ovalbumin and Ear-Diseases

CC chemokine ligand 17 (CCL17/thymus and activation-regulated chemokine: TARC) and CCL22 (macrophage-derived chemokine: MDC) selectively bind to CC chemokine receptor 4 (CCR4). The CCR4 system is considered to be responsible for the pathology of allergic diseases such as atopic dermatitis. To find and develop potential medicines against allergic diseases, we screened an in-house library to search for compounds having a profile as a CCR4 antagonist. From among the screening hits, we focused on 3-{2-[(2R)-2-phenyl-4-(4-pyridin-4-ylbenzyl)morpholin-2-yl]ethyl}quinazoline-2,4(1H,3H)-dione (named RS-1154), which had been newly synthesized in our laboratory. This compound inhibited the binding of [(125)I]CCL17 to human CCR4-expressing CHO cells with an IC(50) value of 27.7 nM and moreover inhibited CCL17-induced migration of DO11.10 mice-derived T helper 2 cells with an IC(50) value of 1.5 nM in vitro. We then examined the effect of RS-1154 in an ovalbumin-induced ear swelling assay. The ear thickness was decreased by intravenous administration of anti-CCL17 or anti-CCL22 antibodies, suggesting that the CCR4 system is involved in the ear swelling. Though partially, the oral administration of RS-1154 also significantly ameliorated the ear swelling at the doses of 30 and 100 mg/kg. Furthermore, the serum level of interleukin-4 decreased after the administration of RS-1154. In this study, we succeeded in obtaining a newly-synthesized compound, RS-1154, which has a potential to inhibit the chemotaxis of T helper 2 cells in vitro and to ameliorate ovalbumin-induced ear swelling in vivo. These results raise the possibility that RS-1154 or one of derivatives might become a therapeutic agent for atopic dermatitis patients.

Topics: Administration, Oral; Animals; Biological Assay; CHO Cells; Cricetinae; Cricetulus; Dermatitis, Atopic; Dermatologic Agents; Ear Diseases; Inhibitory Concentration 50; Interleukin-4; Mice; Mice, Inbred BALB C; Morpholines; Ovalbumin; Quinazolinones; Receptors, CCR4; T-Lymphocytes, Helper-Inducer

To examine the expression of Foxp3 on CD8+ T cells in the spleen during anterior chamber-associated immune deviation (ACAID).. Ovalbumin (OVA) was injected into the anterior chamber (AC) of C57BL/6 mice, and the delayed-type hypersensitivity (DTH) response was measured to evaluate the development of ACAID. The suppressive effect of CD8+ T cells in ACAID mice was determined by a local adoptive transfer (LAT) assay. Flow cytometry was used to assay the frequency of CD8+ Foxp3+ T cells from normal mice, ACAID mice, and control mice receiving an AC injection of PBS (PBS-AC-injected mice). These frequencies were also tested after polyclonal or specific antigen stimulation. The mRNA level of Foxp3 in CD8+ splenocytes from different groups with or without stimulation were determined by reverse transcription-polymerase chain reaction.. OVA injection into the AC induced ACAID, and CD8+ T cells from ACAID mice inhibited the ear-swelling response by OVA-primed responder cells in LAT assay. Flow cytometry analysis showed that the frequency of CD8+ Foxp3+ cells in splenocytes was upregulated in ACAID mice following polyclonal or specific antigen stimulation. Foxp3 mRNA was only detected in CD8+ T cells from ACAID mice after polyclonal stimulation.. An upregulated Foxp3 expression in CD8+ T cells is associated with the development of ACAID, suggesting an involvement of CD8+ Foxp3+ T cells in this model of immune tolerance.

Topics: Adoptive Transfer; Animals; Anterior Chamber; Antigens; CD8-Positive T-Lymphocytes; Cells, Cultured; Ear Diseases; Edema; Flow Cytometry; Forkhead Transcription Factors; Hypersensitivity, Delayed; Immune Tolerance; Lymphocyte Activation; Lymphocyte Count; Mice; Mice, Inbred C57BL; Ovalbumin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spleen; Up-Regulation