bluuebunny/crossref_metadata_2025_split huggingface dataset:
Macrophage-Inflammatory Protein-1α Receptor Expression on Normal and Chronic Myeloid Leukemia CD34+ Cells
Authors: Nicholls Sian E. , Lucas Guy , Graham Gerard J. , Russell Nigel H. , Mottram Rachel , Whetton Anthony D. , Buckle Anne-Marie 
Published: January 2023

Abstract
We have assessed expression of MIP-1α binding sites on the surface of CD34+ cells from normal bone marrow (NBM) and chronic myeloid leukemia (CML) peripheral blood. This study has highlighted a small subpopulation of CD34+ (15.7 ± 6.2% in NBM and 9 ± 4% in CML), which has specific macrophage-inflammatory protein-1α (MIP-1α) cell surface binding sites. Further phenotypic characterization of the receptor-bearing cells has shown that they do not express the Thy-1 Ag, suggesting that they are committed progenitor cells rather than CD34+ Thy+ stem cells. However, more than 80% of methanol-fixed CD34+ cells do bind MIP-1α, suggesting that these cells may possess a pool of internal receptors, although we were unable to induce cell surface expression by cytokine stimulation. The percentage of these CD34+, MIP-1α-R+ cells present in the CD34 compartment of NBM is significantly higher than in CML, implicating lack of binding sites as part of the mechanism for the loss of response to this chemokine seen in CML. Specific Ab to the MIP-1α receptor implicated in HIV infection, CCR5, revealed that very few CD34+ cells expressed these receptors and that expression was confined to the CD34+ Thy− progenitor population. Data presented in this work suggest that active binding sites for the stem cell growth inhibitor MIP-1α are not constitutively expressed on the surface of most resting primitive multipotent cells, and that these cells are not potential targets for HIV-1 infection through CCR5.
Bleomycin Stimulates Lung Fibroblasts to Release Neutrophil and Monocyte Chemotactic Activity
Authors: Takamizawa Akemi , Koyama Sekiya , Sato Etsuro , Masubuchi Takeshi , Kubo Keishi , Sekiguchi Morie , Nagai Sonoko , Izumi Takateru 
Published: January 2023

AbstractWe determined whether human lung fibroblasts might release chemotactic activity for neutrophils (NCA) and monocytes (MCA) in response to bleomycin. The human lung fibroblasts supernatant fluids were evaluated for chemotactic activity by a blind well chamber technique. Human lung fibroblasts released NCA and MCA in a dose- and time-dependent manner in response to bleomycin. Checkerboard analysis of supernatant fluids revealed that both NCA and MCA were chemotactic. Partial characterization revealed that NCA was partly heat labile, trypsin sensitive, and predominantly ethyl acetate extractable. In contrast, MCA was partly trypsin sensitive and ethyl acetate extractable. The release of chemotactic activity was inhibited by lipoxygenase inhibitors and cycloheximide. Molecular sieve column chromatography revealed that both NCA and MCA had multiple chemotactic peaks. NCA was inhibited by leukotriene B4 receptor antagonist and anti-IL-8 and G-CSF Abs. MCA was attenuated by leukotriene B4 receptor antagonist, and monocyte chemoattractant protein-1, GM-CSF, and TGF-β Abs. Leukotriene B4 receptor antagonist and these Abs inhibited the corresponding m.w. chemotactic activity separated by column chromatography. The concentrations of IL-8, G-CSF, monocyte chemoattractant protein-1, GM-CSF, and TGF-β in the supernatant fluids significantly increased in response to bleomycin. These data suggest that lung fibroblasts may modulate inflammatory cell recruitment into the lung by releasing NCA and MCA in response to bleomycin.
IL-4 Induces Mucin Gene Expression and Goblet Cell Metaplasia In Vitro and In Vivo
Authors: Dabbagh Karim , Takeyama Kiyoshi , Lee Heung-Man , Ueki Iris F. , Lausier James A. , Nadel Jay A. 
Published: January 2023

