bluuebunny/crossref_metadata_2025 huggingface dataset:
CD8 lymphocyte subpopulations in Peyer's patches induced by reovirus serotype 1 infection.
Authors: London S D , Cebra-Thomas J A , Rubin D H , Cebra J J
Published: December 2022

CD8 lymphocyte population heterogeneity has been examined by using reovirus serotype 1, strain Lang (reovirus 1/L) as a model infection. We have previously reported that gut mucosal infection with reovirus stimulates the appearance of virus-specific cytotoxic T cell precursors (pCTL) in Peyer's patches (PP). The effectors that mediate reovirus-specific cytotoxicity were found to express both the Thy-1 and CD8 Ag and were MHC-restricted in their recognition of reovirus Ag. To further characterize the virus-specific precursor and effector cells we have analyzed PP cells for the expression of a novel surface Ag (termed germinal center and T cell Ag (GCT)) found on germinal center B cells and a subpopulation of CD8+ T cells. Gut mucosal infection with reovirus 1/L is capable of increasing the proportion of GCT+ CD8+ T cells in PP. Positive selection as well as depletion of GCT+ cells has demonstrated that pCTL can express this Ag, and depletion experiments have demonstrated that effector CTL express the GCT Ag. Thus, a subpopulation of GCT+ cells have been identified as Ag-specific precursor and effector CTL. These observations indicate that the expression of the GCT Ag may provide a means to identify recently stimulated pCTL or effector CTL in gut mucosal tissues.
Novel immunoregulatory functions of phenotypically distinct subpopulations of CD4+ cells in the human neonate.
Authors: Clement L T , Vink P E , Bradley G E
Published: December 2022

Although normal numbers of CD4+ T cells are present in the human neonate, cord blood CD4+ cells are deficient in their ability to provide help for antibody production. In the present studies, we have examined the cellular basis for this functional deficit by analyzing the phenotypic properties and immunoregulatory functions of the subsets of cord blood CD4+ cells defined by anti-CD45RA mAb. In contrast to CD4+ cells from adults, greater than 90% of cord blood CD4+ cells expressed the CD45RA, CD38, and Leu-8 membrane Ag. When neonatal CD4+ cells were cultured with adult B cells and PWM or anti-CD4+ mAb, no helper function was apparent. However, when the small number of CD4+CD45RA- cells in cord blood were purified and similarly analyzed, helper activity comparable to that of adult CD4+CD45RA- cells was found. This helper function was profoundly suppressed by the presence of even small numbers of cord blood (but not adult) CD4+CD45RA+ cells. Irradiation of mitomycin C treatment of neonatal CD4+CD45RA+ cells abrogated their suppressor activity, but did not induce helper capability. However, after activation with PHA and culture in IL-2, cord blood CD4+CD45RA+ cells lost their suppressor activity and acquired the ability to provide help for B cell differentiation. This functional maturation was accompanied by their conversion to the CD4+CD45RA- phenotype. Thus, whereas cord blood CD4+CD45RA+ and CD4+CD45RA- cells share certain properties with the analogous subsets in adults, our data show that the dominant immunoregulatory function of cord blood CD4+ cells is suppression mediated by CD4+CD45RA+ (and CD38+) cells. In view of these phenotypic and functional differences between neonatal and adult CD4+CD45RA+ cells, we propose that "naive" CD4+CD45RA+ cells undergo age-related maturational changes that are unrelated to their postulated activation-dependent post-thymic differentiation into CD4+CD45RA- "memory" cells capable of helper functions.
A study of auto-anti-idiotypes to BSA.
Authors: Forsyth R B , Hoffmann G W
Published: December 2022

In order to study the idiotypic relationships between the antibody populations produced in different species during normal immune responses to ordinary protein Ag, we raised immune sera in mice and chickens by using three protein Ag: BSA, keyhole limpet hemocyanin, and diphtheria toxoid. An avidin-biotin ELISA was used to measure idiotypic binding between antibody populations from these sera. We found that the chicken sera contained auto-anti-idiotypes (AAI) against Ag-specific antibodies that were present in the same serum and that co-purified with those antibodies on Ag-Sepharose columns. These AAI were present in secondary response chicken anti-BSA serum at levels comparable with those of the anti-BSA antibody. The chicken AAI also react specifically with Id in mouse anti-BSA serum. The mouse anti-BSA serum completely inhibits the binding between the chicken Id and AAI. This similarity between the Id of whole populations of antibodies produced in two distantly related species, in the absence of any manipulation with idiotypic or anti-idiotypic reagents, suggests that the AAI detected in this way are internal image antibodies. It indicates there is positive selection for such AAI to be internal images.
Quantitative analysis of membrane cofactor protein (MCP) of complement. High expression of MCP on human leukemia cell lines, which is down-regulated during cell differentiation.
Authors: Seya T , Hara T , Matsumoto M , Akedo H
Published: December 2022

