A Trial to Evaluate the Safety and Preliminary Efficacy of iMesenchymal Stromal Cells(iMSC) in Subjects With SR-aGVHD

Inclusion Criteria: 1.Subjects who understand and voluntarily sign the Informed Consent Form(ICF); 2.4-70 years; 3.Subjects with SR-aGVHD; 4.ECOG≤2; 5.Subjects with II to IV grades of steroid hormone resistance; Exclusion Criteria: 1. Accepted systemic or local treatment of mesenchymal stem cells; 2. Have severe allergy to blood products or have allergy history of heterologous protein; 3. Expected survival period within 3 months; 4. Alanine transaminase(ALT)or Aspartate aminotransferase(AST)\>2\*upper limit of normal(ULN);Creatinine clearance rate≤30ml/min or Blood Urea Nitrogen(BUN)\>2\*upper limit of normal(ULN), International Normalized Ratio (INR)\>1.5\*upper limit of normal(ULN); 5. Have severe hepatic veno-occlusive disease(HVOD); 6. Have severe lung disease like severe lung infection; 7. Have history of severe acute myocardial infarction or have uncontrolled angina pectoris,arrhythmia and severe heart failure; 8. Proved having resistant hypertension within 6 months before enrollment; 9. Have active thrombus; 10. Have untreated or uncertain active solid tumors within 5 years; 11. Have alcohol or drug addiction or with a clear history of mental disorders or with a history of drug abuse or drug use of psychotropic substances; 12. Human immunodeficiency virus(HIV)antibody positive, treponema pallidum (TP) antibody positive; 13. Have active hepatitis B or hepatitis C; 14. Have gastrointestinal symptoms which not caused by GVHD 15. Pregnant or lactating female subjects, or subjects who are unable to comply with contraceptives from the study period to 6 months after the end of this study; 16. Subjects who have participated in other clinical trials and have used other study products within 12 weeks before screening; 17. Not suitable for this clinical trial for other reasons.