The immunotherapy with hMASP-2 DNA nanolipoplexes against echinococcosis in experimentally protoscolex-infected mice

Status and prospect of novel treatment options toward alveolar and cystic echinococcosis

Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are the two most important global parasitic infectious diseases caused by species of Echinococcus granulosus and E. multilocularis, respectively. Although numerous trials have been performed in search of novel therapeutic options to curb the neglected zoonosis, no other nonsurgical options are currently available to replace the licensed anti echinococcal drugs albendazole (ABZ) and mebendazole (MBZ). A safer and more effective treatment plan for echinococcosis is therefore urgently needed to compensate for this therapeutic shortfall. Here, we present a review of the literature for state-of-the-art valuable anti-parasitic compounds and novel strategies that have proved effective against CE and AE, which includes details about the pharmaceutical type, practical approach, experimental plan, model application and protoscolecidal effects in vivo and in vitro. The content includes the current application of traditional clinical chemicals, the preparation of new compounds with various drug loadings, repurposing findings, combined programs, the prospects for Chinese herbal medicines, non-drug administrations and the exploration of target inhibitors based on open-source information for parasitic genes. Next the conventional experimental projects and pharmacodynamic evaluation methods are systematically summarized and evaluated. The demands to optimize the construction of the echinococcosis model and improve the dynamic monitoring method in vivo are also discussed given the shortcomings of in vivo models and monitoring methods.

Synergism therapeutic and immunoregulatory effects of Albendazole + rAd-mIL-28B against Echinococcosis in experiment-infected mice with protoscoleces

The metacestode stage of Echinococcus granulosus can cause cystic echinococcosis (CE), which still widely occurs around the world. Since the early 1970s, benzimidazoles have been shown to inhibit the growth of cysts and used to treat CE. However, benzimidazoles are still ineffective in 20%-40% of cases. In order to explore the new agents against CE, we have investigated the therapeutic effect of the recombinant adenoviral vector expressing mouse IL-28B (rAd-mIL-28B) on protoscoleces-infected mice. In our study, we successfully established the model mice which infected with protoscoleces intraperitoneally. At 18 weeks post-infection, the mice received rAd-mIL-28B (1×10⁷ PFU) weekly by intramuscular injection for 6 weeks. Compared with the untreated control (13.1 ± 2.2 g), there was a significant reduction in cysts wet weight in rAd-mIL-28B group (8.3 ± 3.5 g) (P < 0.05), especially in Albendazole (ABZ) + rAd-mIL-28B group (5.8 ± 1.4 g) (P < 0.01). We also observed the severe damage of the germinal layer and the laminated layer of cysts after treatment. rAd-mIL-28B group showed a prominent increase in the level of Th1 type cytokines (such as IFN-γ, IL-2 and TNF-α). Meanwhile, the frequency of Foxp3⁺ T cells was decreased in the rAd-mIL-28B group (4.83 ± 0.81%) and ABZ + rAd-mIL-28B group (4.60 ± 0.51%), comparing with the untreated group (8.13 ± 2.60%) (P < 0.05). In addition, compared with the untreated control (122.14 ± 81.09 pg/ml), the level of IFN-γ significantly increased in peritoneal fluid in the rAd-mIL-28B group (628.87 ± 467.16 pg/ml) (P < 0.05) and ABZ + rAd-mIL-28B group (999.76 ± 587.60 pg/ml) (P < 0.001). Taken together, it suggested that ABZ + IL-28B may be a potential therapeutic agent against CE.

Echinococcosis is a chronic zoonotic parasitic disease, which is caused by the larval stage of Echinococcus granulosus (E. granulosus) and Echinococcus multiocularis (E. multiocularis). This disease is still widely prevalent in the world and seriously endangers human health and life, causing heavy burdens and economic losses to agriculture and animal husbandry. China is also one of the high incidence areas of the disease. At present, the preferred treatment is surgical excision of the parasitic mass, but patients with multiple cysts appear in multiple organs have to receive drug therapy. The approved chemotherapeutic drugs in clinic, such as albendazole (ABZ) and mebendazole, often do not work expectedly with a high rate of recurrence. Therefore, it is urgent to develop the new anti-echinococcal drug. IL-28B is an important member of type-III IFNs, which is equipped with the capacity of anti-viral activity and anti-tumor. In our previous study, we found that IL-28B could inhibit the proliferation of cervical cancer cells via down-regulating Treg cells in mice. This study mainly studied the therapeutic effect of rAd-mIL-28B on E. granulosus-infected mice, and the results showed that rAd-mIL-28B could relieve the parasitic burden and inhibit Treg cells meanwhile improve the Th1 and Th17 immune responses. It may contribute to another choice for the anti-echinococcal treatment.