bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms of dichotomous action of IL-2-Pseudomonas exotoxin 40 (IL-2-PE40) on cell-mediated and humoral immune response.
Authors: Volk H D , Müller S , Yarkoni S , Diamantstein T , Lorberboum-Galski H 
Published: December 2022

Abstract
IL-2-PE40 is a chimeric protein composed of human IL-2 genetically fused to the amino terminus of a modified form of Pseudomonas exotoxin lacking its cell recognition domain. The immunosuppressive efficacy of IL-2-PE40 was demonstrated in several experimental murine transplant and autoimmune models. However, some observations suggested that IL-2-PE40 could not inhibit the humoral response. In this report, we describe the dichotomous effects of IL-2-PE40 on humoral and cell-mediated immune response in a simple, well characterized in vivo model. Although IL-2-PE40 inhibited the cell-mediated delayed type hypersensitivity reaction to SRBC, it increased the humoral immune response to the same Ag. To understand the mechanism of dichotomous action of IL-2-PE40 on the immune response, IL-2R-bearing T cells were treated with IL-2-PE40 in vitro and the cytokine expression was studied at mRNA and protein level. Similar to IL-2, IL-2-PE40 promoted the expression of T helper 1-like (IFN-gamma) as well as T helper 2-like (IL-4, IL-10) cytokines. These in vitro studies show that IL-2-PE40 can induce signal transduction in activated T cells through the IL-2R before exerting its cytotoxic effect. In contrast to DTH reaction, humoral immune response requires T cell help only for a limited period. Therefore, the short-term stimulation of T helper cells by IL-2-PE40 may be sufficient in vivo to mediate a B cell response in the local environment, whereas the DTH reaction and other cell-mediated immune responses are inhibited by the toxin moiety of the chimeric protein.
Genomic structure, characterization, and identification of the promoter of the human IL-8 receptor A gene.
Authors: Sprenger H , Lloyd A R , Meyer R G , Johnston J A , Kelvin D J 
Published: December 2022

Abstract
Two unique but homologous receptors for the neutrophil chemoattractant, IL-8 have been cloned (designated IL-8RA and IL-8RB), each of which binds IL-8 with high affinity. IL-8RA mRNA expression was found to be regulated by granulocyte-CSF and LPS. In an attempt to understand the tissue-specific expression and to identify transcriptional regulatory elements, we have cloned, sequenced, and characterized the human IL-8RA gene. A lambda-DASH clone encoding the entire human IL-8RA gene was isolated by screening a genomic library with a PCR-generated cDNA. After mapping, subcloning, and sequencing several restriction fragments, a 9.2-kb continuous DNA sequence was obtained. As the sizes of the published cDNA (1.9 kb) and the mRNA determined by Northern blot analysis (2.1 kb) were not in agreement, a full-length cDNA was cloned by using a modified rapid amplification of cDNA ends technique. We identified a 5'-untranslated region of 119 bp. After comparison with the genomic sequence, we found the gene consisted of two exons interrupted by an intron of 1.7 kb. A 1050-bp ORF was encoded entirely in the second exon together with a 834-bp 3'-untranslated region. The immediate GC-rich 5'-flanking region upstream of exon 1 could serve as a constitutively active promoter in chloramphenicol-acetyl-transferase-expression assays. Expression analysis of additional upstream regions suggested the presence of silencer elements between positions -841 and -280. In conclusion, cloning a full-length cDNA permitted us to clone the human IL-8RA gene, identify the genomic structure, and characterize the promoter region.
Lack of expression of the tryptase mouse mast cell protease 7 in mast cells of the C57BL/6J mouse.
Authors: Ghildyal N , Friend D S , Freelund R , Austen K F , McNeil H P , Schiller V , Stevens R L 
Published: December 2022

