title: Construction of single-chain interleukin-12 DNA plasmid to treat airway hyperresponsiveness in an animal model of asthma.
abstract: Allergic asthma is strongly associated with the airway inflammation caused by the dysregulated production of cytokines secreted by the allergen-specific type-2 T helper (Th2) cells. Interleukin (IL)-12 is a heterodimeric cytokine, which strongly promotes the differentiation of naive CD4(+) T cells to the type-1 T helper (Th1) phenotype and suppresses the expression of Th2 cytokines. Therefore, immunotherapy with IL-12 has been suggested as a possible therapy for asthma. In previous studies, we developed a murine model of airway inflammation based on the purified, house dust-mite allergen Der p 1 (Dermatophagodies pteronyssinus) as a clinically relevant allergen. We hypothesized that the expression of IL-12 in the airway may represent an effective therapy for allergic airway diseases. In this study, we investigate whether the local transfer of the IL-12 gene to respiratory tissues modifies allergic inflammation and airway hyper-responsiveness (AHR) in our disease model. To enhance the in vivo delivery of the IL-12 gene, we expressed the murine single-chain IL-12 protein from a nonviral vector to which the two IL-12 subunits (p35 and p40) were linked by a 14- to 18-amino-acid linker. One of these single-chain IL-12s, containing an 18 amino-acid polypeptide linker, was stably expressed and had a high level of biological activity comparable to that of native IL-12 in vitro. In mice with Der p 1-induced asthma, the local administration of this IL-12 fusion gene into the lungs significantly prevented the development of AHR, abrogated airway eosinophilia, and inhibited type-2 cytokine production. These findings indicate that the local transfer of the single-chain IL-12 gene is effective in modulating pulmonary allergic responses and may be a convenient method for future applications of DNA vaccination.
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan, Republic of China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Lee
authors.forename: Y L
authors.initials: YL
authors.lastname: Ye
authors.forename: C I
authors.initials: CI
authors.lastname: Yu
authors.forename: Y L
authors.initials: YL
authors.lastname: Wu
authors.forename: Y L
authors.initials: YL
authors.lastname: Lai
authors.forename: P H
authors.initials: PH
authors.lastname: Ku
authors.forename: R L
authors.initials: RL
authors.lastname: Hong
authors.forename: B L
authors.initials: BL
authors.lastname: Chiang
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D001249:Asthma / Q000235:genetics* / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D001980:Bronchi / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid; D019556:COS Cells; D004195:Disease Models, Animal; D005260:Female; D015316:Genetic Therapy / Q000379:methods; D007167:Immunotherapy / Q000379:methods; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D018664:Interleukin-12 / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000627:therapeutic use*; D008168:Lung / Q000276:immunology / Q000473:pathology; D016210:Methacholine Chloride / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D010957:Plasmids / Q000235:genetics*; D014162:Transfection; D019444:Vaccines, DNA / Q000235:genetics / Q000627:therapeutic use
chemical_list: D000485:Allergens; D019444:Vaccines, DNA; D016210:Methacholine Chloride; D018664:Interleukin-12