DNA vaccine encoding Der p 2 allergen generates immunologic protection in recombinant Der p 2 allergen-induced allergic airway inflammation mice model.
BACKGROUND
DNA immunization is a promising novel type of immunotherapy against allergy. An estimated 79.2% patients with asthma, wheezing and/or rhinitis suffer from Dermatophagoides pteronyssinus group 2 (Der p 2) allegen. The aim of the present study was to determine whether DNA vaccine encoding Der p 2 could generate immunologic protection in recombinant Der p 2 (rDer p 2) allergen-induced allergic airway inflammation mice model and to understand the role of DNA vaccination in specific-allergen immunotherapy for asthma.


METHODS
After DNA vaccination, BALB/c mice were sensitized by intraperitoneal injection (i.p) and challenged by intranasal instillation of rDer p 2. The lung tissues were assessed using hematoxylin and eosin. Mucus-producing goblet cells were identifed using periodic acid-Schiff (PAS)/alcian blue. The total cell number and composition of bronchoalveolar lavage samples were determined. The levels of the cytokines IL-4 and IFN-gamma, as well as IgE and IgG2a in the serum were determined by enzyme-linked immunosorbent assay. Allergen-specific IL-4 and IFN-gamma production by spleen cells were also measured by enzyme-linked immunosorbent assay. Expression of signal transducer and activator of transcription 6 (STAT6) in splenocytes were determined by Western blot.


RESULTS
DNA vaccine encoding Der p 2 allergen inhibited extensive infiltration of inflammatory cells and production of mucin induced by allergen. The influx of eosinophils into the lung interstitium was significantly reduced after administration of DNA vaccine. Significant reductions of IL-4 and increase in levels of IFN-gamma in bronchoalveolar lavage fluid were observed. The allergen-specific IgE was markedly decreased in mice receiving DNA vaccination. Allergen could induce higher IFN-gamma, weaker IL-4 in cultured spleen cells from mice receiving DNA vaccine. DNA vaccination inhibited STAT6 expression of spleen cells induced by allergen.


CONCLUSIONS
These results indicated that DNA vaccine encoding Der p 2 allergen generates immunologic protection in recombinant Der p 2 allergen-induced allergic airway inflammation mice model with regulating the immune response towards a Th1-type reaction.
Li
Guo-Ping
GP
College of Life Sciences, Shenzhen University, Shenzhen 518060, China.
Liu
Zhi-Gang
ZG
Qiu
Jing
J
Ran
Pi-Xin
PX
Zhong
Nan-Shan
NS
D000818:Animals; D039741:Antigens, Dermatophagoides / Q000235:genetics / Q000276:immunology*; D060829:Arthropod Proteins; D001249:Asthma / Q000276:immunology / Q000628:therapy*; D004802:Eosinophilia / Q000517:prevention & control; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D050800:STAT6 Transcription Factor; D018417:Th1 Cells / Q000276:immunology; D015534:Trans-Activators / Q000032:analysis; D014611:Vaccination; D019444:Vaccines, DNA / Q000276:immunology*
D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; C451163:Dermatophagoides pteronyssinus antigen p 2; D007074:Immunoglobulin G; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; C494100:Stat6 protein, mouse; D015534:Trans-Activators; D019444:Vaccines, DNA; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma