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J Kappler

Publications and source records attributed to J Kappler.

At least 145 records · Page 8Linked to original sources

The T cell receptor: the alpha and beta chains define idiotype, and antigen and MHC specificity.

Three independent T cell hybridomas were isolated that have identical specificities for antigen and products of the major histocompatibility complex (MHC). All three react with the same clone-specific antireceptor antibody, and Southern blots show all three contain the same rearranged alpha and beta genes. Variants of one of these hybridomas, DO-11.10, were isolated that had lost the ability to respond to antigen plus MHC. These proved to have lost the DO-11.10-specific alpha or beta genes or both. Fusion of alpha-loss variants to beta-loss variants restored reactivity. These results indicate that the specific recognition of antigen plus MHC is determined solely by the alpha/beta-containing T cell receptor.

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Rearrangement of T-cell receptor beta-chain genes during T-cell development.

The kinetics and order of rearrangements in the gene complex encoding T-cell-receptor beta chains were studied by Southern blot hybridization in a collection of hybridomas derived from fetal thymocytes at various stages of ontogeny (day 14 to day 17). Our results show a steady increase in the frequency of rearranged beta complexes during this period and suggest that these rearrangements occur within the thymus. beta-chain diversity region (D beta) to beta-chain joining region (J beta) joining preceded other types of rearrangements. More complex hybridization patterns consistent with fully rearranged functional beta-chain genes did not begin to accumulate until day 16, 1 day prior to significant surface expression of the receptor protein.

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Characterization of the two heavy chains of the T3 complex on the surface of human T lymphocytes.

The T3 complex has been defined by a group of monoclonal antibodies which react with all human peripheral blood T lymphocytes and a subpopulation of thymocytes. This membrane structure includes glycoproteins of 44 (alpha), 37 (beta), 25 (gamma), and 20 kDa (delta) as well as a nonglycosylated polypeptide of 20 kDa (epsilon). The characterization of the alpha and beta chains has been of particular interest because they may constitute the T cell receptor for antigen. Here we show that the T3 complex prepared by immunoprecipitation from T lymphocytes of a leukemic patient (Sezary syndrome) displays an unusually strong association of the alpha and beta chains with the 20/25-kDa T3 proteins. The alpha and beta chains (48 and 44 kDa) were co-precipitated by anti-20-kDa T3 monoclonal antibodies as a disulfide-linked 90-kDa heterodimer. A minor 220-kDa multimer composed of proteins similar to the alpha and beta chains was also present in these immunoprecipitates. This multimer could be independently precipitated with a new monoclonal antibody WT-31, which detects the larger polypeptide chains of the T3 complex on all human T lymphocytes. After removal of N-linked oligosaccharides, both the alpha and beta chain were found to have 33-kDa peptide backbones with distinct isoelectric points. Using a monoclonal reagent T40/25, a 90-kDa heterodimer, consisting of 40- and 49-kDa chains with peptide backbones of 34 kDa was found to be T3-associated on the T leukemic cell line HPB-ALL. When the alpha and beta chains from the Sezary patient were compared with the corresponding chains from HPB-ALL by peptide mapping, large differences were observed. Taken together, the data presented here provide strong evidence that the T cell receptor for antigen is part of the T3 complex on the surface of human T lymphocytes.

Acetylglucosaminidase↗

Interleukin-induced increase in Ia expression by normal mouse B cells.

The constitutive culture supernatant (SN) of the macrophage tumor line P388D1 (P388 SN) and the concanavalin A (Con A)-induced culture supernatant of the T cell hybridoma FS6-14.13 (FS6 Con A SN) were shown to contain nonspecific factors capable of inducing increased Ia expression by normal resting B cells in a dose-dependent manner. In six consecutive experiments the relative increase in Ia expression induced by P388 SN was 4.9 +/- 0.9, with FS6 Con A SN 10.7 +/- 1.5, and with a combination of both preparations 13.0 +/- 1.7. This increase in Ia expression was observed to occur in virtually all the B cells, reaching maximum levels within 24 h of culture. The interleukin-induced increase in B cell Ia expression occurred in the absence of ancillary signals provided by ligand-receptor Ig cross-linking and despite the fact that virtually all the control B cells, cultured in the absence of factors, remained in G0. These results suggest that functional receptors for at least some interleukins are expressed on normal resting B cells and their effects can be manifest in the absence of additional activating signals. The increased Ia expression induced by the nonspecific factor preparations was shown to be correlated with enhanced antigen-presenting capacity by the B cells to T cell hybridomas. The nature of the interleukins responsible for these effects remains to be definitively determined, however, the activity of FS6 Con A SN was shown to correlate with B cell growth factor activity and increased B cell Ia expression was not observed using interleukin 2 (IL-2) or interferon-gamma, prepared by recombinant DNA technology.

