Tadaatsu Ogita

Allergens of the house dust mite Dermatophagoides farinae—Immunochemical studies of four allergenic fractions

Analysis of the allergenic components of the house dust mite Dermatophagoides farinae was performed. Four different types of proteins reactive with human anti-mite IgE antibodies were identified as four distinct radioprecipitins in radioimmunoelectrophoresis. These were designated as mite allergen reactive with human IgE antibodies (Me) Me 1, Me 2, Me 3, and Me 4 according to their electrophoretic mobility from the slower to the faster. Me 1 and Me 2 were the first and the second prevailing allergens, respectively, in 133 atopic patients subjected to the study. Me 1, on purification by gel filtration and anion exchange chromatography, elicited a single radioprecipitin by radioimmunoelectrophoresis. Me 1 also elicited a single band in sodium dodecyl sulphate-polyacrylamide gel electrophoresis and a single peak in high-performance liquid chromatography. Both methods elicited identical values of 17,000 daltons for the molecular weight of Me 1. The isoelectric point of Me 1 was suggested to be 8.0. Me 1 elicited higher skin reactions compared to that obtained by the crude mite extract when it was assessed in seven atopic patients by serial titration intradermal skin testing.

Cyclosporin A-Induced Suppression of Ongoing IgE Antibody Formation in the Mouse

Persistent anti-ovalbumin (OA) IgE antibody formation in the mouse was suppressed by oral administration of cyclosporin A (Cy A). Spontaneous anti-OA IgE antibody formation in vitro was also suppresse

Preferential Enhancement of IgE Antibody Formation by Bordetella pertussis

Preferential enhancement of IgE antibody response was observed in BALF/c mice by the administration of Bordetella pertussis with antigen (DNP-Salmonella). Correlation between B cell mitogenic activity and adjuvant action among B. pertussis, Salmonella, lipopolysaccharide of Escherichia coli and Ficoll was examined but was not found. Thymus-derived cells seemed necessary to develop adjuvant action of B. pertussis since antibody response in athymic nude mice was not influenced by B. pertussis. Helper function of adoptively transfered spleen cells was enhanced by immunization of the donor mice with carrier antigen in the presence of B. pertussis. The magnitude of enhancement was greatest in IgE class. The results indicated that preferential enhancement of IgE antibody formation by B. pertussis is mediated by the augmentation of carrier-specific helper function.

Human IgE, IgG and IgE Antibody Synthesis in vitro

Human IgE biosynthesis in vitro was studied by co-culturing T and B cells from atopic patients and normal controls in the presence of 10 microliter/ml pokeweed mitogen for 7 days. IgE and anti-mite IgE ab in the culture media significantly correlated with those in plasma. Normal T cells suppressed in vitro production of IgE and IgE ab significantly more than did atopic T cells but no difference was found in IgG production. The culture of B cells alone (T-depleted fraction) produced IgE equally as well as the co-culture of T and B cells. Anti-mite IgE ab was also produced by B cells alone from mite-sensitive patients. However, IgE biosynthesis in vitro was not consistently affected by pokeweed mitogen. The results suggest a deficiency of the T suppressor system in atopy and the existence of T-independent IgE-producing cells.

Interstitial pneumonitis in autoimmune MRLlpr mice and its treatment with cyclosporin A

Age-associated changes of anti-double-stranded (ds) DNA antibodies, anti-single-stranded (ss) DNA antibodies, and serum immune complex concentrations were studied in MRL/lpr mice. All anti-ds DNA antibodies, anti-ss DNA antibodies, and immune complexes began to be detected in the sera of MRL/lpr mice aged 8 to 13 weeks and increased remarkably after 17 weeks of age. Almost no pathological findings were observed histologically in the lungs of MRL/lpr mice aged 8 weeks but interstitial pneumonitis became evident at 14 weeks of age. Peribronchial and perivascular lymphocyte infiltrations were seen in the lungs of 14-week-old MRL/lpr mice and became more severe at 21 weeks of age. Oral administration of cyclosporin A to 15-week-old MRL/lpr mice markedly prolonged their life span. The lungs of 44-week-old MRL/lpr mice given cyclosporin A showed few pathological findings except for minimal perivascular lymphocyte infiltration.

