bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple cis-acting elements are required for proper transcription of the mouse V delta 1 T cell receptor promoter.
Authors: Punturieri A , Shirakata Y , Bovolenta C , Kikuchi G , Coligan J E 
Published: December 2022

Abstract
To gain insight into the developmentally regulated expression of the mouse TCR V delta-gene segments, we have investigated the role of the 5' promoter region of the V delta 1-gene. Transient transfection assays showed that a construct encompassing 267 nucleotides upstream from the mapped transcriptional start site was capable of driving promoter activity when transfected into V delta 1+ T cells. The inclusion of an additional 459-bp 5' segment to this construct did not affect promoter activity. However, a deletion of 222 5' nucleotides from the same construct dramatically decreased promoter activity. In vivo genomic footprinting localized several protein-DNA interactions to the stretch of DNA shown to have transcriptional activity. A computer analysis revealed that the segments of DNA participating in these protein-DNA interactions were identical to the previously described cyclic AMP response element (CRE), E box, and leukemia virus E26 cis-acting elements. Transient transfection assays performed with -267 bp constructs containing mutations at each of the localized cis-acting elements revealed that the CRE, E box, and Ets elements work together in driving promoter activity and that the CRE and Ets elements are the most important for driving transcription. Gel mobility shift analyses showed that each of these cis-acting elements is capable of binding specific nuclear factors present in V delta 1-expressing cells. These data indicate that multiple transcription factors acting in concert are responsible for V delta 1 gene expression.
Relationship of C5a receptor modulation to the functional responsiveness of human polymorphonuclear leukocytes to C5a.
Authors: Van Epps D E , Simpson S J , Johnson R 
Published: December 2022

Abstract
The relationship of C5a receptor expression on human polymorphonuclear leukocytes (PMN) to the functional response of these cells to C5a was studied using flow cytometry. C5a receptor expression was determined with a fluorescein conjugate of C5a and oxidative burst activity was monitored by conversion of dichlorofluorescein to dichlorofluorescein (DCF) as a measure of H2O2 production. These studies showed that after incubation of PMN with increasing concentrations of C5a, and allowing for internalization of bound ligand, more than 40% of the cell surface C5a receptors were internalized before the DCF response to optimal concentrations of C5a was decreased below the levels for untreated control cells. Although C5a responsiveness was lost after preincubation with 10(-8) M C5a, cells remained responsive to formyl peptide. In other studies, cells were preincubated with unlabeled C5a under conditions that provided for internalization of nearly all C5a receptors. PMN were then cultured for up to 90 min and monitored for C5a receptor reexpression and return of cell function. In these studies, the DCF response of PMN to C5a returned to 100% much earlier than the cells regained full expression of C5a receptors. The DCF response to formyl peptide remained intact throughout the period of C5a receptor reexpression. These studies showed that once &gt; 40% of the original population of C5a receptors are reexpressed on the PMN, that these cells regain 100% of their functional responsiveness to C5a in the DCF assay. Evaluation of the affinity and number of C5a receptors using 125I-labeled C5a after receptor reexpression showed that maximal receptor reexpression was approximately 73% of that obtained with control cells and the Kd of reexpressed receptors was 0.60 vs 0.94 nM for control cells. These studies demonstrate that only a portion of the total C5a receptors expressed on PMN are essential to stimulate a 100% functional response in PMN and that the reexpressed receptors are capable of transducing a signal that activates the oxidative burst in these cells.
Nonmitogenic anti-CD3F(ab')2 fragments inhibit lethal murine graft-versus-host disease induced across the major histocompatibility barrier.
Authors: Blazar B R , Taylor P A , Snover D C , Bluestone J A , Vallera D A 
Published: December 2022

