CTLA-4 is a negative regulator of T-cell activation, and its inhibitory effects can be accomplished either by competition with CD28 or by transmitting negative signals through its intracellular domain. To utilize the cytoplasmic domain of CTLA-4 to suppress allergic inflammation, we fused it to a novel protein-transduction domain in the human transcriptional factor Hph-1. Transduction efficiency was verified in vitro and in vivo after ocular, intranasal and intradermal administration. After transduction into T cells, the Hph-1-ctCTLA-4 fusion protein inhibited the production of interleukin (IL)-2, and downregulated CD69 and CD25. Intranasal administration of Hph-1-ctCTLA-4 resulted in markedly reduced infiltration of inflammatory cells, secretion of T helper type 2 (TH2) cytokines, serum IgE levels and airway hyper-responsiveness in a mouse model of allergic airway inflammation. These results indicated that Hph-1-ctCTLA-4 constitutes an effective immunosuppressive protein drug for potential use in the treatment of allergic asthma, via nasal administration.
Bibliographical noteFunding Information:
We thank A. Bothwell and T. Morio for the comments on the manuscript and all members of Immune Cell Engineering Laboratory, Department of Biotechnology, Yonsei University for their spiritual help. This work was supported in part by research grants to S.K.L. from Korea Institute of Industrial Technology Evaluation and Planning (M1-0310-40-0000), Korea Health Industry Development Institute (0412-DB00-0101-0011), Korea Science and Engineering Foundation (2005-00117) and Korea Rural Economic Institute (204081-3). This work was also supported in part by research grants to C.S.P. from the Korea Health 21 R&D Project, Ministry of Health and Welfare, Republic of Korea (01-PJ3-PG6-01GN04-003).
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)