bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gamma delta T cells of human early pregnancy decidua: evidence for local proliferation, phenotypic heterogeneity, and extrathymic differentiation.
Authors: Mincheva-Nilsson L , Kling M , Hammarström S , Nagaeva O , Sundqvist K G , Hammarström M L , Baranov V 
Published: December 2022

Abstract
The uterine mucosa in pregnancy, the decidua, allows placenta formation and survival of the fetus despite the fact that it is semiallogeneic. Decidua contains large numbers of lymphocytes, of which CD56+ cells dominate, followed by T cells expressing either alpha beta or gamma delta TCR. We have investigated the developmental relationship between the CD56- and TCR gamma delta-expressing cells in early pregnancy decidua using dual labeling immunoelectron microscopy, immunoflow cytometry, and cell fractionation. Lymphocyte subpopulations were, in addition, analyzed for expression of the cytokine receptor for IL-7 and c-kit and for mRNA expression of recombinase-activating genes 1 and 2. Four different cell populations could be distinguished: CD56+bright, CD56+dim/TCR gamma delta+low, CD56+dim/TCR gamma delta+high, and TCR gamma delta+low. Recombinase-activating genes 1 and 2 were expressed in the CD56+bright cells and to a limited degree in CD56+dim/TCR gamma delta+low cells. c-kit was preferentially expressed on the CD56+bright cells, while IL-7R was preferentially expressed on CD56+dim/TCR gamma delta+low and CD56+dim/TCR gamma delta+high cells. The CD56+dim TCR gamma delta+low and CD56+dim/TCR gamma delta+high cells displayed the characteristic morphology of large granular lymphocytes, while single positive TCR gamma delta+low cells were usually smaller and did not contain cytoplasmic granules. The gamma delta 1 gene segment was almost exclusively used in the TCR. Gamma delta T cells in mitosis were seen. We suggest that human early pregnancy decidua is a transient site for extrathymic maturation and that the progenitors of TCR gamma delta+ cells are bone marrow-derived immature cells expressing the CD56 (neural cell adhesion molecule) homing receptor.
Cooperation of binding sites for STAT6 and NF kappa B/rel in the IL-4-induced up-regulation of the human IgE germline promoter.
Authors: Messner B , Stütz A M , Albrecht B , Peiritsch S , Woisetschläger M 
Published: December 2022

Abstract
Ig heavy chain class switching is directed by cytokines inducing transcription from unrearranged CH genes. Subsequently, such primed cells can undergo switch recombination to express the selected new isotype. In the case of IgE class switching, IL-4 activates the IgE germline promoter by inducing the interaction of the transcription factor STAT6 (IL-4STAT) with a responsive DNA element in the proximal region of the promoter. This study describes the characterization of two additional cis-acting elements that interact with members of the NF kappa B/rel transcription factor family in an IL-4-independent fashion. Electrophoretic mobility shift assays show that the nucleoprotein complex formed on the upstream site (NF kappa B1) contains the classical p50/p65 heterodimer. The complex on the proximal site (NF kappa B2) appears to be composed of p50 and relB. IgE germline promoter reporter gene constructs carrying point mutations in the NF kappa B2 site were largely unresponsive to IL-4 stimulation in transient transfection experiments, while plasmids with similar mutations in the NF kappa B1 site responded to cytokine stimulation better than the wild-type promoter. The NF kappa B2 effect was dependent on the presence of the STAT6 binding site, demonstrating that the NF kappa B2 motif is necessary but not sufficient for mediating cytokine up-regulation. In addition, the combination of a NF kappa B/rel binding site and the STAT6 response element conferred IL-4 inducibility to a heterologous minimal promoter, while the individual sites had no effect. The available data suggest that the NF kappa B2 nucleoprotein complex may cooperate with DNA-bound STAT6 to achieve IL-4-dependent activation of the human IgE germline gene.
Abbreviated junctional sequences impoverish antibody diversity in urodele amphibians.
Authors: Patel H M , Hsu E 
Published: December 2022