Abstract
Goblet cell metaplasia and mucus hypersecretion are important features in the pathogenesis of asthma. The cytokine IL-4 has been shown to play a role in animal models of asthma, where it induces Th2 lymphocyte differentiation and B lymphocyte IgE class switch. IL-4 has also been implicated in the differentiation of goblet cells via effects on lymphocytes and eosinophils. In this study we hypothesized that IL-4 induces airway epithelial cell mucin gene expression and mucous glycoconjugate production by direct action on these cells. In vitro, cultured airway epithelial cells (NCI-H292) expressed IL-4R constitutively, and IL-4 (10 ng/ml) induced MUC2 gene expression and mucous glycoconjugate production. In vivo, mouse airway epithelial cells expressed IL-4R constitutively, and IL-4 (250 ng) increased MUC5 gene expression and Alcian blue/periodic acid-Schiff-positive staining at 24 h; IL-4 did not increase inflammatory cell numbers in airway tissue or in bronchoalveolar lavage. TNF-α and IL-1β levels in bronchoalveolar lavage were not increased in response to IL-4 instillation. These results indicate that airway epithelial cells express IL-4R constitutively and that IL-4 directly induces the differentiation of epithelium into mucous glycoconjugate-containing goblet cells.
Tissue-Specific Segregation of CD1d-Dependent and CD1d-Independent NK T Cells
Authors: Eberl Gérard , Lees Rosemary , Smiley Stephen T. , Taniguchi Masaru , Grusby Michael J. , MacDonald H. Robson 
Published: January 2023

AbstractNKT cells, defined as T cells expressing the NK cell marker NK1.1, are involved in tumor rejection and regulation of autoimmunity via the production of cytokines. We show in this study that two types of NKT cells can be defined on the basis of their reactivity to the monomorphic MHC class I-like molecule CD1d. One type of NKT cell is positively selected by CD1d and expresses a biased TCR repertoire together with a phenotype found on activated T cells. A second type of NKT cell, in contrast, develops in the absence of CD1d, and expresses a diverse TCR repertoire and a phenotype found on naive T cells and NK cells. Importantly, the two types of NKT cells segregate in distinct tissues. Whereas thymus and liver contain primarily CD1d-dependent NKT cells, spleen and bone marrow are enriched in CD1d-independent NKT cells. Collectively, our data suggest that recognition of tissue-specific ligands by the TCR controls localization and activation of NKT cells.
Glucocorticoids Affect Human Dendritic Cell Differentiation and Maturation
Authors: Piemonti Lorenzo , Monti Paolo , Allavena Paola , Sironi Marina , Soldini Laura , Leone Biagio Eugenio , Socci Carlo , Di Carlo Valerio 
Published: January 2023

AbstractBecause dendritic cells (DC) play a major role in the initiation of T cell-mediated immunity, we studied the effects of glucocorticoids, well-known inhibitors of the immune and inflammatory response, on the differentiation and maturation of human DC. DC were differentiated from human monocytes by culture with GM-CSF and IL-4 for 7 days with and without dexamethasone (Dex). Cells treated with Dex (10−8 M) (Dex-DC) developed a characteristic dendritic morphology; however, membrane phenotype analysis demonstrated that they were not fully differentiated. Dex-DC expressed low levels of CD1a and, unlike untreated cells, high levels of CD14 and CD16. Molecules involved in Ag presentation (CD40, CD86, CD54) were also impaired. In contrast, molecules involved in Ag uptake (mannose receptor, CD32) and cell adhesion (CD11/CD18, CD54) were up-regulated. After exposure to TNF-α or CD40 ligand, Dex-DC expressed lower levels of CD83 and CD86 than untreated cells. Dex-DC showed a higher endocytic activity, a lower APC function, and a lower capacity to secrete cytokines than untreated cells. Overall, these results indicate that DC differentiated in the presence of Dex are at a more immature stage. Moreover, Dex also partially blocked terminal maturation of already differentiated DC. In conclusion, our data suggest that glucocorticoids may act at the very first step of the immune response by modulating DC differentiation, maturation, and function.
Altered Expression Level of a Systemic Nuclear Autoantigen Determines the Fate of Immune Response to Self
Authors: Kawahata Kimito , Misaki Yoshikata , Komagata Yoshinori , Setoguchi Keigo , Tsunekawa Shinji , Yoshikawa Yasuji , Miyazaki Jun-ichi , Yamamoto Kazuhiko 
Published: January 2023

