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J A Bluestone

Publications and source records attributed to J A Bluestone.

At least 235 records · Page 13Linked to original sources
PubMed1987

Analysis of T-cell receptor gamma chain expression in the thymus.

While much is known about the structure and function of the T-cell receptor (TCR) alpha beta heterodimer, information has just begun to emerge about the gamma protein, the product of a third rearranging T-cell receptor gene. We describe the use of antiserum to a carboxy-terminal peptide common to several of the murine gamma chain constant regions and a monoclonal antibody to the murine T3 complex to identify products of this T-cell receptor gene family in a subpopulation of Lyt2-, L3T4- thymocytes. The gamma chain has a molecular weight of 35kD, is disulfide bonded to a 45kD partner termed delta (delta) and is associated with the T3 complex. The cells that bear this second T-cell receptor appear to represent a distinct lineage differentiating within the thymus.

Animals↗
PubMed1987

Thy-1+ dendritic epidermal cells express T3 antigen and the T-cell receptor gamma chain.

The murine epidermis is a heterogeneous epithelium composed of keratinocytes, melanocytes, Langerhans cells, and a recently described subpopulation (2-3%) of bone-marrow-derived leukocytes with a dendritic morphology and the cell surface phenotype Thy-1+, L3T4-, Lyt-2-. Previous studies have demonstrated that cell lines derived from freshly explanted Thy-1+ dendritic epidermal cells (DEC) have abundant mRNA for rearranged T-cell receptor (TCR) gamma-chain genes. Analysis of Thy-1+ DEC in situ, freshly isolated cell suspensions of Thy-1+ DEC, and long-term Thy-1+ DEC lines demonstrated that 100% of the Thy-1+ DEC reacted with a monoclonal antibody to the epsilon chain of the murine T3 complex and that 40-60% of resident Thy-1+ DEC were also reactive with an antiserum to the TCR gamma chain. Two Thy-1+ DEC lines expressed a disulfide-linked 70-kDa molecule that could be precipitated with an anti-gamma-chain antiserum and could be coprecipitated with an antiserum to the T3 delta chain; the molecule appeared as a single 34-kDa band under reducing conditions. The phenotype of Thy-1+ DEC (T3+, L3T4-, Lyt-2-, TCR gamma chain+) thus resembles that of the recently described subpopulation of murine and human lymphocytes that have been identified in the thymus, peripheral blood, and fetal blood.

Animals↗
PubMed1987

Identification of a monoclonal antibody specific for a murine T3 polypeptide.

A monoclonal antibody (145-2C11) specific for the murine T3 complex was derived by immunizing Armenian hamsters with a murine cytolytic T-cell clone. The antibody is specific for a 25-kDa protein component (T3-epsilon) of the antigen-specific T-cell receptor. It reacts with all mature T cells and can both activate and inhibit T-cell function. These results identify T3-epsilon as a cell surface protein involved in the transduction of activation signals.

Animals↗
PubMed1986

Analysis of hybrid H-2D and L antigens with reciprocally mismatched aminoterminal domains: functional T cell recognition requires preservation of fine structural determinants.

Studies of immune recognition of hybrid class I antigens expressed on transfected cells have revealed an apparent general requirement that the N(alpha 1) and C1(alpha 2) domains be derived from the same gene in order to preserve recognition by virus-specific H-2-restricted and allospecific T cells. One exception has been the hybrid DL antigen in which the N domain of H-2Ld has been replaced by that of H-2Dd. Cells bearing this molecule serve as targets for some virus and allospecific CTL. Because cells expressing the reciprocal hybrid LD (N domain of H-2Dd replaced by that of H-2Ld) antigen have not been available, it has not been possible to evaluate whether this exception stemmed from the relatedness of H-2Ld and H-2Dd or whether the DL antigen fortuitously preserved some function of the parent molecule as a rare exception. To assess this question, and to evaluate the contribution of the N and C1 domains of H-2Ld and H-2Dd to serologic and T cell recognition, we have constructed the reciprocal chimeric gene pLD (the N exon of H-2Ld substituted for that of H-2Dd), introduced this into mouse L cells by DNA-mediated gene transfer, and analyzed the expressed product biochemically, serologically, and functionally. Transformant L cells expressing either LD or DL antigens were both reactive with a number of anti-H-2Ld or anti-H-2Dd N/C1-specific monoclonal antibodies, indicating the preservation in the hybrid molecules of determinants controlled by discrete domains. Mab binding was generally greater with cells expressing hybrid DL antigen than with those transformants expressing LD molecules. Moreover, the amount of beta 2M associated with DL antigens was more than that associated with LD. Cells expressing hybrid DL antigens were recognized as targets by bulk and cloned allospecific anti-H-2Dd and anti-H-2Ld CTL, whereas cells expressing LD molecules were not recognized by any of the T cells tested. VSV-specific H-2Ld-restricted CTL failed to lyse VSV-infected targets expressing either DL or LD. These results indicate that T cell reactivity of cells expressing the DL hybrid antigen is an exception to the observed general requirement for class I antigens to possess matched N and C1 domains for functional T cell recognition by T cells restricted to parental antigens.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1986

