Molecular characterization and expression analysis of annexin B3 and B38 as secretory proteins in Echinococcus granulosus

Abstract

Background Cystic echinococcosis is a parasitic zoonotic disease, which poses a threat to public health and animal husbandry, and causes significant economic losses. Annexins are a family of phospholipid-binding proteins with calcium ion-binding activity, which have many functions. Methods Two annexin protein family genes [Echinococcus granulosus annexin B3 (EgAnxB3) and EgAnxB38] were cloned and molecularly characterized using bioinformatic analysis. The immunoreactivity of recombinant EgAnxB3 (rEgAnxB3) and rEgAnxB38 was investigated using western blotting. The distribution of EgAnxB3 and EgAnxB38 in protoscoleces (PSCs), the germinal layer, 18-day strobilated worms and 45-day adult worms was analyzed by immunofluorescence localization, and their secretory characteristics were analyzed preliminarily; in addition, quantitative real-time reverse transcription polymerase chain reaction was used to analyze their transcript levels in PSCs and 28-day strobilated worms stages. The phospholipid-binding activities of rEgAnxB3 and rEgAnxB38 were also analyzed. Results EgAnxB3 and EgAnxB38 are conserved and contain calcium-binding sites. Both rEgAnxB3 and rEgAnxB38 could be specifically recognized by the serum samples from E. granulosus-infected sheep, indicating that they had strong immunoreactivity. EgAnxB3 and EgAnxB38 were distributed in all stages of E. granulosus, and their transcript levels were high in the 28-day strobilated worms. They were found in liver tissues near the cysts. In addition, rEgAnxB3 has Ca2+-dependent phospholipid-binding properties. Conclusions EgAnxB3 and EgAnxB38 contain calcium-binding sites, and rEgAnxB3 has Ca2+-dependent phospholipid-binding properties. EgAnxB3 and EgAnxB38 were transcribed in PSCs and 28-day strobilated worms. They were expressed in all stages of E. granulosus, and distributed in the liver tissues near the hydatid cyst, indicating that they are secreted proteins that play a crucial role in the development of E. granulosus.

Proteomic Profiling and In Silico Characterization of the Secretome of Anisakis simplex Sensu Stricto L3 Larvae

“…Among the most frequently identified protein families in the Anisakis secretome, attention should be paid to the annexin superfamily. Annexins have multiple functions, such as in cellular anti-inflammation, signal transmission, anticoagulation, ion channel regulation, membrane repair, and membrane transport, and likely participate in cell proliferation, differentiation, and apoptosis [41,42]. Furthermore, parasite annexins are considered potential drug and vaccine targets [43].…”

Protective efficacy of six recombinant proteins as vaccine candidates against Echinococcus granulosus in dogs

“…In addition, we found that annexins of E . granulosus s.s. might play an important role in parasite-host interactions and demonstrated that the level of Eg ANXB3 transcription was increased from PSCs to adults [ 23 , 30 ]. This indicates that it has a potential role during the adult stages of infection in dogs.…”

Comparative proteomics analysis of the egg, sparganum, and adult stages of Spirometra mansoni

“…Several studies have highlighted the crucial role of annexins in parasite growth, development, maintenance of cellular structural integrity, and the host's immune response against parasites [29,30,31,32]. For instance, Song et al [33] emphasized the potential signi cance of annexin B3 and annexin B38 in the invasion and development of Echinococcus granulosus protoscoleces. In our investigation, we observed the upregulation of annexin A1, annexin A7, annexin A5, and annexin A4 in the sparganum stages, while other annexins (annexin A3, annexin A2, annexin A13, and annexin A11) exhibited upregulation in the egg stage.…”