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C W Pierce

Publications and source records attributed to C W Pierce.

At least 55 records · Page 3Linked to original sources
PubMed1985

Monoclonal antibodies specific for single chain or two chain GAT-specific suppressor factors: production and analysis of in vitro modulating properties.

Fusion of spleen cells from rats hyperimmunized with T cell hybridoma derived GAT-specific TsF1 or TsF2 suppressor T cell factors has resulted in the generation of hybridomas secreting monoclonal antibodies reactive with the appropriate GAT-TsF used for immunization, and in several cases, reactive with other GAT-TsF1 and TsF2. The monoclonal anti-TsF1 antibodies are capable of modulating in vitro GAT-specific PFC response in a GAT-specific manner; some suppress responses to GAT directly, whereas others reverse GAT-TsF1-mediated suppression of responses. The monoclonal anti-TsF2 antibodies all reverse suppression but are reactive with combinatorial determinants, I-J+ chains or antigen-binding chains of the GAT-TsF2. The data are discussed in terms of the nature of the determinants recognized by these antibodies as well as the potential uses of these reagents for studying the suppressor T cell pathway and potential relationships between Ts1, Ts2, and T helper cells.

Animals↗
PubMed1985

T cell subsets regulating antibody responses to L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) in virgin and immunized nonresponder mice.

T cell subsets from virgin and immunized mice, which are Ir gene controlled nonresponders to GAT, which regulate antibody responses to GAT have been characterized. Virgin nonresponder B10.Q B cells develop GAT-specific antibody responses to GAT, B10.Q GAT-M phi, and GAT-MBSA when cultured with virgin or GAT-primed Lyt-1+, I-J-, Qa1- B10.Q helper T cells. Virgin T cells are radiosensitive, whereas immune T cells are radioresistant (750 R); qualitatively identical helper activity is obtained with T cells from mice immunized with soluble GAT, B10.Q GAT-M phi, and GAT-MBSA. Responses to GAT and GAT-M phi are not observed when virgin or GAT-primed Lyt-1+, I-J+, Qal+ T cells are added to culture of virgin or GAT-primed Lyt-1+, I-J-, Qa1- helper T cells and virgin B cells; the GAT-specific response to GAT-MBSA is intact. The Lyt-1+, I-J+, Qa1+ T cells from mice primed with GAT, GAT-M phi, and GAT-MBSA were qualitatively identical in mediating this suppression. Virgin Lyt-2+ T cells have no suppressive activity alone or with virgin Lyt-1+, I-J+, Qa1+ T cells, whereas responses to GAT, GAT-M phi, and GAT-MBSA are suppressed in cultures of GAT-primed helper T cells containing GAT-primed Lyt-2+ T cells (with or without GAT-primed Lyt-1+, I-J+, Qa1+ T cells). Suppression of responses to GAT-MBSA in cultures of GAT-M phi-primed helper T cells requires both GAT-M phi-primed Lyt-1+, I-J+, Qa1+ T cells and Lyt-2+ T cells; the Lyt-1+, I-J+, Qa1+ T cells appear to function as inducer cells in this case. In cultures containing GAT-MBSA-primed helper T cells, either GAT-MBSA-primed Lyt-1+, I-J+, Qa1+ or Lyt-2+ T cells suppress responses to GAT and GAT-M phi; under no circumstances are responses to GAT-MBSA suppressed by GAT-MBSA-primed regulatory T cells. This regulation of antibody responses to GAT by suppressor T cells is discussed in the context of the involvement of suppressor T cells in responses to antigens under Ir control, and of the evidence that nonresponsiveness to GAT is not due to a defect in the T cell repertoire, but rather is due to an imbalance in the activation of suppressor vs helper T cells.

Animals↗
PubMed1985

Purification and analysis of isoforms of soluble immune response suppressor (SIRS).