Abstract
Although the steady-state level of the mouse mast cell protease (mMCP) 7 transcript is below detection in the serosal and mucosal mast cells of the BALB/cJ mouse, the IL-3-dependent, bone marrow-derived mast cells (mBMMC) of this strain and four other strains contain a high steady-state level of the mMCP-7 transcript. To further analyze the expression of this mast cell tryptase, a mMCP-7-specific IgG was obtained by immunizing a rabbit with a 19-residue synthetic peptide that corresponds to its unique amino acid sequence at residues 160 to 178 (anti-mMCP-7(160-178). In a SDS-PAGE/immunoblot analysis of lysates of BALB/cJ mBMMC, anti-mMCP-7(160-178) IgG recognized a diffuse 31- to 36-kDa protein, which shifted to a sharp 27-kDa protein after treatment with N-glycanase. As assessed immunohistochemically, mMCP-7 protein is present not only in the secretory granules of BALB/cJ mBMMC, but also in the ear mast cells of this strain. In contrast, the ear mast cells of the C57BL/6J mouse do not contain detectable levels of mMCP-7 protein, although the ear mast cells of both mouse strains contain mMCP-5 protein. Because mMCP-7 mRNA and protein also were not detected in mBMMC from the C57BL/6J mouse, the failure of the ear mast cells of this strain to express mMCP-7 is most likely a consequence of an intrinsic abnormality in the mast cell-committed progenitor cells themselves, or in the bone marrow microenvironment that induces its mast cell progenitor cells to express this tryptase.
Endotoxin-induced early gene expression in C3H/HeJ (Lpsd) macrophages.
Authors: Manthey C L , Perera P Y , Henricson B E , Hamilton T A , Qureshi N , Vogel S N 
Published: December 2022

Abstract
C3H/HeJ (Lpsd) macrophages have been shown to respond to certain LPSs, especially from rough mutant bacteria. C3H/OuJ (Lpsn) macrophages are induced by wild-type LPS, rough LPS, or lipid A to express many genes, including TNF-alpha, TNFR-2, IL-1 beta, IP-10, D3, and D8. C3H/HeJ macrophages failed to induce any of these genes when cultured with wild-type LPS or synthetic lipid A, even when pretreated with IFN-gamma. However, rough mutant Salmonella minnesota Ra, Rc, and Rd LPS, and Escherichia coli D31 m3 Rd LPS induced Lpsd macrophages to express a subset of genes within the gene panel. Because bioactive preparations contained trace quantities of endotoxin protein(s), a deoxycholate-modified, phenol-water method was used to repurify rough LPS into an aqueous phase, and extract endotoxin proteins into a phenol phase. Repurified LPS failed to stimulate Lpsd macrophages; however, phenol fractions were approximately 10% as potent in Lpsd macrophages as crude rough LPS. Full potency was restored in C3H/HeJ macrophages when aqueous phase LPS and phenol-phase proteins were co-precipitated, suggesting that LPS and endotoxin proteins interact synergistically. Endotoxin proteins alone induced TNF-alpha, TNFR-2, and IL-1 beta, but not IP-10, D3, and D8 genes in both Lpsd and Lpsn macrophages. Tyrosine phosphorylation of three 41- to 47-kDa proteins was induced by endotoxin proteins, but not by LPS, in Lpsd macrophages. Thus, endotoxin proteins seem to activate a signaling pathway(s) that converges (distal to the Lps gene product) with a subset of LPS-signaling pathways.
Studies of the mechanism of cytolysis by HIV-1-specific CD4+ human CTL clones induced by candidate AIDS vaccines.
Authors: Miskovsky E P , Liu A Y , Pavlat W , Viveen R , Stanhope P E , Finzi D , Fox W M , Hruban R H , Podack E R , Siliciano R F 
Published: December 2022

Abstract
Vaccine-induced, virus-specific CTLs may rapidly eliminate the host cells that first become infected after virus exposure, thereby preventing disseminated infection. Thus, there is much interest in the ability of candidate AIDS vaccines to elicit CTLs. All HIV-1 envelope (env) protein-based vaccines tested to date in seronegative humans induce CTLs from the CD4+ subset. Because the mechanism of cytolysis by CD4+ CTLs is controversial, a detailed study of the cytolytic reactions mediated by vaccine-induced, HIV-1-specific human CD4+ CTL clones was conducted. CD4+ CTL clones induced rapid destruction of Ag-pulsed target cells. Lysis was readily detectable within 15 min. Lysis was not a result of syncytium formation between CD4+ effector cells and env-expressing targets. Target cell destruction was not dependent upon de novo RNA or protein synthesis in either the effector or the target cell. Expression of perforin mRNA was detected by Northern blotting and reverse-transcriptase-PCR in CD4+ CTL clones but not in autologous B lymphoblastoid cell lines. Immunohistochemical studies demonstrated perforin protein in cytoplasmic granules in CD4+ CTL clones. Lysis by CD4+ CTLs was strictly dependent upon extracellular Ca2+ and was highly specific, with no lysis of innocent bystander cells. DNA fragmentation was detectable in target cells, but did not precede 51Cr release. Taken together, these results provide a dramatically different view of cytolysis by human CD4+ CTLs. Target cells are lysed by a rapid and efficient mechanism that involves a preformed mediator and that is functionally similar to the mechanism used by CD8+ CTLs.
Fetal skin-derived MHC class I+, MHC class II- dendritic cells stimulate MHC class I-restricted responses of unprimed CD8+ T cells.
Authors: Elbe A , Schleischitz S , Strunk D , Stingl G 
Published: December 2022

