Evaluation of the Immunogenicity of a Dna Vaccine for Leishmania Major Based on the Leishmania-Activated C Kinase Antigen Using Calcium Phosphate and Chitosan Adjuvants Publisher Pubmed



A Gharaei ABDOLAZIZ ; Mr Rahdar Mahmoud R ; O Jorjani OGHLNIAZ ; S Saberi SEDIGHEH ; M Beiromvand MOLOUK ; Mh Feiz Haddad Mohammad HOSSEIN
Source: Transactions of the Royal Society of Tropical Medicine and Hygiene Published:2025

Abstract

Background: Leishmaniasis represents a significant parasitic disease with global health implications, and the development of an affordable and effective vaccine could provide a valuable solution. This study aimed to evaluate the immunogenicity of a DNA vaccine targeting Leishmania major specifically based on the Leishmaniaactivated C kinase (LACK) antigen, utilizing calcium phosphate nanoparticles (CaPNs) and chitosan nanoparticles (ChitNs) as adjuvants. Methods: Seventy female BALB/c mice, aged 4–6 wk and weighing 20–22 g, were selected and divided into five groups, each consisting of 14 mice. The first group received the plasmid LACK vaccine (pcDN3+LACK), the second group received the pcDN3+LACK vaccine with the CaPN adjuvant (pcDN3+LACK+CaPN), the third group received the pcDN3+LACK vaccine with the ChitN adjuvant (pcDN3+LACK+ChitN), the fourth group was administered phosphate-buffered saline as a negative control and the fifth group did not receive any vaccine, serving as a positive control. The vaccination program involved two intramuscular injections at 3-wk intervals. Three weeks following the final vaccination, the mice were challenged with wild-type L. major promastigotes via intradermal injection at the base of their tails. Clinical signs and lesion sizes were evaluated biweekly using Vernier calipers. Immune responses, including levels of interferon-gamma (IFN-γ ) and interleukin-4 (IL-4), were assessed using ELISA. Results: The groups receiving pcDN3+LACK+ChitN, pcDN3+LACK+CaPN and pcDN3+LACK exhibited the highest increases in IFN-γ titers and the most significant reductions in IL-4 titers. Furthermore, lesion sizes associated with Leishmania infection were reduced in the vaccinated groups, with the most favorable outcomes observed in the pcDN3+LACK+ChitN group. Conclusions: These findings suggest that vaccination utilizing the LACK antigen in conjunction with CaPN and ChitN adjuvants may represent an effective strategy for the control of cutaneous leishmaniasis. © 2025 Elsevier B.V., All rights reserved.