bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional evidence supporting the predicted role of KIR3DS1 in the host response to HIV: KIR3DS1 is an activating receptor expressed by human Natural Killer cells (52.5)
Authors: Pascal Veronique , Yamada Eriko , Martin Maureen P , Alter Galit , Altfeld Marcus , Carrington Mary , Anderson Stephen K , McVicar Daniel W 
Published: January 2023

Abstract
KIR3DL1 is a highly polymorphic inhibitory Killer cell Immunoglobulin-like (KIR) Receptor gene with at least 23 alleles described, including its activating counterpart KIR3DS1. Recently, the KIR3DS1 allele has been shown to slow progression to AIDS in HLABw4*80I individuals. However, due to the lack of specific anti-KIR3DS1 antibody, expression and function have never been reported. In a study of 64 donors, we demonstrate KIR3DS1 expression on a substantial subset of peripheral Natural Killer (NK) cells through its recognition by the monoclonal antibody Z27. The fidelity of this detection method was confirmed by analysis of KIR3DS1 transfectants and the identification of a novel KIR3DS1 null allele. Furthermore, we show that ligation of KIR3DS1 by Z27 leads to NK cell degranulation and interferon gamma secretion. Finally, we document the persistence of KIR3DS1+ NK cells in HIV1 viremic patients. In conclusion, the high frequency of KIR3DS1 expression, together with its ability to activate NK cells, and its maintenance during HIV-1 viremia support the epidemiological data suggesting a critical role for this receptor in controlling HIV-1 pathogenesis.
This project has been funded in part with Federal funds from the NCI and the NIH, under DHHS #N01-C0-12400.
Human vitamin D3-induced antimicrobial activity against Mycobacterium tuberculosis is dependent on cathelicidin (52.7)
Authors: Liu Philip T , Tang Dominic , Krutzik Stephan R , Modlin Robert L 
Published: January 2023

Abstract
One third of the world’s population is infected with Mycobacterium tuberculosis; however, little is known about human host defense mechanisms against this bacterium. We have previously demonstrated that activation of monocytes through TLR2/1 in the presence of sufficient vitamin D3 prohormone (25D3)-induces expression of the antimicrobial peptide cathelicidin, mediated through the conversion of 25D3 into the active hormone (1,25D3). Furthermore, these conditions lead to a VDR-dependent antimicrobial activity against M. tb.; but the role of cathelicidin is unclear. We hypothesize that cathelicidin plays a critical role in the 1,25D3-induced antimicrobial activity, and to address this we utilized the human monocytic cell line THP-1 and siRNA. First, we establish that stimulation of THP-1s with 1,25D3 results in cathelicidin mRNA and protein as well as antimicrobial activity against M. tb.. Using siRNAs specific for cathelicidin, we efficiently knocked down the expression of 1,25D3 induced cathelicidin at both the mRNA and protein levels, whereas a nonspecific siRNA control had no effect. Finally, 1,25D3-induced antimicrobial activity was completely ablated in the presence of siRNA against cathelicidin. Taken together, these data demonstrate that cathelicidin is critically for important host defense against M. tb., and may represent a novel avenue for TB treatment.
Pyrin levels in human monocytes and monocyte derived macrophages regulate IL-1β processing and release (52.8)
Authors: Seshadri Sudarshan , Duncan Michelle Diane , Hart Judith Mary , Gavrilin Mikhail A , Wewers Mark Damian 
Published: January 2023

Abstract
Macrophages and their precursors, monocytes, are key cells involved in the innate immune response. Although both monocytes and macrophages produce caspase-1, the key enzyme responsible for the processing of proIL-1β; macrophages are limited in their ability to process and release functional IL-1β. In this context, since mutations in the pyrin gene (MEFV) cause the inflammatory disorder familial Mediterranean fever, the protein pyrin is believed to regulate IL-1β. To determine whether variations in pyrin levels explain the difference between monocyte and macrophages in IL-1β processing and release, pyrin was studied in fresh human monocytes and monocyte derived macrophages. While fresh monocytes express pyrin protein and MEFV mRNA, monocyte derived macrophages have significantly less pyrin mRNA and protein. Since pyrin levels correlated with IL-1β processing, we asked whether pyrin may promote IL-1β processing and release. Pyrin induced IL-1β processing and release in a dose dependent fashion in HEK293 cells and pyrin overexpression in THP-1 cells confirmed the effect. Conversely, pyrin siRNA suppressed proIL-1β processing in both THP-1 cells and fresh human monocytes. In summary, pyrin expression and IL-1β processing and release is diminished upon the maturation of monocytes to macrophages. In the setting of endotoxin induced activation of mononuclear phagocytes, pyrin appears to augment IL-1β processing and release.
Supported by grant NIH-NHLBI-HL40871 to MDW
Cloning and characterization of equine Toll-like receptor 9 (52.9)
Authors: Zhang Yuwen , Davis Elizabeth G 
Published: January 2023

