1. Elevated plasma levels of IgE in Plasmodium falciparum-primed individuals reflect an increased ratio of IL-4 to interferon-gamma (IFN-γ)-producing cells.
- Author
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Elghazali, G., Perlmann, H., Rutta, A. S. M., Perlmann, P., and Troye-Blomberg, M.
- Subjects
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PLASMODIUM falciparum , *BLOOD plasma , *T cells , *INTERFERONS , *ANTINEOPLASTIC agents , *IMMUNITY - Abstract
People living in Plasmodium falciparum-endemic areas frequently have elevated levels of total as well as P. falciparum-specific serum IgE. This study aimed at investigating whether the elevated serum IgE levels reflect a shift in the balance between CD4+ T helper 1 (Th1) and T helper 2 (Th2) cells in individuals naturally exposed to the P. falciparum parasite. To investigate the role of Thi and Th2 ceils in the human P. falciparum system we used the ELISPOT assay to determine the ratio of IEN-γ- and IL-4-producing cells after specific antigen or mitogen activation in vitro. The donors were individuals who had acquired immunity through natural exposure to the parasite. In response to the specific malaria antigens, very few IL-γ-producing cells were seen. However, in the response of individual donors to the polyclonal T cell activator, leucoagglutinin (La), the anti-malarial IgE levels in plasma were correlated with an increased ratio of IL-4/IFN-γ producing cells. Thus, donors with ratios of IL-4/IFN-γ>1 exhibited mean plasma anti-malarial IgE levels significantly greater than those with ratios <1. In individuals not living in P. fatciparum-endemic areas the ratio of IL-4/IFN-γ was always <1. Taken together, our data suggest a shift in the balance between Th1 and Th2 cells in naturally P. falciparum primed individuals, associated with elevated anti-P. fatciparum plasma IgE levels. The role and biological signilicance of IgE (Th2-type immune response) for protection against F. faiciparum and/or pathogenesis of malaria require further study. [ABSTRACT FROM AUTHOR]
- Published
- 1997
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