Immunoregulatory Effects of Somatic Extract of Toxocara canis on Airway Inflammations in Murine Model

BACKGROUND: The immunomodulatory role of many parasites is well-documented. The current study designed to assess the immunoregulatory effects of the somatic extract (SE) of Toxocara canis on murine model of airway inflammations. METHODS: The experiment was performed in department of parasitology of Tarbiat Mo-dares University, Tehran, Iran from November 2018 to May 2019. Totally 30 female BALB/c mice divided into one control group and two experimental groups (10 mice in each group). The ovalbumin (OVA) group was sensitized with OVA in alum, while the SE group was administered with SE and OVA in alum intraperitoneally. The control group was injected with PBS in alum. Then, SE and OVA groups were intranasally challenged with OVA for three consecutive days and the control group encountered with PBS at the same time. One day after the last challenge, real-time PCR and histopathology survey were conducted on isolated lung tissues. RESULTS: The gene expression of IL-25, IL-33, TNF-α and TLR-4 in SE group was significantly lower than OVA group (P<0.05). The level of IL-10, TGF-β and IFN-γ were considerably higher than the OVA group (P<0.05). The inflammation was reduced in SE group, as the total cell number of bronchoalveolar lavage fluid was less than OVA group. Based on the histopathology findings the inflammation was decreased in SE group compared to the OVA group. CONCLUSION: Although, an inhibitory effect of SE of T. canis on airway inflammations was detected, there is still a long way ahead regarding the indication of the precise mechanisms.