A peptide-nucleic acid immunomodulator with proinflammatory, broad-spectrum antiviral, and potential antineoplastic activities. Immunomodulator OHR/AVR118 stimulates the peripheral blood mononuclear cell (PBMC) production of the proinflammatory cytokines IFN-y, IL-1b, IL-6 and TNF-a. This agent may reduce HIV-1 p24 antigen; viral reverse transcriptase activity; syncitial cell formation; and viral mRNA in infected PBMCs and human CD4+ lymphocyte H9 cells, and may decrease viral loads and increase CD4+ and CD8+ T-cell counts in HIV patients. In vitro, immunomodulator OHR/AVR118 has been shown to induce the maturation of HL60 leukemic cells and to inhibit the invasive and metastatic properties of a highly malignant breast cancer cell line.