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Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection

BACKGROUND: Vaccination is an attractive ecological alternative to the use of acaricides for parasite control. However, effective anti-parasite vaccines against sarcoptic mange have not yet been developed. The purpose of this study was first to identify Sarcoptes scabiei immunodominant antigens and...

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Autores principales: Casais, Rosa, Granda, Victor, Balseiro, Ana, del Cerro, Ana, Dalton, Kevin P., González, Roxana, Bravo, Pablo, Prieto, J. M., Montoya, Maria
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4977775/
https://www.ncbi.nlm.nih.gov/pubmed/27502394
http://dx.doi.org/10.1186/s13071-016-1717-9
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author Casais, Rosa
Granda, Victor
Balseiro, Ana
del Cerro, Ana
Dalton, Kevin P.
González, Roxana
Bravo, Pablo
Prieto, J. M.
Montoya, Maria
author_facet Casais, Rosa
Granda, Victor
Balseiro, Ana
del Cerro, Ana
Dalton, Kevin P.
González, Roxana
Bravo, Pablo
Prieto, J. M.
Montoya, Maria
author_sort Casais, Rosa
collection PubMed
description BACKGROUND: Vaccination is an attractive ecological alternative to the use of acaricides for parasite control. However, effective anti-parasite vaccines against sarcoptic mange have not yet been developed. The purpose of this study was first to identify Sarcoptes scabiei immunodominant antigens and second to evaluate them as vaccine candidates in a rabbit/S. scabiei var. cuniculi model. METHODS: The S. scabiei Ssλ15 immunodominant antigen was selected by immunoscreening of a S. scabiei var. hominis cDNA. The full-length cDNA was sequenced and cloned into the pGEX vector and the recombinant protein expressed in BL21 (DE3) cells and purified. A vaccination trial was performed consisting of a test group (n = 8) immunised with recAgs (a mix of two recombinant antigens, Ssλ15 and the previously described Ssλ20∆B3) and a control group (n = 8) immunised with PBS. All analyses were performed with R Statistical Environment with α set at 0.050. RESULTS: The full-length open reading frame of the 1,821 nt cloned cDNA encodes a 64 kDa polypeptide, the sequence of which had 96 % identity with a hypothetical protein of S. scabiei. Ssλ15 was localised by immunostaining of skin sections in the tegument surrounding the mouthparts and the coxa in the legs of mites. Rabbit immunisation with recAgs induced high levels of specific IgG (P < 0.010) and increased levels of total IgEs. However, no significant clinical protection against S. scabiei challenge was detected. Unexpectedly, the group immunised with the recAgs mix had significantly higher lesion scores (P = 0.050) although lower mean mite densities than those observed in the control group. These results might indicate that the lesions in the recAgs group were due not only to the mites density but also to an exacerbated immunological response after challenge, which is in agreement with the specific high levels of pro-inflammatory cytokines (IL-1 and TNFα) detected after challenge in this group. CONCLUSIONS: The selected antigens delivered as recombinant proteins had no clinical protective efficacy against S. scabiei infestation although immunisation reduced mite density. However, these results pave the way for future studies on alternative production systems, adjuvants, delivery methods and combinations of antigens in order to manage stimulation of clinical protective immune responses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1717-9) contains supplementary material, which is available to authorized users.
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spelling pubmed-49777752016-08-10 Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection Casais, Rosa Granda, Victor Balseiro, Ana del Cerro, Ana Dalton, Kevin P. González, Roxana Bravo, Pablo Prieto, J. M. Montoya, Maria Parasit Vectors Research BACKGROUND: Vaccination is an attractive ecological alternative to the use of acaricides for parasite control. However, effective anti-parasite vaccines against sarcoptic mange have not yet been developed. The purpose of this study was first to identify Sarcoptes scabiei immunodominant antigens and second to evaluate them as vaccine candidates in a rabbit/S. scabiei var. cuniculi model. METHODS: The S. scabiei Ssλ15 immunodominant antigen was selected by immunoscreening of a S. scabiei var. hominis cDNA. The full-length cDNA was sequenced and cloned into the pGEX vector and the recombinant protein expressed in BL21 (DE3) cells and purified. A vaccination trial was performed consisting of a test group (n = 8) immunised with recAgs (a mix of two recombinant antigens, Ssλ15 and the previously described Ssλ20∆B3) and a control group (n = 8) immunised with PBS. All analyses were performed with R Statistical Environment with α set at 0.050. RESULTS: The full-length open reading frame of the 1,821 nt cloned cDNA encodes a 64 kDa polypeptide, the sequence of which had 96 % identity with a hypothetical protein of S. scabiei. Ssλ15 was localised by immunostaining of skin sections in the tegument surrounding the mouthparts and the coxa in the legs of mites. Rabbit immunisation with recAgs induced high levels of specific IgG (P < 0.010) and increased levels of total IgEs. However, no significant clinical protection against S. scabiei challenge was detected. Unexpectedly, the group immunised with the recAgs mix had significantly higher lesion scores (P = 0.050) although lower mean mite densities than those observed in the control group. These results might indicate that the lesions in the recAgs group were due not only to the mites density but also to an exacerbated immunological response after challenge, which is in agreement with the specific high levels of pro-inflammatory cytokines (IL-1 and TNFα) detected after challenge in this group. CONCLUSIONS: The selected antigens delivered as recombinant proteins had no clinical protective efficacy against S. scabiei infestation although immunisation reduced mite density. However, these results pave the way for future studies on alternative production systems, adjuvants, delivery methods and combinations of antigens in order to manage stimulation of clinical protective immune responses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1717-9) contains supplementary material, which is available to authorized users. BioMed Central 2016-08-08 /pmc/articles/PMC4977775/ /pubmed/27502394 http://dx.doi.org/10.1186/s13071-016-1717-9 Text en © The Author(s). 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Casais, Rosa
Granda, Victor
Balseiro, Ana
del Cerro, Ana
Dalton, Kevin P.
González, Roxana
Bravo, Pablo
Prieto, J. M.
Montoya, Maria
Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
title Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
title_full Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
title_fullStr Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
title_full_unstemmed Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
title_short Vaccination of rabbits with immunodominant antigens from Sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
title_sort vaccination of rabbits with immunodominant antigens from sarcoptes scabiei induced high levels of humoral responses and pro-inflammatory cytokines but confers limited protection
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4977775/
https://www.ncbi.nlm.nih.gov/pubmed/27502394
http://dx.doi.org/10.1186/s13071-016-1717-9
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