Membrane cofactor protein (MCP) is a cell-associated regulatory molecule for C system with C3b/C4b binding and factor I-dependent cofactor activity. mAb were raised against MCP and amounts and distribution examined on normal human cells and cell lines. The mean quantity of MCP was 3000 to 7000 copies/cell in normal blood cells, except for E which have no MCP. Of note, PMN did not fully reveal all MCP sites until incubated for greater than 30 min at 37 degrees C. In most tumor cell lines, except for B cell lineages, expression of MCP increased by 2- to 8-fold in comparison with the normal cell counterparts. Strikingly, recombinant granulocyte CSF treatment of myeloid cell lines and hemin treatment of an erythroblastoid cell line, K562, led to a decrease of MCP to near normal levels. In contrast, C3b/C4b receptor (CR1) tended to increase with granulocyte-CSF treatment in several cell lines. We simultaneously determined levels of decay-accelerating factor (DAF) and CR1 in these tumor cells, and tested susceptibility to C3 deposition via activation of the alternative C pathway. Of 21 cell lines we examined, 14 lacked CR1 and two lacked DAF; none, however, lacked MCP. A slight amount of C3 deposition was observed in some myeloid cell lines and EBV-infected B cell lines. However, C3 deposition did not reflect a defect in the regulatory proteins. Tumor cells bearing MCP, lacking CR1 or DAF, and undergoing no C3 deposition, may escape C attack due to the compensatory effect of MCP in the absence of the other regulatory proteins. High expression of MCP provides a convenient means for tumor cells to block C attack and survive in blood stream. We favor the interpretation that MCP is up-regulated in association with certain malignant disorders, and that cell differentiation results in a switch from an MCP-dominant state to a CR1-dominant state.
Effects of IL-1 and cortisol on beta-adrenergic receptors, cell proliferation, and differentiation in cultured human A549 lung tumor cells.
Authors: Nakane T , Szentendrei T , Stern L , Virmani M , Seely J , Kunos G
Published: December 2022

The effects of IL-1 and cortisol, and their interactions on the density of beta-adrenergic receptors (beta AR), cell proliferation, and the adherence of cells to plastic were studied in cultured human A549 lung tumor cells. The density of beta AR, assayed by 125I-pindolol binding, was increased two- to threefold by a 24-h incubation of the cells with IL-1 alpha, IL-1 beta, and TNF-alpha (EC50: 2.7, 8.2, and 24 pM, respectively), although a series of other cytokines and growth factors did not have this effect. Cortisol also increased beta AR density (EC50: 30 nM) and markedly potentiated the effects of IL-1 alpha, IL-1 beta, and TNF-alpha. Neither IL-1 nor cortisol influenced the proportion of cell surface vs internalized beta AR. The IL-1-induced increase in beta AR density was half-maximal after 6 h, was reversible at a similar rate, and was blocked by 1 microM of cycloheximide. The effect of IL-1 on beta AR was specific, as the density of glucocorticoid receptors, measured by 3H-dexamethasone binding, was reduced by IL-1. Both cortisol and IL-1 potentiated the isoproterenol-induced increase in cAMP accumulation. IL-1 inhibited cell proliferation and thymidine uptake, and increased the adherence of A549 cells to the plastic culture flask, as quantified by a cell detachment assay. The effect of IL-1 on cell adherence was not inhibited by cycloheximide. Cortisol decreased cell adherence and prevented the IL-1-induced increase in adherence. The results indicate that multiple effects of IL-1 in a cultured tumor cell line involve different mechanisms, suggesting heterogeneity of IL-1R and/or coupling of IL-1R to distinct, nuclear, and nonnuclear, effector pathways.
Characterization of the enhanced adhesion of neutrophil leukocytes to thrombin-stimulated endothelial cells.
Authors: Toothill V J , Van Mourik J A , Niewenhuis H K , Metzelaar M J , Pearson J D
Published: December 2022

We have characterized the mechanisms by which thrombin enhances neutrophil leukocyte (PMN) adhesion to human endothelial cells in vitro. Thrombin rapidly and transiently increased PMN adhesion by an action on the endothelial cells. The transience of the response was due to at least two factors: desensitization of the endothelial cell responsiveness to thrombin in the continued presence of the agonist; and the lability (t1/2 less than 15 min) of the effector molecules expressed by the endothelium. Experiments with exogenous platelet-activating factor (PAF) and with PAF antagonists demonstrated that PAF production, although it may facilitate the enhanced PMN adhesion seen in response to thrombin, is not sufficient to explain the reaction. By using a variety of antibodies directed against cell surface ligands, and comparing adhesion of PMN to endothelium and to protein-coated surfaces, we deduce that several endothelial ligands not previously reported as playing a role in PMN adhesion are involved in these interactions. Of particular interest was the finding that antibodies recognizing two thrombin-regulated endothelial cell surface ligands, GMP-140 and the CD63-related Ag, both inhibited adhesion of PMN to thrombin- or LPS-pretreated endothelium. We conclude that thrombin acts to enhance PMN adhesion to endothelium at least in part by transiently altering the conformation or level of expression of these ligands.
Vaccination with membrane-associated idiotype provides greater and more prolonged protection of animals from tumor challenge than the soluble form of idiotype.
Authors: Ghosh S K , White L M , Ghosh R , Bankert R B
Published: December 2022

The purpose of this work was to compare the efficacy of immunizing mice with a soluble vs a cell-associated form of a tumor Ag. A murine B cell tumor (2C3), which displays an Id on its cell surface, grows progressively and gives rise to Id-negative tumor variants in nonimmunized animals. We previously reported that the tumor variants arise as a consequence of Id-specific T cell suppression of the Id+ tumor. The Id-specific effector T cells are CD4+, CD8-. Based upon these findings vaccination protocols have been designed and tested to determine whether the expansion of tumor-specific effector T cells would eliminate the Id+ tumors and prevent the subsequent generation of Id- tumor variants in vivo. MHC-restricted T cells typically recognize soluble Ag subsequent to modification by an APC, and APC may ultimately express a processed form of the Ag that is different from that expressed on the surface of the tumor cells. Based upon this assumption, the efficacy of immunizing mice with cell-associated 2C3 Id was compared to immunization with a soluble form of the same Id. Mice were immunized with either irradiated 2C3 cells or syngeneic spleen cells to which 2C3 protein was covalently linked. These immunization protocols provided a complete and lasting protection against a tumor challenge of up to 1 x 10(6) tumor cells. In contrast, most mice hyperimmunized with a soluble form of the Id did not survive this level of tumor challenge in spite of the production of significant levels of anti-Id antibodies. Mice immunized with the soluble form of the Id, which did survive, produced slowly progressing tumors expressing a 1000-fold less of the marker Id. These results illustrate the importance of understanding and properly exploiting a host's natural response to a tumor-specific Ag when designing effective immunization protocols for cancer therapy.
Resistance to H-2-restricted but not to allo-H2-specific graft and cytotoxic T lymphocyte responses in lymphoma mutant.
Authors: Ohlén C , Bastin J , Ljunggren H G , Foster L , Wolpert E , Klein G , Townsend A R , Kärre K
Published: December 2022