Identification of monoclonal antibodies specific for the T cell receptor complex by Fc receptor-mediated CTL lysis.

Monoclonal antibodies (mAb) directed at the T cell receptor complex (TcR) on cloned T cells have generally been identified by their ability to inhibit the clone's antigen-specific function. Because such inhibition is highly dependent on antibody concentration and affinity, detection of anti-clonotypic antibodies to murine alloreactive T cells has been very difficult. In this report, an alternative method is described on the basis of the ability of antibodies specific for the TcR complex to activate T cells in an antigen-independent manner. The assay is based upon the observation that soluble antibodies to human T3 promote lysis of irrelevant, Fc receptor-positive targets by a human CTL line. By using this approach, an anti-TcR mAb has been identified among a panel of murine mAb generated against an alloreactive CTL clone. Induction of lysis by soluble anti-TcR mAb has been shown to require both the expression of Fc receptors on the target cell and conjugate formation between the effector and the target cell. This assay provides a screening procedure that is much more sensitive than inhibition of function, and it preferentially detects antibodies specific for cell surface molecules involved in T cell activation.

Animals↗
PubMed1986

Characterization of T cell receptor gamma chain expression in a subset of murine thymocytes.

While much information exists about the structure and function of the clonally distributed T cell receptor (TCR) alpha beta heterodimer, little is known about the gamma protein, the product of a third rearranging TCR gene. An antiserum to a carboxyl-terminal peptide common to several of the murine gamma chain constant regions and a monoclonal antibody to the murine T3 complex were used to identify products of this TCR gene family in a subpopulation of Lyt2-, L3T4- thymocytes. This subpopulation does not express TCR alpha or full-length TCR beta messenger RNA. The gamma chain is a 35-kilodalton (kD) protein that is disulfide-bonded to a 45-kD partner and is associated with the T3 complex. Analysis of the glycosylation pattern of this thymic gamma chain revealed that the major variable region gamma (V gamma) gene transcribed in activated peripheral T cells is absent from this subpopulation. The cells that bear this second T cell receptor may therefore represent a distinct lineage differentiating within the thymus.

Amino Acid Sequence↗
PubMed1986

Expression and function of asialo GM1 in alloreactive cytotoxic T lymphocytes.

In the present study we examined asialo GM1 (AsGM1) expression and its function in alloreactive cytotoxic T lymphocytes (CTL). We consistently found that the cytotoxic activity of bulk culture-derived allo-CTL was susceptible to the treatment of anti-AsGM1 (alpha AsGM1) plus complement. To further determine whether the expression of AsGM1 was maintained in CTL, we examined cloned T cells. The expression of AsGM1 in the T cell clones was assessed by their susceptibility to lysis by alpha AsGM1 plus complement and the reduction or abrogation of their cytotoxic activity by this treatment. It was found that, with one exception, all Lyt-2+, Thy-1+ CTL clones were AsGM1+ (seven out of eight), independent of their class specificity (class I or class II). In contrast, all Thy-1+, L3T4+ CTL (2) or helper T cell (4) clones AsGM1-. These findings suggested that there was a close association between the expression of AsGM1 and the expression of Lyt-2. The cytotoxic reaction of the anti-class I MHC CTL clones that expressed AsGM1 was blocked by alpha AsGM1 or alpha Lyt-2 antibody. The Lyt-2+, AsGM1+ anti-class II MHC CTL clone-mediated lysis was inhibited by alpha AsGM1. Addition of AsGM1 in micelle form (AsGM1-M) alone also blocked the cytotoxic reactions. Addition of other structurally similar but antigenically different glycolipids or other non-AsGM1-containing liposome preparations did not affect CTL-mediated cytotoxicity. Furthermore, adding both alpha AsGM1 and AsGM1-M together at proper doses inhibited the blocking effect (deblocking) of either alone, and other structurally similar glycolipids did not inhibit the blocking. The deblocking was specific, since AsGM1-M did not affect the blocking by alpha Lyt-2. These findings indicate that not only is AsGM1 expressed in a majority of Lyt-2+ CTL clones, but it may also be involved in the CTL- target interaction to mediate lytic reaction.