Abstract
We have investigated the in vivo administration of nonmitogenic anti-CD3F(ab')2 fragments for the prevention of lethal graft-vs-host disease (GVHD) in irradiated recipients of fully allogeneic bone marrow cells plus splenocyte (BMS) inocula. Recipients of anti-CD3F(ab')2 fragments administered for 1 mo post-bone marrow transplantation (BMT) had 100% survival without clinical or histopathological evidence of GVHD. Controls given saline injections succumbed by 39 days post-BMT. Similar results were obtained in groups of recipient mice given BMS in which T cells were depleted by in vitro anti-Thy-1.2 plus C' treatment. Further studies were undertaken to define mechanistic differences in the two approaches. Using Ly-5 congenic sources of donor bone marrow and spleen, we determined that anti-CD3F(ab')2 fragments induced TCR modulation and T cell depletion. Mature splenic-derived CD4+ cells were depleted to a greater extent than CD8+ cells. Early post-BMT, recipients receiving injections with control saline had the highest number of CD4+ and CD8+ cells (which may cause GVHD) followed by recipients of anti-CD3F(ab')2 fragments, with the fewest CD8+ cells observed in the anti-Thy-1.2 + C' treated group. CD3+CD4-CD8- cells (which may suppress GVHD generation) were present in higher numbers early post-BMT in recipients given anti-CD3F(ab')2 fragments as compared to recipients given anti-Thy-1.2 + C'-treated BMS. In long term survivors, a mononuclear T cell containing infiltrate without evidence of destruction was observed in sites of GVHD (lung and liver), consistent with a "Quilty" effect, which was not observed in either of the other two groups. Although survivors were tolerant of donor skin grafts and rejected third party grafts, recipients given anti-CD3F(ab')2 fragments but not anti-Thy-1.2 + C'-treated BMS had vigorous anti-host proliferative responses. These results demonstrate that although in vitro anti-Thy-1.2 + C' treatment of BMS (which is highly depletionary) and in vivo administration of anti-CD3F(ab')2 fragments (which is modulatory and less depletionary) are both effective strategies for GVHD, the cellular events involved in achieving GVHD prevention are indeed different.
Ig CDR3-like region of the CD4 molecule is involved in HIV-induced syncytia formation but not in viral entry.
Authors: Corbeau P , Benkirane M , Weil R , David C , Emiliani S , Olive D , Mawas C , Serre A , Devaux C 
Published: December 2022

Abstract
The HIV1 envelope glycoprotein gp120 binding site has been previously mapped by genetic studies to the CDR2-like region of the first domain of the CD4 molecule. mAb reactive with epitopes linked to this region (e.g., OKT4A) inhibit both HIV entry into CD4-positive cells and syncytia formation. A second area of this domain, the CDR3-like region, has been shown to be involved in gp120-CD4 interactions, but its role remained so far unclear. We show here that a mAb specific for the CDR3-like region of the CD4 receptor, 13B8-2, actually blocks soluble gp120 binding to CD4, inhibits HIV-induced cell-cell fusion, and prevents viral production by infected cells. However, this mAb fails to inhibit the binding of viral particles to cell-surface CD4 and their entry into CD4-positive cells. These results strongly suggest i) that soluble gp120 and virion-anchored gp120 bind CD4 in distinct manners, ii) that gp120-CD4 interactions required for viral entry and syncytia formation are different, and iii) that mAb binding to the CDR3-like region of the first domain of CD4 affects a post-entry step of the HIV replicative cycle.
Simultaneous presence, in one serum, of four monoclonal antibodies that might correspond to different steps in a clonal evolution from polyreactive to monoreactive antibodies.
Authors: Houdayer M , Bouvet J P , Wolff A , Magnac C , Guillemot J C , Borche L , Dighiero G 
Published: December 2022

Abstract
Three monoclonal IgG of different subclasses (IgG1, IgG2, and IgG4) and one IgA1 were isolated from the serum of patient Per suffering from an immunocytic sarcoma. All four monoclonal Ig shared the same N-terminal sequence of their H chains (VH3). Furthermore, their kappa-chains exhibited identical isoelectric charges and N-terminal sequences (VK2) and expressed the same private idiotope. A strong antitubulin activity was found in IgA1Per and in two of the three monoclonal IgGPer. The specificity was restricted to tubulin for IgA1Per and IgG4Per, whereas IgG1Per also displayed significant polyreactive bindings and IgG2Per failed to react with any of the Ag tested. The monoreactive IgG4Per, as well as the polyreactive IgG1Per, bound a large peptide in the central part of both alpha and beta subunits of tubulin (amino acid position 100 to 300). In contrast, the monoreactive IgA1Per bound to a rarely detected epitope close to residue 310 of these subunits. The tubulin epitope recognized by polyreactive IgG1Per was similar to that of germ-line-encoded polyreactive antibodies. It is hypothesized that IgG4Per- and IgA1Per-producing cells derive from the IgG1Per polyreactive clone after somatic events leading to the production of monoreactive antibodies.
Cytokine expression by germinal center cells.
Authors: Butch A W , Chung G H , Hoffmann J W , Nahm M H 
Published: December 2022

