Search PubMed⌕ Search

Biomedical subjects

C W Pierce

Publications and source records attributed to C W Pierce.

At least 73 records · Page 4Linked to original sources
PubMed1983

Expression of cell surface antigens by suppressor T cell hybridomas. I. Comparison of phenotype and function.

The phenotypic expression of cell surface markers by T cell hybridomas that elaborate suppressor factors specific for the polymers L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) or L-glutamic acid50-L-tyrosine50 (GT) has been analyzed. We found that determinants encoded by the I-J subregion of the H-2 complex were borne on the surface of these hybrid cells and on the factors they secrete, whereas I-J determinants were not expressed by the AKR thymoma fusion parent, BW5147. The level of expression of I-J determinants fluctuated widely depending upon culture conditions, but I-J products and other cell surface markers of normal T cells could be quantitatively increased, or induced to appear, by treatment of the hybridomas with chemical agents, such as dimethyl sulfoxide (DMSO) or phorbol myristate acetate (PMA). In contrast, the surface expression of the viral product gp70 was decreased by the same treatment. Using chemical induction, we typed BW5147, a group of antigen-specific suppressor T cell hybridomas, and two control hybridomas for expression of I-J, Thy-1, Lyt, and H-2K alloantigens. Also, a haplotype-specific hybridoma that produces an antigen-nonspecific factor was analyzed. The results demonstrated that BW5147 failed to express I-J or Lyt alloantigens but expressed Thy-1.1 and H-2Kk gene products. The pattern of expression of these antigens by T cell hybridomas was very complex, but three conclusions could be drawn: 1) Good correlation exists between the expression of certain I-J determinants and the ability of T cell hybridomas to produce suppressor factor. 2) The expression of Thy-1, Lyt, or H-2Kk determinants is variable, and no correlation was found between expression of these antigens and the ability to produce active suppressor factors. 3) I-Jk products contributed by the AKR thymoma fusion partner are expressed by T cell hybridomas.

Absorption↗
PubMed1983

Suppressor T cell activation by human leukocyte interferon.

Murine fibroblast interferon (IFN beta) activates murine suppressor T lymphocytes in vitro, which suppress plaque-forming cell responses by spleen cells. Suppression of human in vitro immune responses by IFN was investigated to determine whether human IFN also activates suppressor T cells. Human leukocyte IFN (IFN alpha) suppressed pokeweed mitogen-induced polyclonal immunoglobulin production by human peripheral blood mononuclear cells (PBMC) by 80 to 90% at doses of 200 to 350 U/ml. Responses by IFN alpha-treated PBMC were suppressed in a dose-dependent manner; control cultures had maximal responses on day 7. PBMC incubated with 10,000 U/ml of IFN alpha contained activated suppressor cells that decreased pokeweed mitogen-stimulated, polyclonal immunoglobulin production by autologous cells by 70 to 80%. Suppression mediated by these cells was prevented by catalase, ascorbic acid, and 2-mercaptoethanol (2-ME). In murine systems, these reagents interfere with expression of suppressor T cell activity by preventing activation of soluble immune response suppressor. Selection procedures with monoclonal antibodies identified the suppressor cell as an OKT8+ (suppressor/cytotoxic) T lymphocyte. Selected OKT8+ cells required less IFN alpha (1000 U/ml) for activation and were effective in smaller numbers than unfractionated activated PBMC. IFN alpha-activated suppressor cells also inhibited proliferation in mixed lymphocyte and mitogen-stimulated PBMC cultures; again, catalase and 2-ME blocked suppression. These results indicate that IFN alpha activates suppressor T cells in human PBMC cultures; the ability of catalase, 2-ME, and ascorbic acid to block suppression suggests that these suppressor T cells have certain similarities to IFN beta or to concanavalin A-activated murine suppressor T cells.

Animals↗
PubMed1983

Purification and initial characterization of the lymphokine soluble immune response suppressor.

