Application of specific cell permeable cathepsin G inhibitors resulted in reduced antigen processing in primary dendritic cells.
The serine protease cathepsin G (CatG) is expressed in primary antigen-presenting cells and regulates autoantigen processing in CatG pre-loaded fibroblasts. To further investigate the function of CatG in the major histocompatibility complex (MHC) class II loading compartments, a specific, cell permeable CatG-inhibitor is needed. In this study, several CatG-inhibitors were tested for their ability to penetrate the cell membrane of peripheral blood mononuclear cells (PBMC). We find that the commercially available reversible CatG-specific inhibitor I (CatG inhibitor) and the irreversible Suc-Val-Pro-Phe(P) (OPh)(2) (Suc-VPF) are both cell permeable and specifically inhibit intracellular CatG in the PBMC. Furthermore, selective inhibition of CatG resulted in reduced tetanus toxin C-fragment (TTC) and hemagglutinin (HA) processing and presentation to CD4(+) T cells. We conclude that these CatG inhibitors can be used for both antigen-processing studies and for modulation of T cell response in situ and in vivo.
Reich
Michael
M
Catheomics, Division of Endocrinology and Diabetes, Department of Internal Medicine I, University Medical Center Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
Lesner
Adam
A
Legowska
Anna
A
Sieńczyk
Marcin
M
Oleksyszyn
Jozef
J
Boehm
Bernhard O
BO
Burster
Timo
T
D017951:Antigen Presentation / Q000187:drug effects* / Q000276:immunology; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D056649:Cathepsin G; D002403:Cathepsins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002463:Cell Membrane Permeability; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology; D006388:Hemagglutinins / Q000276:immunology; D006801:Humans; D010446:Peptide Fragments / Q000276:immunology; D012697:Serine Endopeptidases / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D013744:Tetanus Toxin / Q000276:immunology
D006388:Hemagglutinins; D010446:Peptide Fragments; D015842:Serine Proteinase Inhibitors; D013744:Tetanus Toxin; C040635:tetanus toxin fragment C; D002403:Cathepsins; D012697:Serine Endopeptidases; C534094:CTSG protein, human; D056649:Cathepsin G