Anti-inflammatory activity of chloroquine and amodiaquine through p21-mediated suppression of T cell proliferation and Th1 cell differentiation.
Chloroquine (CQ) and amodiaquine (AQ) have been used for treating or preventing malaria for decades, and their application has expanded into treating inflammatory disease in humans. CQ and AQ are applicable for controlling rheumatoid arthritis, but their molecular mechanisms of anti-inflammatory activity remain to be elucidated. In this study, we examined the effects of CQ and AQ on T cell activation and T cell-mediated immune response. CQ had no significant effect on T cell numbers, but decreased the population of T cells with a high division rate. However, AQ treatment significantly increased the number of cells with low division rates and eliminated cells with high division rates, resulting in the inhibition of T cell proliferation triggered by T cell receptor stimulation, of which inhibition occurred in developing effector T helper and regulatory T cells, regardless of the different exogenous cytokines. Interestingly, the cyclin-dependent kinase inhibitor p21 was significantly and dose-dependently increased by CQ, and more potently by AQ, while other cell cycle regulators were unchanged. Both CQ and AQ elevated the transcription level of p21 though the activation of p53, but also blocked p21 protein degradation in the presence of cycloheximide, causing p21 protein accumulation mainly in the nucleus. Sustained treatment of developing T cells with either CQ or AQ suppressed IFN-γ production in a dose dependent manner and potently inhibited the differentiation of IFN-γ-producing Th1 cells. These results demonstrate that CQ and AQ increase the expression level of p21 and inhibit T cell proliferation and the development of IFN-γ-producing Th1 cells, thereby revealing beneficial roles in treating a wide range of chronic inflammatory diseases mediated by inflammatory T cells.
College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
Sera
S
Oh
College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
Ji Hyun
JH
Shin
College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
Eun Jung
EJ
Jang
College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
Hee Yeon
HY
Won
College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
Hyo Kyeong
HK
Kim
College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
Mi-Gyeong
MG
Jeong
Molecular Neurobiology Laboratory, Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA.
Kwang Soo
KS
Kim
College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea. Electronic address: eshwang@ewha.ac.kr.
Eun Sook
ES
Hwang
D000655:Amodiaquine / Q000008:administration & dosage*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002738:Chloroquine / Q000008:administration & dosage*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018836:Inflammation Mediators / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology*; D018417:Th1 Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D016896:Treatment Outcome
D000893:Anti-Inflammatory Agents; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018836:Inflammation Mediators; D000655:Amodiaquine; D002738:Chloroquine
Amodiaquine; Chloroquine; IFN-γ; Proliferation; p21