Two molecular forms of the lymphokine soluble immune response suppressor (SRIS), obtained from serum-free supernatant fluids of a T cell hybridoma producing SIRS, have been purified by a combination of gel filtration and high performance liquid chromatography (HPLC). Supernatant fluids (8 liters) from the hybridoma 393.D2.6 were concentrated and fractionated on Sephadex G-50 in 0.4 M pyridine/0.4 M acetic acid buffer. Active fractions containing approximately 1 X 10(7) units of SIRS activity and 300 mg protein were fractionated further by reverse phase HPLC on a Lichrosorb RP-18 column in a 1.0 M pyridine-0.5 M acetic acid buffer. A stepwise n-propanol gradient reproducibly eluted SIRS activity in the 20% n-propanol fraction. After three chromatography steps on the Lichrosorb RP-18 column, final purification was obtained with an Si-100 diphenyl column by employing the same buffer and elution system. SIRS eluted in the 30% n-propanol fraction as two discrete protein peaks. Purity of SIRS was assessed by SDS-polyacrylamide gel electrophoresis. The two protein peaks from the fractionation on the diphenyl column each exhibited only one band of protein with m.w. of 21,500 and 14,000, respectively. Additional studies of both molecular species of SIRS showed they possessed functional properties identical to those previously described for crude SIRS. Final purification of the 21,500 SIRS species yielded approximately 10 micrograms of protein and 6 X 10(8) units of SIRS activity or 6 X 10(10) units/mg protein; final purification of 14,000 SIRS species yielded approximately 30 micrograms of protein and a similar amount of SIRS activity or 2 X 10(10) units/mg protein.

Cell Line↗
PubMed1983

Properties of the SIRS suppressor pathway.

The SIRS suppressor pathway is initiated by activation of Ly 2+ T lymphocytes by either con A or IFN beta. SIRS is a protein which has been purified and exists as two species with mol. wts. of 14,000 and 21,500. The target of SIRS is the macrophage and macrophages appear to oxidize or activate SIRS in a peroxide dependent process. Catalase blocks SIRS or IFN beta action by consuming H2O2 and levamisole blocks SIRS or IFN beta by preventing activation or oxidation of SIRS by H2O2. Other agents which block SIRS or IFN beta action include electron donors which can inactivate SIRSox. SIRSox is a potent inhibitor of immune responses and proliferation of normal and neoplastic cells. The mechanism of SIRSox-mediated inhibition of proliferation appears to involve oxidation or modification of protein sulfhydryls. Although the applicability of this pathway to the regulation of immune responses and cellular proliferation remains to be determined, both IFN beta and levamisole have been found to affect a wide variety of cellular processes. The involvement of both IFN beta and levamisole in the SIRS pathway suggests that this pathway may be an important host mechanism for regulating both immune responses and cellular proliferation in general.

Animals↗
PubMed1982

Antigen-specific suppression in genetic responder mice to L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT). Characterization of conventional and hybridoma-derived factors produced by suppressor T cells from mice injected as neonates with syngeneic GAT macrophages.

Spleen cells from C57BL/10 mice injected with syngeneic B10 L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT)-pulsed macrophages (GAT-M phi) within 18 h of birth were unable to respond to soluble GAT, GAT-methylated bovine serum albumin, or B10 GAT-M phi as adults. Spleen cells from these neonatally treated mice responded at control levels to GAT presented in allogeneic M phi and to sheep erythrocytes. Partially purified T cells from these neonatally treated mice suppressed responses by syngeneic virgin, but not primed, spleen cells in an antigen-specific manner and acted during the early phases of the response. These responder GAT-specific suppressor T cells (GAT-TSR) were sensitive to anti-Thy-1 + C and 500-rad irradiation and have the phenotype Ly-1-2+, I-J+; GAT-TSR cells can only suppress responses by spleen cells syngeneic with the GAT-TSR cells at the I-J subregion of H-2. Restimulation of these Ts cells with syngeneic GAT-M phi induces an antigen-specific suppressor factor within the supernatant fluid. The factor, GAT-TsFR, is a glycoprotein with a molecular weight between 48,000 and 63,000, as determined by gel filtration chromatography using isotonic buffers; it bears serologically detectable determinants encoded by the I-J subregion of the H-2 complex, has an antigen-binding site for GAT and L-glutamic acid50-L-tyrosine50, and shares idiotypic determinants with anti-GAT antibodies. The presence of GAT-TsFR in the first 36 h of in vitro culture is required for significant suppression. Furthermore, only responses by spleen cell syngeneic with the cells producing GAT-TsFR at the I-J subregion are suppressed. The fusion of GAT-TsFR-producing cells with BW5147 resulted in generation of two hybridomas with properties and characteristics identical to those of the conventional GAT-TsFR with one exception: conventional and hybridoma 372.D6.5 GAT-TsFR only suppress responses by spleen cells of the I-Jb haplotype, whereas suppression mediated by the second hybridoma GAT-TsFR (372.B3.5) is genetically unrestricted. These hybridoma GAT-TsFR are compared with nonresponder GAT-Ts factor (GAT-TsF) and these responder and nonresponder GAT-TsF are considered in the context of suppressor pathways.

