Both donor and recipient volunteers must be HIV-positive individuals 18 years of age or older who have the HLA-B*57 marker and are receiving care. Donor candidates must have positive HIV antibody tests for at least seven years with a recent CD4 cell count greater than 400 cells/mm?, HIV viral load less than 50 copies/mL, and no previous HIV viral load greater than 1,000 copies/mL. Recipient candidates must have positive HIV antibody tests with a recent CD4 cell count less than 400 cells/mm? and HIV viral load greater than 10,000 copies/mL, and must have failed at least two prior combination antiretroviral regimes and are willing to receive or resume combination antiretroviral therapy. Donor volunteers will be excluded if they have taken certain antiretrovirals drugs, have a medical history of cancer or of other blood-borne illnesses, or have other medical conditions that might interfere with the study. Recipient volunteers will be excluded if they have a medical history of malignant cancer or other medical conditions that might possibly interfere with the study.