2024-03-28T10:12:44Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1250912021-12-27T16:31:53Zcom_10261_79com_10261_1col_10261_332
00925njm 22002777a 4500
dc
Costa, Lourena E.
author
Soto, Manuel
author
Ferraz Coelho, Eduardo Antonio
author
2014-10-15
© 2014 Costa et al. The development of cost-effective prophylactic strategies to prevent leishmaniasis has become a high-priority. The present study has used the phage display technology to identify new immunogens, which were evaluated as vaccines in the murine model of visceral leishmaniasis (VL). Epitope-based immunogens, represented by phage-fused peptides thatimic Leishmania infantum antigens, were selected according to their affinity to antibodies from asymptomatic and symptomatic VL dogs' sera. Methodology/Main Findings: Twenty phage clones were selected after three selection cycles, and were evaluated by means of in vitro assays of the immune stimulation of spleen cells derived from naive and chronically infected with L. infantum BALB/c mice. Clones that were able to induce specific Th1 immune response, represented by high levels of IFN-c and low levels of IL-4 were selected, and based on their selectivity and specificity, two clones, namely B10 and C01, were further employed in the vaccination protocols. BALB/c mice vaccinated with clones plus saponin showed both a high and specific production of IFN-c, IL-12, and GM-CSF after in vitro stimulation with individual clones or L. infantum extracts. Additionally, these animals, when compared to control groups (saline, saponin, wild-type phage plus saponin, or nonrelevant phage clone plus saponin), showed significant reductions in the parasite burden in the liver, spleen, bone marrow, and paws' draining lymph nodes. Protection was associated with an IL-12-dependent production of IFN-c, mainly by CD8+ T cells, against parasite proteins. These animals also presented decreased parasite-mediated IL-4 and IL-10 responses, and increased levels of parasite-specific IgG2a antibodies. Conclusions/Significance: This study describes two phage clones that mimic L. infantum antigens, which were directly used as immunogens in vaccines and presented Th1-type immune responses, and that significantly reduced the parasite burden. This is the first study that describes phage-displayed peptides as successful immunogens in vaccine formulations against VL.
PLoS ONE 9 (2014)
http://hdl.handle.net/10261/125091
10.1371/journal.pone.0110014
25333662
Mimotope-based vaccines of leishmania infantum antigens and their protective efficacy against visceral leishmaniasis