CD19 CAR-T Expressing IL-7 and CCL19 Combined With Anti-PD1 in RR-DLBCL

The goal of this clinical trial is to test CD19-7×19 CAR-T cells combined with Tislelizumab in refractory and relapsed diffuse large B lymphoma. The main question\[s\] it aims to answer are:

question 1：What is the safety of CD19-7×19 CAR-T cells combined with Tislelizumab in the treatment of relapsed or refractory diffuse large B-cell lymphoma.

question 2：What is the efficacy of CD19-7×19 CAR-T cells combined with Tislelizumab in the treatment of relapsed or refractory diffuse large B-cell lymphoma.

Participants will be asked to receive clinical evaluation before CAR-T, including physical examination, blood routine test, biochemical test, imaging test, etc.Peripheral blood lymphocytes will be collected for preparation of CAR-T cells after enrollment. Pretreatment chemotherapy with fludarabine and cyclophosphamide will be used before CAR-T infusion. On the 31st day after CAR-T infusion, Tislelizumab 200mg was given once every 21 days for 6 cycles. Participants will be required to report concomitant medication and adverse events, and their disease was evaluated throughout the study.