PD-1 regulates leishmanicidal activity and IL-17 in dogs with leishmaniasis

Publication date: Available online 31 October 2019Source: Veterinary Immunology and ImmunopathologyAuthor(s): Gabriela Torres Rebech, Gabriela Lovizutto Venturin, Lucas Takeshi Siqueira Ito, Jaqueline Poleto Bragato, Bianca Stefanini de Carvalho Fonseca, Larrissa Martins Melo, Sidnei Ferro Costa, Flávia de Rezende Eugênio, Paulo Sérgio Patto dos Santos, Valéria Marçal Felix de LimaAbstractLeishmaniasis is an immunosuppressive disease caused by protozoa of the genus Leishmania, for which dogs are the domestic reservoir. The programmed cell death-1 molecule (PD-1) is highly expressed in leukocyte cells of dogs with leishmaniasis, and it promotes T lymphocyte exhaustion and suppression of cytokine secretion. Because PD-1 has a suppressive function regarding cell immunity, we evaluated the effect of PD-1 blocking antibodies on NO, ROS and interleukin 17 (IL-17) production and on parasite load in spleen leukocyte cultures from dogs with leishmaniasis. In vitro, PD-1 blocking promoted increased levels of intracellular NO and NO2 and reduced the levels of IL-17 in the culture supernatant, in addition to reducing the parasite load, but it did not change ROS levels. We conclude that PD-1 participates in the regulation of the immune response and that the blocking antibody is effective in restoring host microbicidal activity. This can be investigated in an immunotherapeutic study in the future.
Source: Veterinary Immunology and Immunopathology - Category: Veterinary Research Source Type: research