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The antigen-specific, major histocompatibility complex-restricted receptor on T cells. VI. An antibody to a receptor allotype.

We have prepared a monoclonal antibody, KJ16-133, from the cells of a rat immunized with the purified receptor for antigen plus I-A of a BALB/c T cell hybridoma, DO-11.10. Unlike most other monoclonal anti-receptor antibodies that have been described before, KJ16-133 is not clone specific. It reacts with approximately 20% of the receptors on T cells of normal BALB/c mice. It also reacts with about the same percentage of antigen-specific, major histocompatibility complex (MHC)-restricted or allogeneic I-region specific T cell hybridomas. Reaction of KJ16-133 with a given T cell hybridoma does not seem to depend on the antigen specificity or MHC-restricting element of the T cell in question. The determinant recognized by KJ16-133 has some unexpected properties. It is absent in several strains of mice including SJL/J and SJA/20, but present on the T cells of most other commonly used strains. The determinant recognized therefore does not map to Igh. Our experiments suggest that a clone-specific "antiidiotypic" antibody and KJ16-133 recognize determinants on different parts of the receptor. For example, the binding of a clone-specific antibody to target T cells is relatively temperature insensitive, whereas KJ16-133 binds well to cells at 37 degrees C but poorly to cells at 4 degrees C. The determinant recognized by a clone-specific antibody is sensitive to reduction and alkylation of the receptor, whereas KJ16-133 reactivity is not. Finally, binding of KJ16-133 at saturating concentrations to target T cells does not block the binding of a clone-specific antibody. Similarly, binding of a clone-specific antibody only marginally inhibits binding of KJ16-133. Taken together, these results suggest that KJ16-133 is directed against an allelic determinant on T cells that may be close to the membrane, and not in the receptor binding site for antigen plus MHC. The antibody may recognize an allele of a constant region isotype, or an allele of a J region.

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The role of L3T4 in recognition of Ia by a cytotoxic, H-2Dd-specific T cell hybridoma.

The expression of T4/T8 surface markers on human T cells and of L3T4/Lyt-2 on murine T cells has lead to the association of these surface markers with recognition of either class II or class I major histocompatibility complex (MHC) antigens. It has been suggested that these T cell surface antigens interact with MHC antigens. We have examined the role of L3T4 in the recognition of Dd by the T cell hybridoma, 3DT52.5. This T cell hybridoma was found to be specific for the N/Cl domain of Dd. The recognition of a class I antigen by an Lyt-2-, L3T4+ T cell hybridoma allowed the separate evaluation of interactions between L3T4/Ia and the T cell antigen receptor, Dd. Recognition by this hybridoma resulted in the production of interleukin 2 (IL-2) and cytolytic activity. Antibody blocking experiments have demonstrated that L3T4 was involved in triggering the effector function of 3DT52.5 only on Ia+ stimulator or target cells. We have demonstrated that an L3T4+, Dd-specific T cell hybridoma, 3DT52.5, uses the L3T4 molecule to directly interact with nonpolymorphic Ia determinants.

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Gene transfer of H-2 class II genes: antigen presentation by mouse fibroblast and hamster B-cell lines.

We have transferred the mouse Ak alpha and Ak beta genes, which encode the class II I-Ak molecule, into mouse L-cell fibroblasts and hamster B cells. I-Ak molecules are expressed on the surface of both cell types. The L-cell and hamster B-cell I-Ak molecules appear normal by serological analyses and two-dimensional gel electrophoresis. Furthermore, the I-Ak molecules on L cells can act as targets for the allogenic T-cell killing of the transformed L cells. The I-Ak molecules in both mouse fibroblasts and hamster B cells can present certain antigens to T-cell helper hybridomas. Thus only class II molecules are required to convert the nonantigen-presenting cell. Accordingly, it will be possible to dissect the structure-function relationships existing between Ia molecules, foreign antigen, and T-cell receptor molecules by in vitro site-directed mutagenesis and gene transfer.

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The major histocompatibility complex-restricted antigen receptor on T cells: distribution on thymus and peripheral T cells.