The lymphoma mutant RMA-S escaped graft rejection after transplantation over a minor histocompatibility barrier, whereas it was rejected in H-2 allogeneic mice. The parental control line was rejected in both situations. The mutant, which had been selected against MHC class I molecules retained 5 to 10% of the wild-type H-2Db, Kb, and beta 2-microglobulin expression on the cell surface. It remained sensitive to allo-H-2b CTL in vitro, but was completely resistant to minor histocompatibility antigen-specific, H-2b-restricted CTL. It was equally resistant to other H-2b-restricted responses against internally derived Ag, such as tumor-specific CTL or a CTL clone specific for the influenza virus nucleoprotein. The results indicate a target cell defect that selectively abolishes the sensitivity to H-2-restricted CTL directed against internally processed Ag. This appears sufficient to shift the transplantation response over a minor histocompatibility Ag barrier from rejection to acceptance. There are two possible explanations for the results: 1) a block in the MHC class I-directed pathway for internal Ag processing, and 2) subthreshold H-2/Ag ligand density in relation to triggering requirements of restricted CTL. Regardless of the type of defect, the results demonstrate a difference between allo-H-2-specific and H-2-restricted CTL recognition at the level of the target cell.
Costimulation of proliferative responses of resting CD4+ T cells by the interaction of VLA-4 and VLA-5 with fibronectin or VLA-6 with laminin.
Authors: Shimizu Y , van Seventer G A , Horgan K J , Shaw S
Published: December 2022

Given prior evidence that adhesion molecules play critical roles in T cell recognition, it is important to identify new adhesion pathways and explore their role in T cell activation. Our studies of T cell proliferation complement concurrent studies of T cell adhesion; both demonstrate that resting CD4+ human T lymphocytes express the VLA integrins VLA-4, VLA-5, and VLA-6, and can use these receptors to interact with the extracellular matrix (ECM) proteins fibronectin (VLA-4 and VLA-5) and laminin (VLA-6). VLA-dependent interaction of resting human CD4+ T cells with fibronectin (FN) and laminin (LN) facilitates CD3-mediated T cell proliferation. Specifically, T cells do not proliferate in response to a wide range of concentrations of a CD3 mAb, OKT3, immobilized on plastic. However, coimmobilization with the CD3 mAb of FN or LN, but not other ECM proteins such as fibrinogen and collagen, consistently results in strong T cell proliferation. mAb blocking studies demonstrate that three VLA integrin receptor/ligand interactions mediate costimulation: VLA-4/FN, VLA-5/FN, and VLA-6/LN. VLA-5-dependent binding to FN but not costimulation by FN can be specifically blocked with peptides containing the RGD (arg-gly-asp) tripeptide sequence whereas VLA-4-dependent binding and costimulation can both be efficiently inhibited by a 12 amino acid peptide, LHGPEILDVPST (leu-his-gly-pro-glu-iso-leu-asp-val-pro-ser-thr), derived from the alternatively spliced IIICS region of FN. The costimulation provided by FN and LN in this system is stronger than and distinct from costimulatory signals provided by cytokines, such as IL-1 beta, IL-6,, and IL-7. These results suggest that, such as other adhesion molecules, T cell VLA integrins may also function in a dual capacity as adhesion and signalling molecules. In addition, they suggest that the interaction of T cells in vivo with ECM via VLA integrins plays a role not only in T cell migratory processes but may also influence Ag-specific T cell recognition.
Induction of macrophage-mediated tumor cytotoxicity by a hamster monoclonal antibody with specificity for lipopolysaccharide receptor.
Authors: Chen T Y , Bright S W , Pace J L , Russell S W , Morrison D C
Published: December 2022

Experiments have been carried out to assess the immunostimulatory activity of a hamster IgM mAb (mAb5D3) with specificity for an 80-kDa LPS-binding protein expressed on murine macrophages and monocytes. The addition of mAb5D3 to cultures of murine bone marrow-derived macrophages activated these cells to become tumoricidal for mastocytoma cells in vitro. The activity of mAb5D3 was enhanced in the presence of IFN-gamma. Neither mAb5D3 nor LPS were able to activate macrophages from the LPS-hyporesponsive C3H/HeJ mouse, although these cells responded normally to heat-killed Listeria monocytogenes. The results of several experiments establish that the observed LPS-like activity of mAb5D3 was not due to contaminating endotoxin: 1) the activity of mAb5D3 but not LPS was heat labile at 100 degrees C; 2) the activity of LPS but not mAb5D3, was inhibited by addition of polymyxin B; and 3) quantitative estimates of endotoxin contamination by Limulus amoebocyte lysate reactivity. These experiments thus demonstrate that mAb5D3 can serve as an agonist for LPS-dependent macrophage responses and, when considered with those of our companion paper showing specificity of mAb5D3 for the 80-kDa LPS-binding protein, provide strong support for the concept that the 80-kDa LPS-binding protein previously identified serves as a functional receptor for LPS on murine macrophages.
Costimulatory requirements of murine Th1 clones. The role of accessory cell-derived signals in responses to anti-CD3 antibody.
Authors: Williams I R , Unanue E R
Published: December 2022