Abstract
Of the six complementarity-determining regions (CDR) forming the structure of the Ab combining site, CDR3 of heavy chain is the most variable in length and sequence. Diversity of this loop is determined by the number of gene segments involved, extent of addition to or deletion from the joining genes, and imprecision of the site of recombination. In neonatal mice and Xenopus tadpoles, the last two factors occur less frequently than in adults, which in tadpoles result in low affinity Ab responses that do not mature. In contrast, adult urodele amphibians make larval-like responses and are notorious for lifelong poor immunocompetence. The mechanism for this is not known, and in this study we cloned germline VH genes from the axolotl and obtained rearrangements to these VH gene segments by reverse-transcriptase PCR. These sequences were analyzed for heavy chain junctional diversity and found to be even less variable than that in newborn mouse or Xenopus tadpoles, although for different reasons. Only 29% of the CDR3 loop in the axolotl consisted of somatically generated sequences, compared with 44% in tadpole, 39% in newborn mice, and 57% in both adult mice and Xenopus. This distinguishing feature of axolotl CDR3 results not only from shorter junctional sequences, but also unusually extensive integration of germline JH sequence. As the CDR3 loop is the most important portion of the Ig sequence for determining Ab combining site diversity, our data provide the molecular basis for a contributing factor in the deficient urodele amphibian Ab responses.
Induction of protective CTL responses against the Plasmodium yoelii circumsporozoite protein by immunization with peptides.
Authors: Franke E D , Corradin G , Hoffman S L 
Published: December 2022

Abstract
To determine the optimum combination, concentration, and formulation of synthetic peptides and adjuvants to induce protective CTL responses against the Plasmodium yoelii circumsporozoite protein (PyCSP), BALB/c mice were immunized with linear and multiple antigen peptides (MAP) including PyCSP CTL and Th epitopes in Montanide's ISA51, Lipofectin, and Lipofectamine. An H-2K(d)-restricted PyCSP CTL epitope, SYVPSAEQI (amino acids (aa) 280-288), recognized by protective CTL clones, was included in the following peptides: a 9-aa linear peptide (SYVPSAEQI; PyCSP9), a 20-aa linear peptide (aa 280-299; SYVPSAEQILEFVKQISSL; PyCSP20), a MAP containing four branches of PyCSP20 (MAP(280-299)), and a linear peptide and a MAP(MAP(280-299)p2p30) in which PyCSP20 was colinearly synthesized with two universal Th epitopes from tetanus toxin (p2p30). A MAP containing the PyCSP Th epitope (aa 57-70; KIYNRNIVNRLLGD) was included in some experiments. The highest specific lytic activity against peptide-pulsed target cells was obtained with splenocytes from mice immunized with three doses at 3-wk intervals of MAP(280-299)p2p30 in Lipofectin or Lipofectamine. Forty percent of the mice immunized with MAP(280-299)p2p30 and Lipofectin were protected against sporozoite challenge. Immunization with CTL and Th epitopes co-linearly synthesized in a MAP induced significantly better CTL than did immunization with the same sequence as a linear peptide, or immunization with a mixture of two individual MAPs, one with the CTL epitope and the second with the Th epitope.
Human tryptase fibrinogenolysis is optimal at acidic pH and generates anticoagulant fragments in the presence of the anti-tryptase monoclonal antibody B12.
Authors: Ren S , Lawson A E , Carr M , Baumgarten C M , Schwartz L B 
Published: December 2022

Abstract
Human tryptase is uniquely regulated by its association with heparin and resists inhibition by biological protease inhibitors. The effects of pH and B12, an IgG anti-tryptase mAb, on cleavage of the synthetic substrate tosyl-Gly-Pro-Lys-p-nitroanilide and of the biological substrate fibrinogen by tryptase were examined. Tosyl-Gly-Pro-Lys-pnitroanilide cleavage was optimal at neutral pH and was inhibited by the B12 mAb at acidic and neutral pH values. At pH 7.5, inhibition was reversible and noncompetitive. In contrast, the optimal pH for tryptase to cleave fibrinogen was acidic. B12 dramatically enhanced the rate and extent that tryptase cleaved all three fibrinogen subunits at pH 6.0 to 6.5, but inhibited these activities at neutral pH. Major fibrinogen cleavage fragments generated at acidic pH by the B12:tryptase complex were identical with those made by plasmin. Thus, at acid pH, tryptase alone destroyed the ability of fibrinogen to clot, while the B12:tryptase complex increased the rate of fibrinogenolysis and also generated the anticoagulant, fragment D. The acidic pH optimum for tryptase fibrinogenolysis may direct this activity to tissue sites of inflammation. A putative biological equivalent to B12 would limit tryptase fibrinogenolytic activity at sites of neutral pH, such as blood, but would augment activity at acidic sites.
HLA-Cw3 expression on porcine endothelial cells protects against xenogeneic cytotoxicity mediated by a subset of human NK cells.
Authors: Seebach J D , Comrack C , Germana S , LeGuern C , Sachs D H , DerSimonian H 
Published: December 2022

