Clinical Study of Cord Blood-derived CAR NK Cells Targeting CD19/CD70 in Refractory/Relapsed B-cell Non-Hodgkin Lymphoma

Inclusion Criteria: 1. Voluntarily participate in the study and sign the informed consent; 2. Age 18-75, male and female; 3. Histologically confirmed diffuse large B-cell lymphoma (DLBCL), transformed follicular lymphoma (tFL), primary mediastinal B-cell lymphoma (PMBCL), mantle cell lymphoma (MCL), and other inert B-cell NHL transforming types: (1)refractory or recurrent DLBCL and tFL must be approved by 2 line immune disease relapse after chemotherapy treatment; (2) refractory definition large B cell lymphoma (research SCHOLAR - 1 standard) : more than 4 courses first-line immune chemotherapy disease progression; The stable time of the disease is equal to or less than 6 months; Or disease progression or recurrence within 12 months after autologous hematopoietic stem cell transplantation; (3) refractory or recurrent MCL must be 1 line with immune chemotherapy; BTK inhibitors are resistant or intolerant as 2-line therapy; (4)always treatment must include CD20 single resistance (unless the subjects for CD20 negative) and anthracycline-based; 4\. There was at least one measurable lesion with the longest diameter ≥1.5 cm; 5\. Predicted survival ≥12 weeks; 6\. The expression of CD19 or CD70 in biopsy sections of tumor tissue was positive; 7\. ECOG score 0-2; 8\. Adequate reserve of organ functions: 1. cereal third transaminase, aspartate aminotransferase 2.5 x or less UNL (upper limit of normal); 2. creatinine clearance (Cockcroft - Gault method) or 60 mL/min. 3. serum total bilirubin and alkaline phosphatase (1.5 x or less UNL. 4. glomerular filtration rate \> 50 mL/min 5. heart ejection fraction (EF) 45% or higher; 6. indoor natural air environment, basic oxygen saturation \> 92% 7. blood routine: neutrophils absolute number \> 1000 cells/mm3, platelet count 45 x109, 8.0 g/dL hemoglobin; 9\. Allowed to have received a previous stem cell transplant 10\. Approved anti-B-cell lymphoma therapies, such as systemic chemotherapy, systemic radiotherapy and immunotherapy, had been completed for at least 3 weeks before the study. The eluting period of targeted drug regimens without chemotherapy was 2 weeks; 11\. Patients who had previously received CAR T cell therapy and failed to respond to a 3-month evaluation or relapsed were admitted; 12\. Female subjects of childbearing age must test negative for pregnancy and agree to use effective contraceptive methods during the trial 13\. Two tests have come back negative for COVID-19. Exclusion Criteria: 1. Allergic to any of the components of cell products; 2. History of other tumors; 3. Acute GvHD or generalized chronic GvHD with grade II-IV (Glucksberg standard) after previous allogeneic hematopoietic stem cell transplantation; Or being treated with anti-GVHD; 4. Had received gene therapy in the past 3 months; 5. Active infections requiring treatment (other than simple urinary tract infections and bacterial pharyngitis), however, prophylactic antibiotics, antiviral and antifungal infections are allowed; 6. Subjects infected with hepatitis B (HBsAg positive, but HBV-DNA\<103 is not excluded) or hepatitis C virus (including virus carriers), syphilis and other acquired and congenital immunodeficiency diseases, including but not limited to HIV-infected persons; 7. Subjects with Grade III or IV cardiac insufficiency according to the New York Heart Association Cardiac Function Grading criteria; 8. Patients who received antitumor therapy in the early stage but the toxicity reaction did not recover (CTCAE 5.0 toxicity reaction did not recover to ≤ level 1, except fatigue, anorexia and alopecia); 9. Subjects with a history of epilepsy or other central nervous system diseases; 10. Skull enhanced CT or MRI showing evidence of central nervous system lymphoma; 11. Lactating women who refuse to stop breastfeeding; 12. Any other circumstances that the investigator believes may increase the subject's risk or interfere with the test results.