All patients receive azithromycin and paromomycin, and patients are randomized to add either IL-12 or placebo. IL-12 (or placebo) injections are given twice a week. Patients take their study medications for 4 weeks. During this time, they will be asked to record bowel movements and any symptoms they experience. Patients return to the clinic at least twice a week to receive IL-12 (or placebo) injections. At Weeks 2 and 4, patients are seen by one of the principal investigators. Blood samples are obtained for viral load measurements and CD4 count, as well as routine urinalysis. Patients undergo upper endoscopy with jejunal biopsy and colonoscopy with ileal biopsy between Weeks 2 and 4 of therapy for assays of intestinal cytokine expression. A final clinic visit occurs 12 weeks post-therapy for a physical exam and blood tests.