Abstract
There is increasing evidence that NK cells make an important contribution to human anti-porcine xenogeneic cytotoxicity. Most allogeneic as well as autologous normal cells are not susceptible to NK cell-mediated cytotoxicity because they express inhibitory molecules encoded within the MHC class I loci. The protective signal is delivered to NK cells through killer cell-inhibitory receptors expressing different MHC class I specificities. It has been proposed that xenogeneic target cells may be susceptible to NK cell-mediated lysis because their MHC class I molecules fail to be recognized by human killer cell-inhibitory receptors. To explore this hypothesis, we examined the effect of human MHC class I expression on porcine target cell lysis by human NK cells. An immortalized porcine bone marrow-derived endothelial cell line (2A2) was transfected with three different human MHC class I allelic genes (HLA-A2, -B27, or -Cw3). The cytotoxic activity of several GL183+ NK clones, which lysed untransfected porcine cells effectively, was substantially blocked by the presence of HLA-Cw3. In contrast, HLA-Cw3-positive cells were not protected against lysis by GL183- EB6+ NK clones. The expression of HLA-B27 or HLA-A2 molecules on pig target cells did not provide substantial protection from lysis by any of the NK clones tested. In addition to confirming the hypothetical basis of NK cell-mediated killing of xenogeneic targets, these results have practical implications as an approach to overcoming NK cell-mediated cytotoxicity, which may be an obstacle to pig-to-human xenotransplantation.
Nuclear localization of RelB is associated with effective antigen-presenting cell function.
Authors: Pettit A R , Quinn C , MacDonald K P , Cavanagh L L , Thomas G , Townsend W , Handel M , Thomas R 
Published: December 2022

Abstract
Dendritic cells (DC) are potent APCs that enter resting tissues as precursors and, after Ag exposure, differentiate and migrate to draining lymph nodes. The phenotype of RelB knockout mice implicates this member of the NF kappa B/Rel family in DC differentiation. To further elucidate the role of RelB in DC differentiation, mRNA, intracellular protein expression, and DNA binding activity of RelB were examined in immature and differentiated human DC, as well as other PB mononuclear cell populations. RelB protein and mRNA were detected constitutively in lymphocytes and in activated monocytes, differentiated DC, and monocyte-derived DC. Immunohistochemical staining demonstrated RelB within the differentiated lymph node interdigitating DC and follicular DC, but not undifferentiated DC in normal skin. Active nuclear RelB was detected by supershift assay only in differentiated DC derived from either PB precursors or monocytes and in activated B cells. These RelB+ APC were potent stimulators of the MLR. The data indicate that RelB expression is regulated both transcriptionally and post-translationally in myeloid cells. Within the nucleus, RelB may specifically transactivate genes that are critical for APC function.
IL-4 and IL-13 production in differentiated T helper type 2 cells is not IL-4 dependent.
Authors: Huang H , Hu-Li J , Chen H , Ben-Sasson S Z , Paul W E 
Published: December 2022

Abstract
CD4+ T cell differentiation into cells capable of producing IL-4 and IL-13 (Th2 cells) requires the presence of IL-4 and is STAT-6 dependent. Here we show that IL-4 is not required for IL-4 or IL-13 production by Th2 cells. Anti-IL-4 or anti-IL-4R Ab did not diminish IL-4 production by Th2 cells in response to TCR-mediated stimulation, nor did IL-4 enhance IL-4 production in response to stimulation of Th2 cells with limiting amounts of Ag. Th2 cells prepared from IL-4 knockout mice were capable of producing IL-13 mRNA in response to stimulation with immobilized anti-CD3. IL-4 did not increase IL-13 mRNA expression. Despite the failure of IL-4 to effect IL-4 production by primed Th2 cells, a STAT-6 binding element was demonstrated in the IL-4 promoter. The authenticity of this element was demonstrated by oligonucleotide competition, by supershifting with anti-STAT-6 Ab, and by IL-4-inducible effects on transcription of a reporter gene under the control of a multimerized element fused to an IL-4 minimal promoter. Nonetheless, an IL-4 promoter construct lacking the STAT-6 binding element was as effective as a construct containing this element in anti-CD3-induced reporter transcription. Thus, this element, if biologically active, must function at a step in T cell responsiveness distinct from the acute production of IL-4 by Th2 cells in response to Ag or anti-CD3.
Selective binding of shc-SH2 domain to tyrosine-phosphorylated zeta but not gamma-chain upon CD16 ligation on human NK cells.
Authors: Galandrini R , Palmieri G , Paolini R , Piccoli M , Frati L , Santoni A 
Published: December 2022