Abstract
Innate immunity relies on a series of germline-encoded pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs), to detect conserved microbial components. TLRs have recently emerged as key PRRs that detect microbial infection and trigger antimicrobial host defense responses. TLR9 is typically expressed intracellularly in immune cells such as dendritic cells. The molecular ligand for TLR9 is unmethylated bacterial CpG DNA. Following cell activation though TLR9, dendritic cells mature and secrete cytokines that initiate naïve T helper lymphocytes to polarize to a Th1 bias. Th1 directed activity is essential for host control of intracellular infection. We cloned and characterized equine TLR9. The deduced equine TLR9 protein has more than 80% homology to that of human, monkey, bovine, canine, feline, porcine, and sheep based on our sequence analysis. We found equine TLR9 expression in spleen, lymph nodes, and peripheral blood leukocytes based on quantitative real time PCR. Flow cytometric analysis revealed that equine TLR9 was expressed in CD4+ T, CD8+ T, and B lymphocytes, particularly in MHC class II expressing cells. Equine TLR9 expression was enhanced by phytohemagglutinin or CpG DNA stimulation. From these data we suggest that the TLR9 ligand, CpG DNA, is a potential equine vaccine adjuvant signaling an antigen-specific Th1 bias for pronounced host immunity.
Complement receptors 1 and 2 influence immune responses in a B cell receptor-independent manner (53.1)
Authors: Jacobson Amanda , Weis Janis , Weis John 
Published: January 2023

Abstract
The CD21/35 proteins are complement receptors which places them squarely within the realm of controlling and interpreting activation states of the innate immune response. The main function for CD21/35 has been identified as a co-receptor for the B cell receptor complex and mice deficient in the CD21/35 proteins have impaired IgG3 antibody responses to a variety of antigens.
We were interested in better understanding the effect of CD21/35 deficiency on immune responses. Our analysis of gene expression profiles of resting and immunized wild type (WT) and CD21/35 deficient animals indicates the enhanced expression of a wide range of inflammatory mediators from CD11b+ cells in the absence of CD21/35 on B cells. Complement activation plays a key role in the differential gene expression observed in the CD21/35 deficient mouse, as depletion of C3 within the animal returned inflammatory gene expression within the spleen to wild type levels. Finally, C3 depletion prior to immunization favors enhanced antigen-specific IgG3 production in the CD21/35−/− mouse, whereas a negative effect on antibody production is observed in the WT mouse. These data suggest that the overall environment of the CD21/35−/− spleen is quite different from that of the WT animal. These differences may directly impact responses, such as IgG3 production, that have previously been considered solely dependent upon the activity of the CD21/BCR co-receptor.
NIH-AI-24158 to JHW and NIH-AI-32223 to JJW
Impaired responses to pneumococcal polysaccharide in CD21/35-deficient mice are caused by dysregulated CD19 expression (53.14)
Authors: Haas Karen M. , Tedder Thomas F. 
Published: January 2023

Abstract
Humoral responses to T cell-independent type 2 (TI-2) antigens, such as pneumococcal polysaccharide (PPS), are critical for providing rapid protection during infections. Complement receptor 1/2 (CD21/35) expression is required for optimal antibody responses, as CD21/35-deficient (CD21/35−/−) mice mount impaired humoral immune responses to TI-2 antigens. CD21/35 associates with CD19, a potent regulator of B cell Src family kinase activity. Altered CD19 expression has dramatic effects on B cell subset development and functional activity. Importantly, CD21/35 deficiency results in significantly increased CD19 expression. To determine whether altered CD19 expression levels in CD21/35−/− mice affect TI-2 responses, CD21/35−/− mice deficient in CD19 were generated and analyzed for their responsiveness to TI-2 antigens, including type 3 PPS and haptenated-Ficoll. CD21/35−/− mice generated impaired TI-2 antibody responses to each antigen, whereas CD19−/− mice generated normal or augmented responses. Remarkably, CD21/35−/−CD19+/− and CD21/35−/−/CD19−/− mice generated normal or augmented TI-2 antibody responses. This data indicates that impaired responses to TI-2 antigens in CD21/35−/− mice are likely to be caused by elevated CD19 activity due to the absence of CD21/35 negative regulation. Thus, CD21/35 regulates CD19 expression and activity to promote optimal humoral responses to TI-2 antigens.
Identification of a phagocytic complement C3d receptor in rainbow trout (53.15)
Authors: Li Jun , Zhang Yong-An , Sunyer Oriol 
Published: January 2023