Animals↗
PubMed1986

Somatic cell variants express altered H-2Kb allodeterminants recognized by cytolytic T cell clones.

The present studies have made use of in vitro derived H-2Kb mutants to analyze the fine specificity of alloreactive cytotoxic T lymphocytes (CTL). The variants were derived by negatively selecting mutagenized tumor cells with a monoclonal anti-H-2Kb antibody and positively selecting for residual cells expressing serologically altered H-2Kb molecules. Details of this procedure are described in the companion paper. Selected populations of bulk alloreactive and cloned CTL were examined for recognition of the variants. In contrast to the serologic findings presented in the companion paper, there does not appear to be a correlation between the monoclonal antibody used to select the R8 variant and the CTL specificities recognized. In several instances, CTL clones could discriminate between variants having identical serologic profiles. Therefore, it would appear that the CTL have a large repertoire of allorecognition, even when generated across a mutant anti-Kb combination reflecting only a few amino acid differences. In addition, a diverse set of epitopes can be recognized on the Kb molecule. Finally, in some instances a change in what would appear to be a single amino acid resulted in a profound alteration of CTL recognition even though the Kb mutant molecule expressed limited serologic changes. These results support the idea that small changes in the H-2Kb molecule can have dramatic effects on CTL even though there are relatively little effects on serologic recognition of the target molecule.

Animals↗
PubMed1986

Alloresistance to engraftment of allogeneic donor bone marrow is mediated by an Lyt-2+ T cell in mixed allogeneic reconstitution (C57BL/10Sn + B10.D2/nSn----C57BL/10Sn).

In the mixed allogeneic reconstitution (B10 + B10.D2----B10) model, alloresistance to engraftment of allogeneic donor results if the syngeneic component of the mixed bone marrow inoculum is not depleted of Lyt-2+ cells before transplantation. Resultant experimental animals repopulate as fully syngeneic, reject B10.D2 skin allografts, and are reactive to B10.D2 lymphoid cells in vitro, as assessed by mixed lymphocyte culture proliferative and cellular cytotoxicity assays. In contrast, depletion of Lyt-2-reactive cells from the syngeneic component of the mixed bone marrow inoculum results in mixed lymphopoietic chimerism and specific in vivo transplantation tolerance to B10.D2 allogeneic donor skin grafts and in vitro unreactivity to B10.D2 lymphoid elements. Full reactivity to third party is evident both in vitro and in vivo in these animals. This model may be helpful in further study of the syngeneic host-type cell phenotypes responsible for alloresistance to bone marrow engraftment.

Animals↗
PubMed1986

Cloned cytotoxic T lymphocytes that recognize an I-A region product in the context of a class I antigen.

Cloned CTLs QM3 and QM7 isolated from a bulk CTL line B10.QBR anti-B10.MBR recognized a combination of the H-2Kb molecule and an I-Ak subregion gene product. Such a combinatorial specificity was revealed by complementation of the target antigen in F1 animals between two negative parental strains carrying H-2Kb and I-Ak, respectively. We confirmed the involvement of the H-2Kb molecule by blocking killing with anti-Kb mAb and failure of certain mutant H-2Kb genes to complement with I-Ak to generate the determinant in F1 animals. Although the nature of the I-Ak subregion gene product is not definitive, there was a correlation between the expression of Ia antigens on the cell surface and susceptibility of the cells to lysis by these CTLs, suggesting that it is the classical I-Ak class II antigen.

Animals↗
PubMed1986

Serologic and T cell recognition of truncated transplantation antigens encoded by in vitro deleted class I major histocompatibility genes.