Abstract
One of the hallmarks of systemic autoimmune diseases is immune responses to systemic nuclear autoantigens. We have examined the fate of the immune response against a nuclear autoantigen using human U1 small nuclear ribonucleoprotein-A protein (HuA) transgenic (Tg) mice by adoptive transfer of autoreactive lymphocytes. We obtained two Tg lines that have different expression levels of the transgene. After spleen cells from HuA-immunized wild-type mice were transferred to Tg mice and their non-Tg littermates, these recipients were injected with HuA/IFA to induce a recall memory response. HAB69, which expressed a lower amount of HuA, exhibited a vigorous increase in the autoantibody level and glomerulonephritis. Moreover, the autoreactivity spread to 70K autoantigen. Alternatively, in HAB64, which expressed a higher amount of HuA, the production of autoantibody was markedly suppressed. The immune response to HuA autoantigen was impaired as demonstrated in a both delayed-type hypersensitivity response and proliferation assay. This inhibition was Ag-specific and was mediated by T cells. These data suggest that the expression level of systemic autoantigens influences the outcome of the immune response to self.
Plasma Membrane Potential in Thymocyte Apoptosis
Authors: Dallaporta Bruno , Marchetti Philippe , de Pablo Manuel A. , Maisse Carine , Duc Huynh-Thien , Métivier Didier , Zamzami Naoufal , Geuskens Maurice , Kroemer Guido 
Published: January 2023

Abstract
Apoptosis is accompanied by major changes in ion compartmentalization and transmembrane potentials. Thymocyte apoptosis is characterized by an early dissipation of the mitochondrial transmembrane potential, with transient mitochondrial swelling and a subsequent loss of plasma membrane potential (ΔΨp) related to the loss of cytosolic K+, cellular shrinkage, and DNA fragmentation. Thus, a gross perturbation of ΔΨp occurs at the postmitochondrial stage of apoptosis. Unexpectedly, we found that blockade of plasma membrane K+ channels by tetrapentylammonium (TPA), which leads to a ΔΨp collapse, can prevent the thymocyte apoptosis induced by exposure to the glucocorticoid receptor agonist dexamethasone, the topoisomerase inhibitor etoposide, γ-irradiation, or ceramide. The TPA-mediated protective effect extends to all features of apoptosis, including dissipation of the mitochondrial transmembrane potential, loss of cytosolic K+, phosphatidylserine exposure on the cell surface, chromatin condensation, as well as caspase and endonuclease activation. In strict contrast, TPA is an ineffective inhibitor when cell death is induced by the potassium ionophore valinomycin, the specific mitochondrial benzodiazepine ligand PK11195, or by primary caspase activation by Fas/CD95 cross-linking. These results underline the importance of K+ channels for the regulation of some but not all pathways leading to thymocyte apoptosis.
Molecular Cloning and Characterization of a Novel CD1 Gene from the Pig
Authors: Chun Taehoon , Wang Kai , Zuckermann Federico A. , Gaskins H. Rex 
Published: January 2023

