1R. F. and A. M. G. have contributed equally to this work.
The protease allergen Der p 1 cleaves cell surface DC-SIGN and DC-SIGNR: experimental analysis of in silico substrate identification and implications in allergic responses
Article first published online: 23 JAN 2007
Clinical & Experimental Allergy
Volume 37, Issue 2, pages 231–242, February 2007
How to Cite
Furmonaviciene, R., Ghaemmaghami, A. M., Boyd, S. E., Jones, N. S., Bailey, K., Willis, A. C., Sewell, H. F., Mitchell, D. A. and Shakib, F. (2007), The protease allergen Der p 1 cleaves cell surface DC-SIGN and DC-SIGNR: experimental analysis of in silico substrate identification and implications in allergic responses. Clinical & Experimental Allergy, 37: 231–242. doi: 10.1111/j.1365-2222.2007.02651.x
- Issue published online: 23 JAN 2007
- Article first published online: 23 JAN 2007
- Submitted 24 July 2006; revised 12 October 2006; accepted 14 November 2006
- dendritic cell;
- Der p 1;
Background The cysteine protease Der p 1 from the house dust mite Dermatophagoides pteronyssinus is one of the most potent allergens known. An attractive mechanism for a component of Der p 1 allergenicity lies in its ability to cleave key regulatory molecules from leucocyte surfaces, subverting cellular function and driving abnormal immunoglobulin E (IgE) responses.
Objective Although CD23, CD25 and CD40 have already been identified as major Der p 1 targets, other significant substrates may also exist.
Methods To investigate this, knowledge of the proteolytic properties of Der p 1 was used to perform in silico digestion of human dendritic cell surface proteins, using the prediction of protease specificity (PoPS) bioinformatics tool, in conjunction with cellular in vitro analysis and cleavage site determination.
Results Targets identified included DC-SIGN and DC-SIGNR, two C-type lectins implicated mostly in pathogen trafficking. Treatment of positively expressing cells with Der p 1 led to loss of detectable surface DC-SIGN and DC-SIGNR. Digestion of purified soluble recombinant DC-SIGN and DC-SIGNR, followed by N-terminal sequencing and MALDI mass spectrometry, indicated in each case one major cleavage site and several minor sites, the former correlating well with Der p 1 enzymology and the folded state of the substrate proteins. Loss of DC-SIGN from the cell surface led to reduced binding of intracellular adhesion molecule-3, an endogenous DC-SIGN ligand expressed on naïve T cells which is thought to be involved in T-helper type 1 cytokine signalling.
Conclusion These data provide evidence of lectin involvement in the initiation of the allergic response and the value of using genome-wide in silico digestion tools.