1. Department of Obstetrics and Gynecology, The 2nd Xiangya Hospital, Central South University, Changsha, Hunan, China
2. Department of Microbiology, Immunology, and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
3. Department of Immunology, Central South University, Changsha, Hunan, China
4. Department of Obstetrics and Gynecology, The 3rd Xiangya Hospital, Central South University, Changsha, Hunan, China