We examined the role of accessory cell-derived signals in promoting growth and lymphokine production by murine Th1 clones. Five of six Th1 clones failed to proliferate to immobilized anti-CD3 antibody despite producing IL-2 and IFN-gamma. These clones became unresponsive to Ag after exposure to anti-CD3. With the addition of irradiated splenic accessory cells (SAC), Th1 clones proliferated to anti-CD3 and produced greater amounts of IL-2 and IFN-gamma. High doses of plate-bound anti-CD3 completely inhibited responses of these clones to IL-2 and diminished the growth-promoting activity of SAC. The costimulatory effects of SAC on growth of Th1 clones were also seen in the presence of exogenous IL-2, indicating that enhanced IL-2 production alone was not responsible for the costimulatory effect. Delivery of the costimulatory signal from SAC required their close proximity to the T cells. The costimulatory activity of SAC was not reproduced by the addition of IL-1, IL-6, or IL-1 plus IL-6. IL-7 induced weak proliferation of Th1 clones, but did not synergize with plate-bound anti-CD3. Our results suggest a model in which SAC-derived costimulatory signals regulate growth of Th1 cells primarily at the level of cell cycle progression rather than at the level of IL-2 production.
Association of glycosylation-inhibiting factor with plasma membranes of T suppressor cell hybridomas.
Authors: Iwata M , Katamura K , Mori A , Yamagushi K , Grey H , Ishizaka K
Published: December 2022

The glycosylation inhibiting factor (GIF) was detected in EGTA extracts of the OVA-specific Ts cell hybridoma, 231F1 cells and 71B4 cells, which constitutively secrete GIF. The lymphokine in both culture supernatants and EGTA extracts failed to bind to OVA-Sepharose. Association of GIF with the plasma membrane was confirmed by surface labeling of the 231F1 cells with 125I. The major species of GIF in the extract was 14.4-kDa peptide as determined by SDS-PAGE, and was identical to that detected in culture supernatants. Pretreatment of the cells with monoclonal anti-GIF switched the cells from the formation of unglycosylated IgE-BF to the formation of glycosylated IgE-BF, indicating that the membrane-associated GIF is involved in the determination of the nature of IgE-binding factor during their biosynthesis. When the hybridoma was stimulated with OVA-pulsed APC, EGTA extracts of the cells contained GIF having affinity for OVA. The binding of the OVA-binding GIF in the EGTA extracts to OVA-Sepharose was inhibited by a synthetic peptide, which corresponds to amino acid residues 307-317 in the OVA molecule and represents the epitope recognized by TCR on the cells. The OVA-binding GIF in the extracts bound to the monoclonal anti-TCR-alpha chain, H-28-710 and the mAb 14-12, which is specific for the Ag-binding chain of effector type suppressor factor, and suppressed the in vivo antibody response of BDF1 mice to DNP-OVA in a carrier-specific manner. Evidence was obtained that indicated that the Ag-binding chain was associated with nonspecific GIF chain on the cell surface of the Ag-stimulated cells.
Differential inhibition of T and B cell function in IL-4-dependent IgE production by cyclosporin A and methylprednisolone.
Authors: Renz H , Mazer B D , Gelfand E W
Published: December 2022

The present study examines the role of the immunosuppressive agents methylprednisolone (MPN) and cyclosporin (Cs)A on IL-4-dependent IgE and IgG production. Addition of optimal amounts of IL-4 (100 U/ml) to cultures of tonsil mononuclear cells resulted in a mean increase in IgG production of 175% and in IgE production of 2460%. Frequency analysis of IgE- and IgG-producing B cells, using an ELISA spot assay, showed parallel increases in both Ig production and numbers of Ig-secreting B cells. IgE production was also enhanced by addition of IL-2 (10 U/ml) and maximal IgE production was obtained with a combination of IL-4 and IL-2. MPN (10(-7) M) and CsA (1 microgram/ml) markedly reduced IL4-induced IgE and IgG production as well as numbers of Ig-secreting cells in a dose-dependent fashion. The suppression of Ig production by the cyclosporins was restricted to the immunosuppressive compounds CsA, CsG, and dihydro-CsD, but not the nonimmunosuppressive drug CsH. Delayed addition of CsA revealed that inhibition was maximal when the drug was added during the first 48 h after addition of IL-4 to the culture. Addition of IL-2 (10 U/ml) partially overcame the inhibition induced by CsA. In coculture experiments, in which separated T or B cells were precultured with the drugs and the cells were then combined and further incubated in the presence of IL-4, the suppressive effects of CsA on IgE production were related to pretreatment of the T but not B cells. The maximum inhibiting effects of MPN were similarly observed when the drug was present in the cultures from the beginning, and addition of IL-2 also partially reversed this inhibition. In contrast to the results with CsA, pretreatment of the B but not T cells with MPN-reduced IgE production. These studies demonstrate that IL-4 increases both numbers of IgE-secreting cells as well as IgE production and CsA and MPN differentially affect the responding T and B cells, resulting in inhibition of Ig production.
Lymphocyte adhesion to cultured Peyer's patch high endothelial venule cells is mediated by organ-specific homing receptors and can be regulated by cytokines.
Authors: Chin Y H , Cai J P , Johnson K
Published: December 2022

