Identification of a Novel Antigen of Schistosoma mansoni Shared with Plasmodium falciparum and Evaluation of Different Cross-Reactive Antibody Subclasses Induced by Human Schistosomiasis and Malaria

• Published in: Infection and Immunity 2006-06, Vol.74 (6), p.3347-3354
• Main Authors: Pierrot, Christine, Wilson, Shona, Lallet, Hélène, Lafitte, Sophia, Jones, Frances M, Daher, Wassim, Capron, Monique, Dunne, David W, Khalife, Jamal
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antibodies, Helminth - blood; Antibodies, Protozoan - blood; Antigens, Helminth - chemistry; Antigens, Helminth - immunology; Biological and medical sciences; Cross Reactions; Diseases caused by trematodes; Fundamental and applied biological sciences. Psychology; Fungal and Parasitic Infections; Helminthic diseases; Human protozoal diseases; Humans; Immunoglobulin G - classification; Infectious diseases; Malaria; Malaria, Falciparum - immunology; Medical sciences; Microbiology; Molecular Sequence Data; Parasitic diseases; Plasmodium falciparum; Plasmodium falciparum - immunology; Protozoal diseases; Schistosoma mansoni; Schistosoma mansoni - immunology; Schistosomiases; Schistosomiasis mansoni - immunology
• ISSN: 0019-9567; 1098-5522
• DOI: 10.1128/IAI.01724-05

Plasmodium falciparum and Schistosoma mansoni are often found in human coinfections, and cross-reactive antibodies to different components of the two parasites have been detected. In this work, we identified a cross-reactive S. mansoni gene product, referred to as SmLRR, that seems to belong to the leucine-rich repeat protein family. Comparative analysis of SmLRR revealed 57% similarity with a putative gene product encoded in the P. falciparum genome. Antibodies to SmLRR were found in experimental infections and in both S. mansoni- and P. falciparum-infected individuals. Correlative analysis of human anti-SmLRR responses in Kenya and Uganda suggested that malaria and schistosomiasis drive the immunoglobulin G3 (IgG3) and IgG4 isotypes, respectively, against SmLRR, suggesting that there is differential regulation of cross-reactive isotypes depending on the infection. In addition, the levels of anti-SmLRR IgG4, but not the levels of IgG3, correlated positively with the intensity of S. mansoni infection.