Degradation of human secretory immunoglobulin A by Blastocystis
- 300 Downloads
Microbial immunoglobulin A (IgA) proteases cleave human secretory IgA, promoting the mucosal adhesion of pathogens. To investigate if the enteric protozoan Blastocystis degrades human secretory IgA, cell lysate and conditioned medium from two species were exposed to immunoglobulin A. Secretory IgA was cleaved by both cell lysate and conditioned medium with mainly cysteine proteinase activity in B. hominis B isolate and aspartic proteinase activity in B. ratii WR1 isolate. These findings suggest that Blastocystis proteases may play a role in parasite survival in vivo.
KeywordsBlastocystis Immunoglobulin A Mucosal Proteinases Protozoa
This work was supported by generous grants from the National Medical Research Council (R-182-000-058-213) and the Faculty of Medicine, National University of Singapore. We thank Ms. Geok Choo Ng, Mr. Ramachandran for technical support and helpful discussions. Thanks are also due to Ms. Tan Mui Hong, Ms. Tan Li Li and Dr. Punam Dahiya, for their contributions. The present experiments were carried out in compliance with the laws and regulations of Singapore.
- Alexeieff A (1911) Sur la nature des formations dites kystes de Trichomonas intestinalis. C R Soc Biol 71:296–298Google Scholar
- Challacombe SJ, Sweet SP (1997) Salivary and mucosal immune responses to HIV and its co-pathogens. Oral Dis Suppl 1:S79–S84Google Scholar
- Doyle PW, Helgason MM, Mathias RG, Proctor EM (1989) Epidemiology and pathogenicity of Blastocystis hominis. J Clin Microbiol 28:116–121Google Scholar
- Noel C, Dufernez F, Gerbod D, Edgcomb VP, Viscogliosi PD, Ho LC, Singh M, Wintjens R, Sogin ML, Capron M, Pierce R, Zenner L, Viscogliosi E (2005) Molecular phylogenies of Blastocystis isolates from different hosts: implications for genetic diversity, identification of species, and zoonosis. J Clin Microbiol 43:348–355CrossRefPubMedGoogle Scholar
- Quezada-Calvillo R, Lopez-Revilla R (1986) IgA protease in Entamoeba histolytica trophozoites. Adv Exp Med Biol 216B:1283–1288Google Scholar
- Renegar KB, Small PA Jr (1999) Passive immunization: systemic and mucosal. In: Ogra PL, Mestecky J, Lamm ME, Strober W, Bienenstock J, McGhee JR (eds) Mucosal immunology, 2nd ed. Academic Press, New York, NY, pp 729–738Google Scholar
- Russel MW, Kilian M, Lamm ME (1999) Biological activities of IgA. In: Ogra PL, Mestecky J, Lamm ME, Strober W, Bienenstock J, McGhee JR (eds) Mucosal immunology, 2nd edn. Academic Press, New York, NY, pp 225–240Google Scholar