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S L Epstein

Publications and source records attributed to S L Epstein.

33 records · Page 2Linked to original sources
PubMed1985

A cell surface ELISA in the mouse using only poly-L-lysine as cell fixative.

An ELISA using plates coated with mouse spleen cells has been developed for analysis of antibodies to cell surface antigens. Such assays have been used extensively with human cells or with tumor cells in various species, but application to normal mouse lymphocytes has been limited. Use of normal spleen cells allows access to the genetic resources offered by recombinant, congenic, and mutant mouse strains, in the preparation of cell-coated ELISA plates, the use of glutaraldehyde was found to be unnecessary and it was eliminated, thereby avoiding the destruction of some cell surface determinants. Poly-L-lysine, which was used to treat plates, was found to provide sufficient adherence and preservation of the cells. Binding of biotinylated monoclonal antibodies to cells could be detected at approximately 10 ng/well. In inhibition assays, unlabeled antibodies could be detected at approximately 10 ng/well. Cell-coated plates are stable once prepared, and can be stored for months before use. The assay described can be used to quantitate levels of antibody to a particular epitope, and can also be adapted for screening of fusions for monoclonal antibodies to cell surface antigens.

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PubMed1985

Characterization of a dominant anti-Ia idiotype using the IA mutant mouse strain B6.C-H-2bm12.

Initial studies of antibody recognition of Ia molecules using the IA mutant mouse strain bm12 suggested that two anti-Ia monoclonal antibodies (mAbs), 25-9-17 and 34-5-3, share several features: (1) indistinguishable serologic specificity including a lack of reactivity with Iabm12, (2) binding of the same spatial epitope (cluster), and (3) definition of a cross-reactive idiotype (CRI) as defined by xenogeneic antisera. In the present study we characterize a rabbit anti-idiotype (anti-Id) to 25-9-17 by affinity chromatography, and demonstrate that it detects at least two distinct idiotopes, one shared by 25-9-17 and 34-5-3 designated CRI (25-9-17) and one unique for 25-9-17 molecules. Experiments were also undertaken to determine whether CRI (25-9-17) represents a measurable component of allogeneic humoral responses to Iab antigens. By both absorption analyses of a polyspecific antiserum and production of antigenically-restricted antisera using bm12 mice, CRI (25-9-17) was found to represent a significant proportion of the antibodies to Iab. By several criteria it was shown that the CRI (25-9-17)+ molecules were among the antibodies defining the serologic lesion of bm12 mice. In preparation for future studies to alter in vivo T-cell responses involving recognition of Ia (e.g. graft vs host disease and allogeneic transplant rejection), various immunization protocols and mouse strains were tested for induction of Id (25-9-17) following in vivo administration of various anti-idiotypic reagents. Rabbit anti-Id (25-9-17) successfully induced CRI (25-9-17) positive molecules in all strains tested regardless of IA or Ig genotype. Moreover, some of these treated mice produced antibodies to an Ia determinant missing on bm12 cells, suggesting that they recognize the same serologic determinant as mAb 25-9-17.

Animals↗
PubMed1983

Idiotypes of anti-major histocompatibility complex antibodies.

Our studies to date indicate that treatment with anti-idiotype to monoclonal anti-MHC antibodies can markedly influence the repertoire of anti-MHC antibodies expressed. The antibodies discussed here appear to represent two classes, one of which is public, probably representing expression of a germ line gene, and the second of which probably represents either a somatic variant of a germ line gene or one of a very large number of germ line genes devoted to the same specificity. In either case, this class of idiotype arises only rarely following antigen, but is readily induced by anti-idiotype treatment. There may indeed exist a third class of anti-MHC monoclonal antibodies representing distant somatic diversification from a germ line gene. Our only indication of this so far is that certain idiotypes are only induced after multiple boosts with anti-idiotypes rather than a single treatment. This finding, however, may reflect again the enormous number of different ways in which anti-MHC antibodies to the same nominal specificity can be produced. Finally, our results in adoptive transfer systems indicate that manipulation of idiotype expression by anti-idiotype treatment probably involves a complex pathway of cellular interactions. If, as we expect, these intercellular interactions involve idiotype and/or anti-idiotypic receptors, they should provide a model for mechanistic studies of the in vivo immune network.