Abstract
Fc gamma RIII (CD16) is a hetero-oligomeric receptor composed of a ligand-binding alpha subunit associated with homo- or heterodimers of the TCR zeta- and Fc epsilon RI gamma-chains. We have previously demonstrated that CD16 ligation promotes complex formation between tyrosine-phosphorylated shc and Grb2, leading to activation of ras signaling pathway in human NK cells. Here we report that CD16 engagement induces rapid shc association with the tyrosine-phosphorylated receptor complex in human NK cells. In vitro binding studies demonstrate that this interaction is mediated by the shc-SH2 domain, and immunodepletion experiments indicate that the zeta- but not the gamma-chain has the capability to mediate this association. Jurkat cell clones expressing CD16-zeta or -gamma homodimers have been used to gain more information about the mechanism of shc/CD16 association. Our data show that, while engagement of both receptors induces tyrosine phosphorylation of shc and Grb2 recruitment, shc-SH2/receptor complex association is evident only in CD16-zeta but not in CD16-gamma transfectants. Overall, our data demonstrate that the adaptor protein shc can be recruited to the activated CD16 complex by interaction with tyrosine-phosphorylated zeta-chain in a SH2-dependent manner. These results also provide further support to the notion that zeta- and gamma-chains might couple to different biochemical pathways.
Signal transduction for melatonin in human lymphocytes: involvement of a pertussis toxin-sensitive G protein.
Authors: García-Pergañeda A , Pozo D , Guerrero J M , Calvo J R 
Published: December 2022

Abstract
We analyzed the melatonin signal transduction in human blood lymphocytes. High affinity melatonin receptors were identified by specific binding of 2-[125I]melatonin ([125I]MEL) to human lymphocyte membranes. Scatchard analysis of [125I]MEL binding revealed high affinity receptors, with a dissociation constant (Kd) of 0.45 nM and a binding capacity (Bmax) of 7.8 fmol/mg protein. Specific [125I]MEL binding was reduced markedly by GTP and its nonhydrolyzable analogues guanosine 5'-beta, gamma-imidotriphosphate (Gpp(NH)p) and guanosine 5'-O-(3-triphosphate) (GTP-gamma-S). Gpp(NH)p inhibited in a dose-dependent manner the [125I]MEL specifically bound to human lymphocyte membranes with a half-maximal inhibition (IC50) of 3.5 +/- 0.6 microM Gpp(NH)p. Treatment of human lymphocyte membranes with Gpp(NH)p increased the Kd value (Kd = 1.20 nM). Melatonin inhibited significantly and in a dose-dependent manner forskolin-stimulated cAMP production in intact human lymphocytes. Melatonin was able to stimulate diacylglycerol production in a dose-dependent manner in human lymphocyte membranes. Pertussis toxin treatment inhibited the specific [125I]MEL binding and blocked the ability of melatonin to both inhibit forskolin-stimulated cAMP production and stimulate diacylglycerol production. Pertussis toxin ADP-ribosylation and Western blot experiments demonstrated the protein expression of alpha i1/2, alpha i3/0, and beta gamma complexes of G proteins in human lymphocyte membranes. The results strongly suggest a pertussis toxin-sensitive melatonin signal transduction pathway in human lymphocytes that involves the inhibition of adenylyl cyclase and the stimulation of phospholipase C.
Calcium ionophore-treated peripheral blood monocytes and dendritic cells rapidly display characteristics of activated dendritic cells.
Authors: Czerniecki B J , Carter C , Rivoltini L , Koski G K , Kim H I , Weng D E , Roros J G , Hijazi Y M , Xu S , Rosenberg S A , Cohen P A 
Published: December 2022