Abstract
Germinal centers (GC) primarily consist of B cells along with a small number of T cells (5 to 10%) and follicular dendritic cells (FDC) (&lt; or = 1%). Although extensive Ag-driven B cell proliferation and maturation occurs in GC, very little is known about the role of cytokines in the development of GC B cells. Therefore, to identify cytokines present in the GC microenvironment that may influence B cell development, we systematically examined cytokine gene expression by GC cells. GC T cells (CD57+/CD4+), GC B cells (CD77+), and FDC (HJ2+) were isolated from human tonsils by cell sorting using a flow cytometer. Freshly isolated GC cells were examined for mRNA expression for IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, TNF-alpha, and IFN-gamma using reverse transcription polymerase chain reaction. Freshly isolated GC T cells consistently expressed IL-4 mRNA (11 of 12 tonsils), whereas CD57- Th cells (mostly non-GC Th cells) were often negative for IL-4 mRNA. When the other nine cytokine mRNA were studied, freshly isolated CD57+ Th cells occasionally expressed mRNA for IL-10, TNF-alpha, and IFN-gamma. CD57- Th cells were occasionally positive for IL-1 beta, IL-10, IFN-gamma, and TNF-alpha, and negative for IL-2 and IL-6. Freshly isolated GC B cells as well as FDC failed to express detectable quantities of mRNA for all 10 cytokines that were studied. Thus, IL-4 is the only cytokine out of 10 that is consistently expressed in GC and may be important for the development of B cells in GC. After stimulation of CD57+ Th cells with PWM, production of IL-4 mRNA was dramatically reduced, whereas CD57- Th cell production of IL-4 was greatly augmented. This finding indicates that GC T cells may differ from other Th cells in cytokine gene expression and that results of cytokine production obtained after in vitro stimulation do not always reflect in vivo results.
Analysis of IL-2, IL-4, and IFN-gamma-producing cells in situ during immune responses to protein antigens.
Authors: Bogen S A , Fogelman I , Abbas A K 
Published: December 2022

Abstract
Immunohistochemistry has been used to define the patterns and kinetics of IL-2, IL-4, and IFN-gamma production at the sites of Ag exposure and in the lymphoid tissues of immunized mice, and to examine the anatomic relationships between cytokine-producing T cells and various APC or Ag-stimulated B cells. The earliest detectable cytokine response to administration of a protein Ag in adjuvant was the appearance of IFN-gamma-producing NK cells at the site of immunization by day 3. T lymphocytes producing IL-2, IL-4, and IFN-gamma were initially detected in draining lymph nodes and spleen within 7 days after immunization, and IL-2-producing cells were present at the immunization site several weeks later. Thus, T cell activation is initiated within lymphoid tissues, and these cells migrate back to depots of Ag. The IFN-gamma produced by NK cells early after immunization may regulate the phenotype of the subsequent Ag-specific T cell response. Using a hapten to which the antibody response is oligoclonal and dominated by a single idiotype, Ag-stimulated (idiotype-producing) B cells could also be detected by immunohistochemistry. These B cells were present in the same areas of lymphoid tissues as cytokine-producing T lymphocytes. Two-color staining showed that idiotype-producing B cells were in close proximity to both IL-2- and IL-4-producing T cells, suggesting that T cells producing either of these cytokines could provide helper function for the B cells. Finally, after subcutaneous immunization with adjuvant, IL-2+ T cells were found adjacent to F4/80+ macrophages, suggesting that macrophages function as important APC in this response.
A mutant antigen-presenting cell defective in antigen presentation expresses class II MHC molecules with an altered conformation.
Authors: Dang L H , Lien L L , Benacerraf B , Rock K L 
Published: December 2022

