Improvement in clinical signs and cellular immunity of dogs with visceral leishmaniasis using the immunomodulator P-MAPA

Abstract

This study investigated the immunotherapeutic potential of the protein aggregate magnesium-ammonium phospholinoleate-palmitoleate anhydride immuno-modulator (P-MAPA) on canine visceral leishmaniasis. Twenty mongrel dogs presenting clinical symptoms compatible with leishmaniasis and diagnosis confirmed by the detection of anti-leishmania antibodies were studied. Ten dogs received 15 doses of the immunomodulator (2.0 mg/kg) intramuscularly, and 10 received saline as a placebo. Skin and peripheral blood samples were collected following administration of the immunomodulator. The groups were followed to observe for clinical signals of remission; parasite load in the skin biopsies using real-time PCR, the cytokines IL-2, IL-10 and IFN-γ in the supernatant of peripheral blood mononuclear cells stimulated in vitro with either total promastigote antigen or phytohemagglutinin measured by capture ELISA, and changes in CD4⁺ and CD8⁺ T cell subpopulations evaluated by flow cytometry. Comparison between the groups showed that treatment with the immunomodulator promoted improvement in clinical signs and a significant reduction in parasite load in the skin. In peripheral blood mononuclear cell cultures, supernatants showed a decrease in IL-10 levels and an increase in IL-2 and IFN-γ. An increase in CD8⁺ T cells was observed in peripheral blood. In addition, the in vitro leishmanicidal action of P-MAPA was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and no leishmanicidal activity was detected. These findings suggest that P-MAPA has potential as an immunotherapeutic drug in canine visceral leishmaniasis, since it assists in reestablishing partial immunocompetence of infected dogs.

Insights on adaptive and innate immunity in canine leishmaniosis

“…The most common drugs used for CanL are the meglumine antimoniate, miltefosine and allopurinol. However, in recent years attempts have been made to use immumodulatory molecules for treatment of CanL such as the protein aggregate magnesium-ammonium phospholinoleate-palmitoleate anhydride immumo-modulator (P-MAPA) (Santiago et al 2013) that appears to induce TLR2 in human embryonic kidney (HEK) cells (Favaro et al 2012) and in canine macrophages (Melo et al 2014 b ). The treatment with this immumodulator resulted in an improvement in clinical signs and a significant reduction in parasite load in the skin.…”

“…The treatment with this immumodulator resulted in an improvement in clinical signs and a significant reduction in parasite load in the skin. Peripheral blood mononuclear cells (PBMC) cultures also showed an increase in IL-2 and IFN- γ and a decrease in IL-10 levels (Santiago et al 2013). Taken together, the findings from this study indicated that P-MAPA has the potential to be used as an immunotherapeutic drug in CanL (Santiago et al 2013).…”

Immunotherapy and Immunochemotherapy in Visceral Leishmaniasis: Promising Treatments for this Neglected Disease

“…Using an immunomodulator, Santiago et al (126) tested the immunotherapeutic effect for CVL of a protein aggregate of magnesium–ammonium phospholinoleate–palmitoleate anhydride (P-MAPA) obtained by fermenting the fungus Aspergillus oryzae . P-MAPA showed immunomodulatory activity, with greater stimulation of cellular immunity and no toxic effects in mice and dogs (127).…”

“…To investigate the immunotherapeutic potential of P-MAPA, symptomatic dogs were submitted to a protocol of 15 doses of the immunomodulator (2.0 mg/kg) intramuscularly. An increase in CD8 + T cells in peripheral blood, a decrease in IL-10 levels, and an increase in IL-2 and IFN-γ, improved clinical signs, and reduced skin parasitism were obtained after immunotherapy (126). …”

Biogenic Synthesis of Important Environmental Minerals: Magnesium Phosphate Compounds and Perspectives

“…These observations suggested that P-MAPA has potential as an immunotherapeutic drug in canine visceral leishmaniasis, but not in vitro, since it assists in reestablishing partial immunocompetence of infected dogs. 97 Several parameters in healthy and Leishmania-infected dogs treated with P-MAPA were studied. Macrophages in culture of peripheral blood mononuclear cell (PBMC) were isolated.…”