Recent advances in characterization of Echinococcus antigen B.

Area of Science:

• Parasitology
• Immunology
• Molecular Biology

Background:

• Antigen B (AgB) is a major immunogenic lipoprotein in Echinococcus granulosus infections.
• AgB is composed of approximately 8 kDa subunit monomers and exhibits significant genetic variability.
• AgB homologues are also found in Echinococcus multilocularis.

Purpose of the Study:

• To review recent advances in the molecular and immunological characterization of AgB from E. granulosus and E. multilocularis.
• To highlight the genetic diversity of E. granulosus AgB (EgAgB) genes and their potential in serodiagnosis.
• To discuss the role of AgB in immune response modulation and its presence in different parasite life stages.

Main Methods:

• Analysis of genetic variability of EgAgB genes, identifying four clades (EgAgB8/1-4).
• Evaluation of recombinant EgAgB subunits (rEgAgB8/1, rEgAgB8/2) for serodiagnosis of cystic echinococcosis.
• Identification and characterization of five AgB homologues (EmAgB8/1-5) in E. multilocularis.

Main Results:

• EgAgB shows high genetic variability, with EgAgB8/2 potentially outperforming EgAgB8/1 in serodiagnosis.
• EgAgB functions as a protease inhibitor, modulating host immune responses (e.g., inhibiting neutrophil recruitment, promoting Th2 response).
• Five distinct AgB homologues identified in E. multilocularis, with developmental stage-specific expression.

Conclusions:

• AgB is a crucial antigen in both E. granulosus and E. multilocularis infections, with significant genetic diversity.
• Understanding AgB's molecular and immunological properties is vital for developing improved diagnostic tools and therapeutic strategies for echinococcosis.
• The distinct EgAgB variants and their immunomodulatory functions warrant further investigation.