Abstract
In higher vertebrates, activation of the complement system leads to cleavage of C3 into C3b which binds covalently to complement-activating particles. The C3d degradation fragment of C3b is thereafter produced upon cleavage by factor I and is known to bind to complement receptor type 2 (CR2). The presence of CR2 on B cells enables the uptake of C3d-antigen complexes and together with the B cell receptor, CR2 plays a synergistic role in the activation of these cells. While CR2 has been characterized in mammals, its presence in non-mammalian species remains to be studied. Here we present evidence for the existence of phagocytic C3d receptors in teleost fish B lymphocytes. To evaluate the presence of C3d receptors in trout B cells, we generated FITC-labeled monomers and tetramers of trout C3d and assessed their binding to trout leukocytes. Binding of C3d to trout B cells could be inhibited both by anti-trout C3 antibodies and by unlabeled C3d. Biotinylated C3d was then used to coat 2μm FITC-conjugated streptavidin beads. Trout B lymphocytes were able phagocytose C3d-beads at a much higher ratio than BSA-beads or beads alone. Internalization of beads was inhibited by soluble C3d. To address further the identity of this receptor, we have recently cloned a trout molecule that shows the highest degree of homology to CR1/2 molecules from mammals. Thus far, our results suggest the existence of a trout C3d receptor that has a role in the phagocytosis of C3d-coated particles. Whether this receptor plays a role in adaptive immunity is currently being investigated in our laboratory.
Hematopoietic stem cells did not have a synchronized defect with age-related thymic involution during murine aging (81.5)
Authors: Su Dong-Ming , Zhu Xike , Gui Jingang 
Published: January 2023

Abstract
Previous reports suggested that aging early T-lymphocyte progenitors (ETPs) derived from bone marrow (BM) hematopoietic stem cells (HSCs) have an intrinsic defect and insufficiency in aged thymus, which triggers age-related thymic involution, but our studies suggest otherwise. We grafted fetal thymus into a kidney capsule of the aged mice, in which aging HSCs could fully generate all thymocyte subpopulations and restore normal thymopoiesis under intact physiological conditions in aged animals. We found that aging ETPs were not deficient initially because both BM HSC and early-stage ETPs—DN1a absolute cell numbers were not significantly reduced although late-stage ETPs—DN1b cells significantly decreased. Moreover, proliferation of the aging ETPs remained unchanged although their apoptotic rate increased. Conversely, provision of sufficient young HSCs/ETPs intravenously or intrathymically failed to restore thymopoiesis in aging host mice. Meanwhile, we demonstrated that young progenitors could seed young and aged thymi without significant difference via intravenous injection. The results exclude insufficient and defective HSCs/ETPs as causes for age-related thymic involution. Our findings indicate that an intrinsic defect in aging T-lymphocyte progenitors is unlikely and HSCs are not synchronal defective with age-related thymic involution during murine aging.
(This work was supported by US NIH grant R21AI064939 to DMS).
INVOLVEMENT OF UROKINASE-TYPE PLASMINOGEN ACTIVATOR RECEPTOR IN HEMATOPOIETIC STEM CELL MOBILIZATION (81.7)
Authors: Montuori Nunzia , Selleri Carmine , Ricci Patrizia , Visconte Valeria , Carriero Maria Vincenza , Rotoli Bruno , Ragno Pia , Rossi Guido 
Published: January 2023