Soluble immune response suppressor (SIRS) isolated from the T cell hybrid 393D2.6 was originally reported to exist as at least two m.w. forms and to migrate on reverse-phase high-performance liquid chromatography columns as three separate species. In experiments presented here, a further analysis of the different chromatographic forms of SIRS has been carried out. SIRS-alpha elutes from C-18 reverse-phase columns in 20% propanol. When SIRS-alpha is subjected to isoelectric focusing, three biologically active species are isolated at approximately pH7, approximately pH6, and approximately pH5 (SIRS-alpha 7, SIRS-alpha 6, and SIRS-alpha 5, respectively). SIRS-beta elutes in 30% propanol, and on isoelectric focusing the biologic activity is found only at approximately pH7 (SIRS-beta 7). Both the alpha and beta forms of SIRS have nearly identical m.w. when subjected to molecular sieve chromatography and migrate with a m.w. of 11,000. The molecular basis for these isoforms is not yet clear but is consistent with earlier studies showing two separate messenger RNA species coding for SIRS.

Animals↗
PubMed1984

Regulatory mechanisms in immune responses to heterologous insulins. II. Suppressor T cell activation associated with nonresponsiveness in H-2b mice.

Murine antibody responses to insulins are controlled by MHC-linked Ir genes. Although mice of the H-2b haplotype do not make antibody in response to pork insulin, we demonstrate in this communication that immunization with pork insulin stimulates radioresistant, Lyt-1+2- helper T cells that are capable of stimulating secondary antibody responses to pork insulin in vitro, but that this activity is masked by radiosensitive, Lyt-1-2+, I-J+ suppressor T cells. The suppressor T cells, present after immunization with pork insulin but not beef insulin, suppress the secondary response to pork but not beef insulin. The amino acid sequences of pork and beef insulins differ only at the A-chain loop; thus, pork insulin-specific suppressor T cells appear to recognize the A-chain loop determinant of pork insulin. The amino acid sequences of mouse and pork insulin are identical in the A-chain loop, which suggests that these suppressor T cells may be self-reactive. If this interpretation is correct, these suppressor T cells could be involved in the maintenance of self-tolerance to insulin. Nevertheless, these data clearly demonstrate that genetically determined nonresponsiveness in H-2b mice is conferred by activation of dominant, insulin-specific suppressor T cells (Ts), rather than by a defect in the stimulation of insulin-specific helper T cells (Th).

Animals↗
PubMed1984

Identification and initial characterization of concanavalin A- and interferon-induced human suppressor factors: evidence for a human equivalent of murine soluble immune response suppressor (SIRS).

Human suppressor T cells activated by leukocyte interferon have properties similar to murine suppressor cells activated by interferon or by concanavalin A. Murine suppressor cells release a soluble mediator, soluble immune response suppressor (SIRS), which accounts, at least in part, for suppressive activity in murine systems. To compare and contrast murine and human suppressor pathways, we evaluated the suppression of human polyclonal plaque-forming cell responses by concanavalin A, by leukocyte interferon, and by immune interferon, or by suppressor cells activated by these agents. In each instance, suppressive activity was prevented by levamisole, ascorbic acid, catalase, or 2-mercaptoethanol, agents known to interfere with murine SIRS activity. Furthermore, concanavalin A, immune interferon, and leukocyte interferon induced T lymphocytes to release 110,000 to 150,000 m.w. proteins which suppressed responses only when added early in the culture period. As with murine SIRS, suppression by each of these human factors was inhibited by 2-mercaptoethanol, ascorbic acid, catalase, or levamisole. The reaction of human suppressor factors with H2O2 (10(-6) M) activated suppressor factors so that they suppress responses when added late in the culture period. Human suppressor factors were protease- and acid (pH 2)-sensitive. The similarities between these human suppressor factors and murine SIRS show the existence of a human SIRS pathway.

Animals↗
PubMed1984

T cell subsets in (responder x nonresponder)F1 mice regulating antibody responses to L-glutamic acid60-L-alanine30-L-tyrosine (GAT).