Adhesion of lymphocytes to high endothelial venule (HEV) cells is the first step in the migration of these cells from blood into lymph nodes and Peyer's patches (PP). In the present study, we isolated and cultured HEV cells from PP of the rat and assessed their capacity to interact with lymphocytes. Flow cytometric analysis with a rat HEV-specific mAb KJ-4 revealed that greater than 90% of the cultured cells were stained by the antibody. Furthermore, confluent monolayers of PP HEV cells retained the capacity to support the adhesion of lymphocytes from spleen, thoracic duct, and lymph nodes but not binding of immature cells from thymus and bone marrow, which are deficient in cells capable of binding to HEV in vivo. In addition, intraepithelial lymphocytes that preferentially migrated into mucosal lymphoid tissues were also enriched in cells that adhered to the endothelial monolayers. The binding process required energy, was calcium-dependent, and could be inhibited by cytochalasin D, trypsin, and mixed glycosidase. Interestingly, pretreatment of PP HEV cells with rTNF, IFN-gamma, or granulocyte-macrophage CSF significantly increased the endothelial adhesiveness for thoracic duct lymphocytes in a time- and dose-dependent manner. In contrast, stimulation of lymphocytes with phorbol ester or TNF resulted in the rapid modulation of the surface expression of the PP homing receptor and decrease in lymphocyte binding to normal or TNF-stimulated HEV cells. The adhesion of lymphocytes to normal or cytokine-stimulated HEV cells can be blocked by pretreatment of lymphocytes, but not HEV cells, with the PP homing receptor-specific 1B.2.6 antibody. Taken together, these experiments provide strong evidence that the interaction between lymphocytes and cultured HEV cells are mediated by adhesive mechanisms that regulate lymphocyte entry into PP in vivo and that cytokines can promote HEV adhesiveness for lymphocytes through increased expression of organ-specific ligands on HEV cells.
Epitope mapping of human thyroglobulin. Heterogeneous recognition by thyroid pathologic sera.
Authors: Henry M , Malthièry Y , Zanelli E , Charvet B
Published: December 2022

Thyroglobulin is the major Ag of the thyroid gland involved in autoimmune pathologies. Epitope mapping was carried out with a rabbit polyclonal immune serum against fusion proteins expressed in prokaryotic cells. After screening of an initial human thyroglobulin cDNA library and subcloning of immunoreactive clones, seven epitopes were characterized and localized on the human thyroglobulin monomeric molecule. One was close to each extremity of the molecule, and five others were concentrated in the middle, covering a sixth of this 2748-amino-acid chain. The immunoreactivities of 18 autoimmune sera from different thyroid pathologies were tested against the seven previously characterized epitopes. Those from Hashimoto's thyroiditis were the most immunoreactive. Immune responses were heterogeneous for sera from different pathologies as well as for those from the same pathology. The central epitopes and the near-C-terminal epitope, however, were the epitopes most often recognized by the immune sera. These findings show that some autoepitopes overlap accurately with some heteroepitopes characterized by a polyclonal immune serum directed against the mature protein.
Enrichment and function of urushiol (poison ivy)-specific T lymphocytes in lesions of allergic contact dermatitis to urushiol.
Authors: Kalish R S , Johnson K L
Published: December 2022

The frequencies of urushiol (poison ivy)-specific T cells were determined in the lesional skin and peripheral blood of patients with allergic contact dermatitis to urushiol. Lesions of urushiol dermatitis were biopsied and the T cells retrieved. Frequencies of Ag-specific cells were determined by limiting dilution assay. Enrichment of urushiol specific T cells was detected in lesional skin or blister fluid of five of five of these donors as well as seven of seven donors with urushiol patch tests. There was also enrichment relative to tetanus toxoid specific T cells in blood and skin of six of seven donors. The frequency of lesional T cells specific for urushiol was less than 1/100 and generally less than 1/1000. Furthermore, the frequency of urushiol specific T cells was often less than 1/10,000 in the peripheral blood during an acute eruption. Autoreactive T cells that proliferated to autologous irradiated PBMC were also enriched in skin lesions relative to blood in 5/5 urushiol patch tests. These autoreactive T cells were expanded and found to be CD4+. It has been proposed that such autoreactive T cells recognize autologous DR and may have a role in immunoregulation. Urushiol-specific T cells were expanded from limiting dilution wells of two donors and characterized. The majority of the urushiol-specific cells were CD8+, and 13/43 lines were suppressive for PWM-induced IgG synthesis.
[125I]fibrin deposition occurs at both early and late intervals of IgE-dependent or contact sensitivity reactions elicited in mouse skin. Mast cell-dependent augmentation of fibrin deposition at early intervals in combined IgE-dependent and contact sensitivity reactions.
Authors: Mekori Y A , Galli S J
Published: December 2022

When elicited in the skin of mice, either IgE-dependent immediate hypersensitivity reactions or T cell-dependent contact sensitivity (CS) reactions result in local extravasation of [125I]fibrinogen and deposition of [125I]fibrin. However, these two types of reaction differ in kinetics and in requirement for IgE, mast cells, or T cells. In the present study, we investigated the kinetics and magnitude of [125I]fibrin deposition in combined IgE-dependent and CS reactions elicited simultaneously at the same site and compared the results with those obtained when the two reactions were elicited at separate sites. We found that [125I]fibrin deposition in pure IgE-dependent reactions was greater at 2 or 6 h after challenge than at 24 h, but that significant fibrin deposition persisted at those sites 24 h after challenge. In CS reactions, [125I]fibrin deposition was detected as early as 2 h after challenge, indicating that fibrin deposition accompanies the "early component" of CS detected by Van Loveren et al. with the use of measurements of tissue swelling. But much more [125I]fibrin deposition was present in CS reactions at 24 h than at 2 or 6 h after Ag challenge. When IgE-dependent and CS reactions were elicited at the same site, [125I]fibrin deposition at early intervals (2 to 6 h) after challenge was increased three- to 25-fold compared with that seen in isolated CS reactions, but at 24 h the results in the combined reactions were virtually identical to those in CS responses. Studies in genetically mast cell-deficient and congenic normal mice indicated that mast cells were required for expression of the IgE-dependent augmentation of [125I]fibrin deposition observed at early intervals in combined IgE-dependent and CS reactions, but not for the [125I]fibrin deposition associated with "pure" CS reactions. These findings indicate that the net effect of IgE-dependent mast cell activation on CS responses is to increase the fibrin deposition associated with these responses, but this effect is appreciated only at early intervals after elicitation of the reaction.
Hemorrhage in mice produces alterations in pulmonary B cell repertoires.
Authors: Robinson A , Abraham E
Published: December 2022

