Edited by: Hans-Uwe Simon
A granular variant of CD63 is a regulator of repeated human mast cell degranulation
Article first published online: 22 MAR 2010
© 2010 John Wiley & Sons A/S
Volume 65, Issue 10, pages 1242–1255, October 2010
How to Cite
Schäfer, T., Starkl, P., Allard, C., Wolf, R. M. and Schweighoffer, T. (2010), A granular variant of CD63 is a regulator of repeated human mast cell degranulation. Allergy, 65: 1242–1255. doi: 10.1111/j.1398-9995.2010.02350.x
- Issue published online: 7 SEP 2010
- Article first published online: 22 MAR 2010
- Accepted for publication 1 February 2010
- mast cell;
- repeated degranulation;
To cite this article: Schäfer T, Starkl P, Allard C, Wolf RM, Schweighoffer T. A granular variant of CD63 is a regulator of repeated human mast cell degranulation. Allergy 2010; 65: 1242–1255.
Background: Mast cells are secretory immune cells whose degranulation can provoke acute allergic reactions. It is presently unclear, however, whether an individual mast cell can repeatedly degranulate or turns dysfunctional after a single antigen stimulus. This work thus aims to better define the mast cell life cycle, with particular focus on new target structures for therapeutic or diagnostic approaches in allergy.
Methods: Monoclonal antibodies were raised against degranulated cord blood-derived human mast cells. A subset of these antibodies that exclusively recognized degranulated mast cells, but did not cross-react with quiescent mast cells or other hematopoietic cell types, became key reagents in subsequent experiments.
Results: We identified a granular variant of tetraspanin CD63 as an exclusive molecular marker of degranulated human mast cells. Mutant analyses indicate that a cysteine cluster around residue C170 and protein glycosylation at residue N172 account for the antibody specificity. Here, we show that mast cells, which underwent an initial FcεRI-mediated degranulation, can be degranulated for at least another cycle in vitro. Repeated degranulation, however, requires an IgE/antigen stimulus that differs from the preceding one. Furthermore, the new variant-specific anti-CD63 antibodies effectively impair repeated cycles of mast cell degranulation.
Conclusion: Our findings indicate that mast cells are stable, multiple-use cells, which are capable of surviving and delivering several consecutive hits. Surface expression of the novel CD63 variant is a distinguishing feature of such primed cells. Reagents directed against this molecular hallmark may thus become valuable diagnostic and therapeutic agents.