[Contribution to the study of ontogeny of the cells synthetizing IgE class immunoglobulins (author's transl)].

It is known that a treatment, initiated with birth, of repeated injections of anti-mu heavy chain sera leads in mice to considerable decrease of the serum level of the various classes of immunoglobulins : IgM, IgA, IgG1, IgG2. A similar treatment led to similar results in rats but, in addition, made it clear that the IgE serum level was also decreased by the treatment. Moreover, a series of injections of an anti-rat IgD serum also produced a significative decrease of the IgE serum level. The results suggest that the precursor cells of the IgE plasma cells are bearing molecules of IgM and IgD classes on their membrane.