Type 1 diabetes (T1D) is an autoimmune disease characterized by a progressive immune distruction of pancreat beta cells and deterioration of endogenous insulin secretion. Regulatory T cells (Treg) are fuctionally deficient in T1D, leading to the loss of immune tolerance to the islets and the initiation of an autoimmune attack. Previouse studies have revealed the potential theraputic effects of autologous Treg transplantation in T1D. We have modified the preparation protocol for autologous Tregs. The purpose of this study is to assess the safety and effect of autologous Treg therapy in patients with T1D.

Inclusion Criteria:

• Meet the diagnostic criteria of T1DM based on the 2021 version of the Chinese Guidelines for Diagnosis and Treatment of Type 1 Diabetes;
• Aged 8 to 65 years;
• At least one islet autoantibody positive and/or fasting C-peptide does not exceed 300pmol/L;
• Must be capable of providing written, signed, and dated informed consent and willing to comply with research requirements in the study.

Exclusion Criteria:

• The condition of diabetic ketoacidosis has not been controlled;
• Severe allergic constitution;
• Known or suspected tumor;
• Acute pancreatitis, and severe heart, liver, kidney, rheumatic immune, respiratory, nervous or infectious diseases.
• Suffering from gestational diabetes mellitus, single gene mutation diabetes mellitus, diabetes mellitus caused by pancreatic damage or other secondary diabetes mellitus (such as diabetes mellitus caused by Cushing's syndrome, thyroid dysfunction or acromegaly, etc.);
• Women who are pregnant or have a pregnancy plan before and after treatment, and women who are breastfeeding.
• Mental illness, alcohol or drug abuse, unable to cooperate with treatment;
• According to the judgment of the investigator, there are other clinical conditions that may endanger the safety of the subjects.