Abstract
Much effort is underway to define the immunological functions of the CD1 multigene family, which encodes a separate lineage of Ag presentation molecules capable of presenting lipid and glycolipid Ags. To identify porcine CD1 homologues, a cosmid library was constructed and screened with a degenerate CD1 α3 domain probe. One porcine CD1 gene (pCD1.1) was isolated and fully characterized. The pCD1.1 gene is organized similarly to MHC class I and other CD1 genes and contains an open reading frame of 1020 bp encoding 339 amino acids. Expression of pCD1.1 mRNA was observed in CD3− thymocytes, B lymphocytes, and tissue macrophages and dendritic cells. The pCD1.1 cDNA was transfected into Chinese hamster ovary cells, and subsequent FACS analysis demonstrated that mAb 76-7-4, previously suggested to be a pig CD1 mAb, recognizes cell surface pCD1.1. Structurally, the pCD1.1 α1 and α2 domains are relatively dissimilar to those of other CD1 molecules, whereas the α3 domain is conserved. Overall, pCD1.1 bears the highest similarity with human CD1a, and the ectodomain sequences characteristically encode a hydrophobic Ag-binding pocket. Distinct from other CD1 molecules, pCD1.1 contains a putative serine phosphorylation motif similar to that found in human, pig, and mouse MHC class Ia molecules and to that found in rodent, but not human, MHC class-I related (MR1) cytoplasmic tail sequences. Thus, pCD1.1 encodes a molecule with a conventional CD1 ectodomain and an MHC class I-like cytoplasmic tail. The unique features of pCD1.1 provoke intriguing questions about the immunologic functions of CD1 and the evolution of Ag presentation gene families.
Characteristics of Sequences Around Individual Nucleotide Substitutions in IgVH Genes Suggest Different GC and AT Mutators
Authors: Spencer Jo , Dunn Mark , Dunn-Walters Deborah K. 
Published: January 2023

AbstractSomatic hypermutation affects Ig genes during T-dependent B cell responses and is characterized by a high frequency of single base substitutions. Hypermutation is not a completely random process; a study of mutations in different systems has revealed the presence of sequence motifs that target mutation. In a recent analysis of the sequences surrounding individual mutated bases in out-of-frame human IgVH genes, we found that the target motifs around mutated G’s and C’s are reverse complements of each other. This finding suggests that hypermutation acts on both strands of DNA, which contradicts evidence of a strand-dependent mechanism as suggested by an observed bias in A and T mutations and the involvement of transcriptional machinery. We have now extended our database of out-of-frame genes and determined the sequence motifs flanking mutated A and T nucleotides. In addition, we have analyzed the flanking sequences for different types of nucleotide substitutions separately. Our results confirm the relationship between the motifs for G and C mutations and show that the motifs surrounding mutated A’s and T’s are weaker and do not have the same relationship. Taken together with our observation of A/T strand bias in out-of-frame genes, this observation suggests that there is a semitargeted G/C mutator that is strand-independent and a separate A/T mutator that is strand-dependent and is less reliant on the local target sequence.
Antigen-Induced Somatic Diversification of Rabbit IgH Genes: Gene Conversion and Point Mutation
Authors: Winstead Candace R. , Zhai Shi-Kang , Sethupathi Periannan , Knight Katherine L. 
Published: January 2023

AbstractDuring T cell-dependent immune responses in mouse and human, Ig genes diversify by somatic hypermutation within germinal centers. Rabbits, in addition to using somatic hypermutation to diversify their IgH genes, use a somatic gene conversion-like mechanism, which involves homologous recombination between upstream VH gene segments and the rearranged VDJ genes. Somatic gene conversion and somatic hypermutation occur in young rabbit gut-associated lymphoid tissue and are thought to diversify a primary Ab repertoire that is otherwise limited by preferential VH gene segment utilization. Because somatic gene conversion is rarely found within Ig genes during immune responses in mouse and human, we investigated whether gene conversion in rabbit also occurs during specific immune responses, in a location other than gut-associated lymphoid tissue. We analyzed clonally related VDJ genes from popliteal lymph node B cells responding to primary, secondary, and tertiary immunization with the hapten FITC coupled to a protein carrier. Clonally related VDJ gene sequences were derived from FITC-specific hybridomas, as well as from Ag-induced germinal centers of the popliteal lymph node. By analyzing the nature of mutations within these clonally related VDJ gene sequences, we found evidence not only of ongoing somatic hypermutation, but also of ongoing somatic gene conversion. Thus in rabbit, both somatic gene conversion and somatic hypermutation occur during the course of an immune response.
CD28 Costimulation Augments IL-2 Secretion of Activated Lamina Propria T Cells by Increasing mRNA Stability Without Enhancing IL-2 Gene Transactivation
Authors: Gonsky Rivkah , Deem Richard L. , Lee Doo Han , Chen Alice , Targan Stephan R. 
Published: January 2023

