This is an open single-arm clinical study aimed at evaluating the safety and tolerance of allogeneic γ9δ2 T cell injection in the treatment of patients with recurrent hematologic tumors after allogeneic hematopoietic stem cell transplantation.

To evaluate the safety and in vivo dynamics of allogeneic γ9δ2 T cell in the treatment of recurrent hematologic tumors after allogeneic hematopoietic stem cell transplantation patients, and to explore the appropriate therapeutic dose.

Inclusion Criteria:

1. Age 12-65 (inclusive)；

2. Patients with recurrent hematologic tumors after allogeneic hematopoietic stem cell transplantation；

3. Basically normal liver and kidney function (as demonstrated by the following laboratory tests prior to initial γ9δ2 T cell therapy)

   • Alanine transaminase/aspartate transaminase < 2.5×ULN；
   • serum creatinine < 1.5×ULN；
   • total bilirubin level < 1.5×ULN；

4. No obvious hereditary disease;

5. Normal cardiac function, cardiac ejection index above 55%;

6. Women of reproductive age (15 to 49 years) must undergo a pregnancy test within 7 days before starting treatment and the result is negative, and use contraception during the clinical trial period and within 3 months after the last cell transfusion;

7. Sign informed consent.

Exclusion Criteria:

1. Patients with simple extramedullary recurrence;

2. Pregnant and lactating women;

3. Organ failure;

   • Heart: Ⅲ level and Ⅳ level;
   • Liver: reach the grade C Child - Turcotte liver function;
   • Kidney, renal failure and uremia period;
   • Lung: symptoms of severe respiratory failure;
   • Brain: consciousness disorder.

4. Patients with a history of solid organ transplantation;

5. Uncontrollable infectious diseases or other serious diseases, including but not limited to infections (such as HIV positive), congestive heart failure, unstable angina, arrhythmia, psychosis, or restricted social circumstances or those that the attending physician considers to pose unpredictable risks;

6. Patients with systemic autoimmune diseases or primary immunodeficiency;

7. Patients with allergic constitution;

8. Use of systemic steroid drugs;

9. Chronic diseases requiring the use of immunological agents or hormone herapy;

10. Prior treatment with any other immune cells;

11. Participated in similar clinical trials within 30 days;

12. Received radiation therapy within 4 weeks from the time of enrollment;

13. Researchers don't think clinical trials are appropriate for other reasons.