Azithromycin is able to control Toxoplasma gondii infection in human villous explants

Castro-Filice et al. Journal of Translational Medicine 2014, 12:132 http://www.translational-medicine.com/content/12/1/132 RESEARCH Open Access Azithromycin is able to control Toxoplasma gondii infection in human villous explants Letícia S Castro-Filice1, Bellisa F Barbosa1, Mariana B Angeloni1, Neide M Silva2, Angelica O Gomes1, Celene M O S Alves1, Deise A O Silva2, Olindo A Martins-Filho3, Maria C Santos4, José R Mineo2 and Eloisa A V Ferro1* Abstract Background: Although Toxoplasma gondii infection is normally asymptomatic, severe cases of toxoplasmosis may occur in immunosuppressed patients or congenitally infected newborns. When a fetal infection is established, the recommended treatment is a combination of pyrimethamine, sulfadiazine and folinic acid (PSA). The aim of the present study was to evaluate the efficacy of azithromycin to control T. gondii infection in human villous explants. Methods: Cultures of third trimester human villous explants were infected with T. gondii and simultaneously treated with either PSA or azithromycin. Proliferation of T. gondii, as well as production of cytokines and hormones by chorionic villous explants, was analyzed. Results: Treatment with either azithromycin or PSA was able to control T. gondii infection in villous explants. After azithromycin or PSA treatment, TNF-α, IL-17A or TGF-β1 levels secreted by infected villous explants did not present significant differences. However, PSA-treated villous explants had decreased levels of IL-10 and increased IL-12 levels, while treatment with azithromycin increased production of IL-6. Additionally, T. gondii-infected villous explants increased secretion of estradiol, progesterone and HCG + β, while treatments with azithromycin or PSA reduced secretion of these hormones concurrently with decrease of parasite load. Conclusions: In conclusion, these results suggest that azithromycin may be defined as an effective alternative drug to control T. gondii infection at the fetal-maternal interface. Keywords: Azithromycin, Human placental villi, Trophoblast, Cytokines, Sex hormones, Toxoplasma gondii Introduction Toxoplasma gondii is an obligate intracellular protozoan parasite that infects a wide range of hosts, including humans. During pregnancy, primary infection can result in the vertical transmission of T. gondii tachyzoites, potentially having severe consequences for the fetus, such as retinochoroiditis as well as hydrocephalus and intracranial calcification [1]. The risk of fetal infection by T. gondii increases as pregnancy progresses [2,3]. Nevertheless, the consequences of fetal infection are more severe the earlier infection occurs during pregnancy [4]. * Correspondence: 1 Laboratory of Immunophysiology of Reproduction, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Av. Pará 1720, Uberlândia, MG 38400-902, Brazil Full list of author information is available at the end of the article A combination of pyrimethamine, sulfadiazine and folinic acid (PSA) or spiramycin are standard care for treatment of toxoplasmosis in cases of fetal infection [5,6]. Treatment with spiramycin is administered immediately after diagnosis of maternal infection [7], and since this macrolide does not cross placenta, it is not suitable for treatment of fetal infections [8]. PSA is the recommended combination for pregnant women treatment who acquire the infection after 18 weeks of gestation. However, pyrimethamine is potentially teratogenic and should not be used in the first trimester of pregnancy [8]. Pyrimethamine is a folic acid antagonist and its use in pregnancy has been associated with increased risk of neural tube defects [9]. This drug is potentially toxic, usually causing gradual dose-related bone marrow depression, chromosomal damage and mutagenicity [9,10]. Folinic acid is used for reduction and prevention of hematological toxicities caused by © 2014 Castro-Filice et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Castro-Filice et al. Journal of Translational Medicine 2014, 12:132 http://www.translational-medicine.com/content/12/1/132 pyrimethamine [8]. Alternative drugs for treatment of toxoplasmosis, such as trimethoprim-sulfamethoxazole or clindamycin, have shown activity in vitro and in mouse models, but clinical studies to establish their efficacy have not been conclusive [10]. Thus, there is an urgent need for more effective and non-toxic chemotherapeutic agents and novel drug targets to be identified for treatment of T. gondii infection during pregnancy. Azithromycin is a semisynthetic azalide antibiotic that is structurally related to erythromycin, but has a broader spectrum of antibacterial activity and a more favorable pharmacokinetic profile. Furthermore, administration is required only once per day [11-13]. Azithromycin also inhibits protein synthesis in the plasmodial apicoplast and, thus, has activity against both Plasmodium falciparum and P. vivax [12]. Azithromycin is widely used for the treatment of community-acquired pneumonia and chlamydia during pregnancy, and has been safely administered in all trimesters of gestation [14,15]. Studies have shown that animals receiving 60 times the recommended dose of azithromycin for humans do not have decreased fertility or demonstrated harmful effects on the fetus [16]. Given that azithromycin is considered safe during pregnancy and the fact that it may have activity against pathogens, such as Plasmodium and Toxoplasma, it has been suggested as a candidate for intermittent preventive treatment during pregnancy [7,17]. Previous studies have shown that azithromycin treatment in pregnant Calomys callosus and human trophoblast cells (lineage BeWo) was able to control T. gondii infection, suggesting that it may be an alternative drug for prevention of congenital infection [18,19]. Additionally, azithromycin has anti-inflammatory properties through modulating the production of proinflammatory cytokines that are produced during T. gondii infection [20]. Thus, the aim of the present study was to evaluate the efficacy of azithromycin in the control of T. gondii infection in third trimester human villous explants cultures compared to traditional therapy (PSA). Methods Placental samples Placental tissues were obtained from 24 women after elective cesarean section deliveries (36 to 40 weeks of pregnancy). Exclusion criteria included pre-eclampsia, chronic hypertension, infectious disease including toxoplasmosis, chorioamnionitis, chronic renal disease, cardiac disease, connective tis (...truncated)