KN5501 Cell Injection for Refractory SLE(CLEAR)

The goal of this clinical trial is to learn about the safety, pharmacokinetics and pharmacodynamics profile of KN5501 cell injection in adults with systemic lupus erythematosus(SLE). It will also learn if KN5501 cell injection works to treat refractory SLE. The main questions it aims to answer are: 1. Is KN5501 cell injection safe in adults with SLE? And the maximum tolerated dose? 2. Does KN5501 cell injection lower the disease activity of SLE in adults with refractory SLE？ Participants will: Receive one or multiple (3 to 5 times) intravenous infusion of KN5501 cell injection at inpatient ward after lymphodepletion. Visit the clinic at predefined frequency (from 1 week interval to 12-16 weeks' interval) for checkups and tests.