HIV-infected people who are at least 18 years old, whose CD4+T cell count is 100 cells per microliter or less, and who have not previously been treated with combination antiretroviral therapy or have taken the drugs for less than 3 months and more than 6 months before screening for this study may be eligible to participate. Candindates must also live within the wider DC area so that acute problems after therapy initiation will be evaluated at NIH. Candidates are evaluated before starting therapy with a medical history and physical examination, blood and urine tests, electrocardiogram, chest x-ray and CT scan of the chest, tuberculin skin testing, apheresis, and possibly an intestinal (gut) and lymph node biopsy (surgical removal of a small piece of tissue for microscopic examination). For apheresis, blood is collected through a needle in an arm vein and spun in a machine that separates the blood components. The white blood cells and plasma are removed, and the red cells and platelets are returned through the same needle or through a needle in a vein in the other arm.