Proteolytically inactive per a 10 allergen of Periplaneta americana modulates Th2 response and enhances IL-10 in mouse model.
BACKGROUND
Purified allergens with reduced IgE reactivity are required to improve the safety and efficacy of allergen-specific immunotherapy (IT).


OBJECTIVE
The present study investigates the efficacy of purified cockroach allergen immunotherapy with proteolytically active and inactive Per a 10 in allergic mouse model.


METHODS
Balb/c mice were sensitized intraperitoneally with cockroach extract (CE) and purified allergen Per a 10 in separate groups. Mice were treated subcutaneously with phosphate-buffered saline (PBS), CE, active and inactive Per a 10 and challenged intranasally. Antigen specific IgE, IgG1 and IgG2a in serum and cytokines IL-4, IL-13, IFN-gamma, IL-10, TGF-beta in bronchoalveolar lavage (BAL) fluid and spleen culture supernatant (CS) were estimated by enzyme-linked immunosorbent assay. Lung histology was analyzed by hematoxylin and eosin staining.


RESULTS
IT with Per a 10 demonstrated significant reduction in IgE levels in serum, IL-4 levels in BAL fluid, CS, and eosinophilic infiltration in lungs than PBS-treated mice. This was associated with significantly increased IL-10 secretion in BAL fluid and CS. IT with Per a 10 effectively suppressed T-helper type 2 (Th2) response in mice sensitized with Per a 10 than CE group. Further, IT with inactive Per a 10 showed maximum reduction in systemic and airway inflammation and induced maximum IL-10 release in BAL fluid and CS than other antigens.


CONCLUSIONS
IT with Per a 10 effectively suppressed Th2 response and lung inflammation in Per a 10- or CE-sensitized mice. The beneficial effects of IT with inactive Per a 10 are more pronounced than active Per a 10.
Srivastava
Deepsikha
D
Allergy and Immunology Section, Institute of Genomics and Integrative Biology (CSIR), Delhi University Campus, Room 509, Mall Road, Delhi, 110007, India.
Mehta
Amit Kumar
AK
Arora
Naveen
N
Gaur
Shailendra Nath
SN
Singh
Bhanu Pratap
BP
D000485:Allergens / Q000276:immunology*; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology / Q000821:virology; D002478:Cells, Cultured; D003888:Desensitization, Immunologic; D004195:Disease Models, Animal; D006967:Hypersensitivity; D056747:Immunomodulation; D019476:Insect Proteins / Q000276:immunology; D016753:Interleukin-10 / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D010526:Periplaneta / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology* / Q000821:virology
D000485:Allergens; D019476:Insect Proteins; D016753:Interleukin-10