Schistosoma mansoni Infection in Preschool-Aged Children: Development of Immunoglobulin E and Immunoglobulin G4 Responses to Parasite Allergen-Like Proteins

Specific immunoglobulin E (IgE) responses are upregulated during chronic schistosome infection and during allergy. These responses are tightly regulated during schistosomia-sis. We have previously shown that IgE regulation depends on the extent and length of exposure to individual parasite allergen-like proteins. Here we compare the development of IgE and immunoglobulin G4 (IgG4) responses to the differ-entially expressed allergen-like proteins SmTAL1 and SmTAL2 among preschool-aged children from 2 villages with different levels of Schistosoma mansoni transmission. We found a lack of SmTAL1 responsiveness among all chil-dren, but evidence for IgG4-dependent IgE-SmTAL2 desen-sitization in both villages, occurring earlier among children from the village where the level of transmission was greater. Findings provide insights into the development and regula-tion of allergic-type immune responses