Journal of Medical Microbiology and Infectious Diseases

en Evaluation of Transgenic Iranian Lizard Leishmania Encoding Human IL-12 as a Candidate Vaccine Against Experimental Cutaneous Leishmaniasis in Susceptible BALB/c Mice Other Other Original article Original article <div style="text-align: justify;">Introduction: Leishmaniasis is a neglected tropical disease that causes significant morbidity worldwide, particularly in developing countries. Despite ongoing efforts, there is no widely approved human vaccine against this disease. Live, non-pathogenic organisms such as Leishmania tarentolae have emerged as promising candidates for vaccine development due to their safety profile and ability to present antigens in a native context. This study aimed to evaluate transgenic Iranian Lizard Leishmania (I.L.L.) encoding human IL-12 (hIL-12) as a candidate vaccine against experimental cutaneous leishmaniasis in susceptible BALB/c mice. Methods: BALB/c mice were divided into six groups and immunized subcutaneously with either transgenic L. tarentolae-hIL-12 (G1 and G2), wild-type L. tarentolae (G3 and G4), or RPMI-1640 medium (G5 and G6). Three weeks post-immunization, animals received a booster injection. Two weeks after the booster, challenged groups (G1, G3, and G5) were infected with Leishmania major promastigotes. Lesion progression was measured weekly for 11 weeks. IgG2a responses were assessed using ELISA, while cytokine responses (IFN-γ, IL-17, IL-10, TNF-α) were quantified after stimulation with soluble L. major antigen (SLA). Parasite burden in spleens was evaluated by real-time PCR. Results: Mice vaccinated with transgenic I.L.L.-hIL-12 developed significantly stronger cellular and humoral immune responses than the control groups. Elevated IFN-γ, IL-17 and IgG2a levels indicated a predominantly Th1-biased immune response, while increased IL-10 production suggested a concomitant regulatory response. Vaccinated mice also exhibited smaller lesion sizes and lower splenic parasite burdens than the control groups, indicating partial protection against L. major infection. Conclusion: The transgenic L. tarentolae-hIL-12 strain effectively induced protective immunity in susceptible BALB/c mice, supporting its potential as a novel and safe live vaccine platform for cutaneous leishmaniasis due to L. major.</div> Leishmania tarentolae, Leishmania major, Interleukin-12, Vaccines, Parasite burden 0 0 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-622-3&slc_lang=en&sid=1 Tahereh Donyavi tdonyavi@yahoo.com 0000-0002-8502-2780 No 1Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Medical Biotechnology Department, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran Rouzbeh Chegeni chegenr@yahoo.com 0000-0002-0973-6570 No University of Westminster, London, United Kingdom Mojgan Bandehpour bandehpour@gmail.com 0000-0002-5309-9476 No Cellular and Molecular Biology Research Center, Systems Biology Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran Samira Mohammadi-Yeganeh smyeganeh@gmail.com 0000-0003-0430-6325 No Cellular and Molecular Biology Research Center, Systems Biology Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran Hadi Zahedi- Zavaram hadizahedi65@gmail.com 0000-0002-7384-8913 No Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Bahram Kazemi bahram_14@yahoo.com 0000-0002-3072-8831 Yes Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mehdi Namjoomanesh 0009-0000-4613-6972 No Islamic Azad University, North Tehran Branch, Tehran, Iran