Nosocomial pneumonia occurs frequently after hemorrhage and trauma and contributes to the increased incidence of morbidity and mortality after severe injury. The production of secretory antibodies by mucosally associated B cells is an important component of pulmonary host defense mechanisms. To determine the effects of hemorrhage on pulmonary B cell function, we examined hemorrhage induced alterations in pulmonary B cell repertoires. There were no changes in the relative distribution of T or B cells among intraparenchymal pulmonary lymphocytes after blood loss. Hemorrhage induced decreases of between 5- and 10-fold in the frequencies and numbers of pulmonary B cell clonal precursors specific for the bacterial Ag levan and Pseudomonas aeruginosa polysaccharide. These decreases in numbers and frequencies of bacterial Ag-specific pulmonary B cell clonal precursors were present between 3 and 10 days after blood loss. Similar decreases in numbers and frequencies were found among pulmonary clonal precursors specific for the autoantigen mouse transferrin, but not for the autoantigen dsDNA or the external antigens OVA and keyhole limpet hemocyanin. These results demonstrate that hemorrhage produces marked alterations in pulmonary B cell repertoires, which may contribute to postinjury abnormalities in host defenses.
Requirement of endogenous tumor necrosis factor/cachectin for recovery from experimental peritonitis.
Authors: Echtenacher B , Falk W , Männel D N , Krammer P H
Published: December 2022

By intrasplenic immunization we raised a rat mAb (mAb V1q; IgG2a, kappa) with a potent neutralizing activity against natural mouse TNF (1 microgram/ml mAb V1q/100 U/ml TNF). mAb V1q was used to study the role of endogenous TNF in experimental peritonitis induced by sublethal cecal ligation and puncture. mAb V1q persisted for over 5 days in the serum of mice injected with 100 micrograms of the antibody and, therefore, proved useful for in vivo experiments. As little as 20 micrograms mAb V1q/mouse prevented lethal shock of the animals by 400 micrograms LPS/mouse. In sublethal cecal ligation and puncture i.p. injection of mAb V1q directly and up to 8 h after induction of experimental peritonitis lead to death of the animals within 1 to 3 days. The lethal effect of mAb V1q was compensated by injection of recombinant mouse TNF. Similar mAb V1q effects as in immunocompetent mice were shown in severe combined immune deficiency mice deficient of mature functional B and T cells. Taken together, these data suggest that during the early phase of peritonitis endogenous TNF may stimulate nonlymphoid cells such as granulocytes, macrophages, platelets, and fibroblasts to ingest bacteria and to localize inflammation, respectively. These beneficial effects of TNF may determine survival. Thus, our data may have implications for the therapeutic management of a beginning peritonitis.
Transforming growth factor beta 1 increases IgA isotype switching at the clonal level.
Authors: Kim P H , Kagnoff M F
Published: December 2022

Transforming growth factor beta 1 (TGF beta 1) has important effects on expression of the IgA isotype. TGF beta 1 alone, or in combination with IL-5 or IL-2 increases IgA secretion by populations of LPS-activated surface IgA negative (sIgA-) spleen B cells, while concurrently decreasing IgM and IgG secretion. The present study demonstrates the activity of TGF beta 1 as an IgA isotype switch factor at the clonal level. Stimulation of LPS-activated sIgA- spleen B cell populations with TGF beta 1, or a combination of TGF beta 1 and IL-2, resulted in a significant increase in total numbers of IgA secreting cells, and this increase ultimately was paralleled by an increase in total IgA secretion. Using limiting dilution analysis, TGF beta 1 was shown to increase the frequency of IgA secreting B cell clones, by approximately 20-fold. This was not accompanied by increased numbers of IgA secreting cells/clone. In contrast, IL-2 does not have activity as an IgA switch factor, but does increase IgA production by B cells already committed to secrete that isotype. Cell cycle inhibitors such as thymidine and hydroxyurea also selectively increased numbers of IgA secreting cells and total IgA secretion among populations of LPS-activated sIgA- spleen B cells. This suggests the IgA enhancing activity of TGF beta 1 may, in part, be related to its ability to inhibit cell growth.
Identification of a polypeptide sequence that mediates nuclear localization of the acute phase protein C-reactive protein.
Authors: Du Clos T W , Mold C , Stump R F
Published: December 2022

