Immunological features and efficacy of the recombinant subunit vaccine LTB-EMY162 against Echinococcus multilocularis metacestode

Abstract

Alveolar echinococcosis is a zoonotic disease caused by the infection of the larval stage Echinococcus multilocularis with worldwide distribution especially in the northwest China. It is important to develop a well-tolerated immunoprophylaxis against E. multilocularis for alveolar echinococcosis control. In this study, a prokaryotic expression system for recombinant immunogen LTB-EMY162 was established, and the immunological features, sensitized lymphocyte, IL-4/IFN-γ secreted, prophylactic effect, and therapeutic effect were also evaluated. Arctic Express (DE3) system, Ni-charged and molecular sieve chromatography were used to obtain a high-purity 29 kDa protein. The ELISA and lymphocyte proliferation assay showed that LTB-EMY162 induced high-titer specific IgG against EMY162 and E. multilocularis protoscoleces protein in BALB/c mice and promoted sensitized T lymphocyte cell proliferation, and LTB-EMY162 stimulated Th cell to secrete IL-4 and IFN-γ and induced a Th1/Th2 mixed type immunological response. We also found that LTB-EMY162 significantly inhibited the cysts formation by challenging with 1000 E. multilocularis protoscoleces. The growth of protoscoleces and cysts were also significantly decreased by treating with LTB-EMY162 in 1000 protoscoleces intraperitoneal injection therapeutic mice model. In conclusion, we have constructed a subunit vaccine LTB-EMY162 which has prevention and therapeutic effect against E. multilocularis infection.

Therapeutic effect on Alveolar echinococcosis by targeting EM-Leucine aminopeptidase

“…Liver function is not a particularly sensitive evaluation index in clinical cases and it is only used to determine the preoperative nutritional status of patients with hepatic alveolar echinococcosis and AE-related autologous liver transplantation in order to evaluate the effect of surgery (24, 25). The expression of key proteins of E. multilocularis is not measured in animal model (7,16,21), because few substances are secreted into the tissue due to the presence of insect protein and cyst and no specific antibody is currently available for verification. For these reasons, we have evaluated not only the sizes of cysts but also parasite infiltration and growth in the liver through MRI, ultrasound and pathological examination.…”

“…All mice were intraperitoneally injected with 2000 protoscoleces obtained from the Research Center for High Altitude Medicine Basic Immunology Laboratory for Zoonosis (16). After that, mice were randomized into rEM-LAP group, Model group and three Ubenimex concentration groups (2.5 mg/kg, 5 mg/kg, and 7.5 mg/kg) with 6 mice in each group, and they were sacrificed 60 days later for evaluation of the infection, growth and invasion of E. multilocularis.…”

“…The specific antibodies were detected with HRP-conjugated goat anti-mouse IgG1, lgG2a, lgG, lgM, lgA, and lgE. TMB was added and incubated at room temperature for 10 min (16). The absorbance at 450 nm was measured by a microplate reader (TECAN, Switzerland).…”

Immunization with EmCRT-Induced Protective Immunity against Echinococcus multilocularis Infection in BALB/c Mice

“…After the final wash, the substrate 3, 3’, 5, 5’-tetramethylbenzidine (TMB, Beyotime Biotechnology, Shanghai,, China) was added to each well, and the reaction was stopped with stop solution (Beyotime Biotechnology, Shanghai,, China). Quantification of the reaction was determined by measuring the absorbance at 450 nm in an ELISA reader [ 30 , 31 ].…”

MiR-374b-5p Regulates T Cell Differentiation and Is Associated with rEg.P29 Immunity

“…IL-10 characterizes immune tolerance in a number of parasitic disease models [41]. The vaccination of rEg.P29 may enhance miR-374b-5p expression induced by a decreased secretion of IL-10, a cytokine typically associated with immunoregulation responses, which appears to limit and ultimately terminate inflammatory responses [42,43].…”