A Study of GNTI-122 in Adults Recently Diagnosed With T1D

Inclusion Criteria: 1. Male and female participants aged ≥18 to ≤55 years with recently diagnosed (within 180 days of Screening) T1D according to American Diabetes Association criteria. 2. Participant has residual β-cell function during Screening, defined as random C-peptide ≥ 0.2 nmol/L. 3. Positive for at least one T1D-associated autoantibody. 4. Able and willing to provide written, informed consent as approved by the IRB. 5. Is confirmed positive for the HLA-DRB1\*04:01 allele. 6. Has adequate vascular access to undergo leukapheresis with no known contraindications. 8\. Female participants of childbearing potential must have a negative serum pregnancy test at Screening, must be not lactating, and must agree to protocol-specified contraception. 9\. Male participants of childbearing potential must agree to protocol specified contraception. 10\. Other than T1D, participant is in good general health. Exclusion Criteria: 1. Type 2 diabetes. 2. Experienced DKA within 4 weeks prior to or during Screening. 3. Unwilling or unable to comply with study procedures or schedule. 4. Chronic or uncontrolled medical condition. 5. Has another active or autoimmune or inflammatory disease with the exception of well-controlled Hashimoto's thyroiditis, celiac disease, or vitiligo. 6. Participation in another clinical study or active follow-up in a prior study.