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IgE and IgG4 antibodies to bovine milk fat globule membrane in atopic eczema patients: A study of their occurrence, relevance, and antigenic specificity
J. ALLERGY CLIN. IMMUNOL. MAY 1966
16 Abstracts was attributed to formation of an antibody to DNFB receptor. When groups of sensitizedanimals were injected with interferonsa$ (IFNa,B) during DNFB sensitizationor with cyclophosphamide2 days before sensitizationoccurred, the steepdecline in the intensity of the skin reactionto challenge with DNFB on day 14 failed to occur, and if lFNo,B or DNFB were withheld until later in sensitization, the antireceptor antibody effect was not abrogated. Passivetransfer experiments in which single cell suspensionsobtained from lymph nodes draining the DNFB sensitizedskin sites were first incubated with either (I) normal mouse serum, (2) pooled mouse serum from sets of animals sensitized with DNFB 14 days previously, (3) pooled serum from setsof mice injected with buffer, (4) pooled serum from mice injected with lFNo,B on days 0 and 1 of sensitization,or (5) pooled serum from mice injected 2 days before DNFB sensitization with cyclophosphamidedemonstratedthat the decline in contact sensitivity observed 14 days after DNFB sensitization could indeed be attributed to an anti-DNFB receptor antibody whose elaboration could be partly prevented by treatment of the sensitizedanimals with IFN or cyclophosphamide.This enhancementof delayed hypersensitivity induced by lFNa,B is probably due to inhibition of a suppressorT cell circuit that controls the inhibition of production of contact dermatitis antireceptor antibody. D. S.
IgE and lgG4 antibodies to bovine milk fat globule membrane in atopic eczema patients: A study of their occurrence, relevance, and antigenic specificity Shakib F, Morrow Brown H, Redhead R, Phelps A: Clin Allergy 15:265, 1985. Although 50% of children with cow’s milk allergy suffer with atopic eczema (AE) with marked elevation in serum levels of IgE, milk-specific IgE is difficult to demonstrate. When it is demonstrable, the high level of IgE in AE correlates poorly with milk sensitivity. These findings lead some authors to speculatethat milk hypersensitivity is due to antigens that may arise during milk digestion rather than those found in native milk proteins. To date milk-specific lgG4 has also failed to correlate with AE activity. Since researchinto cardiovasculardiseasehas prompted investigators to consider cream fraction antigens located on the fat globule membrane (FGM) as the immunogens that elicit an IgG response, the authors investigated the possible role of FGM antigen in eliciting the lgG4 and IgE responsesin eczema patients. Twenty patients (15 children and five adults) whose AE was exacerbatedby milk ingestion were studied along with suitable nonatopic control subjects. All the subjectswere skin tested with food and environmental antigens, serum anti-FGM IgE was determined by RAST, and serum anti-FGM-lgG4 was examined by ELISA. The FGM antigen was prepared from the encasingmembrane of the cream fraction of milk lipid globules that is produced
in the cow by exocytosis from mammary gland secretory epithelium. The FGM-specific IgE and lgG4 determinations were of no greater diagnostic significance than other diagnostic means already in use with the use of whole milk antigens. Cross-inhibition experiments demonstrated that the anti-FGM IgE and lgG4 are actually directed against the a-casein fraction of cow’s milk. D. S.
Uromodulin: A unique 85 kilodalton immunosuppressive glycoprotein isolated from urine of pregnant women Muchmore AV, Decker JM: Science 229:479, 1985.
An immunoregulatory glycoprotein, active in vitro, and free of a-fetoprotein was isolated from human pregnancy urine on sodium dodecyl sulfate-polyacrylamide gel electrophoresisby these authors and termed uromodulin (UM). Urine was obtained from 20- to 40-weeks pregnant women, passed over concanavalin A-Sepharose columns, which were washed and eluted with a-methyl mannose. The eluate was dialyzed againstdeionized water, lyophilized, and after resuspensionin phosphate-buffered saline, was placed on a Fractogel SS column. Elution patterns were determined for the fractions in order that the first peak could be dialyzed, resuspended, applied to preabsorbent wicks, and focused on isoelectric focusing gels. By elution from the wick, a fraction was obtained that could be concentrated in Centricon filters at a cutoff of 30 kilodalton (kd). Focusingbuffers could be removed by molecular sieving columns. The material obtained by these maneuverswas assayedby ELISA with rabbit antiserum in a sandwich technique. At each step in the fractionation, the biologic activity was tested in vitro by determination of T cell-proliferation inhibition that is supposedto occur when these cultured cells are challenged with tetanus toxoid. When the antiurine fraction rabbit antiserum was used as a probe of the unfractionated urine in a Western blot experiment, a lone major band at 85 kd was found. The rabbit heteroantiserum could be conjugated to CNBr-activated Sepharoseand used as an immunosorbent for crude pregnancy urine from which the 85 kd fraction could be eluted and its immunosuppressiveactivity demonstrated in vitro. Furthermore, a pure IgG could be prepared from the rabbit heteroantiserum to probe the immunosuppressivein vitro activity of the 85 kd fraction. The 85 kd urine fraction material was immunosuppressivefor T cells sensitized with numerous antigens and had no effect on B cells stimulated with pokeweed mitogen. A strong influence was found on in vitro development of spontaneous monocyte-mediated cytotoxicity regulatory suppressor cells, but only when it was at the inception of the cell culture. The data suggest that UM interferes with an early step in interimmune cell collaboration and may play an important role in suppressingmaternal immunologic responsesagainst non-self fetal antigens. D. S.
