title: T cell mediation of abnormally low production of ovalbumin-specific immunoglobulin A in patients allergic to eggs.
abstract: Cells producing IgA specific to ovalbumin (OVA) were detected with an assay of plaque-forming cells (PFC). Non-T cells were separated on a polystyrene resin column and were further depleted of B cells that bound sheep erythrocytes (SRBC) by SRBC-rosette sedimentation. The cells were recombined with T cells separated on a polystyrene resin column, stimulated with OVA antigen, and then cultured for 5 d. The number of OVA-specific IgA-PFC from the lymphocytes of infants allergic to hen's eggs (7 +/- 5 per 7 x 10(4) non-T cells, n = 9) was significantly less than that of PFC from lymphocytes of age-matched controls (110 +/- 18 per 7 x 10(4) non-T cells, n = 7) and from those of children with atopic dermatitis who were not allergic to hen's eggs (90 +/- 30 per 7 x 10(4) non-T cells, n = 4). Patients' B cells added to the culture supernatant from OVA-stimulated normal T cells (82 +/- 18 per 7 x 10(4) non-T cells, n = 4) were able to produce the specific IgA to levels comparable to those of normal B cells (92 +/- 9 per 7 x 10(4) non-T cells, n = 6), but the patients' T cells did not cause normal B cells to produce the antibody (8 +/- 2 per 7 x 10(4) non-T cells, n = 4). This indicates that the patients' T cells were less able than were normal T cells to promote the production of OVA-specific IgA-PFC. Until the age of 6 y, the ability of the patients' lymphocytes to produce specific IgA was abnormally low; from that age on, it was normal. At the stage of allergen entry, this transiently low production of OVA-specific IgA may contribute to the onset of allergy to hen's eggs.
authors.affiliation: Department of Pediatrics, Saitama Medical School, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Noma
authors.forename: K
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: I
authors.initials: I
authors.lastname: Yoshizawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kawano
authors.forename: K
authors.initials: K
authors.lastname: Ichikawa
authors.forename: T
authors.initials: T
authors.lastname: Mukouyama
authors.forename: M
authors.initials: M
authors.lastname: Baba
mesh_terms: D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007070:Immunoglobulin A / Q000276:immunology*; D007223:Infant; D008297:Male; D010047:Ovalbumin / Q000276:immunology*; D010063:Ovum / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
chemical_list: D007070:Immunoglobulin A; D010047:Ovalbumin