IgE Levels in Nude Mice

IgE levels in nude mice were estimated by the one-step single radial radiodiffusion method antisera prepared by immunization of guinea pigs with an IgE-rich fraction obtained from sera of normal mice infected with Nippostrongylus brasiliensis and immunized with DNP-ovalbumin in alum gel. 3 out of 8 nude mice had IgE levels significantly higher than those of normal mice.

Anti-double strand (ds) DNA antibody formation by NZB/W (F1) spleen cells in a microculture system detected by solid-phase radioimmunoassay

A solid-phase radioimmunoassay method was devised to detect mouse anti-double strand (ds) DNA antibody. This method could easily detect the anti-dsDNA antibody in 1 : 10,000 dilutions (1 unit) of pooled 9-10-month-old female NZB/W F1 sera. The sensitivity was about 10(3)- and 10(2)-fold higher than that of the modified Farr method and of the double antibody technique respectively. NZB/W mice developed high titer anti-dsDNA antibody as they grew older. Spleen cells brought to a microculture system using flat-bottomed polystyrene plates produced anti-dsDNA antibody clearly detectable by solid-phase radioimmunoassay. Anti-dsDNA antibody produced in vitro (y units) was in close correlation with the anti-dsDNA antibody titer of the spleen donor (x units) (y = 4.8 X 10(-2) x -65, gamma = 0.94, P less than 0.001). A combination of the microculture system and solid-phase radioimmunoassay was recommended for the characterization of anti-dsDNA antibody-forming cells.

Human IgE Antibody-Forming Cells

In vitro IgE and antimite IgE antibody (IgE Ab) synthesis was investigated. Peripheral blood lymphocytes (PBL) from atopic patients depleted of E-rosetting T cells developed IgE and IgE Ab in the absence of pokeweed mitogen (PWM), and it was not significantly affected by addition of T cells or of PWM. 1,000 R irradiation decreased more than 50% of the IgE and IgE Ab-producing capacity in 2 of 8 cases, but the remainder were not significantly affected. Increase of the γ-ray dose from 1,000 to 12,000 R did not result in more suppression. Radio-resistant as well as radio-sensitive subpopulations may exist in the PBL of atopic patients, The radio-sensitive component of IgE and IgE Ab formation was suppressed by PWM, while the radio-resistant component was not affected.

A solid-phase enzyme immunoassay for anti-acetylcholine receptor antibody in myasthenia gravis patients

A solid-phase enzyme immunoassay for the measurement of anti-acetylcholine receptor antibodies in the sera of patients with myasthenia gravis is reported. Sufficient amounts of acetylcholine receptor for the sensitive detection of anti-acetylcholine receptor antibody were directly fixed to Costar serocluster 96-well EIA plates coated with poly-L-lysine hydrobromide. The solid-phase enzyme immunoassay detected anti-acetylcholine receptor antibodies in 91% of the myasthenia gravis patients including 4 out of 4 ocular type myasthenia patients, anti-acetylcholine receptor antibodies of which were not detectable by the immunoprecipitation assay. Correlation between antibody titers measured by enzyme immunoassay and the immunoprecipitation assay was significant.

A study of the rat passive cutaneous anaphylaxis (PCA) reaction for the assay of mouse IgE antibody

Abstract The rat PCA reaction for assay of mouse IgE antibody was investigated. PCA reactivity was examined in rats with different characteristics in terms of strain, sex, age and rearing conditions. Sprague-Dawley (S-D), Fischer and Wistar strain rats were almost equally appropriate for the assay. The male rat was recommended in spite of the comparable PCA reactivity to the female since the male showed less non-specific bluing. PCA reactivity of the germ-free rat was comparable to that of the conventional animal. PCA reactivity appeared at 3 weeks of age, increased up to 11–13 weeks and remained constant until 40 weeks of age. PCA titers assayed in the rostral, caudal, lateral or central side of the back were comparable. The PCA reaction was poor when elicited with a 15 min sensitization period, became progressively stronger to reach a plateau at 4 h and remained constant until 72 h. Heating conditions required to demonstrate thermolability of IgE antibodies were studied. Incubation of undiluted antiserum at 56°C for 2 h abolished the reaginic activity. Reaginic activity of an antiserum diluted in saline was relatively resistant to heat, but diluted reaginic antibody was equally sensitive to heat in the presence of normal mouse serum (NMS) or HGG in the dileunt. NMS must be coexistent with reaginic antibody on heating to confer thermolability since preheated NMS used for dilution had no effect on the PCA titer of an antiserum.