Polarized Th2 like cells, in the absence of Th0 cells, are responsible for lymphocyte produced IL-4 in high IgE-producer schistosomiasis patients

Our analysis showed that high and low IgE-producers responded equally to schistosomiasis antigens as determined by proliferation. Moreover, patients from both groups displayed similar percentages of circulating lymphocytes. However, high IgE-producers had an increased percentage of activated CD4+ T cells as compared to the low IgE-producers. Moreover, intracellular cytokine analysis, after short-term stimulation with anti-CD3/CD28 mAbs, showed that IgE high-producers display an increase in the percentage of T lymphocytes expressing IL-4 and IL-5 as compared to IgE low-responders. A coordinate control of the frequency of IL-4 and IL-5 producing lymphocytes in IgE high, but not IgE low-responders, was observed.High IgE phenotype human schistosomiasis patients exhibit a coordinate regulation of IL-4 and IL-5 producing cells and the lymphocyte derived IL-4 comes from true polarized Th2 like cells, in the absence of measurable Th0 cells as measured by co-production of IL-4 and IFN-γ.Schistosomiasis is a disease caused by a helminth parasite and effects more than 200 million people. Infected individuals mount a strong proliferative response in vitro to parasite antigens, and anti-worm and egg antibodies are abundant as well [1,2]. Although effective treatment is available, due to socio-economical conditions of the endemic countries, re-infection is highly prevalent and may lead to the establishment of pathology.Correlations have been made between intensity of infection and anti-parasite IgE antibody responses in human schistosomiasis [3]. It has been shown that patients with high levels of circulating IgE anti-SWAP are resistant to re-infection [4-7]. Further studies demonstrated that this immunoglobulin isotype, correlated with resistance to re-infection, was mainly directed to a specific component of SWAP, the sm22 antigen [8]. Moreover, individuals who live in an endemic area, but were never infected with S. mansoni, display high levels of anti-parasite IgE [9]. Early