Animals↗
PubMed1982

Preparation of soluble immune response suppressor and macrophage-derived suppressor factor.

Concanavalin A-activated murine suppressor T cells act via the mediator, soluble immune response suppressor (SIRS) which non-specifically suppresses IgM and IgG antibody responses to a variety of antigens, cytotoxic T lymphocyte responses and proliferative responses to alloantigens and mitogens in vitro. SIRS is a protein with an apparent MW of 45,000-55,000; the target of SIRS is the macrophage (M phi). M phi following treatment with SIRS release a second factor, M phi-derived suppressor factor (M phi-SF), which is directly responsible for the observed suppression of responses. Moreover. M phi-SF appears to be modified SIRS by all criteria used to date; M phi-SF can be obtained by reacting SIRS with low concentrations of H2O2 in the absence of M phi. Thus, M phi appear to serve only as a source of H2O2 and the mechanism of M phi-SF action action appears to have an oxidative basis. M phi-SF activity is lost following treatment with sulfhydryl reagents such as 2-mercaptoethanol, dithiothreitol or cysteine, reducing agents such as NaBH4 and a variety of peroxidase substrates such as pyrogallol, phenylenediamine, and ascorbic acid. Additionally, M phi-SF-mediated inhibition can be reversed by high concentrations of 2 mercaptoethanol or dithiothreitol under appropriate conditions. Since M phi-SF appears to be modified SIRS, oxidized by peroxide, and not a distinct second mediator produced by M phi in response to SIRS, we propose eliminating the term M phi-SF and using SIRSox to denote the active form of SIRS produced either by the SIRS-H2O2 reaction or SIRS-treated M phi.

Animals↗
PubMed1982

Activation of a suppressor T-cell pathway by interferon.

In addition to antiviral activities, murine fibroblast (type I) interferon (IFN-beta) suppresses immune responses. The mechanism(s) by which IFN-beta suppresses antibody responses by murine spleen cells to sheep erythrocytes in vitro has been investigated. IFN-beta-mediated suppression is partially or completely prevented by catalase, 2-mercaptoethanol, and certain peroxidase substrates (ascorbic acid, potassium iodide, and tyrosine). These same reagents also block suppression by mediators from concanavalin A-activated murine suppressor T cells, soluble immune response suppressor (SIRS)/macrophage-derived suppressor factor (Mphi-SF), and act by inactivating Mphi-SF or preventing formation of Mphi-SF from SIRS. Therefore, these experiments suggested that IFN-beta may act by inducing production of a molecule that has properties of SIRS. Treatment of spleen cells with IFN-beta leads to generation of a population of Lyt2+ suppressor T cells that acts by elaborating a soluble factor. This IFN-beta-induced suppressor T-cell factor (IFN-TsF) has properties in common with SIRS. First, both SIRS and IFN-TsF suppress antibody responses with the same characteristic kinetic pattern; responses initiate normally but prematurely terminate after day 4 of culture. Second, IFN-TsF and SIRS are of comparable size (45,000-55,000 daltons) and are converted to Mphi-SF by low (1 microM) concentrations of H2O2 or by macrophages. Third, Mphi-SF obtained from IFN-TsF or SIRS is inactivated by similar concentrations of reagents such as ascorbic acid, potassium iodide, and 2-mercaptoethanol. These data show that the immunosuppressive properties of IFN-beta are due, at least in part, to its ability to activate suppressor T cells that produce mediators that appear to be analogous to those in the SIRS/Mphi-SF pathway of immunosuppression.

Animals↗
PubMed1981

Haplotype-specific suppression of antibody responses in vitro. I. Generation of genetically restricted suppressor T cells by neonatal treatment with semiallogeneic spleen cells.