C-reactive protein (CRP) is the prototypic human acute phase serum protein. CRP binds to several nuclear Ag including chromatin, histones, and small nuclear ribonucleoproteins. Binding to sites of tissue inflammation and the nuclei of inflammatory cells has been demonstrated in vivo. We also noticed significant similarity between CRP and nucleoplasmin, a molecule with nuclear localization activity. We therefore decided to test whether CRP was capable of nuclear localization. CRP and the control protein human serum albumin were FITC-conjugated and microinjected into living VERO cells. The cells were incubated at 37 degrees C for 15 min and then examined by fluorescence microscopy. Nuclear localization of CRP but not albumin was rapid and a high nuclear to cytoplasmic ratio was seen, consistent with active nuclear transport. Incubation at reduced temperature inhibited nuclear uptake by CRP. A synthetic peptide, RKSLKK, from the CRP sequence, when coupled to FITC-albumin, also mediated nuclear localization. Nuclear localization of the related protein, serum amyloid P component, was also seen and a homologous nuclear localization signal was identified. Because CRP was previously demonstrated to inhibit RNA transcription and enhance chromatin degradation it is proposed that CRP may play a unique role in injured cells to alter processing of damaged nuclei. Biochemical, structural and sequence comparisons between the CRP/serum amyloid P component family of proteins (pentraxins) and the nucleoplasmin/B23 family of proteins showed regions of sequence homology that may be related to their shared cyclic pentameric structure.
Molecular characterization and functional analysis of the leukocyte surface protein CD31.
Authors: Stockinger H , Gadd S J , Eher R , Majdic O , Schreiber W , Kasinrerk W , Strass B , Schnabl E , Knapp W
Published: December 2022

The CD31 Ag is a surface glycoprotein of 130 kDa with a broad cellular distribution. We show that among peripheral human blood cells, it is expressed on monocytes, granulocytes, platelets, and a subpopulation of lymphocytes. Activation of granulocytes leads to down-regulation of CD31 molecule expression. Sequence analysis and quantitative measurements of the relatedness of the CD31 molecule to other known proteins demonstrate that it consists of six Ig constant domains and that each domain bears substantial similarity to Fc gamma R domains. We find, however, that the CD31 molecule does not bind Ig Fc domains. On human monocytes we demonstrate that CD31 mAb recognizing certain epitopes of the CD31 molecule induce the generation of reactive oxygen metabolites. No such effect was seen with human granulocytes. By using two CD31 mAb, termed 1B5 and 7E4, we analyzed the requirements for activation of the monocyte respiratory burst via CD31 Ag in more detail. We show that signal transduction occurs via formation of a CD31 Ag-mAb-Fc gamma R complex involving either Fc gamma RI (CD64) or Fc gamma RII (CDw32) molecules.
Mycobacterium leprae-specific T cells from a tuberculoid leprosy patient suppress HLA-DR3-restricted T cell responses to an immunodominant epitope on 65-kDa hsp of mycobacteria.
Authors: Haanen J B , Ottenhoff T H , Lai A Fat R F , Soebono H , Spits H , de Vries R R
Published: December 2022

The polar tuberculoid type (TT) of leprosy, characterized by high T cell reactivity to Mycobacterium leprae, is associated with HLA-DR3. Surprisingly, DR3-restricted low T cell responsiveness to M. leprae was found in HLA-DR3-positive TT leprosy patients. This low responsiveness was specifically induced by M. leprae but not by M. tuberculosis and was seen only in patients and not in healthy controls. We studied this patient-specific, M. leprae-induced, DR3-restricted low T cell responsiveness in depth in one representative HLA-DR3-positive TT leprosy patient by using T cell clones. From this patient two types of T cell clones were obtained: one type was cross-reactive with M. tuberculosis and recognized an immunodominant epitope (amino acids 3 to 13) on the 65-kDa heat shock protein (hsp) the other type was M. leprae specific and reacted to a protein other than the 65-kDa one. To examine whether these M. leprae-specific T cell clones were responsible for the DR3-restricted low responsiveness to M. leprae, we tested them for the ability to suppress the proliferation of the DR3-restricted, 65-kDa, hsp-reactive clones. The DR3-restricted, M. leprae-specific T cells completely suppressed the proliferative responses of DR3-restricted, cross-reactive T cell clones to the 65-kDa hsp from the same patient as well as from other individuals. Also, DR3-restricted responses to an irrelevant Ag were suppressed by the M. leprae-specific T cell clones. However, no suppression of non-DR3-restricted T cell responses was seen. Although the mechanism must still be elucidated, this M. leprae-induced, DR3-restricted immunosuppression may at least partly explain the observed DR3-associated low T cell responsiveness in TT leprosy patients.
Glutathione S-transferase. Novel vaccine against Fasciola hepatica infection in sheep.
Authors: Sexton J L , Milner A R , Panaccio M , Waddington J , Wijffels G , Chandler D , Thompson C , Wilson L , Spithill T W , Mitchell G F
Published: December 2022

The potential of GST as a vaccine candidate against liver fluke infection in ruminants was studied by vaccinating sheep (n = 9) with GST purified from adult worms of Fasciola hepatica and challenging with 500 F. hepatica metacercariae. The immunization induced a high antibody response to GST in contrast to the poor or undetectable response to this Ag observed in naturally infected sheep. Throughout the trial, the progress of the fluke infection was monitored by measuring RBC hemoglobin levels, the extent of liver damage and the fecal egg output in the sheep. This analysis indicated that a subpopulation (n = 4) of the GST vaccinated animals exhibited no anemia, reduced liver damage and a lower mean fecal egg count relative to the infected control group suggesting a lower fluke burden in these animals. Worm burdens in the livers of the GST vaccine group (107 +/- 22) were 57% lower than in the infected control group (250 +/- 25). The subpopulation of the GST vaccine group demonstrated a 78% reduction in mean worm burdens relative to the control group. These results show that GST of adult F. hepatica is a novel Ag that can significantly protect sheep against liver fluke infection. The results suggest that the immune response to GST is directed to the juvenile worm reducing the number of worms that can establish in the liver of the vaccinated animals.
Mlsa generated suppressor cells. I. Suppression is mediated by double-negative (CD3+CD5+CD4-CD8-) alpha/beta T cell receptor-bearing cells.
Authors: Bruley-Rosset M , Miconnet I , Canon C , Halle-Pannenko O
Published: December 2022

