1. Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
2. Department of Rheumatology and Immunology, The General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
3. Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA