title: Seasonal variations in in vitro synthesis of rye pollen-specific IgE by human peripheral mononuclear cells. Functional heterogeneity within the IgE-B pool.
abstract: Peripheral blood mononuclear B cells from 6 rye pollen-allergic patients, with no consistent perennial symptoms, were isolated before (July), during (October) and after (February and May) the pollen season. The T-depleted cells were fractionated on a discontinuous percoll density gradient and the B cell fractions, together with unfractionated B cells, incubated in vitro for quantitation of spontaneous synthesis of rye pollen-specific IgE. Markedly higher levels of IgE were synthesised by the fractions, as opposed to unfractionated B cells. The low-density fraction (B5) contributed most towards synthesis in the pollen season and the denser B6 cells in the pre- and post-pollen season. All low-density B cell fractions (B1-3-B5) and some high-density fractions contained large but variable amounts of preformed specific IgE which was retained, even in the absence of de novo synthesis in vitro, during the post- and pre-pollen season. Since only a fraction of this preformed IgE escaped into culture supernatants the contribution of preformed IgE to in vitro IgE synthesis in general may require reappraisal.
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology* / Q000473:pathology; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D008297:Male; D011058:Pollen; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000473:pathology*; D012621:Seasons; D012434:Secale
chemical_list: D007073:Immunoglobulin E