Grafting of cells from B10.D2 (H-2d) donors into H-2 compatible lethally irradiated (DBA/2 x B10.D2)F1 hosts results in a severe graft-vs-host reaction (GVHR), developed against DBA/2 non-H-2 Ag, with only 0 to 10% of animals surviving. This GVHR mortality rate is dramatically reduced (90 to 100% of animals survive) by donor preimmunization against Mlsa determinants. The protection against GVHR correlates with a decreased B10.D2 anti-DBA/2 proliferative response in vitro. Both in vivo and in vitro phenomena are associated with activation of CD5+ suppressor T cells in the spleens of immunized mice. The present work was designed to study the origin of these suppressor cells and to further characterize their phenotype. The results show that significant suppression is not inducible in "B" mice. In contrast, in mice that were only thymectomized or else pretreated in vivo with anti-CD4 or anti-CD8 mAb, the suppressor cells are activated as efficiently as in normal mice. The suppression of GVHR mortality and proliferative responses in vitro is lost after depletion from preimmunized splenocytes of CD5+ T cells and remains unaltered after depletion of CD4+ or CD8+ T cells or both. Depletion of asialo GM1+ cells removes all NK activity, whereas the suppression is decreased only slightly. FACS analysis showed that double-negative (DN) cells from normal and immunized mice contain both CD3+ and CD3- cells; the vast majority of the CD3+ DN T cells express the alpha/beta T cell receptor. Suppression of GVHR and of proliferative responses in vitro are abrogated after elimination of CD3+ cells. These results suggest that Mlsa generated suppressor cells: 1) are derived from post-thymic long-lived T cell precursors; 2) are low asialo GM-1+ but do not exhibit NK activity; 3) belong to a subset of peripheral CD5+ DN T cells bearing a CD3-associated alpha/beta-heterodimer.
Quantitative analysis of serum IL-6 and its correlation with increased levels of serum IL-2R in HIV-induced diseases.
Authors: Honda M , Kitamura K , Mizutani Y , Oishi M , Arai M , Okura T , Igarahi K , Yasukawa K , Hirano T , Kishimoto T
Published: December 2022

We have devised a luminescence sandwich ELISA for the quantification of IL-6 in both sera and cell culture supernatants, which had a detection limit of 100 fg/ml of test sample. By using the luminescence sandwich-ELISA, low but measurable levels of IL-6 (9.5 pg/ml on average) were found in the sera from normal individuals. The serum levels of IL-6 were elevated in HIV-seropositive asymptomatic carriers (55.5 pg/ml on average), and the IL-6 levels were correlated with the degree of HIV-induced disease progression (AIDS-related complex 106.8 pg/ml on average and (AIDS 283 pg/ml). IL-6 immunoreactivity in the sera of AIDS patients eluted at a 25,000 m.w. major peak, which was biologically active and heat-stable, and a 500,000 m.w. minor peak in size-exclusion HPLC. Interestingly, a significant correlation was observed between the serum IL-6 levels and soluble IL-2R levels. In vitro, HIV infection of PHA-activated PBMC led to enhanced release of IL-6 into the culture supernatants. Moreover, soluble IL-2R release was markedly increased by adding exogenous IL-6, whereas it was decreased by adding the neutralizing anti-IL-6 mAb to the cultures. These results demonstrate that increased IL-6 levels are significantly associated with sIL-2R levels, and suggest a cause of the increased levels of this receptor in patients with HIV infection. Furthermore, both serum IL-6 and serum IL-2R levels in HIV infection reflect the stage of the HIV-induced disease.
IL-2-dependent proliferation of murine T cells requires expression of both the p55 and p70 subunits of the IL-2 receptor.
Authors: Jankovic D L , Rebollo A , Kumar A , Gibert M , Thèze J
Published: December 2022

An IL-4-dependent T cell clone (LD8) was isolated from the murine IL-2-dependent cytotoxic T cell line C30.1. This clone has lost the capacity to proliferate in response to IL-2 after long-term culture in IL-4. LD8 cells express the p70, but not the p55, subunit of the IL-2R on their cell surface. The number of p70 IL-2R molecules on LD8 cells is comparable with the number of high-affinity IL-2R on the parental C30.1 cell line. LD8 cells can efficiently internalize IL-2 through the p70 IL-2R subunit. Following stimulation by IL-2, LD8 cells up-regulate p70 IL-2R mRNA, but do not express p55 IL-2R mRNA. IL-2-dependent proliferation of LD8 cells was reconstituted after introduction and expression of a human p55 IL-2R cDNA. To further investigate the role of p70 IL-2R, we have measured IL-2-induced proliferation of C30.1 cells in the presence of three anti-p55 IL-2R mAb (5A2, PC61, and 7D4) that recognize different epitopes. Under the experimental conditions used, the combination of anti-p55 IL-2R mAb prevents the formation of high-affinity IL-2R, but does not affect the binding of IL-2 to p70 IL-2R or IL-2 internalization. However, these three mAb inhibit proliferation of C30.1 cells even in the presence of IL-2 concentrations sufficient to saturate p70 IL-2R. Together these results demonstrate that p70 IL-2R alone is not sufficient to transmit IL-2-induced growth signals and that formation of p55-p70 IL-2R complex is required for IL-2-dependent proliferation of murine T cells.