Comparative analysis of full-length antigen II/3 from Echinococcus multilocularis and E. granulosus

Area of Science:

• Parasitology
• Immunology
• Molecular Biology

Background:

• Alveolar echinococcosis (AE) and cystic echinococcosis (CE) are parasitic diseases caused by Echinococcus species.
• Recombinant Echinococcus multilocularis antigen II/3-10 is a potential diagnostic tool for AE, but its recognition in CE is poor.
• The antigen II/3 is present in both E. multilocularis and E. granulosus.

Purpose of the Study:

• To investigate the reasons for the lack of recognition of recombinant antigen II/3 by cystic echinococcosis patients.
• To compare the reactivity of antigens derived from E. multilocularis and E. granulosus in patients with echinococcosis.

Main Methods:

• Generated complementary DNA (cDNA) from full-length II/3 genes of E. granulosus and E. multilocularis using reverse transcription and PCR.
• Subcloned and expressed cDNA fragments in E. coli as fusion proteins with glutathione S-transferase.
• Purified recombinant proteins and assessed antibody-binding characteristics using ELISA with patient sera.

Main Results:

• Sequence analysis revealed high conservation of the primary sequence of antigen II/3 between E. granulosus and E. multilocularis.
• Sera from CE patients showed no significant differences in reactivity with antigens derived from either Echinococcus species.
• The lack of antigen II/3 recognition in CE is likely due to factors other than minor differences in the primary sequence.

Conclusions:

• The primary sequence of antigen II/3 is highly conserved between E. granulosus and E. multilocularis.
• Minor sequence variations do not explain the differential recognition of antigen II/3 in AE versus CE.
• Further research is needed to identify the specific factors responsible for the lack of antigen II/3 recognition in cystic echinococcosis.