Brazilian strains of Toxoplasma gondii are controlled by azithromycin and modulate cytokine production in human placental explants

Abstract

BackgroundToxoplasma gondii is a protozoan parasite that causes congenital toxoplasmosis by transplacental transmission. Parasite strains are genetically diverse and disease severity is related to the genotype. In Uberlândia city, Brazil, two virulent strains were isolated: TgChBrUD1 and TgChBrUD2. Congenital toxoplasmosis is more prevalent in South America compared to Europe, and more often associated with severe symptoms, usually as a result of infection with atypical strains.MethodsConsidering that T. gondii has shown high genetic diversity in Brazil, the effectiveness of traditional treatment may not be the same, as more virulent strains of atypical genotypes may predominate. Thus, the aim of this study were to evaluate the Brazilian strain infection rate in human villous explants and the azithromycin efficacy with regard to the control of these strains compared to traditional therapy. Villi were infected with RH, ME49, TgChBrUD1 or TgChBrUD2 strains and treated with azithromycin, spiramycin or a combination of pyrimethamine plus sulfadiazine. The villous viability was analyzed by LDH assay and morphological analysis. Parasite proliferation, as well as production of cytokines was analyzed by qPCR and ELISA, respectively. Statistical analysis was performed using the GraphPad Prism 5.0.ResultsThe treatments were not toxic and TgChBrUD1 infected villi showed a higher parasite burden compared with others strains. Treatments significantly reduced the intracellular proliferation of T. gondii, regardless of the strain. TgChBrUD1-infected villi produced a larger amount of MIF, IL-6 and TGF-β1 compared with other infected villi. Azithromycin treatment increased MIF production by RH- or TgChBrUD2-infected villi, but in ME49- or TgChBrUD1-infected villi, the MIF production was not altered by treatment. On the other hand, azithromycin treatment induced lower IL-6 production by ME49- or TgChBrUD1-infected villi.ConclusionsAzithromycin treatment was effective against T. gondii Brazilian strains compared with conventional treatment. Also, the TgChBrUD1 strain replicated more in villi and modulated important cytokines involved in parasite control, showing that different strains use different strategies to evade the host immune response and ensure their survival.

Copaifera spp. oleoresins impair Toxoplasma gondii infection in both human trophoblastic cells and human placental explants

“…It was demonstrated by www.nature.com/scientificreports/ our research group that IL-6 is a multifaceted cytokine involved in the control of T. gondii infection in human monocytes and human trophoblastic cells 72,73 . Besides, this cytokine was also associated with the parasite control in infected-villous explants 30,31,33 . Several studies have demonstrated that human trophoblastic cells and human villous explants produce MIF and, this cytokine release has an important role during infection by different parasites, including T. gondii.…”

“…Several studies have demonstrated that human trophoblastic cells and human villous explants produce MIF and, this cytokine release has an important role during infection by different parasites, including T. gondii. Besides that, this cytokine has a critical function to reduce T. gondii proliferation in maternal-fetal interface 29,31,33,[74][75][76][77] . Thus, based on the literature and our data, we proposed that the modulation of cytokine production in BeWo cells during T. gondii infection by oleoresins is dependent on both the Copaifera species and the concentration of oleoresin used.…”

“…Several studies have demonstrated that human trophoblastic cells and human villous explants produce MIF and, this cytokine release has an important role during infection by different parasites, including T. gondii. Besides that, this cytokine has a critical function to reduce T. gondii proliferation in maternal–fetal interface 29 , 31 , 33 , 74 – 77 .…”

“…In this context, our group showed that azithromycin treatment reduced the vertical transmission of T. gondii tachyzoites in pregnant Calomys callosus rodents and was able to control parasite infection in human trophoblastic cells (BeWo cells) 28,29 . Moreover, we demonstrated that azithromycin treatment promoted inhibition of proliferation of T. gondii Brazilian strains in human villous explants from the third trimester of pregnancy 30,31 . Also, our work with other compounds showed that both enrofloxacin and toltrazuril impairs T. gondii infection in vitro, ex vivo, and in vivo experimental models 32,33 .…”

Galectina-3 controla a proliferação intracelular de Toxoplasma gondii em células trofoblásticas humanas (linhagem BeWo)

“…Assim, várias pesquisas buscam alternativas para o tratamento da toxoplasmose. A azitromicina é um desses tratamentos alternativos que já foi estudada em células de linhagem humana e explantes placentários humanos mostrando eficácia contra a infecção (FRANCO et al, 2014;RIBEIRO et al, 2017;FRANCO et al 2019).…”