Immune responses to GAT are controlled by H-2-linked Ir genes; soluble GAT stimulates antibody responses in responder mice (H-2b) but not in nonresponder mice (H-2q). In nonresponder mice, soluble GAT stimulates suppressor T cells that preempt function of helper T cells. After immunization with soluble GAT, spleen cells from (responder x nonresponder: H-2b X H-2q)F1 mice develop antibody responses to responder H-2b GAT-M phi but not to nonresponder H-2q GAT-M phi. This failure of immune F1 spleen cells to respond is due to an active suppressor T cell mechanism that is activated by H-2q, but not H-2b, GAT-M phi and involves two regulatory T cell subsets. Suppressor-inducer T cells are immune radiosensitive Lyt-1 +2-, I-A-, I-J+, Qa-1+ cells. Suppressor-effector T cells can be derived from virgin or immune spleens and are radiosensitive Lyt-1-2+, I-A-, I-J+, Qa-1+ cells. This suppressor mechanism can suppress responses of virgin or immune F1 helper T cells and B cells. Helper T cells specific for H-2b GAT-M phi are easily detected in F1 mice after immunization with soluble GAT; helper T cells specific for H-2q GAT-M phi are demonstrated after elimination of the suppressor-inducer and -effector cells. These helper T cells are radioresistant Lyt-1+2-, I-A+, I-J-, Qa-1- cells. These data indicate that the Ir gene defect in responses to GAT is not due to a failure of nonresponder M phi to present GAT and most likely is not due to a defective T cell repertoire, because the relevant helper T cells are primed in F1 mice by soluble GAT and can be demonstrated when suppressor cells are removed. These data are discussed in the context of mechanisms for expression of Ir gene function in responses to GAT, especially the balance between stimulation of helper vs suppressor T cells.

Animals↗
PubMed1984

Soluble immune response suppressor (SIRS) inhibits microtubule function in vivo and microtubule assembly in vitro.

Soluble immune response suppressor (SIRS) is a product of concanavalin A-stimulated murine T cells that, when activated or oxidized by macrophages or H2O2 (SIRSox), suppresses in vitro immune responses and inhibits cell division by normal and neoplastic cells. SIRSox is inactivated by a variety of electron donors, which suggests that SIRSox may be an oxidizing agent. Incubation of lymphocytes with SIRSox, but not with SIRS, partially reversed concanavalin A-mediated inhibition of capping of membrane immunoglobulin on B cells, and disrupted the cytoplasmic array of microtubules visualized by fluorescence microscopy. SIRSox also inhibited microtubule assembly in vitro in a concentration-dependent manner. Inactivation of SIRSox by dithiothreitol prevented SIRSox-mediated reversal of inhibition of capping and inhibition of microtubule assembly. These results reveal a pattern of SIRSox activity similar to sulfhydryl-dependent cytoskeletal disrupting agents (e.g., N-ethylmaleimide, cytochalasin A, p-benzoquinone), and suggest that SIRSox-mediated suppression of proliferation may involve interference with sulfhydryl-dependent cytoskeletal events critical for cell division.

Animals↗
PubMed1984

Antigen presentation by the BCL1 murine B cell line: in vitro stimulation by LPS.

We examined the antigen-presenting capacity of BCL1 tumor cells, which are capable of differentiating in vitro with respect to immunoglobulin synthesis/secretion under the influence of LPS. In vivo passaged BCL1 cells depleted of host cell contamination either by positive selection employing panning with anti-lambda reagents, or by elimination of latex-ingesting adherent cells, are capable of MHC-restricted antigen presentation to a GAT-immune T cell line. The BCL1 cells act as antigen-presenting cells when freshly explanted, but gradual loss of this function occurs, and cells cultured for 3.5 days cannot present antigen unless LPS is included during the culture period. BCL1 cells are equivalently Ia+ after the culture period with or without LPS stimulation. Other B cell lines capable of antigen presentation appear to express this trait constitutively, and the in vivo passaged BCL1 line is therefore unique among B cell lines in having antigen-presenting cell function that can be modulated. The data suggest that freshly explanted or LPS-cultured BCL1 cells are heterogeneous with respect to antigen-presenting capacity, and the basis for this heterogeneity is being sought. BCL1 offers an opportunity to study requirements for antigen presentation by B cells.

Animals↗
PubMed1983

Antigen-specific suppressor T cell interactions. II. Characterization of two different types of suppressor T cell factors specific for L-glutamic acid50-L-tyrosine50 (GT) and L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT).