AbstractThe pathways leading to activation in lamina propria (LP) T cells are different from peripheral T cells. LP T cells exhibit enhanced IL-2 secretion when activated through the CD2 pathway. Coligation of CD28 leads to synergistic enhancement of IL-2 secretion. Previous studies have characterized the CD28 augmentation of TCR-mediated signaling in peripheral blood T cells through transcriptional activation of an IL-2 promoter CD28 response element (CD28RE), along with enhanced mRNA stability. This study characterized molecular events involved in CD28 costimulation of IL-2 production in LP mononuclear cells (LPMC). LPMC exhibited increased IL-2 production in response to CD28 costimulation, compared with cells activated through CD2 alone. IL-2 secretion was paralleled by increased expression of IL-2 mRNA, resulting from enhanced IL-2 mRNA stability. In contrast to transcriptional activation in PBMC, EMSA revealed that CD28 coligation of CD2-activated LPMC does not result in increased binding of trans-factors to the CD28RE, nor did Western blots detect changes in I-κBα or I-κBβ levels following CD28 coligation. Furthermore, CD28 coligation fails to enhance IL-2 promoter-reporter or RE/AP construct expression in CD2-activated LPMC. The results reported herein indicate that the molecular mechanisms involved in CD28 cosignaling and regulation of IL-2 secretion in LP T cells are unique to that compartment and differ from those seen in peripheral blood T cells. These observations suggest a biological significance for different mechanisms of IL-2 activation in initiation and maintenance of the cytokine repertoire found in the mucosa.
A Peptide Binding Motif for I-Eg7, the MHC Class II Molecule That Protects Eα-Transgenic Nonobese Diabetic Mice from Autoimmune Diabetes
Authors: Gregori Silvia , Trembleau Sylvie , Penna Giuseppe , Gallazzi Fabio , Hammer Juergen , Papadopoulos George K. , Adorini Luciano 
Published: January 2023

Abstract
The nonobese diabetic (NOD) mouse, a model of spontaneous insulin-dependent diabetes mellitus (IDDM), fails to express surface MHC class II I-Eg7 molecules due a deletion in the Eα gene promoter. Eα-transgenic NOD mice express the EαEβg7 dimer and fail to develop either insulitis or IDDM. A number of hypotheses have been proposed to explain the mechanisms of protection, most of which require peptide binding to I-Eg7. To define the requirements for peptide binding to I-Eg7, we first identified an I-Eg7-restricted T cell epitope corresponding to the sequence 4–13 of Mycobacterium tuberculosis 65-kDa heat shock protein (hsp). Single amino acid substitutions at individual positions revealed a motif for peptide binding to I-Eg7 characterized by two primary anchors at relative position (p) 1 and 4, and two secondary anchors at p6 and p9. This motif is present in eight of nine hsp peptides that bind to I-Eg7 with high affinity. The I-Eg7 binding motif displays a unique p4 anchor compared with the other known I-E motifs, and major differences are found between I-Eg7 and I-Ag7 binding motifs. Analysis of peptide binding to I-Eg7 and I-Ag7 molecules as well as proliferative responses of draining lymph node cells from hsp-primed NOD and Eα-transgenic NOD mice to overlapping hsp peptides revealed that the two MHC molecules bind different peptides. Of 80 hsp peptides tested, none bind with high affinity to both MHC molecules, arguing against some of the mechanisms hypothesized to explain protection from IDDM in Eα-transgenic NOD mice.
Mucosal T Lymphocyte Numbers Are Selectively Reduced in Integrin αE (CD103)-Deficient Mice
Authors: Schön Michael P. , Arya Anu , Murphy Elizabeth A. , Adams Cassandra M. , Strauch Ulrike G. , Agace William W. , Marsal Jan , Donohue John P. , Her Helen , Beier David R. , Olson Sara , Lefrancois Leo , Brenner Michael B. , Grusby Michael J. , Parker Christina M. 
Published: January 2023

