AUTHOR=Paladi Carolina S. , da Silva Danielle A. M. , Motta Priscila D. , Garcia Daniel M. , Teixeira Daniela , Longo-Maugéri Ieda M. , Katz Simone , Barbiéri Clara L. 

TITLE=Treatment of Leishmania (Leishmania) Amazonensis-Infected Mice with a Combination of a Palladacycle Complex and Heat-Killed Propionibacterium acnes Triggers Protective Cellular Immune Responses

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00333

DOI=10.3389/fmicb.2017.00333

ISSN=1664-302X

ABSTRACT=<p>Palladacycle complex DPPE 1.2 was previously reported to inhibit the <italic>in vitro</italic> and <italic>in vivo</italic> infection by <italic>Leishmania (Leishmania) amazonensis</italic>. The aim of the present study was to compare the effect of DPPE 1.2, in association with heat-killed <italic>Propionibacterium acnes</italic>, on <italic>L. (L.) amazonensis</italic> infection in two mouse strains, BALB/c and C57BL/6, and to evaluate the immune responses of the treated animals. Foot lesions of <italic>L. (L.) amazonensis</italic>-infected mice were injected with DPPE 1.2 alone, or associated with <italic>P</italic>. <italic>acnes</italic> as an adjuvant. Analysis of T-cell populations in the treated mice and in untreated controls was performed by FACS. Detection of IFN-γ-secreting lymphocytes was carried out by an ELISPOT assay and active TGF-β was measured by means of a double-sandwich ELISA test. The treatment with DPPE 1.2 resulted in a significant reduction of foot lesion sizes and parasite burdens in both mouse strains, and the lowest parasite burden was found in mice treated with DPPE 1.2 plus <italic>P. acnes</italic>. Mice treated with DPPE 1.2 alone displayed a significant increase of TCD4<sup>+</sup> and TCD8<sup>+</sup> lymphocytes and IFN-γ secretion which were significantly higher in animals treated with DPPE 1.2 plus <italic>P. acnes</italic>. A significant reduction of active TGF-β was observed in mice treated with DPPE 1.2 alone or associated with <italic>P. acnes</italic>. Moreover, DPPE 1.2 associated to <italic>P. acnes</italic> was non-toxic to treated animals. The destruction of <italic>L. (L.) amazonensis</italic> by DPPE 1.2 was followed by host inflammatory responses which were exacerbated when the palladacycle complex was associated with <italic>P. acnes</italic>.</p>