Characterization Analysis of Schistosoma japonicum Plasma Membrane Repair Relative Gene Myoferlin

Abstract

Myoferlin is a member of the ferlin family of proteins, which are involved in plasma membrane repair, and has been identified as one of the tegument proteins of Schistosoma japonicum. The tegument proteins are potential candidates for vaccines and new drug targets. In this study, myoferlin of S. japonicum (SjMF) was cloned, expressed and characterized, the potential of SjMF recombinant protein (rSjMF) as a vaccine candidate was evaluated, and the effect of praziquantel on SjMF was detected by Real-time PCR. Immunofluorescence showed that this protein was mainly distributed on the surface of worms at different stages. Sequence analysis revealed that the SjMF open reading frame was conserved at all stages of the S. japonicum life cycle. And SjMF transcription was upregulated in 42-day-old worms, and was significantly higher in female worms. Western blotting revealed that rSjMF showed strong immunogenicity. The cytokine profile and IgG isotype analysis demonstrated that rSjMF plus ISA206 immunization induced a mixed T helper (Th)1/Th2 response. Purified rSjMF emulsified with ISA206 adjuvant significantly reduced worm burden from 21.8% to 23.21% and liver egg number from42.58% to 28.35%. Besides, SjMF transcription was downregulated when worms were exposed to low-dose praziquantel (PZQ) and upregulated when PZQ was degraded, accompanied by recovery of damaged tegument. When worms were exposed to high-dose PZQ, SjMF transcription was downregulated all the time and the damaged tegument did not recover. These findings indicated that SjMF is a potential vaccine against S. japonicum and provides the basis for further investigations into the biological function of SjMF.

Schistosome Vaccine Adjuvants in Preclinical and Clinical Research

“…The same antigen formulated with FCA or ISA 206 induced a moderate mixed Th1/Th2 immune response post vaccination, but this mixed immune response shifted to a Th2 response after parasite maturation and the onset of egg production [ 45 ]. This mixed immune response was also observed by Lin et al , who used ISA 206 as an adjuvant for the SjMF antigen in a murine model [ 23 ]. This study found reduced worm burdens (21.8%–23.2%) and liver egg number (42.5%–28.3%) [ 23 ].…”

“…This mixed immune response was also observed by Lin et al , who used ISA 206 as an adjuvant for the SjMF antigen in a murine model [ 23 ]. This study found reduced worm burdens (21.8%–23.2%) and liver egg number (42.5%–28.3%) [ 23 ]. Notably, the novel adjuvant ISA 70M provided an enhanced humoral and cell-mediated immune response in this study; it comprises a high grade injectable mineral oil and an extremely refined emulsifier obtained from mannitol and purified oleic acid of vegetable origin, and is a modified version of the successful veterinary adjuvant, ISA 70.…”

Characterization of VAMP2 in Schistosoma japonicum and the Evaluation of Protective Efficacy Induced by Recombinant SjVAMP2 in Mice

“…Our previous observation revealed that when schistosomes were treated with a complete dose (200 mg/kg) of PZQ, the tegument and sub-tegument of the worms were severely damaged, which finally resulted in the deaths of the treated worms. However, when the worms were treated with an incomplete dose (40 mg/kg) of PZQ, the damaged tegument recovered gradually post-treatment [ 44 ]. In this study, we noticed the similar result.…”

Characterization of Schistosoma japonicum tetraspanning orphan receptor and its role in binding to complement C2 and immunoprotection against murine schistosomiasis

“…Two weeks after the final vaccination, mice were challenged percutaneously with 40 ± 1 viable cercariae, as described by Smithers and Terry [ 14 , 29 ]. Six weeks after challenge, worms were perfused from the hepatic portal system and counted.…”

“…Schistosomes must evade the host immune responses, which is attributed in part to their tegument [ 11 ]. Thus, schistosomal proteins on the surface of the tegument and some regulatory proteins that impede the complement cascade might represent ideal molecules for the discovery of vaccine candidates [ 9 , 12 – 14 ].…”