Animals↗
PubMed1983

Idiotypic and fluorometric analysis of the antibodies that distinguish the lesion of the I-A mutant B6.C-H-2bm12.

The serologic lesion of the I-A mutant mouse strain, bm12, was investigated with the use of monoclonal anti-Iab antibodies and anti-idiotypic (Id) reagents produced against these antibodies. In a fluorometric analysis, three different monoclonal anti-Iab antibodies (25-9-17, 34-5-3, 28-16-8) failed to bind bm12 cells, whereas two anti-Iab antibodies (25-5-16 and 17/227), which bound bm12 cells, showed about one-half the fluorescence intensity that they showed in binding to Iab antigens. Of the three monoclonal antibodies that failed to react with bm12 cells, two antibodies (25-9-17 and 34-5-3) were found to bind the same steric site on Iab molecules (cluster I). In contrast, the antibodies (25-5-16 and 17/227) that reacted with both Iab and Iabm12 antigens were found to bind a second distinct site (cluster II). The binding of antibody 28-16-8 to Iab antigens inhibited reciprocally the binding of cluster I and II anti-Iab antibodies, suggesting a possible third site, sterically located intermediate between the other two sites. To assess the relatedness of the antibodies defining the serologic lesion of bm12 mice, xenogeneic and syngeneic anti-Id reagents were produced against antibodies 25-9-17 and 28-16-8. By using these anti-Ids in a binding site-related inhibition assay, a cross-reactive idiotype was detected that is shared by 25-9-17 and 34-5-3 antibodies; thus these two monoclonal antibodies share several features, including 1) idiotypic determinants, 2) failure to bind bm12 cells, 3) binding the same spatial Iab site, and 4) having indistinguishable serologic fine specificity that corresponds with a previously defined predominant alloantigenic determinant recognized in the bm12 anti-Iab humoral response. Therefore, several parameters of antibody recognition of Ia can now be correlated with structural changes in Ia molecules. These findings will potentiate future studies of the T cell recognition of these same Ia epitopes.

Animals↗
PubMed1982

Idiotypes of anti-Ia antibodies. II. Effects of in vivo treatment with xenogeneic anti-idiotype.

The effects of in vivo treatment with xenogeneic anti-idiotypic antibodies were examined in an anti-Ia idiotypic system. Monoclonal antibody 14-4-4S, specific for Ia.7, has been shown to bear idiotopes that are expressed at readily detectable levels in conventional alloantibody responses. Sera from mice treated with purified anti-idiotypic antibodies (anti-Id) were found to contain inhibitory activity in an ELISA specific for the 14-4-4S Id, whereas sera from control mice treated with heterologous normal Ig did not. In addition, sera of anti-Id-treated C3H.SW mice contained specific anti-I-E activity, shown by binding to B10.A(2R) but not B10.A(4R) LPS blasts in flow microfluorometry. The anti-I-E induced by anti-Id included more IgG1 than IgG2. Even though a significant amount of anti-I-E activity was present in the serum, absorption analysis showed that most of the idiotope-positive antibody was not I-Ek-specific. Penetrance of induction of anti-I-E by anti-Id was 100% in the C3H.SW mice tested, and activity persisted in the serum for at least 8 to 9 mo in some cases. B10 mice produced only marginal anti-I-E activity after treatment, suggesting that induction is due to specific triggering rather than due entirely to a resemblance of anti-Id to the I-E antigen. The results thus indicate long-lasting alterations in an anti-Ia idiotypic system in the absence of exposure to conventional antigen, and represent specific manipulation of anti-Ia immunity.

Animals↗
PubMed1981

Anti-idiotypes to monoclonal anti-H-2 antibodies. II. Expression of anti-H-2Kk idiotypes on antibodies induced by anti-idiotype or H-2Kk antigen.

