Cathepsin A is expressed in primary human antigen-presenting cells.


Cathepsins are expressed in antigen-presenting cells (APC). These cathepsins are known to regulate antigen processing and degradation of the invariant chain (Ii) into the class II-associated Ii peptide (CLIP), which occupies the peptide-binding groove of the major histocompatibility complex (MHC) class II molecule. Previous studies have identified the serine carboxypeptidase cathepsin A (CatA) in various tissues and cells; however, it is not clear whether CatA is also expressed in primary human APC. We demonstrate the expression of CatA in B lymphoblastoid cells (BLC), primary human B cells, both subsets of myeloid dendritic cells (mDC1 and mDC2), as well as in plasmacytoid DC. PMSF or lactacystin-mediated inhibition of serine proteases in BLC-derived lysosomal proteases resulted in the inhibition of amino acid release from the C-terminal end of two model peptides. This inhibition did not occur by using a proline rich peptide. Our data suggest that CatA is involved in the C-terminal fine-tuning of antigenic T cell epitopes in human APC.

DOI: 10.1016/j.imlet.2009.11.010

Cite this paper

@article{Reich2010CathepsinAI, title={Cathepsin A is expressed in primary human antigen-presenting cells.}, author={Michael Reich and K. -D. Spindler and Michael Burret and Hubert Kalbacher and Bernhard B{\"{o}hm and Timo Burster}, journal={Immunology letters}, year={2010}, volume={128 2}, pages={143-7} }