In:
The Journal of Immunology, The American Association of Immunologists, Vol. 172, No. 4 ( 2004-02-15), p. 2439-2445
Abstract:
Basophil contribution to the IL-4 pool in filarial infections was assessed using PBMC from 20 patients with active filarial infections and from 9 uninfected subjects. Patient basophils released histamine in response to Brugia malayi Ag (BmAg). They also released IL-4 within 2 h after exposure to BmAg, as assessed by intracellular cytokine flow cytometry. This IL-4 induction was Ag specific, as IL-4 was not detected in BmAg-exposed basophils obtained from uninfected subjects. Although there were, on average, 64 times more CD4+ T cells than basophils in the peripheral circulation of filaria-infected patients, the absolute numbers of basophils and CD4+ T cells producing IL-4 per 100,000 PBMC were equivalent (geometric mean: 16 IL-4-producing basophils/100,000 PBMC vs 22 IL-4-producing CD4+ T cells/100,000 PBMC). Basophils also released IL-4 in response to both low and high concentrations of BmAg, whereas CD4+ T cells released IL-4 only after incubation with a high concentration of BmAg, raising the possibility that basophils, due to their lower threshold for activation, may actually release IL-4 more frequently than CD4+ T cells in vivo. Furthermore, IL-4 production in vitro by Ag-stimulated purified basophils or CD4+ T cells provided evidence that basophils release greater quantities of IL-4 per cell than CD4+ T cells in response to BmAg. These results suggest that, when Ag-specific IgE is present in a filaria-infected individual, basophils function to amplify the ongoing Th2 response by releasing IL-4 in greater amounts and possibly more frequently than CD4+ T cells in response to filarial Ag.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.172.4.2439
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
2004
detail.hit.zdb_id:
1475085-5
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