This study investigates the infusion safety and potential curative properties of ex-vivo expanded γδ T cells obtained from the same donor for patients who have hematological malignancies and have accepted allogeneic hematopoietic stem cell transplantation.

This is a single-center, open-label, single-arm study to evaluate the safety and efficacy of ex-vivo expanded γδ T cell in patients with hematological malignancies after allogeneic hematopoietic stem cell transplantation. γδ T cell will be separated from peripheral blood of the same donors. After expansion in vitro, they will be infused to the patients as an immunotherapy treatment.

Inclusion Criteria:

1. Patients with hematological malignancies after allogeneic hematopoietic stem cell transplantation；

2. Age criteria: 18-65 years;

3. Weight criteria: > 40kg;

4. Organ function criteria:

   Cardiac function: Left ventricular ejection fraction (LVEF) ≥40%, Pulmonary function: Indoor oxygen saturation≥95%, Alanine aminotransferase and aspartate aminotransferase ≤ 2.5×ULN (upper limit of normal value), Total bilirubin ≤ 1.5×ULN, Serum creatinine ≤ 1.5×ULN;

5. Life expectancy of at least 4 months;

6. ECOG (Eastern Cooperative Oncology Group) score ≤ 2;

7. Patients able to understand and sign written informed consent.

Exclusion Criteria:

1. GVHD (graft versus host disease) ≥ grade Ⅱ；
2. Thrombotic microangiopathy；
3. Posttransplant lymphoproliferative disorders；
4. Uncontrolled infection or other uncontrolled medical or psychiatric disorders which may preclude patients to undergo clinical studies (discretion of the attending physician)；
5. Patients with chronic diseases that require treatment with immune agents or hormones;
6. Suffering from systemic autoimmune disease or immunodeficiency disease;
7. Systemic use of steroids;
8. Allergic constitution;
9. Hemorrhagic disease or coagulation disorders;
10. Patients participating in other clinical trials within 30 days prior to enrollment;
11. Patients receiving radiotherapy within 4 weeks prior to enrollment;
12. Pregnant or breastfeeding women;
13. According to the researcher's judgment, the patient has other unsuitable conditions.