A monoclonal antibody, KJ16-133, which binds to antigen-specific, major histocompatibility complex-restricted (Ag/MHC) receptors on about 20% of BALB/c peripheral T cells has been used to examine the expression of these receptors on thymocytes and different subpopulations of peripheral T cells. Although KJ16-133-reactive receptors were found on mature thymocytes at similar frequencies and levels as on peripheral T cells, these molecules were absent from the first cells to enter the thymus, and in less mature thymocyte populations KJ16-133-reactive cells were less frequent than in the periphery and bore lower quantities of receptor. These results showed that Ag/MHC receptors are present on the surfaces of immature thymocytes, albeit at variable levels, during the time that the repertoire of these cells for Ag/MHC is thought to be selected. Additional experiments showed that KJ16-133 could not be used to distinguish T-cell receptors with different restriction specificities, i.e., for Class I or Class II products of the MHC.

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Functional and inducible expression of a transfected murine class II major histocompatibility complex gene.

Using the spheroplast fusion technique, we have introduced the cloned E beta b gene into two d haplotype cell lines, the B lymphoma line A20-2J and the macrophage tumor line P388D1. Analysis with a monoclonal antibody indicates that the product of the transfected E beta b gene associates with the endogenous E alpha chain to form an E alpha dE beta b complex. While expression of E alpha dE beta b is constitutive in A20-2J cells transfected with the E beta b gene, surface expression of E alpha dE beta b is detected in transfected macrophage cells only after treatment of cells with culture supernatants from concanavalin A (Con A)-stimulated T cells. Transfected B lymphoma cells and transfected Con A supernatant-treated macrophage cells have acquired the ability to present antigen to E alpha dE beta b-restricted T-cell hybridomas. The observed inducible expression of the transfected gene in the macrophage host indicates that sequences responsible for regulated expression of the E beta b gene may be associated with the transfected gene. In combination with directed mutagenesis, the system described here provides a means to study (i) E beta b sequences that are important in determining the restriction specificity of the E molecule and (ii) sequences associated with the E beta gene that may be important in the regulation of E beta chain expression.

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The major histocompatibility complex-restricted antigen receptor on T cells. IV. An antiidiotypic antibody predicts both antigen and I-specificity.

In order to prove that a monoclonal antibody, KJ1-26.1, reacted with the idiotypic portion of the receptor for antigen plus major histocompatibility complex product (Ag/MHC) on the T cell hybridoma D0-11.10, 397 independent T cell hybridomas prepared from BALB/c T cells primed with ovalbumin were screened by ELISA for reactivity with the antibody. Of these T cell hybridomas one, 7D0-286, and a subclone of this hybridoma, 7D0-286.2, reacted strongly and consistently with KJ1-26.1. Further analysis revealed that KJ1-26.1 blocked the reaction of 7D0-286 with Ag/MHC, and that 7D0-286 had the same fine specificity both for Ag and MHC as D0-11.10. None of 207 other BALB/c T cell hybridomas specific for ovalbumin shared these fine specificity patterns. Thus, reaction with KJ1-26.1 defined the specificity of a T cell hybridoma both for Ag and MHC, suggesting that KJ1-26.1 reacted with the receptors for Ag/MHC on the T cells in question. KJ1-26.1 precipitated an 85-kdalton molecule from 7D0-286.2 that on reduction ran as a diffuse spot of approximately 43 kdaltons. A similar molecule was precipitated from D0-11.10.

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The major histocompatibility complex-restricted antigen receptor on T cells. II. Role of the L3T4 product.

We have examined the role of the murine homologue of Leu-3 T4, L3T4, in recognition of antigen in association with products of the major histocompatibility complex (Ag/MHC) by murine T cell hybridomas. A series of ovalbumin (OVA)/I-Ad-specific T cell hybridomas were ranked in their sensitivity to Ag/I by measuring their ability to respond to low doses of OVA, or their sensitivity to inhibition by anti-I-Ad antibodies. T cell hybridomas with low apparent avidity for OVA/I-Ad, i.e. that did not respond well to low concentrations of OVA and were easily inhibited by anti-I-Ad, were also easily inhibited by anti-L3T4 antibodies. The reverse was true for T cell hybridomas with apparent high avidity for Ag/MHC. We found that the presence of low doses of anti-L3T4 antibodies caused T cell hybridomas to respond less well to low doses of Ag, and to be more easily inhibited by anti-I-Ad antibodies. These results suggested that the role of the L3T4 molecule is to increase the overall avidity of the reaction between T cells and Ag-presenting cells. In support of this idea was the discovery of several L3T4- subclones of one of our L3T4+ T cell hybridomas, D0.11.10. The L3T4- subclones had the same amount of receptor for OVA/I-Ad as their L3T4+ parent, as detected by an anti-receptor monoclonal antibody. The L3T4- subclones, however, responded less well to low doses of OVA, and were more easily inhibited by anti-I-Ad antibodies than their L3T4/ parent. These results showed that the L3T4 molecule was not required for surface expression of, or functional activity of, the T cell receptor for Ag/MHC. The L3T4 molecule did, however, increase the sensitivity with which the T cell reacted with Ag/MHC on Ag-presenting cells.