Abstract
Ag presentation by APC to class II MHC-restricted T cells involves a sequence of events: 1) intracellular processing of protein Ag into immunogenic peptides, 2) specific binding of peptides to class II MHC molecules, and then 3) transport of the MHC-peptide complexes to the plasma membrane. The critical event in the activation of T cells by APC is the recognition of MHC-associated antigenic determinants by the TCR/CD3 complex. In this report we describe the isolation and characterization of a mutant APC with a defect in an intracellular process that results in its inability to form MHC-peptide complexes for recognition by T cells. The mutant APC cannot present many different protein Ag with both I-A and I-E molecules but is able to present processing-independent peptides. The functional defect in the mutant APC is not caused by either a decrease in expression or a structural mutation in class II MHC molecules. Further, there is no mutation in the invariant chain (li) and it displays a normal kinetics of association and dissociation from the class II MHC molecules during biosynthesis. Although the mutation is not in the genes encoding for the class II MHC molecules or li, the mutant APC expresses class II MHC molecules with distinct serological epitopes suggestive of an altered conformation. Pulse-chase experiments suggest that a conformational difference between I-Ad molecules of wild-type and mutant cells occurs after the class II molecules exit from the endoplasmic reticulum but while they are still associated with li. The mutant cell produces few compact (SDS-resistant) class II heterodimers. This mutant APC provides a tool for studying the cell biology of Ag processing and presentation.
Phosphatidylserine enhances the ability of epidermal Langerhans cells to induce contact hypersensitivity.
Authors: Girolomoni G , Pastore S , Zacchi V , Cavani A , Marconi A , Giannetti A 
Published: December 2022

Abstract
Phosphatidylserine (PS) modulates several immune functions in vitro, including T cell activation, antibody and cytokine production, and macrophage growth. In the present work we studied the effects of PS on the induction of contact hypersensitivity (CH) in mice. BALB/c mice painted with PS (9.4-75 mg/kg) and with a sensitizing dose of DNFB or oxazolone on the same skin site exhibited a dose-dependent augmentation of CH reactions to either DNFB (&gt; 60%) or oxazolone (&gt; 35%), respectively. Bovine brain PS-enriched phospholipid mixture, lyso-PS, and dipalmitoyl-PS also induced similar enhanced CH responses, whereas phosphatidylglycerols had no effect. Increased CH was observed only when PS was applied from 2 days before to 12 h after DNFB. Immunization of naive syngeneic mice with skin grafts that were treated with PS and DNFB also led to enhanced (&gt; 50%) CH responses. In addition, immunization by iv injection of epidermal cell suspensions enriched for Langerhans cells (LC) or of purified LC that were treated with PS (1-100 microM, 30 min, 37 degrees C), and then modified in vitro with DNBS (1 mg/ml, 30 min, 37 degrees C) led to increased (&gt; 30-75%) CH responses in recipient syngeneic animals. Finally, adoptive transfer of DNFB-immune lymph node cells obtained from mice that were treated with PS induced augmented CH responses in recipient animals. The results suggest that PS is capable of up-regulating the induction of CH in mice by stimulating the APC function of epidermal LC.
Functional CD4 T cell subset interplay in an intact immune system.
Authors: Murray J S , Madri J , Pasqualini T , Bottomly K 
Published: December 2022

Abstract
Immunization with human collagen IV has been shown to lead to the selective activation of Th-1 and Th-2-like cells in vivo depending on the I-A genotype of the mice. Mice expressing I-As generate Th-1 cells, and mice expressing I-Ab generate Th-2 cells after immunization. We examined the response of (bxs)F1 hybrid mice to determine the types of CD4 T cell activated. We found that Th-1-like responses dominated, in that CD4 T cells from human collagen IV-primed mice displayed good proliferative responses and little ability to induce antibody formation, and secreted IFN-gamma and not IL-5. Most of the Th-1-like activity of F1 hybrid T cells was I-As restricted. Inhibition of Th-1 cell priming using anti-I-As antibody administered with the priming Ag in vivo revealed Th-2-like activity, in that the CD4 T cells now secreted IL-5 and not IFN-gamma and induced antibody formation. Additional studies indicated that anti-IFN-gamma treatment in vivo also revealed Th-2 cells, suggesting that I-As-restricted CD4 T cells producing or controlling the production of IFN-gamma suppress Th-2 priming.
Regulated expression of a receptor for hyaluronan-mediated motility on human thymocytes and T cells.
Authors: Pilarski L M , Miszta H , Turley E A 
Published: December 2022