Gene constructions encoding a leader sequence and the C2, transmembrane, and intracytoplasmic exons of both H-2Ld (pLd-C2) and H-2Dd (pDd-C2) were expressed as cell surface proteins when stably introduced into mouse L cells. Distinct proteins of 17.5 and 16 kd precipitated from pDd-C2 transformants reacted with a C2 domain-specific monoclonal antibody, whereas the pLd-C2 transformants expressed a single 19 kd glycoprotein. A xenoantiserum specific for the exon VI/VIII fusion peptide of H-2Dd precipitated only the 16 kd product, suggesting that this protein was derived from an alternately spliced transcript lacking exon VII of the native gene. CTL specifically recognized the pLd-C2 and pDd-C2 gene products, indicating the existence of CTL reactive against polymorphic determinants in the C2 domain of class I antigens.

Animals↗
PubMed1986

Cross-reactive recognition by antigen-specific, major histocompatibility complex-restricted T cells of a mitogen derived from Mycoplasma arthritidis is clonally expressed and I-E restricted.

In order to determine whether or not the major histocompatibility complex (MHC)-encoded restriction element used by a T cell in the recognition of its primary antigen affected its ability to be cross-reactively stimulated by MAS (a soluble product of Mycoplasma arthritidis), a panel of cloned, soluble antigen-specific I-A- and I-E-restricted T cells were tested for their ability to cross-reactively recognize and respond to MAS. Initial studies indicated that all of the cloned T cells tested were capable of responding to MAS in the presence of genetically E alpha E beta-expressing (I-E+), but not E alpha E beta-non-expressing (I-E-) accessory cells (AC). However, subsequent studies demonstrated that the ability of most of these T cell clones to mount proliferative responses to MAS in the presence of I-E+ AC was dependent upon the presence of Lyt-1+2- T cells in the irradiated spleen cells which were used as AC sources. When T cell-depleted, I-E+ populations of spleen cells or an I-E+ antigen-presenting line (WEHI-5) were used as AC sources, only 6 of the 34 clones tested were found to be directly responsive to MAS. Subsequent to stimulation by MAS plus I-E product, these MAS-reactive T cell clones were capable of "recruiting" bystander T cells to proliferate. Finally, the ability of a given T cell clone to respond to MAS plus I-E product did not appear to be influenced by the restriction element used by that clone in its response to other antigens since both I-A-restricted and I-E-restricted T cell clones were responsive to MAS plus I-E in equivalent proportions. Thus, the data presented indicated that I-E-restricted T cell reactivity to MAS is a clonally expressed property of T cells that is independent of their conventional antigen specificities and MHC restriction patterns.

Animals↗
PubMed1986

Somatic cell variants of H-2Kb: a point mutation in the first extracellular domain results in altered immune recognition.

A cell-surface-associated variant H-2K product was expressed by an Abelson virus-induced pre-B-cell line after chemical mutagenesis with ethyl methane sulfonate. The variant cell line (R8.313) was previously demonstrated to have altered allodeterminants in Kb as demonstrated by both Kb-specific monoclonal antibody binding and alloreactive cytotoxic T lymphocyte (CTL) cytolysis. The mutant H-2Kb gene from R8.313 was cloned and characterized in detail. DNA sequence analysis of the region of the gene corresponding to the three extracellular domains identified a single point mutation resulting in a leucine-to-phenylalanine substitution at amino acid residue 82. The site of mutation within the alpha 1 domain was confirmed by oligonucleotide hybridization analysis. Mouse L-cell fibroblasts transfected with the mutant gene were recognized with the same monoclonal antibody binding and CTL lytic pattern as the R8.313 cell line, confirming that the altered phenotype of the mutant cell line was due to a point mutation in the H-2Kb gene. These data further extend the hypothesis that the region of amino acid residues 70-90 in the alpha 1 domain is important in the formation of both antibody and CTL-defined recognition structures on major histocompatibility complex class I molecules.

Animals↗
PubMed1986

Effect of selective T cell depletion of host and/or donor bone marrow on lymphopoietic repopulation, tolerance, and graft-vs-host disease in mixed allogeneic chimeras (B10 + B10.D2----B10).