Abstract
Dendritic cells are very potent, if not the most effective, stimulator cells for the induction of primary T cell immune responses. We have established, from murine fetal skin, growth factor-dependent cell lines with a pronounced dendritic shape and a phenotype similar to that of fetal Langerhans cells (i.e., MHC class I+/II). Functionally, these lines induce a vigorous proliferation of allogeneic, but not syngeneic, CD8+ lymphocytes. T cell blasts thus generated are capable of lysing various target cells in an MHC class I-restricted fashion. Our contention that this skin cell-induced MHC class I-restricted activation of CD8+ lymphocytes occurs in the absence of CD4+ T cells is based on 1) the lack of FACS-detectable CD4+ T cells in the purified CD8+ T cell population, 2) the lack of reactivity of purified CD4+ T cells to MHC class I-disparate fetal skin cell lines, and 3) the inhibition of the fetal skin cell-induced MLR by anti-CD8/MHC class I, but not anti-CD4/MHC class II, mAb. Skin cell-induced activation of unprimed CD8+ T cells was found to be critically dependent on physical contact between stimulator and responder cells and the expression of the costimulatory molecule B7 on fetal skin cell lines. Lines described in this study may represent a powerful tool for studying the molecular events occurring in the induction of MHC class I-restricted primary immune responses, understanding their pathophysiologic role, and perhaps may prove useful for vaccination purposes against selected pathogens.
Recognition of trophoblasts by gamma delta T cells.
Authors: Heyborne K , Fu Y X , Nelson A , Farr A , O'Brien R , Born W 
Published: December 2022

Abstract
The juxtaposition of maternal and fetal tissues in the hemochorial placenta has led to speculation that maternal recognition of fetal Ags present on trophoblasts might play an important role in reproductive biology. We report here for the first time such recognition of trophoblasts by T lymphocyte hybridomas representative of certain cells present in the maternal decidua. Trophoblast recognition is TCR dependent and is mediated by members of the V gamma 1+ subset of gamma delta T lymphocytes, a population that we previously have shown to be associated with heat shock protein-60 reactivity. Recognition occurred in experiments in which trophoblast clones or freshly prepared trophoblasts were used and requires cell-cell interaction. Although the maternal-fetal immune relationship typically has been cast in terms of an allograft, the T cell recognition of trophoblasts as described herein is not MHC-restricted, inasmuch as freshly prepared trophoblasts from beta 2-microglobulin-deficient mice were found to be stimulatory. Furthermore, the trophoblast ligand that mediates this recognition is probably a conserved mammalian molecule, because a human trophoblast cell line is also stimulatory. Our findings suggest a novel form of T cell recognition, and may provide an enhanced understanding of the maternal-fetal immune relationship.
Activation and proliferation of follicular dendritic cell-like cells by activated T lymphocytes.
Authors: Kim H S , Zhang X , Choi Y S 
Published: December 2022

Abstract
Follicular dendritic cell (FDC)-like cell lines (HK cells) from human tonsils were established to investigate the functional role of FDC in the germinal centers of lymphoid follicles. Although HK cells exhibited CD21, CD23, DRC-1, CD40, VCAM-1, ICAM-1, and HJ2 that were expressed on human tonsilar FDC at early stages of establishment, they lost DRC-1, CD21, and CD23 within 3 days of culture. Morphologic and functional characterization studies suggest that HK cells are quite distinct from fibroblasts. The growth requirement of HK cells is different from the previously reported FDC-like cell lines. Functionally, these cells bound B cells but not T cells, and supported B cell proliferation. The culture supernatants of HK cells had costimulatory activity on the proliferation of anti-mu- or anti-CD40-activated B cells, and the activity dramatically increased after 12-O-tetradecanoylphorbol 13-acetate stimulation. Interestingly, anti-CD3 Ab activated T cell bound to HK cells, inducing the phenotypic changes and the growth of HK cells. The T-HK cell interactions not only involve the well known adhesion ligand/receptor pathways (VLA-4/VCAM-1 and LFA-1/ICAM-1), but also involve CD40-CD40 ligand as shown by inhibitory effect of soluble CD40 (CD40.Fc). The cellular interactions between T and HK cells and cytokine production suggest that activated T cells not only stimulate resting B cells directly, but also support B cell maturation indirectly by stimulating the development of FDC. Hence HK cells may be useful in identifying the surface molecules and cytokines of FDC involved in the GC formation.
Endotoxin and lipid A stimulate proliferation of human T cells in the presence of autologous monocytes.
Authors: Mattern T , Thanhäuser A , Reiling N , Toellner K M , Duchrow M , Kusumoto S , Rietschel E T , Ernst M , Brade H , Flad H D 
Published: December 2022

