Inhibitory activity of a ceramide library on interleukin-4 production from activated T cells Jin Park, a,b Qian Li, c Young-Tae Chang c and Tae Sung Kim a,b, * a Department of Pharmacy, College of Pharmacy, Chonnam National University, Gwangju 500-757, Republic of Korea b Research Institute of Drug Development, Chonnam National University, Gwangju 500-757, Republic of Korea c Department of Chemistry, New York University, New York, NY 10003, USA Received 13 November 2004; revised 17 January 2005; accepted 18 January 2005 Abstract—Allergic diseases are hypersensitivity disorders associated with the production of specific immunoglobulin E (IgE) to envi- ronmental allergens. Interleukin (IL)-4, produced primarily by CD4 + T cells, is an important stimulus for the switch of the antibody isotype to IgE in both mice and humans. In this study we investigated the inhibitory activity of IL-4 production in activated T cells by screening ceramide derivatives prepared by solid phase combinatorial chemistry. Many ceramide derivatives significantly inhib- ited IL-4 production in T cells. In particular, ceramide derivatives with a lauroyl group showed strong inhibitory activities on IL-4 production in both phorbol 12-myristate 13-acetate (PMA)-activated EL4 T cells and antigen-primed cells, suggesting that they can be used as compounds for the development of anti-allergic agents. Ó 2005 Elsevier Ltd. All rights reserved. 1. Introduction Ceramide refers to a family of highly hydrophobic mole- cules that contain a variable length fatty acid linked to sphingosine or a related long chain base. 1 Ceramide has a number of important physiologic functions that regulate cellular homeostasis including regulation of the stress response, induction of cell differentiation, reg- ulation of cell cycle arrest and apoptosis. 2 IL-4, a pleiotropic cytokine produced by activated T cells, basophils and mast cells, regulates many cellular and humoural immune responses. Dysregulation of IL- 4 expression results in uncontrolled allergic inflamma- tion including asthma and aberrant immune responses to pathogens. 3 IL-4 has a variety of other effects in hepatopoietic tissues. It increases the expression of class II MHC molecules in B cells, 4 enhances expression of CD23, 5 and up-regulates the expression of the IL-4 receptor. 6 IL-4 also has an important role in tissue adhesion. 7 Previous studies have showed that the glycosphingolipids derived from tumours or parasites exhibited immunosup- pressive activity. 8 A role for ceramides in regulating the immune response was suggested based on several obser- vations, including its role in apoptosis, TCR expression, T cell proliferation, T cell activation and cytokine expres- sion. 9 Because ceramides play a diversity role in regula- tion of immune responses and immunosuppressive activity, especially T cell responses, 10 we synthesize a cer- amide library and investigate their inhibitory activities on IL-4 production concerned with allergic inflammation. 2. Results and discussion A ceramide library was synthesized by a solid phase combinatorial chemistry as previously described (Fig. 1A). 11 A library of 80 compounds was generated using 8 sphingosine-like core structures and 10 acyl groups (Fig. 1B). The synthetic compounds were characterized by high-resolution mass spectrometry and 1 H NMR to confirm their identity and purity. To examine the effects of the ceramide compounds on IL-4 production, EL4 T cells were stimulated in vitro for 48 h with PMA in the absence or presence of cera- mide derivatives. As indicated in Table 1 and Figure 2, 0968-0896/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.bmc.2005.01.027 Keywords: Ceramide library; Interleukin-4; T cells; Allergy. * Corresponding author. Tel.: +82 62 530 2935; fax: +82 62 530 2911; e-mail: taekim@chonnam.ac.kr Bioorganic & Medicinal Chemistry 13 (2005) 2589–2595