Reconstitution of lethally irradiated mice with a mixture of T cell-depleted syngeneic plus T cell-depleted allogeneic bone marrow (B10 + B10.D2----B10) leads to the induction of mixed lymphopoietic chimerism, excellent survivals, specific in vivo transplantation tolerance to subsequent donor strain skin grafts, and specific in vitro unresponsiveness to allogeneic donor lymphoid elements as assessed by mixed lymphocyte reaction (MLR) proliferative and cell-mediated lympholysis (CML) cytotoxicity assays. When B10 recipient mice received mixed marrow inocula in which the syngeneic component had not been T cell depleted, whether or not the allogeneic donor marrow was treated, they repopulated exclusively with host-type cells, promptly rejected donor-type skin allografts, and were reactive in vitro to the allogeneic donor by CML and MLR assays. In contrast, T cell depletion of the syngeneic component of the mixed marrow inocula resulted in specific acceptance of allogeneic donor strain skin grafts, whether or not the allogeneic bone marrow was T cell depleted. Such animals were specifically unreactive to allogeneic donor lymphoid elements in vitro by CML and MLR, but were reactive to third party. When both the syngeneic and allogeneic marrow were T cell depleted, variable percentages of host- and donor-type lymphoid elements were detected in the mixed reconstituted host. When only the syngeneic bone marrow was T cell depleted, animals repopulated exclusively with donor-type cells. Although these animals had detectable in vitro anti-host (B10) reactivity by CML and MLR and reconstituted as fully allogeneic chimeras, they exhibited excellent survival and had no in vivo evidence for graft-vs-host disease. In addition, experiments in which untreated donor spleen cells were added to the inocula in this last group suggest that the presence of T cell-depleted syngeneic bone marrow cells diminishes graft-vs-host disease and the mortality from it. This system may be helpful as a model for the study of alloresistance and for the identification of syngeneic cell phenotypes, which when present prevent engraftment of allogeneic marrow.

Animals↗
PubMed1985

Evidence for a regulatory idiotypic network in the in vivo response to H-2 antigens.

Treatment of BALB/c mice with purified pig antiidiotype to 11-4.1 (anti-H-2Kk) monoclonal antibody has been found previously to induce the appearance of idiotype-bearing molecules (Id') in the serum of these mice, in the absence of detectable antigen-binding activity. In the present study we examined the effect of subsequent immunization of such antiidiotype-primed mice with the original H-2Kk antigen. Skin grafting of virgin BALB/c mice with BALB.K skin did not generate any detectable Id' antibodies when tested by enzyme-linked immunosorbent assay (ELISA). In contrast, grafting of antiidiotype-primed mice with BALB.K skin specifically boosted ther serum level of Id' molecules. Challenge of antiidiotype-primed mice with either B10.D2 or rat skin had no effect on the production of such Id' molecules. Absorption studies demonstrated that the majority of Id' molecules induced by H-2Kk antigenic stimulus and detected in ELISA are antigen-nonbinding molecules, thus indicating specific restimulation by the original H-2Kk antigen of nonbinding idiotype-positive B cell clones. The relevance of these findings to the existence of network interactions in the immune response to H-2 antigens is discussed.

Animals↗
PubMed1985

Characterization of mixed allogeneic chimeras. Immunocompetence, in vitro reactivity, and genetic specificity of tolerance.

Mixed allogeneically reconstituted mice (B10 + B10.D2----B10) that specifically accept B10.D2 tail skin allografts were examined for in vivo and in vitro immunocompetence, patterns of hematopoietic repopulation, and in vitro reactivity. In vitro, mixed allogeneic chimeras (B10 + B10.D2----B10) manifested specific tolerance in mixed lymphocyte reactions and cell-mediated lympholysis to B10 and B10.D2 splenocytes, with normal responses to third-party (B10.BR) cells. Such chimeras were immunocompetent in B cell and helper T cell responses, as assessed by their primary plaque forming cell responses to in vivo sheep red blood cell immunization. This is in contrast to fully allogeneic chimeras, which responded less well. In addition, survival of the mixed allogeneic chimeras in a conventional animal facility was superior to that of fully allogeneic chimeras, and similar to syngeneically reconstituted (B10----B10) mice. Specific tolerance to skin grafts, degree of allogeneic engraftment, and persistence of chimerism was also assessed in a noncongenic mixed allogeneic combination (B10 + C3H----B10). Such animals manifested specific hyporeactivity to C3H skin allografts, but eventual chronic rejection of the grafts occurred in spite of stable and persistent mixed chimerism. MHC-congenic (B10.BR) skin grafts were accepted indefinitely in the same animals, suggesting that skin-specific non-major histocompatibility complex antigens were responsible for rejection of the C3H skin allografts.

Animals↗