Abstract
In this paper we describe a new activity of LPS and partial structures: the induction of DNA synthesis and lymphokine production of human T lymphocytes. The LPS-induced T cell proliferation is dose dependent and requires 100 to 10,000 ng/ml of LPS or synthetic lipid A (compound 506) for optimal stimulation. In contrast, the synthetic lipid A precursor Ia (compound 406) is not active but rather antagonizes LPS-induced proliferation. The proliferation is accompanied by the expression of mRNA for the Th1 cell-derived lymphokines IFN-gamma and IL-2, but not for the Th2 lymphokines IL-4, IL-5, or IL-10. Highly enriched T lymphocyte preparations with less than 0.1% monocytes are not stimulated by LPS, showing that monocytes are required for T cell proliferation. Reconstitution experiments show that only monocytes, but not B lymphocytes, are able to support induction of DNA synthesis. Separating LPS-stimulated monocytes from T lymphocytes by a membrane, permeable for cytokines but not for cells, abolishes T cell proliferation. Fixation of monocytes with paraformaldehyde also abrogates their accessory function for T cells. If the monocytes are preincubated for 2 h at 37 degrees C with LPS and then washed, they still are able to induce T cell proliferation in the absence of additional LPS. Our results indicate that human T cells respond in a monocyte-supported manner to LPS exposure by proliferation and lymphokine production. We hypothesize that this reactivity of T lymphocytes to LPS may be of clinical relevance.
MHC control of the naive TCR alpha-chain repertoire.
Authors: Merkenschlager M , Benoist C , Mathis D 
Published: December 2022

Abstract
The naive T cell repertoire is shaped by interactions between developing thymocytes and thymic stroma. Both positive and negative selection involve the clonotypic TCR and MHC molecules carrying self-peptides. Except for the MHC-dependent effects of superantigens on TCR V beta usage; there has been little evidence that the TCR structure of naive T cell varies with the selecting MHC products. To examine this point from another angle, in particular the TCR alpha-chain, we have analyzed alpha-chain usage in a system in which the vast majority of T cells express a transgene-encoded TCR beta-chain, compatible with efficient T cell development on a wide range of MHC haplotypes. Endogenous TCR alpha-chains are thus selected without interference from the forces known to act on TCR-beta, permitting us to observe MHC influences on alpha-chain selection. We have used V alpha-specific Abs to quantitate alpha-chain usage in MHC congenic, MHC recombinant, and MHC transgenic mice and provide evidence that the naive TCR alpha-chain repertoire is under MHC control. The data demonstrate a direct impact of known MHC class II products but also reflect more complex influences, apparently involving other gene products within the MHC. Sequence analysis of differentially selected TCR suggests that selection acts on the entire alpha-chain, including V alpha, J alpha, and the junctional region.
Transgene CD23 expression on lymphoid cells modulates IgE and IgG1 responses.
Authors: Texido G , Eibel H , Le Gros G , van der Putten H 
Published: December 2022

Abstract
Transmembrane (m) and soluble (s) forms of CD23 perform activities related to various immune functions. Abnormal expression patterns of CD23 on lymphoid cells have been associated with certain pathologic conditions. To explore the effects of CD23 when it is overexpressed, on lymphoid cell development and immune function in vivo, transgenic mice were generated. These mice overexpressed either mCD23 or a 38-kDa molecular form of sCD23. Transgene expression under the control of Thy-1-regulatory sequences and the mouse Ig heavy chain enhancer (E mu) was prominent in thymus, spleen, bone marrow, and lymph nodes. Cells that expressed the transgenes included most thymocytes, peripheral CD4+ and CD8+ T cells, IgM+/highIgD-/low immature B cells, and IgMlowIgDhigh mature B cells. To resolve the expression pattern in the B cell lineage unambiguously, we used mice that carried a transgene and a disrupted endogenous CD23 gene simultaneously. Neither mCD23 nor sCD23 overexpression caused significant alterations in lymphoid cell maturation. In addition, basal serum levels of IgE and IgG1 proved to be normal. In three different experimental immune response paradigms, mCD23 transgenic, but not sCD23 and nontransgenic mice proved to be impaired in increasing serum levels of polyclonal IgE up to expected levels. In addition, mCD23 transgenic mice showed below normal increases of serum IgG1 levels in two of the three immune responses. In the presence of activated T cells and appropriate lymphokines, B cells from mCD23 mice secreted normal amounts of IgE and IgG1 in vitro, which suggests that there was no serious impairment of the T-B cell contact required for Ig production. In addition, there is no evidence for a significant role of mCD23 in IgE clearance. Therefore, we discuss alternative mechanisms by which mCD23+ B and/or T cells influence Ig production.
Trimeric structure of human proliferating cell nuclear antigen. Implications for enzymatic function and autoantibody recognition.
Authors: Brand S R , Bernstein R M , Mathews M B 
Published: December 2022