Abstract
Cleaved forms of soluble urokinase-receptor (c-suPAR) have been detected in body fluids from patients affected by various tumors. We reported increased c-suPAR levels in sera of healthy donors during granulocyte colony-stimulating factor (G-CSF)-induced mobilization of CD34+hematopoietic stem cells (HSCs). Then, we investigated the effects of uPAR84–95, a c-suPAR-derived chemotactic peptide, on mobilization of mouse CD34+ hematopoietic stem/progenitor cells (HSCs/HPCs). We first demonstrated that uPAR84–95 stimulated in vitro dose-dependent migration of mouse CD34+ M1 leukemia cells and inactivated CXCR4, the chemokine receptor primarily responsible for HSC retention in bone marrow (BM). uPAR84–95 intraperitoneal administration induced rapid leukocytosis, which was associated with an increase in peripheral blood CD34+ HSCs/HPCs. In vitro colony assays confirmed that uPAR84–95 mobilized hematopoietic progenitors, showing an absolute increase in circulating colony-forming cells. uPAR84–95 mobilizing activity was comparable to that of G-CSF; however, neither synergistic nor additive effect was observed combining the two molecules. These findings demonstrate for the first time in vivo biological effects of c-suPAR. Its capability to mobilize HSCs suggests potential clinical applications in HSC transplantation.
Bystander immuno-modulatory effects of human neural stem cell line, HB1.F3, on lymphocyte proliferation induced by mitogens and alloantigens (81.9)
Authors: kim su-young , Kim Jung Sik , Park Chung Gyu 
Published: January 2023

Abstract
A stable clonal cell line of human neural stem cells (NSCs), HB1.F3, has been shown therapeutic effect on acute stroke or intracerebral haemorrhage by the mechanisms of cell replacement and several bystander effects. To investigate the bystander immunomodulatory functions of HB1.F3 cells, we examined immunosuppressive effects of HB1.F3 on T cell effector functions in vitro. We found that heat-labile soluble factors from hNSCs culture supernatant are attributed to the inhibition of peripheral blood lymphocytes (PBLs) proliferation induced by mixed lymphocyte reaction (MLR) or phorbol myristate acetate (PMA)/ionomycin. In contrast to inhibitory effect of HB1.F3, they promoted cytokine secretion from PBLs including IFN-r, TNF-a, IL-10, IL-6 during mixed lymphocyte reaction by soluble factor dependant-manner. HB1.F3 cell line expressed TGF-beta and Trail mRNA, not FasL. we confirmed that the apoptosis induction of PBLs by HB1.F3 is one of the mechanisms of T cell proliferation inhibition during MLRs. In summary, HB1.F3 cells could suppress the T cell proliferation by induction of apoptosis and promote both inflammatory and immune suppressive cytokines. This study suggested that therapeutically effective hNSCs cell line on several stroke models might be due to the bystander immunomodulatory functions by the secretion of immunosuppressive soluble factors.
Growth Factor Independence 1b (Gfi1b) is an E2A Target Gene that Modulates Gata3 in T Cell Lymphomas. (82.3)
Authors: Xu Wei , Kee Barbara L. 
Published: January 2023

Abstract
T cell development depends on the activity of multiple transcription factors, including E2A and Gata3. E2A proteins are required for normal T lymphopoiesis and to prevent T lymphocyte progenitor transformation. Ectopic expression of E2A proteins in E2A-deficient lymphomas results in growth arrest and apoptosis indicating that these cells remain responsive to the targets of E2A. We identify the transcriptional repressor Growth factor independence 1b (Gfi1b) as a target of E2A that promotes growth arrest and apoptosis in lymphomas. Gfi1b expression in primary T lymphocyte progenitors is dependent on E2A and excess Gfi1b prevents the outgrowth of T lymphocyte progenitors in vitro. We also find that Gfi1b represses expression of Gata3, a transcription factor whose appropriate regulation is required for survival of lymphomas and T lymphocyte progenitors. Ectopic expression of Gata3 in lymphomas promotes expression of Gfi1b indicating that these proteins may function in an auto-regulatory loop that maintains appropriate levels of Gata3. Therefore, we propose that E2A proteins prevent lymphoma cell expansion, at least in part, through regulation of Gfi1b and modulation of Gata3 expression.
The regulation of T cell development and leukemogenesis by Ikaros: mechanism of action through Notch. (82.4)
Authors: Chari Sheila , Kathrein Katie , Winandy Susan 
Published: January 2023

