Infection of Hooded Lister rats with Nippostrongylus brasiliensis resulted in an increase in IgE-bearing B lymphocytes to between 40 and 50% of the total B cells in mesenteric lymph nodes (MLN). Examination of MLN cells from infected rats by double immunofluorescence revealed that more than 93% of IgE-bearing cells possess IgD determinants, and greater than 94% of IgE-bearing cells bear IgM determinants. The results indicate that the majority of IgE-bearing cells are actually IgE, IgD, IgM triple bearing cells. Mesenteric lymph node cells from Nb-infected rats produce a lymphokine, IgE-B cell generating factor, that can induce IgM-bearing normal bone marrow lymphocytes to express surface IgE. Evidence was obtained that the major source of the factor was IgE, IgD, IgM triple bearing cells. Treatment of MLN cells from infected rats with anti-IgE or its F(ab')2 fragments induces an enhanced production of IgE-B cell generating factor, whereas the Fab' monomer of the antibody failed to do so. The results indicate that bridging of surface IgE is required for enhancement of factor production. This idea was supported by the fact that bridging of cell-bound Fab' monomer with anti-rabbit IgG induced an enhancement of factor production. It was also found that cells treated with anti-IgD showed enhanced factor activity in culture supernatants, whereas cells treated with anti-IgM did not. Pretreatment of cells with anti-IgM inhibited the anti-IgE- or anti-IgD-induced increase in factor production. It appears that bridging of surface IgM on triple bearing cells provides a signal different from that initiated by bridging of either surface IgE or IgD.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Immunology|
|Publication status||Published - 1980|
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