<i>Toxocara canis</i> and <i>Toxocara cati</i> Somatic and Excretory-Secretory Antigens Are Recognised by C-Type Lectin Receptors

• Main Authors: Marie-Kristin Raulf, Bernd Lepenies, Christina Strube
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Pathogens
• Subjects: MGL-1; MCL; Dectin-1; PRR; immune evasion; toxocarosis
• Online Access: https://www.mdpi.com/2076-0817/10/3/321

<i>Toxocara canis</i> and <i>Toxocara cati</i>, the worldwide occurring intestinal roundworms of canids and felids, represent an important public health threat due to various disease manifestations in humans. Host recognition of pathogens is mediated by pattern recognition receptors (PRRs). Myeloid C-type lectin receptors (CLRs) are PRRs and recognise carbohydrate structures of various pathogens. As <i>Toxocara</i> excretory-secretory products (TES) are predominantly composed of glycoconjugates, they represent suitable targets for CLRs. However, the range of host-derived CLRs recognising <i>Toxocara</i> spp. is still unknown. Using a CLR-hFc fusion protein library, <i>T. canis</i> and <i>T. cati</i> L3 somatic antigens (TSOM) were bound by a variety of CLRs in enzyme-linked immunosorbent assay (ELISA), while their TES products interacted with macrophage galactose-type lectin-1 (MGL-1). Two prominent candidate CLRs, MGL-1 and macrophage C-type lectin (MCL), were selected for further binding studies. Immunofluorescence microscopy revealed binding of MGL-1 to the oral aperture of L3. Immunoblot experiments identified distinct protein fractions representing potential ligands for MGL-1 and MCL. To evaluate how these interactions influence the host immune response, bone marrow-derived dendritic cell (BMDC) assays were performed, showing MCL-dependent <i>T. cati</i>-mediated cytokine production. In conclusion, MGL-1 and MCL are promising candidates for immune modulation during <i>Toxocara</i> infection, deserving further investigation in the future.