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Journal articles
In Vitro Evaluation of a Soluble Leishmania Promastigote Surface Antigen as a Potential Vaccine Candidate against Human Leishmaniasis
Abstract : PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several
Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice.
We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a
L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L.
braziliensis (CCLb) or visceral leishmaniasis due to L. donovani (CVLd) and in healthy individuals. Healthy individuals were
subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum
infection) or non immune/naive individuals (HLR: Healthy Low Responders), depending on whether they produce high or
low levels of IFN-c in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected
in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-c, granzyme B and IL-
10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-a in more. No significant cytokine response was
observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase
in CD4+ T cells producing IFN-c after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the
percentage of IFN-c-producing CD4+ T cells and the released IFN-c. We showed that the LaPSA-38S protein was able to
induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection
indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity
of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection
Cited literature [64 references]
https://hal-riip.archives-ouvertes.fr/pasteur-01098532
Contributor : Institut Pasteur Tunis <>
Submitted on : Friday, December 26, 2014 - 1:45:55 PM
Last modification on : Monday, October 19, 2020 - 2:58:07 PM
Long-term archiving on: : Friday, March 27, 2015 - 11:35:53 AM
Contributor : Institut Pasteur Tunis <>
Submitted on : Friday, December 26, 2014 - 1:45:55 PM
Last modification on : Monday, October 19, 2020 - 2:58:07 PM
Long-term archiving on: : Friday, March 27, 2015 - 11:35:53 AM
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