Abstract
A receptor for hyaluronan-mediated motility (RHAMM) has been shown to promote cell locomotion. Among human T lineage lymphocytes, RHAMM is expressed only on a subset of thymocytes, being absent on mature peripheral T cells from blood, spleen, and lymph node. Among thymocytes, RHAMM is selectively expressed on a subset of CD3+ CD45RA+R0+ cells, and functions in motility as shown by the ability of anti-RHAMM to reduce the speed of thymocyte locomotion from 11 microns/minute to 3 microns/min. Although freshly isolated multi-negative (MN) thymocytes (CD3-4-8-19-) lack RHAMM, its expression is induced on day 3 of culture in a variety of conditions that support differentiation, as assessed by acquisition of CD3. When MN thymocytes are cultured on plates coated with fibronectin, expression of RHAMM is prolonged, but on uncoated surfaces, its expression is transient and lost by day 7 of culture with PHA or IL-2. Culture of MN thymocytes on thymic epithelial layers, with or without IL-2, resulted in a lack of RHAMM expression. Because in the absence of epithelial cells, RHAMM is expressed, the effect appears to be one of inhibition. Although expression of RHAMM by MN thymocytes cultured with IL-2 on uncoated surfaces is transient, addition of cyclosporin A resulted in prolonged expression. These observations are consistent with the view that cyclosporin A inactivates a RHAMM-directed inhibitory mechanism. Mature peripheral blood T cells transiently express RHAMM upon culture with PHA, PMA, or IL-2. T cells that expressed RHAMM after culture with PMA alone lacked RHAMM when stimulated by mitogenic CD2 antibodies with or without CD28 antibody, indicating inhibition of RHAMM expression. Thus expression of RHAMM is regulated by a RHAMM-directed inhibitory mechanism induced by stimulation through CD2/CD28. A similar mechanism may operate in thymocyte/epithelial cell cultures. These results suggest the inhibition of RHAMM during early, presumably sessile, thymic progenitor development, followed by its induction during developmental stages when locomotion is required. The apparently strong negative regulatory control over RHAMM expression by microenvironmental factors and by known thymic and T cell signaling molecules supports this view.
Role of TNF-alpha in CD8+ cytotoxic T lymphocyte-mediated lysis.
Authors: Ratner A , Clark W R 
Published: December 2022

Abstract
The possibility that lymphokines such as TNF-alpha produced by CD8+ CTL are responsible for acute (short term) target cell damage induced by CTL has been debated for many years. However, the slow kinetics of TNF-induced target cell death stands in sharp contrast to the rapid target cell lysis mediated by CTL. We find that cloned CD8+ CTL activated through their TCR secrete TNF-alpha. On the other hand, our cloned CTL also have a membrane form of TNF-alpha, and they kill TNF-alpha-sensitive target cells not recognized through the TCR in a slow (18-h) lytic reaction using this surface-associated TNF-alpha. There is no secreted TNF-alpha release during this interaction. Cyclosporin A and protein synthesis inhibitors block TNF-alpha secretion, but have no effect on slow lysis mediated by the CTL. On the other hand, TNF-alpha-resistant variants are greatly resistant to slow lysis, and antibodies to TNF-alpha strongly inhibit this slow lysis. Thus, although secreted TNF-alpha does not seem to be the mechanism behind slow lysis, some form of TNF-alpha, most likely the membrane-associated form, must be involved. Not only does surface TNF-alpha appear to be biologically active in these CTL, but its expression is enhanced severalfold upon activation of the CTL through the TCR. This may be important in vivo, where surface TNF-alpha could preserve the localized nature of cytolysis and endow a CTL with an additional, albeit slower, mechanism of cell lysis. Finally, we find that although activated CTL clearly use the membrane form of TNF-alpha in slow lysis, they appear not to use TNF-alpha, in any form, during acute lysis, even under conditions in which degranulation and perforin assembly are blocked.
Endotoxin-induced expression of endotoxin binding sites on murine bone marrow cells.
Authors: Girard R , Pedron T , Chaby R 
Published: December 2022

Abstract
A variety of binding sites for endotoxin (LPS) have been identified on leukocytes. However, the sequence of expression of these receptors, and their interrelations, are poorly understood. In this report, we show that in LPS-responsive hosts, interaction of nanomolar concentrations of LPS with bone marrow cells induces the expression of new specific LPS-binding sites. Cells from LPS-nonresponsive (C3H/HeJ) mice do not express these receptors after LPS treatment. Experimental differences in the conditions allowing the induction and the detection of these binding sites (influence of Leishmania lipophosphoglycan, role of serum), support the hypothesis that interaction of LPS with primary receptors on bone marrow cells triggers the expression of secondary LPS receptors, and that the two types of receptors have distinct fine specificities.