Abstract
The mucosal lymphocyte integrin αE(CD103)β7 is thought to be important for intraepithelial lymphocyte (IEL) localization or function. We cloned the murine integrin gene encoding αE, localized it to chromosome 11, and generated integrin αE-deficient mice. In αE−/− mice, intestinal and vaginal IEL numbers were reduced, consistent with the known binding of αEβ7 to E-cadherin expressed on epithelial cells. However, it was surprising that lamina propria T lymphocyte numbers were diminished, as E-cadherin is not expressed in the lamina propria. In contrast, peribronchial, intrapulmonary, Peyer’s patch, and splenic T lymphocyte numbers were not reduced in αE-deficient mice. Thus, αEβ7 was important for generating or maintaining the gut and vaginal T lymphocytes located diffusely within the epithelium or lamina propria but not for generating the gut-associated organized lymphoid tissues. Finally, the impact of αE deficiency upon intestinal IEL numbers was greater at 3–4 wk of life than in younger animals, and affected the TCR αβ+ CD8+ T cells more than the γδ T cells or the TCR αβ+ CD4+CD8− population. These findings suggest that αEβ7 is involved in the expansion/recruitment of TCR αβ+ CD8+ IEL following microbial colonization. Integrin αE-deficient mice will provide an important tool for studying the role of αEβ7 and of αEβ7-expressing mucosal T lymphocytes in vivo.
CD40-CD40 Ligand Interaction Is Central to Cell-Mediated Immunity Against Toxoplasma gondii: Patients with Hyper IgM Syndrome Have a Defective Type 1 Immune Response That Can Be Restored by Soluble CD40 Ligand Trimer
Authors: Subauste Carlos S. , Wessendarp Matthew , Sorensen Ricardo U. , Leiva Lily E. 
Published: January 2023

Abstract
Cell-mediated immunity that results in IL-12/IFN-γ production is essential to control infections by intracellular organisms. Studies in animal models revealed contrasting results in regard to the importance of CD40-CD40 ligand (CD40L) signaling for induction of a type 1 cytokine response against these pathogens. We demonstrate that CD40-CD40L interaction in humans is critical for generation of the IL-12/IFN-γ immune response against Toxoplasma gondii. Infection of monocytes with T. gondii resulted in up-regulation of CD40. CD40-CD40L signaling was required for optimal T cell production of IFN-γ in response to T. gondii. Moreover, patients with hyper IgM (HIGM) syndrome exhibited a defect in IFN-γ secretion in response to the parasite and evidence compatible with impaired in vivo T cell priming after T. gondii infection. Not only was IL-12 production in response to T. gondii dependent on CD40-CD40L signaling, but also, patients with HIGM syndrome exhibited deficient in vitro secretion of this cytokine in response to the parasite. Finally, in vitro incubation with agonistic soluble CD40L trimer enhanced T. gondii-triggered production of IFN-γ and, through induction of IL-12 secretion, corrected the defect in IFN-γ production observed in HIGM patients. Our results are likely to explain the susceptibility of patients with HIGM syndrome to infections by opportunistic pathogens.