C57BL/10 mice were injected with semiallogeneic (B10.D2 X C57BL/10)F(1) spleen cells via the anterior facial vein within 24 h of birth to induce tolerance to B10.D2 (H-2(d)) alloantigens. Spleen cells from these mice as adults developed reduced, but significant, mixed lymphocyte and cytotoxic lymphocyte responses in vitro to H-2(d) stimulator cells and these treated mice rejected first-set B10.D2 skin grafts within a normal time-course, indicating that at best only a state of partial tolerance had been induced. Spleen cells from these mice failed to develop antibody responses to a variety of antigens in vitro when H-2(d) macrophages were in the cultures. Partially purified T cells from these neonatally treated mice suppressed primary antibody responses by normal syngeneic spleen cells in the presence of H-2(d) but not other allogeneic macrophages. These radiosensitive, haplotype-specific suppressor T (Ts) cells inhibited primary antibody responses by blocking initiation of the response, but failed to suppress secondary antibody responses and mixed lymphocyte or cytotoxic lymphocyte responses by appropriate responding spleen cells. To activate H-2(d) haplotype-specific Ts cells, stimulation with IA(d) subregion antigen(s) was necessary and sufficient; syngenicity at the I-A subregion of H-2 between the activated Ts cells and target responding spleen cell populations was also necessary and sufficient to achieve suppression. Comparable results have been obtained with spleen cells from BALB/c mice injected as neonates with (B10.D2 x C57BL/10)F(1) spleen cells where IA(b) antigens activate the haplotype-specific Ts cells. Implications for the significance of this population of haplotype-specific Ts cells in immune regulation are discussed and the properties of these Ts cells are compared and contrasted with other antigen-specific and nonspecific Ts cells whose activity is restricted by I- region products.

Animals↗
PubMed1981

Haplotype-specific suppression of antibody responses in vitro. II. Suppressor factor produced by T cells and T cell hybridomas from mice treated as neonates with semiallogeneic spleen cells.

Culture supernatant fluids from spleen cells from C57BL/10 or BALB/c mice neonatally treated with semiallogeneic (B 10.D2 x B10)F1 cells to induce haplotype-specific suppressor T cells and restimulated with macrophages syngeneic at I-A with the allogeneic haplotype encountered as neonates contain a soluble factor capable of suppressing primary in vitro antibody responses of normal syngeneic spleen cells in a non-antigen-specific manner. This haplotype-specific suppressor factor, TsF-H, has also been recovered in culture fluids of a T cell hybridoma produced by fusion of the AKR thymoma BW5147 and the haplotype-specific suppressor T cells. TsF-H is inactivated by low pH (3.5) trypsin, for 30 min at 50 degrees C, and has a molecular weight in the range of 45,000 to 68,000. Studies with specific immunoabsorbents demonstrate the presence of determinants encoded by the I-A subregion of the haplotype of the T cell producing TsF-H but not I-J subregion or immunoglobulin constant-region determinants on the TsF-H. Suppression is restricted to primary in vitro antibody responses, and not secondary antibody, mixed lymphocyte, or cytotoxic lymphocyte responses by spleen cells syngeneic at the I-A subregion of H-2 with the T cell producing the factor. The properties and activities of TsF-H and the haplotype-specific suppressor T cell are compared and contrasted with antigen-specific and genetically restricted suppressor T cells and their factors.

Animals↗
PubMed1981

Conversion of soluble immune response suppressor to macrophage-derived suppressor factor by peroxide.

After incubation with soluble immune response suppressor (SIRS), a product of concanavalin A-activated Ly2+ T cells, macrophages release a factor that suppresses in vitro antibody responses, DNA synthetic responses to T-cell and B-cell mitogens, and division of several tumor cell lines. This factor, macrophage-derived suppressor factor (M phi-SF), is a protein with an apparent Mr of 55,000 that is inactivated by sulfhydryl compounds, certain amines, and iodide but not by other halides. In experiments reported here, conventional SIRS and SIRS produced by a cloned T-cell hybridoma were used to analyze formation of M phi-SF by SIRS-treated macrophages. Formation of M phi-SF was insensitive to inhibitors of protein and prostaglandin synthesis but was sensitive to catalase and cyanide, indicating that M phi-SF was not a newly synthesized product and that peroxide was important to its formation. As M phi-SF and SIRS have similar molecular weights and other properties, it is possible that M phi-SF is SIRS modified by peroxide. To test this possibility, SIRS was treated with H2O2 and M phi-SF activity was determined. H2O2 at 0.1-1 pM was sufficient to convert SIRS to M phi-SF; the reaction required approximately 15-20 min and was sensitive to cyanide. Several conventional peroxidase substrates inactivated M phi-SF produced by the SIRS-H2O2 reaction or by SIRS-treated macrophages. In addition, catalase and several of the compounds that directly inactivate M phi-SF also partially interfere with SIRS-mediated suppression of antibody responses. Collectively, these data suggest that SIRS-treated macrophages produce H2O2, which converts SIRS to M phi-SF, which has properties of an oxidized peroxidase-like protein and acts by oxidizing cellular components essential for cell division.