Abstract
The development of T cells from multipotent progenitors into lineage-committed cells is dependent upon instructive signals from the microenvironment and the genetic regulatory networks that transmit these signals. The nuclear factor Ikaros (Ik) is a zinc-finger regulatory protein that is essential for normal lymphocyte development. Ik deficiency in mice results in aberrant lymphocyte development, including abrogation of B cell development, hyperproliferative TCR responses, and T cell leukemogenesis. Similarly, the Notch receptor regulates transcription and is required for normal T cell development. Constitutive activation of the Notch pathway in lymphoid progenitors results in similar phenotypes as some of those witnessed in Ik null mice. The collaboration between reduced Ik activity and increased Notch activation in promoting leukemogenesis has been extensively documented for the T cell lineage in humans and mice. However, the molecular mechanisms of this cooperation, as well as the implications of this partnership for thymocyte development and leukemic transformation remain unexplored. In this study, we have assessed the levels at which Notch deregulation occurs in Ik deficient leukemia cells and premalignant thymocytes in terms of Notch cleavage and its target gene expression. We have also examined the extent of Notch activation in the absence of Ik in vitro and ex vivo.
IL-17A-Producing Tn cells escape thymic selection and regulate granulopoiesis in Rag-1−/− mice. (83.16)
Authors: Smith Emily , Stark Matthew A , Zarbock Alexander , Bender Tim , Ley Klaus 
Published: January 2023

Abstract
Interleukin- (IL-) 23 and IL-17A play pivotal roles in the regulation of granulopoiesis in mice via a regulatory neutrostat feedback loop. Dendritic cells (DC) and macrophages release IL-23 in response to microbial products. IL-23 enhances the release of IL-17A from three Tn cell subsets, CD4−CD8−αβlow, CD4+CD8−αβ+ and γδ+. IL-17A levels correlate with neutrophil (PMN) and G-CSF levels in the blood. The feedback loop is closed by the trafficking of PMN’s into the tissues, their apoptosis and engulfment by resident DC, which curbs secretion of IL-23. As most granulopoiesis is controlled by T cells, athymic (nude) mice are neutropenic. However, Rag-1−/− mice have normal PMN numbers and if crossed onto a neutrophillic mouse background, remain neutrophilic, suggesting that immature T cells also regulate granulopoiesis. Here, we show that WT and Rag-1−/− mouse splenocytes secrete IL-17A without TCR cross-linking, and Tn cells are found in the thymus, spleen and MLN of both mouse models. Characterization of these cells places them into the DN1e category of prothymocytes which do not express classical lineage markers and are CD25−, CD117−, CD24− and CD44+. Adoptive transfer of Rag-1−/− thymocytes into nude mice rescued their neutropenia, with 99.8% of PMN’s being recipient derived. Thus, IL-17A-producing thymocytes are able to escape thymic selection and regulate granulopoiesis in the periphery of mice.
Supported by NIH HL 73361
BCR Signaling Generates NF-kB2 (p100) For BR3-Mediated Processing And Survival (83.2)
Authors: Stadanlick Jason E , Scholz Jean L. , Miller Juli P. , Cancro Michael P. 
Published: January 2023

Abstract
Signaling through both the B cell receptor (BCR) and the BLyS receptor, BR3, are required for primary B cell survival. Therefore, understanding how the downstream signaling pathways from these receptors interact should help reveal the molecular mechanisms underlying primary B cell selection and survival. The classical and non-classical NF-kB pathways are an attractive starting point for interrogation, since its members operate downstream of several key B cell signaling systems. Accordingly we have examined BLyS-mediated signaling and survival both in isolation as well as in the context of signals derived form the BCR. In NH3T3 cells expressing BR3, as well as in primary splenic B cells, we find that BLyS signaling via BR3 predominantly activates the non-classical pathway. This is evidenced by an increase in p52 levels and the corresponding diminution of the p100 pool upon BLyS treatment. In contrast, while BCR signaling potently upregulates p100 levels, it does not result in processing to the active p52 form. However, simultaneous BCR and BR3 signaling yields both p52 accumulation and sustained p100 availability. These findings suggest a model whereby BCR signaling is required to maintain available substrate for the viability-promoting BR3 pathway. In support of this model, blockade of proximal BCR signaling with a Syk kinase inhibitor leads to the depletion of p100 stores and the failure of BLyS-mediated survival. Together, these findings lead us to propose a model whereby BCR signaling rations a key survival pathway substrate, thus governing selection and homeostasis.