16 Abstracts was attributed to formation of an antibody to DNFB receptor. When groups of sensitizedanimals were injected with interferonsa$ (IFNa,B) during DNFB sensitizationor with cyclophosphamide2 days before sensitizationoccurred, the steepdecline in the intensity of the skin reactionto challenge with DNFB on day 14 failed to occur, and if lFNo,B or DNFB were withheld until later in sensitization, the antireceptor antibody effect was not abrogated. Passivetransfer experiments in which single cell suspensionsobtained from lymph nodes draining the DNFB sensitizedskin sites were first incubated with either (I) normal mouse serum, (2) pooled mouse serum from sets of animals sensitized with DNFB 14 days previously, (3) pooled serum from setsof mice injected with buffer, (4) pooled serum from mice injected with lFNo,B on days 0 and 1 of sensitization,or (5) pooled serum from mice injected 2 days before DNFB sensitization with cyclophosphamidedemonstratedthat the decline in contact sensitivity observed 14 days after DNFB sensitization could indeed be attributed to an anti-DNFB receptor antibody whose elaboration could be partly prevented by treatment of the sensitizedanimals with IFN or cyclophosphamide.This enhancementof delayed hypersensitivity induced by lFNa,B is probably due to inhibition of a suppressorT cell circuit that controls the inhibition of production of contact dermatitis antireceptor antibody. D. S.
IgE and lgG4 antibodies to bovine milk fat globule membrane in atopic eczema patients: A study of their occurrence, relevance, and antigenic specificity Shakib F, Morrow Brown H, Redhead R, Phelps A: Clin Allergy 15:265, 1985. Although 50% of children with cow’s milk allergy suffer with atopic eczema (AE) with marked elevation in serum levels of IgE, milk-specific IgE is difficult to demonstrate. When it is demonstrable, the high level of IgE in AE correlates poorly with milk sensitivity. These findings lead some authors to speculatethat milk hypersensitivity is due to antigens that may arise during milk digestion rather than those found in native milk proteins. To date milk-specific lgG4 has also failed to correlate with AE activity. Since researchinto cardiovasculardiseasehas prompted investigators to consider cream fraction antigens located on the fat globule membrane (FGM) as the immunogens that elicit an IgG response, the authors investigated the possible role of FGM antigen in eliciting the lgG4 and IgE responsesin eczema patients. Twenty patients (15 children and five adults) whose AE was exacerbatedby milk ingestion were studied along with suitable nonatopic control subjects. All the subjectswere skin tested with food and environmental antigens, serum anti-FGM IgE was determined by RAST, and serum anti-FGM-lgG4 was examined by ELISA. The FGM antigen was prepared from the encasingmembrane of the cream fraction of milk lipid globules that is produced
in the cow by exocytosis from mammary gland secretory epithelium. The FGM-specific IgE and lgG4 determinations were of no greater diagnostic significance than other diagnostic means already in use with the use of whole milk antigens. Cross-inhibition experiments demonstrated that the anti-FGM IgE and lgG4 are actually directed against the a-casein fraction of cow’s milk. D. S.
Uromodulin: A unique 85 kilodalton immunosuppressive glycoprotein isolated from urine of pregnant women Muchmore AV, Decker JM: Science 229:479, 1985.
An immunoregulatory glycoprotein, active in vitro, and free of a-fetoprotein was isolated from human pregnancy urine on sodium dodecyl sulfate-polyacrylamide gel electrophoresisby these authors and termed uromodulin (UM). Urine was obtained from 20- to 40-weeks pregnant women, passed over concanavalin A-Sepharose columns, which were washed and eluted with a-methyl mannose. The eluate was dialyzed againstdeionized water, lyophilized, and after resuspensionin phosphate-buffered saline, was placed on a Fractogel SS column. Elution patterns were determined for the fractions in order that the first peak could be dialyzed, resuspended, applied to preabsorbent wicks, and focused on isoelectric focusing gels. By elution from the wick, a fraction was obtained that could be concentrated in Centricon filters at a cutoff of 30 kilodalton (kd). Focusingbuffers could be removed by molecular sieving columns. The material obtained by these maneuverswas assayedby ELISA with rabbit antiserum in a sandwich technique. At each step in the fractionation, the biologic activity was tested in vitro by determination of T cell-proliferation inhibition that is supposedto occur when these cultured cells are challenged with tetanus toxoid. When the antiurine fraction rabbit antiserum was used as a probe of the unfractionated urine in a Western blot experiment, a lone major band at 85 kd was found. The rabbit heteroantiserum could be conjugated to CNBr-activated Sepharoseand used as an immunosorbent for crude pregnancy urine from which the 85 kd fraction could be eluted and its immunosuppressiveactivity demonstrated in vitro. Furthermore, a pure IgG could be prepared from the rabbit heteroantiserum to probe the immunosuppressivein vitro activity of the 85 kd fraction. The 85 kd urine fraction material was immunosuppressivefor T cells sensitized with numerous antigens and had no effect on B cells stimulated with pokeweed mitogen. A strong influence was found on in vitro development of spontaneous monocyte-mediated cytotoxicity regulatory suppressor cells, but only when it was at the inception of the cell culture. The data suggest that UM interferes with an early step in interimmune cell collaboration and may play an important role in suppressingmaternal immunologic responsesagainst non-self fetal antigens. D. S.