TY - JOUR AU - Aunguldee, Thuntawat AU - Gerdprasert, Orapin AU - Tangteerawatana, Piyatida AU - Jariyapongskul, Amporn AU - Leelayoova, Saovanee AU - Wongsatayanon, Benjamas Thanomsub PY - 2021/09/30 Y2 - 2024/03/29 TI - Immunogenicity and potential protection of DNA vaccine of Leishmania martiniquensis against Leishmania infection in mice JF - The Journal of Infection in Developing Countries JA - J Infect Dev Ctries VL - 15 IS - 09 SE - Original Articles DO - 10.3855/jidc.14472 UR - https://jidc.org/index.php/journal/article/view/34669604 SP - 1328-1338 AB - <p>Introduction: In Thailand, <em>Leishmania martiniquensis </em>is the predominant species causing cutaneous and visceral leishmaniasis. Its incidence has been increasing among immunocompetent and immunocompromised hosts. We developed a prototype DNA vaccine using a partial consensus sequence of the cysteine protease B (<em>cpb</em>) gene derived from <em>L. martiniquensis</em> from Thai patients.</p><p>Methodology: The laboratory inbred strain of albino BALB/c mice were immunized intramuscularly three times at 2-week intervals (weeks 0, 2, and 4) with <em>cpb</em> plasmid DNA (pcDNA_<em>cpb</em>) with or without the adjuvant, monoolein (pcDNA_<em>cpb</em>-MO). Mice were challenged at week 6 with <em>L. martiniquensis </em>promastigotes. Sera were analysed for IgG1, IgG2a, interferon gamma and interleukin 10 (IFN-γ and IL-10, respectively) levels at weeks 0, 4, and 9. Additionally, livers and spleens were also analysed for parasite burden using immunohistochemistry and real-time polymerase chain (qPCR) assays.</p><p>Results: Three weeks after promastigote challenge, vaccinated mice showed significantly increased levels of IgG<sub>2a</sub> and IFN-γ while IL-10 level was significantly reduced when compared with those in the control group (<em>p </em>&lt; 0.01). Parasite burden in the livers and spleens of vaccinated mice significantly decreased. In addition, a significant increase in mature granuloma formation in the livers when compared with those of the control group (<em>p </em>&lt; 0.05) was found, indicating increased T-helper cells (Th1)-induced inflammation and destruction of amastigotes. Monoolein produced a booster effect to enhance the mouse Th1 protective immunity.</p><p>Conclusions: The prototype DNA vaccine could induce a Th1 immune response that conferred potential protection to the <em>L. martiniquensis</em> promastigote challenge in BALB/c mice.</p> ER -