• voluntary to sign the ICF

• aged between 18-65 years old (inclusive)

• diagnosed with diffuse systemic sclerosis according to 2013 ACR Systemic Sclerosis Classification Criterion

• meet the definitions of refractory/progressive as below:

‣ refractory: non-respondent to or disease recurrence after remission with conventional therapies. Conventional therapies are defined as treated for more than 6 months with low dose steroids (≤ 15 mg prednisone equivalent), cyclophosphamide, antimalarials, azathioprine, mycophenolate mofetil, methotrexate, leflunomide, tacrolimus, cyclosporin or biologics such as rituximab, belimumab, telitacicept, tocilizumab;

⁃ progressive: having below manifestations within 6 months

• mRSS increases by \>= 3

∙ FVC decreases by \> 10% or FVC decreases by \> 5% and DLCO decreases by \> 15%

• without systemic active infections within 2 weeks of leukapheresis, e.g., infectious pneumonia, tuberculosis

• available vascular access for leukapheresis

• major organ functions:

‣ Renal function: CrCl ≥50 ml/min (Cockcroft/Gault equation)

⁃ Bone marrow function: ANC ≥ 1000/uL, absolute lymphocyte count ≥100/uL, Hb ≥90 g/L, Platelet count ≥75 x 10\^9/L. Blood transfusion and infusion of growth factors within 7 days of eligibility assessment are not allowed.

⁃ Liver function: ALT ≤ 3 x ULN, AST ≤ 3 x ULN, total bilirubin ≤ 2 x ULN (in case of Gilbert syndrome, total bilirubin ≤ 3 x ULN)

⁃ Coagulation: INR ≤ 1.5 x ULN, PT ≤1.5 x ULN

⁃ Cardiac function: LVEF ≥ 55%

• negative result of serum β-hCG measurement for women of childbearing potential at screening and within 48 hours of the first dose of lymphodepletion

• Female subjects with childbearing potential or male subjects with partners of childbearing potential should adopt medically effective contraception or abstinence from enrollment to 2 years after the end of the study; female subjects with childbearing potential should have a negative serum hCG test within 7 days of enrollment and not in lactation