Animals↗
PubMed1981

Mechanism of action of macrophage-derived suppressor factor produced by soluble immune response suppressor-treated macrophages.

After a 2-hr incubation with soluble immune response suppressor (SIRS), a product of concanavalin A-activated murine T cells, macrophages release a factor, M phi-derived suppressor factor (M phi-SF), which nonspecifically suppresses immune responses in vitro. The mechanism(s) of action of M phi-SF and range of cell types affected by M phi-SF have been investigated. M phi-SF suppressed antibody responses to background levels if added at culture initiation and by 80 to 90% if added as late as 2 hr before assay. Primary and secondary IgM and IgG antibody responses, proliferative responses to T cell and B cell mitogens, antibody and protein secretion, and the division of several tumor cell lines in culture were inhibited by M phi-SF. Division of synchronized tumor cells was inhibited when M phi-SF was added at any point prior to and during mitosis; this inhibition could be reversed with 2-mercaptoethanol. In the presence of M phi-SF, asynchronous tumor cells accumulated in the cell cycle just prior to cell division and could be released into mitosis by 2-mercaptoethanol. These data indicate that M phi-SF inhibits cell division by causing a block at or in mitosis and suggest that M phi-SF may be a general inhibitor of cellular proliferation and possibly of protein secretion.

Animals↗
PubMed1980

Sendai virus-specific, H-2-restricted cytotoxic T lymphocyte responses of nude mice grafted with allogeneic or semi-allogeneic thymus glands.

The in vitro secondary cytotoxic T lymphocyte (CTL) response to Sendai virus-treated stimulator cells by primed spleen cells from thymus gland-grafted nude mice was examined. BALB/c (H-2d) nude mice grafted with allogeneic C57BL/10 (H-2b) thymus glands developed CTL responses directed exclusively to Sendai virus-infected H-2d target cells. (C57BL/6 X BALB/c)F1 nude mice grafted with thymus glands of either parent developed CTL responses preferentially against infected target cells expressing the MHC antigens present in the parental thymus graft, but also had detectable activity for infected target cells of the parental haplotype not expressed in the thymus. These results provide evidence against the concept that self recognition by MHC-restricted CTL is directed exclusively by the MCH type of the thymus.

Animals↗
PubMed1980

Activities of nonspecific and specific suppressor T-cell factors in immune responses.

Suppressor T cells modulate both humoral and cell-mediated immune responses by antigen-specific and nonspecific mechanisms. Moreover, soluble factors either secreted by or extracted from these suppressor T cells efficiently mediate the immunoregulatory activities of these cells. The molecular properties and mechanism(s) of action of a nonspecific and an antigen-specific suppressor T-cell factor, both of which regulate antibody responses, will be compared and contrasted. The nonspecific factor, soluble immune response suppressor (SIRS), is produced by Concanavalin A-stimulated T cells and is not separable from MIF activity. The antigen-specific suppressor factor (GAT-TsF) is extracted from T cells stimulated with the synthetic terpolyper L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT). These two factors differ markedly in molecular properties, target cells and mechanism(s) of action. The comparison of the mechanism(s) of action of nonspecific and antigen-specific suppressor T-cell factors provides useful insights into the various pathways operative for regulation of antibody responses. The understanding of the interrelationships among these two classes of immunoregulatory molecules and how they may act to modulate antibody responses are essential for therapeutic manipulation of immune responses and control of the inflammatory response. This is especially important with the nonspecific factor, SIRS, and provides a model in which to study the interface of immune responses and inflammatory responses.

Animals↗