Eligibility Criteria:
Inclusion Criteria:
* Recent diagnosis (within 100 days of enrollment) of T1DM
* Positive for at least one diabetes autoantibody (Glutamate decarboxylase \[GAD-65GAD65\], IA2, ZnT8, ICA and Insulin, if obtained within 10 days of the onset of exogenous insulin therapy)
* Peak stimulated C-peptide level \> 0.2 pmol/mL following a mixed-meal tolerance test (MMTT)
* Willingness to provide written informed consent (either the subject or the subject's legally authorized representative).
Exclusion Criteria:
* Severe reaction or anaphylaxis to human monoclonal antibodies
* History of malignancy or significant cardiovascular disease (including history of myocardial infarction, angina, use of anti-anginal medicines (e.g., nitroglycerin), or abnormal stress test)
* History of recent or ongoing uncontrolled bacterial, viral, fungal, or other opportunistic infections
* Evidence of infection with hepatitis B virus (HBV) as defined by hepatitis B surface antigen, HBsAg; hepatitis C virus (HCV) defined by anti-HCV antibodies; human immunodeficiency virus (HIV); or toxoplasmosis
* Positive tuberculin skin test (PPD)
* Clinically active infection with Epstein-Barr virus (EBV)-EBV viral load ≥ 10,000 copies per 10\^6 PBMCs; cytomegalovirus (CMV) -CMV viral load ≥10,000 copies per mL whole blood; or tuberculosis (TB)
* Diagnosis of liver disease or hepatic enzymes, as defined by ALT and/or AST ≥ 2 times the upper limit of normal
* Prior or current treatment that is known to cause a significant, ongoing change in the course of T1DM or immunologic status, including high-dose inhaled, extensive topical or systemic glucocorticoids
* Current or prior (within the last 30 days) use of metformin, sulfonylureas, glinides, thiazolidinediones, exenatide, liraglutide, DPP-IV inhibitors or amylin
* Current use of any medication known to influence glucose tolerance (e.g., atypical antipsychotics, diphenylhydantoin, thiazide, or other potassium-depleting diuretics, β-adrenergic blockers, niacin)
* Any of the following hematologic abnormalities, confirmed by repeat tests at least 1 week apart:
1. White blood count \<4000/μL or \>14,000/μL;
2. CD4+ count below the lower limit of normal;
3. Platelet count \<150,000 /μL; or
4. Hemoglobin \<10 g/dL.
* Females who are pregnant, lactating, or planning on pregnancy during the 2-year study period
* History of bone marrow transplantation, or autoimmune disease associated with lymphopenia
* Any medical condition that in the opinion of the principal investigator would interfere with safe completion of the trial
* Prior participation in a clinical trial that could potentially affect T1DM or immunologic status
* Receipt of a live vaccine (e.g., varicella, measles, mumps, rubella, cold-attenuated intranasal influenza vaccine, bacillus Calmette-Guérin, and smallpox) in the 6 weeks before enrollment
* Participation in an investigational clinical trial within the last six weeks.