• Development of an Innovative HTLV-1 Protease: Human Fcγ1 Recombinant Fusion Protein Produced in the CHO Eukaryotic Expression System
  • Sanaz Ahmadi Ghezeldasht,1,*
    1. Blood Borne Infections Research Center, Academic Center for Education, Culture, and Research (ACECR), Razavi Khorasan, Mashhad, Iran


  • Introduction: Human T-cell leukaemia virus type 1 (HTLV-1) is the causative agent of two life-threatening diseases, adult T cell leukaemia/lymphoma (ATLL), and HTLV-1-associated myelopathy/tropical spastic (HAM/TSP). HTLV-1 protease (HTLV-1-PR) is an aspartic protease that holds promise as a target for therapeutic interventions, similar to human immunodeficiency virus-PR inhibitors (HIV-PR). Thus, the present investigation aimed to design and express the human Fc fusion recombinant-PR (HTLV-1-PR:hFcγ1) for two purposes: identifying a blocking substrate as a potential therapeutic or a subunit peptide vaccine.
  • Methods: The MT2-cell line was employed to amplify the DNA sequences encoding the HTLV-1-PR using specific primers with Not1 and Xba1 restriction enzyme sites. Subsequently, the construct was cloned into the pTZ57R/T TA plasmid and, following verification of the PR sequence, subcloned into the pDR2ΔEF1α Fc-expression vector to create pDR2ΔEF1α.HTLV-1-PR:hFcγ1. The integrity of the recombinant DNA was confirmed by sequencing to ensure that the engineered construct was in the correct frame. The recombinant fusion protein was then generated in the Chinese hamster ovary cell (CHO) system and purified from the supernatant using HiTrap-rPA column affinity chromatography
  • Results: Subsequently, the immunofluorescence assay (IFA) co-localisation method indicated that the HTLV-1-PR:hFc recombinant fusion protein exhibited appropriate folding as it interacted with the anti-Fcγ antibody; the Fcγ1 tag contributed to the formation of HTLV-1-PR:hFcγ1 as a dimeric secretory protein.
  • Conclusion: The development and production of HTLV-1-PR may have implications for identifying a blocking substrate as a potential therapeutic molecule, as well as for assessing its immunogenicity and potential protection against HTLV-1 infection through animal model experimentation.
  • Keywords: Adult T cell leukaemia/lymphoma (ATLL) · Chinese hamster ovary cell (CHO)expression system · HTLV-1