Induction of T-helper type 2 cytokine release and up-regulated expression of protease-activated receptors on mast cells by recombinant American cockroach allergen Per a 7.

Abstract

BACKGROUND:

The cockroach is a major source of indoor allergens, which cause perennial rhinitis and asthma. Per a 7 is one of the major allergens from the American cockroach, eliciting IgE reaction in over 50% of sera from allergic individuals. However, the actions of Per a 7 in the pathogenesis of allergic diseases remain poorly understood.

OBJECTIVE:

The aim of the study was to investigate the effects of Per a 7 on the expression of protease-activated receptors (PARs) on murine mast cells and the release of T-helper type 2 (Th2) cytokines from these cells. Methods Per a 7 gene was cloned and expressed in Escherichia coli. The purified recombinant Per a 7 (rPer a 7) was used to challenge murine mast cells P815 and the expression of PARs was determined by using real-time quantitative RT-PCR and flow cytometry. The release of IL-4 and IL-13 was detected with ELISA.

RESULTS:

rPer a 7 was solubly expressed in E. coli and the purified rPer a 7 reacted with 75% (six out of eight) of the sera from cockroach-allergic patients. Following stimulation of rPer a 7, the expression of PAR-1, PAR-2, PAR-3 and PAR-4 mRNAs on P815 cells increased by 8.7-, 6.8-, 14.4- and 8.8-fold, respectively, following 2- and 6-h incubation periods, and the expression of PAR-1, PAR-2 and PAR-4 proteins was enhanced following 16-h incubation. rPer a 7 provoked approximately up to a 4.8- and 2.3-fold increase in IL-4 and IL-13 release from P815 cells following 6- and 16-h incubation periods.

CONCLUSION:

rPer a 7 induced up-regulation of PAR expression on P815 cells and provoked Th2 cytokines IL-4 and IL-13 secretion from these murine mast cells, which implicated that this major cockroach allergen is likely to contribute to the development of cockroach-related allergic disease.

• Authors: Z Zhang, H Zhang, H Yang, L Zhang, X Chen, X Zheng, S He
• Journal: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology (Clin Exp Allergy) Vol. 38 Issue 7 Pg. 1160-7 (Jul 2008) ISSN: 1365-2222 [Electronic] England
• PMID: 18691294 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Allergens
• Antigens, Plant
• Interleukin-13
• Receptors, Proteinase-Activated
• Recombinant Proteins
• allergen Per a 7, Periplaneta americana
• Interleukin-4
• Immunoglobulin E

Topics

• Allergens (immunology)
• Animals
• Antigens, Plant
• Cell Line, Tumor
• Cockroaches (immunology)
• Gene Expression
• Humans
• Immunoglobulin E (blood)
• Interleukin-13 (biosynthesis, immunology)
• Interleukin-4 (biosynthesis, immunology)
• Mast Cells (immunology, metabolism)
• Mice
• Receptors, Proteinase-Activated (metabolism)
• Recombinant Proteins (immunology)
• Th2 Cells (immunology, metabolism)
• Up-Regulation