Murine lymphocytes bearing receptors for the Fc portion of IgE molecules (FcRε) were monitored by a rosette-forming cell assay using DNP-specific IgE-coated TNP-sheep red blood cell (SRBC) indicator cells. Infection of female CAF1 mice with Nippostrongylus brasiliensis induced a 3- to 7-fold increase in the number of FcRε+ lymphocytes in both spleen and mesenteric lymph nodes. This increase was paralleled by a 7- to 10-fold enhancement of IgE production in the serum of infected mice. More than 15% of both FcRε+ and FcRγ(2b+) cells were induced in 2-way mixed lymphocyte culture reactions (MLR) between CAF1 and C57BL/6 spleen cells. Induction of FcRε+ cells peaked as early as 8 hr, whereas the frequency of FcRΓ(2b+) cells rose progressively higher by 24 and 60 hr after culture initiation. Equal proportions of FcRε+ cells were observed in both B and T lymphocyte populations. FcRε+ cells were also induced in vitro in cultures of spleen cells incubated with monoclonal IgE (1 to 25 μg/ml) but not with IgG1, IgG2b, or IgM. Likewise, the rosette-forming abilities of FcRε+ cells, induced by incubation with IgE or 2-way MLR, were inhibited by pretreatment with monoclonal IgE, but not with IgG1, antibodies. Suppressive factor of allergy (SFA), prepared from complete Freund's adjuvant (CFA)-induced ascites, selectively inhibited induction of FcRε+, but not FcRγ(2b+) cells in 2-way MRL. SFA also inhibited induction of FcRε+ cells by exposure of normal CAF1 spleen cells to monoclonal IgE. SFA, added to cultures of lymphocytes before or early after the exposure of CAF1 spleen cells to IgE, optimally inhibited induction of FcRε, whereas delayed addition of SFA 14 hr after the IgE stimulus failed to alter the frequency of induced FcRε+ lymphocytes. Collectively, these data demonstrate that murine FcRε+ lymphocytes can be actively induced in vivo and in vitro in conditions associated with elevation of the level of IgE or after activation in 2-way MLR, and 1 mechanism of action of SFA is to regulate the early events of this induction of the FcRε+ lymphocytes.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Immunology|
|State||Published - 1981|
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