Petkov, StefanKilpeläinen, AthinaBayurova, EkaterinaLatanova, AnastasiaMezale, DzeinaFridrihsone, IlseStarodubova, ElizavetaJansons, JurisDudorova, AlesjaGordeychuk, IlyaWahren, BrittaIsaguliants, Maria2024-02-272024-02-272023-01Petkov, S, Kilpeläinen, A, Bayurova, E, Latanova, A, Mezale, D, Fridrihsone, I, Starodubova, E, Jansons, J, Dudorova, A, Gordeychuk, I, Wahren, B & Isaguliants, M 2023, 'HIV-1 Protease as DNA Immunogen against Drug Resistance in HIV-1 Infection : DNA Immunization with Drug Resistant HIV-1 Protease Protects Mice from Challenge with Protease-Expressing Cells', Cancers, vol. 15, no. 1, 238, pp. 1-45. https://doi.org/10.3390/cancers150102382072-6694https://dspace.rsu.lv/jspui/handle/123456789/15336Publisher Copyright: © 2022 by the authors.DNA immunization with HIV-1 protease (PR) is advanced for immunotherapy of HIV-1 infection to reduce the number of infected cells producing drug-resistant virus. A consensus PR of the HIV-1 FSU_A strain was designed, expression-optimized, inactivated (D25N), and supplemented with drug resistance (DR) mutations M46I, I54V, and V82A common for FSU_A. PR variants with D25N/M46I/I54V (PR_Ai2mut) and with D25N/M46I/I54V/V82A (PR_Ai3mut) were cloned into the DNA vaccine vector pVAX1, and PR_Ai3mut, into a lentiviral vector for the transduction of murine mammary adenocarcinoma cells expressing luciferase 4T1luc2. BALB/c mice were DNA-immunized by intradermal injections of PR_Ai, PR_Ai2mut, PR_Ai3mut, vector pVAX1, or PBS with electroporation. All PR variants induced specific CD8+ T-cell responses revealed after splenocyte stimulation with PR-derived peptides. Splenocytes of mice DNA-immunized with PR_Ai and PR_Ai2mut were not activated by peptides carrying V82A, whereas splenocytes of PR_Ai3mut-immunized mice recognized both peptides with and without V82A mutation. Mutations M46I and I54V were immunologically silent. In the challenge study, DNA immunization with PR_Ai3mut protected mice from the outgrowth of subcutaneously implanted adenocarcinoma 4T1luc2 cells expressing PR_Ai3mut; a tumor was formed only in 1/10 implantation sites and no metastases were detected. Immunizations with other PR variants were not protective; all mice formed tumors and multiple metastasis in the lungs, liver, and spleen. CD8+ cells of PR_Ai3mut DNA-immunized mice exhibited strong IFN-γ/IL-2 responses against PR peptides, while the splenocytes of mice in other groups were nonresponsive. Thus, immunization with a DNA plasmid encoding inactive HIV-1 protease with DR mutations suppressed the growth and metastatic activity of tumor cells expressing PR identical to the one encoded by the immunogen. This demonstrates the capacity of T-cell response induced by DNA immunization to recognize single DR mutations, and supports the concept of the development of immunotherapies against drug resistance in HIV-1 infection. It also suggests that HIV-1-infected patients developing drug resistance may have a reduced natural immune response against DR HIV-1 mutations causing an immune escape.458248680enginfo:eu-repo/semantics/openAccessCD8+ T-cell responseDNA immunogendrug resistanceHIV-1HIV-1-protein-expressing tumorsmammary gland adenocarcinoma 4T1luc2 cellsmetastatic activityproteaseprotection from tumor challengetumor growth3.1 Basic medicine3.2 Clinical medicine1.1. Scientific article indexed in Web of Science and/or Scopus databaseOncologyCancer ResearchSDG 3 - Good Health and Well-being/dk/atira/pure/researchoutput/researchoutputtypes/contributiontojournal/article10.3390/cancers15010238http://www.scopus.com/inward/record.url?scp=85146016708&partnerID=8YFLogxK