OBJECTIVES: I. Determine whether adoptive immunotherapy comprising donor-derived CD8+, CMV-specific, major histocompatibility complex class I-restricted cytotoxic T-lymphocyte (CTL) clones (CD8+ CMV-specific CTL clones) and CD4+ CMV-specific T-helper (Th)-cell clones is effective in preventing CMV viremia and disease in CMV-positive patients with malignancies requiring allogeneic bone marrow or peripheral blood stem cell transplantation. II. Determine whether the transfer of CD4+ CMV-specific Th-cell clones to patients with deficient responses can reconstitute CD4+ Th-cell activity and augment adoptively transferred CD8+ CMV-specific CTL clones.