag effectively to T cells. In this study we sought to identify the proteases that DC employ during antigen processing. The murine epidermal-derived DC line Xs52, when pulsed with PPD, optimally activated the PPD-reactive Th1 clone LNC.2F1 as well as the Th2 clone LNC.4k1, and this activation was completely blocked by chloroquine pretreatment. These results validate the capacity of XS52 DC to digest PPD into immunogenic peptides inducing antigen specific T cell immune responses. XS52 DC, as well as splenic DC and DCs derived from bone marrow degraded standard substrates for cathepsins B, C, D/E, H, J, and L, tryptase, and chymases, indicating that DC express a variety of protease activities. Treatment of XS52 DC with pepstatin A, an inhibitor of aspartic acid proteases, completely abrogated their capacity to present native PPD, but not trypsin-digested PPD fragments to Th1 and Th2 cell clones. Pepstatin A also inhibited cathepsin D/E activity selectively among the XS52 DC-associated protease activities. On the other hand, inhibitors of serine proteases (dichloroisocoumarin, DCI) or of cystein proteases (E-64) did not impair XS52 DC presentation of PPD, nor did they inhibit cathepsin D/E activity. Finally, all tested DC populations (XS52 DC, splenic DC, and bone marrow-derived DC) constitutively expressed cathepsin D mRNA. These results suggest that DC primarily employ cathepsin D (and perhaps E) to digest PPD into antigenic peptides.
Metadaten
Author:Mansour Mohamadzadeh, Hamid Mohamadzadeh, Melissa Brammer, Karol Sestak, Ronald B. Luftig
URN:urn:nbn:de:hebis:30-11547
DOI:https://doi.org/10.1186/1476-8518-2-8
ISSN:1476-8518
Pubmed Id:https://pubmed.ncbi.nlm.nih.gov/15287985
Parent Title (English):Journal of immune based therapies and vaccines
Publisher:Biomed Central
Place of publication:London
Document Type:Article
Language:English
Year of Completion:2004
Date of first Publication:2004/08/02
Publishing Institution:Universit├Ątsbibliothek Johann Christian Senckenberg
Release Date:2005/06/22
Tag:Dendritic cell; Dendritic cell population; Protease activity; Protein purify derivative; Splenic dendritic cell
Volume:2
Issue:1, Art. 8
Page Number:9
First Page:1
Last Page:9
Note:
This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
HeBIS-PPN:191539074
Institutes:Medizin / Medizin
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung 2.0