We have previously reported that two types of suppressor T cell factors (TsF) specific for L-glutamic acid50-L-tyrosine50 (GT) or L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) can be distinguished based upon differences in their ability to suppress responses by allogeneic mice. Injection of GAT or GT induces a suppressor T cell subset that produces an antigen-binding, I-J+, genetically unrestricted, specific suppressor factor (TsF1). Injection of this factor plus small amounts of antigen induces a second-order suppressor T cell that produces an antigen-binding, I-J+, genetically restricted, specific suppressor factor (TsF2). In this report, we demonstrate that these two factors are also biochemically distinct. Monoclonal TsF1 molecules are composed of a single polypeptide chain that bears both the antigen-binding site and I-J determinant, whereas TsF2 molecules are composed of two disulfide-linked polypeptide chains, one of which is antigen-binding and I-J-, and the other, nonantigen-binding, I-J+. The antigen-binding chain must be added at culture initiation to achieve suppression, but the I-J+ chain can be added as late as day 3 with complete suppression observed. However, isolated chains from TsF2-producing hybridomas derived from three different haplotypes were unable to suppress immune responses when chains from heterologous TsF2 were mixed. Indirect evidence is presented that suggests that this restriction is because the chains fail to interact rather than the inability of the target cells to recognize both chains.

Alkylation↗
PubMed1983

Purification and characterization of an L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT)-specific suppressor factor from genetic responder mice.

A hybridoma-derived, GAT-specific suppressor T cell factor (GAT-TsFR) from responder C57BL/10 mice has been purified to apparent chemical homogeneity using reversed phase HPLC techniques. 40 l of starting material yielded approximately 880 micrograms protein with a specific activity of 28.4 X 10(3) S50 U/ng protein representing a purification factor of 4.2 X 10(6). Purified GAT-TsFR is a hydrophobic protein with a minimum molecular weight of 18,000 that is capable of forming biologically active aggregates with molecular weights of 28,000, 64,000 and approximately 84,000 and has a pI of 6.4. GAT-TsFR is a glycoprotein that binds GAT and GT, but not GA, and bears determinants encoded by the I-J subregion of the H-2 complex. This GAT-TsFR derived from an H-2b responder haplotype to GAT is compared with GAT-TsF derived from the nonresponder H-2q haplotype on the basis of biochemical and some serological properties.

Amino Acids↗
PubMed1983

T and B cells that recognize the same antigen do not transcribe similar heavy chain variable region gene segments.

We have attempted to determine whether T cells and B cells that have the same antigenic specificity and whose receptors share idiotypic determinants in fact express similar VH gene segments. To do this, we have obtained and characterized a cDNA clone containing the entire coding sequence for the VH gene from a glutamic acid60/alanine30/tyrosine10 (GAT)-binding immunoglobulin that carries the CGAT idiotype. The GAT-VH clone was hybridized to Northern blots of GAT-specific T cell RNAs; there was no evidence of a T cell transcript that hybridized to the GAT-VH probe. The T cells analyzed included: (a) 10 GAT-binding suppressor T cell hybridomas, 6 of which secreted factors with CGAT idiotypic determinants, (b) one GAT-specific helper T cell hybridoma, and (c) two GAT-specific helper T cell lines grown in the absence of feeder cells. The detection limit of the Northern blot analysis was 1-2 copies of a particular mRNA species per cell for the hybridomas and 5-10 copies per cell for the T cell lines. Therefore, we conclude that T and B lymphocytes responding to GAT do not utilize similar VH gene segments. Furthermore, the presence of idiotypic determinants on T lymphocytes does not necessarily imply close structural similarity between T and B cell antigen receptors.

Animals↗
PubMed1983

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.

Animals↗
PubMed1983

RNA transcripts for I-J polypeptides are apparently not encoded between the I-A and I-E subregions of the murine major histocompatibility complex.

The I-J subregion of the mouse major histocompatibility complex has been reported to encode antigenic determinants expressed by suppressor T cells. Previously, cosmid clones were obtained from mouse sperm DNA that contain all of the sequences between the I-A and I-E subregions, where I-J has been mapped genetically. However, hybridization of these sequences to RNA prepared from several I-J-positive suppressor T-cell hybridomas did not reveal the presence of a transcript. In addition, no rearrangements in this DNA were detected in the suppressor T cells that we have analyzed. Our results indicate that the I-J polypeptides are not encoded between the I-A and I-E subregions of the major histocompatibility complex. We discuss several hypotheses concerning the possible location and expression of I-J genes.

Animals↗