Abstract
The proliferating cell nuclear Ag (PCNA) is a DNA replication factor postulated to function as a sliding clamp around DNA. PCNA is also a target for autoimmunity in systemic lupus erythematosus. The autoantigenicity of PCNA is highly conformation-dependent, and reaction with most anti-PCNA sera requires a nearly full-length PCNA molecule. Here we describe the use of gel filtration and glycerol gradient sedimentation to analyze the native structure and size of PCNA. PCNA from three sources was studied (PCNA from HeLa cells, PCNA purified after its overexpression in bacteria, and PCNA produced in the wheat germ cell-free translation system) as well as mutant forms of PCNA translated in vitro. In each case, full-length PCNA behaved as a trimer. Analysis of mutant proteins revealed a correlation between the trimeric form and binding to the common type of human anti-PCNA autoantibody, suggesting that the Abs are specific for the active form of the protein. These findings are consistent with the idea that autoantibodies are generated as a response to native Ag and provide experimental support for the hypothesis that PCNA serves its processive function in DNA replication as a trimeric ring structure.
Characterization of peptide binding to the murine MHC class I H-2Kk molecule. Sequencing of the bound peptides and direct binding of synthetic peptides to isolated class I molecules.
Authors: Brown E L , Wooters J L , Ferenz C R , O'Brien C M , Hewick R M , Herrmann S H 
Published: December 2022

Abstract
Peptides that are bound by the murine class I MHC molecule H-2Kk have been isolated and sequenced. The initial step in the fractionation was affinity column isolation of the peptide-class I complex from either RDM-4 or x5563 tumor cell lines. Acid denaturation of the complex followed by HPLC fractionation of the peptides allowed us to sequence individual peptides, as well as pools of peptides. To date, a total of 10 sequences have been characterized, and all were 8 mers. The sequences were variable except for glutamic acid in the second position (P2) and isoleucine in the eighth (P8), which were highly conserved. To further study peptide binding to H-2Kk, a competitive binding assay consisting of the immobilized histocompatibility protein and a biotinylated self-peptide for signal generation was developed. A complete set of single-alanine variants for this one self-peptide was tested in the assay, demonstrating that substitution at P2 and P8 markedly decreased the affinity for the class I molecule; alanine at position 3 had an intermediate effect on binding. A comparison of the identified self-peptides for binding to H-2Kk showed that they differed in affinity by more than one order of magnitude. Influenza virus nucleoprotein peptide, SDY EGR LI, associated with the plate-bound class I molecule, and the resulting MHC-peptide complex could trigger TNF release by influenza-primed CTLs. This result demonstrated the functional activity of the plate-bound H-2Kk-peptide complex.
Identification of a novel HLA-B27 subtype by restriction analysis of a cytotoxic gamma delta T cell clone.
Authors: Del Porto P , D'Amato M , Fiorillo M T , Tuosto L , Piccolella E , Sorrentino R 
Published: December 2022

Abstract
Seven HLA-B27 alleles are known, which share the same allospecificity, but differ by one to six amino acid substitutions. Herein, we describe a novel HLA-B27 allele, provisionally named B27-ci, which is expressed by an individual from whom a B27-restricted gamma delta T cell clone has been derived. This clone recognizes B cell lines from the proband and all of the other B27-positive members of the family, but does not lyse B cell lines that express other HLA-B27 alleles. The amino acid sequence deduced from three B27-ci cDNA clones was found to differ from the B*2705 sequence by one amino acid substitution (Asp to His) in position 116 of the alpha 2 domain. This position has been shown to lie in the floor of the F pocket, where it plays a key role in determining the nature of the amino acid side chain that will fit into this pocket. Moreover, the fact that the clone described here possesses a TCR-gamma delta indicates that this subset of cells not only can be HLA-restricted, but also can finely discriminate among classical class I molecules.