Inclusion Criteria:

- Recipients age 18 or older of an HLA-non-identical,living or deceased donor kidney
transplant.

- A willing renal donor who consents for subsequent donation of donor blood for testing
throughout the follow-up period and for use of his/her kidney in this experimental
study.

Exclusion Criteria:

- Immunosuppressive drug therapy within 1 year prior to enrollment.

- Active malignancy or history of malignancy within 5 years of enrollment.

- Any history of blood malignancy or lymphoma.

- Any known immunodeficiency syndrome, including HIV infection.

- Absence of EBV or CMV specific antibodies in cases with evidence of EBV and/or CMV
infection.

- Women of child-bearing potential unwilling or unable to use an acceptable method of
birth control.

- Women who are pregnant or breastfeeding at the time of enrollment or study drug
administration.

- Donor age <18 years.

- Subjects with protocol-specific etiologies of underlying renal disease.

- Subjects with a positive T-cell lymphocytic crossmatch or historical evidence of
donor specific alloantibody by solid phase or flow-based detection methods.

- Prior solid organ transplant or potential to require a concurrent organ or cell
transplant.

- Positive Hepatitis B or C antibodies and PCR positive for the same.

- Active (tuberculosis) TB requiring treatment within the previous 3 years.

- Known positive PPD unless chest x-ray is negative or treatment for latent TB has been
completed.

- Active infection or other contraindications.

- History of drug or alcohol abuse within the past 5 years.

- Psychotic disorders which would interfere with adequate study follow-up.

- Active peptic ulcer disease, chronic diarrhea, or gastric malabsorption.

- All women 40 years or older with first degree family history of breast cancer will be
required to have a screening mammogram within 6 months of study enrollment.

- Subjects with suspicion of breast malignancy which cannot be ruled out will be
excluded.

- Belatacept use within 30 days prior to the day 1 visit.

- Prisoners or individuals who are involuntarily incarcerated.