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Evidence for two distinct classes of murine B cell growth factors with activities in different functional assays.

Several previously described B cell growth factor (BCGF) activities from a number of mouse monoclonal T cell sources were compared in different functional assays. The results indicate that there are two distinct classes of BCGF defined by functional activity and source. BCGF I, whose prototype is (EL4)BCGF, synergized with anti-Ig in the proliferation of normal splenic B cells but had no activity when dextran sulfate (DXS), rather than anti-Ig, was used to costimulate the same source of B cells. BCGF I also failed to directly stimulate BCL1 tumor B cells. In contrast, BCGF II, whose prototype is (DL)BCGF, showed a reciprocal pattern of activity. BCGF II failed to synergize with anti-Ig-costimulated normal B cells to give good proliferative responses. Sources of BCGF II also directly stimulated (no anti-Ig or DXS added) B cells of the BCL1 tumor-carrying mice. These results suggest that the two BCGF may have activity on two subsets of B cells that respond differentially to induction with the two polyclonal B cell activators, anti-Ig and DXS. The possibilities that these different patterns of response occur in separate lineages of B cells and/or in B cells in different states of differentiation is discussed.

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Antigen recognition by H-2-restricted T cells. I. Cell-free antigen processing.

We examined the ability of a set of cloned chicken ovalbumin (cOVA)-specific, Id-restricted, T cell hybridomas to produce interleukin-2 in response to cOVA presented by the Ia+ B cell lymphoma line, A20-2J. Although viable A20-2J cells presented native, denatured, and fragmented cOVA more or less equally well, A20-2J cells that were glutaraldehyde-fixed could present only enzymatically or chemically fragmented cOVA. These results suggest that antigen fragmentation may be both necessary and sufficient to define accessory cell processing of soluble antigens so that they may be recognized in association with I-region molecules by T cells.

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Three T cell hybridomas do not contain detectable heavy chain variable gene transcripts.

We attempted to determine whether T cells express any VH gene segments. cDNA libraries were constructed from one suppressor and two helper T cell hybridomas. Both the library construction and screening were designed to maximize detection of a wide range of VH gene segments. One screening method should detect about half of the sequenced VH genes, while the second should detect most of these genes. The probability of detecting a VH gene homologous to the probes and present at 10 copies per cell was 77% for one helper cell cDNA library, 88% for the second helper cell library, and greater than 99% for the suppressor cell library. No cDNA clones with VH gene segments were detected. From this result, we conclude that VH gene segments are not likely to encode the antigen-specific receptor in the cells we tested.

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The major histocompatibility complex-restricted antigen receptor on T cells. I. Isolation with a monoclonal antibody.

An antibody-secreting B cell hybridoma, KJ1-26.1, has been prepared from mice immunized with the T cell hybridoma DO-11.10, which recognizes chicken ovalbumin in association with I-Ad (cOVA/I-Ad). KJ1-26.1 blocks I-restricted antigen recognition by DO-11.10 and a subclone of this T cell hybridoma, DO-11.10.24, which has the same specificity for cOVA/I-Ad as its parent. KJ1-26.1 does not block I-restricted antigen recognition by any other T cell hybridoma tested, including a number of T cell hybridomas closely related to DO-11.10, with similar, but not identical, specificities for antigen/I. Moreover, KJ1-26.1 binds to DO-11.10 and DO-11.10.24, but not to any other T cell hybridomas tested, including three subclones of DO-11.10 that have lost the ability to recognize cOVA/I-Ad. Thus, in every regard KJ1-26.1 appears to be binding to all or part of the receptors for antigen/I on the T cell hybridoma DO-11.10. KJ1-26.1 appears to bind to approximately 15,000 molecules/cell on the surface of DO-11.10. The antibody precipitates an 80,000 dimer from the cells, which on reduction migrates as 40-44,000 monomers. The receptor(s) for antigen/I on DO-11.10 therefore includes molecules with these properties.

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