Abstract
Human peripheral blood contains a small subpopulation of immature dendritic cells (iDC) distinguished from circulating monocytes by their low expression of CD14. We utilized leukapheresis and countercurrent centrifugal elutriation to obtain myeloid origin mononuclear cell (MOMC) fractions of monocytes and iDC for study. These subpopulations were ultrastructurally and immunophenotypically similar before culture. After a 20- to 96-h culture either alone, with recombinant human granulocyte-monocyte CSF, or with endotoxin, greater up-regulation of costimulatory molecule expression was observed among iDC than among monocytes, and only iDC expressed the activation molecule CD83. Treatment with rhIL-4 caused many MOMC to develop morphologic properties of dendritic cells within 96 h, but costimulatory molecule up-regulation and CD14 down-regulation were heterogeneous, and CD83 expression was infrequent. In contrast, calcium ionophore (CI) treatment induced rapid and consistent effects in MOMC from both healthy volunteers and cancer patients, including down-regulated CD14 expression, acquisition of dendritic cell morphologic properties, up-regulated MHC and costimulatory molecule expression, and de novo CD83 expression. Many such effects occurred within 20 h of treatment. CI treatment activated purified CD14+ monocytes and also enhanced the spontaneous activation of purified CD14-/dim iDC in culture. Unfractionated MOMC, purified monocytes, and purified iDC displayed equivalently enhanced T cell-sensitizing efficiency following CI treatment. CD4+ T cell sensitization to keyhole limpet hemocyanin and CD8+ T cell sensitization to MART-1 melanoma-associated peptide were achieved in a single culture stimulation. Therefore, circulating monocytes and iDC can be induced by CI to manifest properties of activated DC, providing large numbers of efficient, nontransformed autologous APC for T cell sensitization strategies.
Molecular basis of HLA-C recognition by p58 natural killer cell inhibitory receptors.
Authors: Kim J , Chwae Y J , Kim M Y , Choi I H , Park J H , Kim S J 
Published: December 2022

Abstract
NK cells express several inhibitory receptors that recognize class I MHC molecules expressed on target cells. The NK cell inhibitory receptors (KIRs) provide a key regulatory function for NK cells via specific interaction with MHC/peptide complexes, but the molecular details for recognition of class I MHC molecules by KIRs still remain unclear. Here we report cDNA cloning and expression of p58 KIRs and a p50 killer cell activatory receptor (KAR) from a Korean blood donor and demonstrate direct binding between recombinant soluble p58 KIRs and recombinant soluble HLA-C molecules. We identified three p58/p50 killer cell receptors (KAR-K1, KIR-K6, and KIR-K7), which are homologous to p50 cl-39, p58 47.11, and p58 cl-6, respectively. Native gel shift assay revealed that p58 KIR-K6 and KIR-K7 bind both HLA-Cw3 and HLA-Cw6 molecules, but p50 KAR-K1 binds neither of the HLA-C molecules. However, binding of HLA-C molecule by p58 KIR is affected by the antigenic peptide bound on the MHC molecule, suggesting that the p58 KIR binding to the HLA-C molecule may be dependent on the peptide. In addition, the binding interaction requires the presence of both p58 Ig domains, suggesting that the binding mode of HLA-C and p58 KIR may have some similarity to that of the neonatal Fc receptor and the Fc fragment of Ab and may be distinct from that of TCR and MHC.
Bovine IgG repertoire is dominated by a single diversified VH gene family.
Authors: Sinclair M C , Gilchrist J , Aitken R 
Published: December 2022

Abstract
Using methods based upon the PCR, we have analyzed sequences that encode the V domain of bovine Ig heavy chain. Pairwise comparison indicates that the heavy chain repertoire in cattle is dominated by a single VH gene family that is homologous to human VHII. The third complementarity-determining region (CDR3) is particularly variable and 60% of the sequences encode a CDR3 in excess of 21 amino acids. Southern blots, single-stranded conformation polymorphism analysis, and sequencing of segments from the germline indicate that the dominant VHII gene family is of small size, comprising as few as 10 unique members, and carries a very low level of diversity in CDRs 1 and 2. Comparison of germline VH sequences with those gathered from adult bovine splenic cDNA demonstrates a pattern of nucleotide substitution that is consistent with diversification through somatic hypermutation.