Anti-idiotypic antibodies were prepared against two monoclonal anti-H-2Kk antibodies, 11-4.1 and 3-83P. These reagents were used to examine idiotype (Id) expression on anti-H-2Kk antibodies induced by the in vivo administration of the anti-idiotypic antibodies and/or H-2Kk antigen. Treatment of BALB/c mice with anti-Id induced both antigen-binding and nonantigen-binding Id-positive molecules in the absence of antigen. The level of production of anti-Id-induced Id (Id') has been shown to be linked to VH genes using allotype congenic mice and backcross analyses. The idiotypes expressed on the Id' induced in anti-Id-treated mice were closely related or identical to those of the original monoclonal anti-H-2Kk antibody. However, the idiotopes were present on immunoglobulins of different subclasses and in some cases were not all expressed on the same molecules, as reflected by differences in their antigen specificities and isoelectric focusing patterns. In vivo administration of anti-Id had a marked influence on the subsequent humoral response to immunization with H-2 antigen.

Animals↗
PubMed1981

Idiotypes of anti-Ia antibodies. I. Expression of the 14-4-4S idiotype in humoral immune responses.

The idiotype of a mouse monoclonal anti-I-E antibody, 14-4-4S, has been studied using a heterologous anti-idiotypic reagent. This antibody recognizes Ia. 7, an antigenic specificity present in all strains expressing a product of the I-E subregion. Expression of the 14-4-4S idiotype in humoral immune responses was analyzed by an idiotype-specific enzyme-linked immunosorbent assay system. The idiotype was readily detectable in C3H.SW anti-C3H alloantisera, the same immunization combination from which the hybridoma was derived. Absorption analysis demonstrated the anti-I-E specificity of the idiotype-positive molecules in these alloantisera. Penetrance of idiotype expression was high among individual C3H.SW immune mice (9 of 10 tested). To examine genetic requirements for idiotype expression, an immunization was performed using as responders CWB mice, congenic with C3H.SW but differing at the heavy chain allotype loci. Immune sera of individual CWB mice contained very little or no idiotype, demonstrating that levels of idiotype expression are influenced by allotype-linked genes, although the influence of other genes has not been ruled. The 14-4-4S idiotype therefore represents a shared idiotype of anti-Ia antibodies and provides opportunities for analysis of the idiotypes of cellular receptors for the corresponding Ia antigen.

Animals↗
PubMed1977

Quantitative measurement of mouse IgG subclasses with the use of heteroantisera: the importance of allotype considerations.

Double antibody radioimmunoassays have been used to determine the quantities of IgG1, IgG2a and IgG2b in samples of normal serum IgG from BALB/cJ, AKR/J and C57BL/6J inbred mice. The assays employed subclass-specific goat antisera which had been prepared with BALB/c myeloma proteins as immunogens and as immunoabsorbents. 125I-labeled BALB/c myeloma proteins were used as probes. Results indicate that partial resolution of mouse IgG subclasses was achieved by ion exchange chromatography on DEAE-Sephadex. Nearly all of the protein in BALB/cJ and AKR/J IgG fractions could be accounted for as IgG1, IgG2a and IgG2b, and IgG2a was the predominant species observed. However, considerably less protein in C57BL/6J IgG fractions of purity similar to the BALB/cJ fractions could be accounted for as these three subclasses, and virtually no IgG2a was detected. Furthermore, an IgG2a myeloma protein bearing the C57BL/6 allotype failed to inhibit the IgG2a-specific assay significantly. Thus the IgG2a-specific antibody in the goat heteroantiserum employed appeared to consist nearly exclusively of antibody to BALB/c Ig-1a allotypic determinants. These findings point to the importance of allotype considerations in the use of heteroantisera to quantitate IgG subclasses.

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PubMedDate not supplied

Genetics of the induction of antigen-specific immunity in anti-idiotype-treated mice and derivation of monoclonal Ab3 antibodies.

Antiidiotypic antibodies can be used as a means other than antigen of clone-specific intervention in the immune system. In a number of cases, antiidiotypic antibodies induce potent, antigen-specific responses without exposure of the recipient animals to antigen, and a better understanding of such responses will aid in the application of idiotype manipulation to both immunological and practical problems. The Ia. 7 system expresses a major, cross-reactive idiotype on antibodies to an epitope of the mouse I-E antigen. Here, we examine genetic control of the I-E-specific response to anti-idiotype in this model system. Results demonstrate that both heavy chain allotype-linked and non-allotype-linked loci contribute to the control of this response. In addition, monoclonal antibodies representing the non-antigen-specific portion of the Ab3 response were derived. Two idiotype-positive clones were demonstrated to be of IgM isotype, contrasting with previous data showing that the serum Ab3 response is predominantly IgG1.

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