bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytokine Requirements for Production of a Novel Anti-CD8-Resistant CTL Population
Authors: Lamousé-Smith Esi S. N. , Dougall David S. , McCarthy Susan A. 
Published: December 2022

AbstractA population of CD8+ CTL can be generated in vitro in the presence of anti-CD8 mAb. Due to their apparent high avidity characteristic, these anti-CD8-resistant CD8+ CTL may have important functional in vivo roles in graft rejection, and may be important in antiviral and antitumor responses. We have previously reported that this anti-CD8-resistant subset of CD8+ CTL demonstrates functional differences from anti-CD8-sensitive CD8+ CTL. One important difference between the subsets is the markedly greater dependence of anti-CD8-resistant CTL upon exogenous cytokines for their generation in vitro. In this study, we have investigated in detail the cytokine requirements for the generation of allospecific CD8+ CTL in vitro and have found that IL-4 can augment the generation of anti-CD8-sensitive but not anti-CD8-resistant CTL, whereas IL-2 or IL-12 can augment the generation of both anti-CD8-sensitive and anti-CD8-resistant CTL. However, anti-CD8-resistant CTL require at least 10-fold higher concentrations of IL-2 than do anti-CD8-sensitive CTL. This more stringent IL-2 requirement precludes the efficient generation of anti-CD8-resistant CTL in vitro in the absence of exogenous IL-2 because they cannot produce sufficient IL-2 to meet their needs, in contrast to anti-CD8-sensitive CTL. By providing exogenous cytokines to allospecific CTL generation cultures, we further demonstrate that anti-CD8-resistant CTL can be functionally skewed to the Tc1 subset, but differ from anti-CD8-sensitive conventional CTL in that they cannot be skewed to the Tc2 subset.
Estrogen Receptor α Is Necessary in Thymic Development and Estradiol-Induced Thymic Alterations
Authors: Staples J. Erin , Gasiewicz Thomas A. , Fiore Nancy C. , Lubahn Dennis B. , Korach Kenneth S. , Silverstone Allen E. 
Published: December 2022

AbstractEstrogens affect the development, maturation, and function of multiple organ systems, including the immune system. One of the main targets of estrogens in the immune system is the thymus, which undergoes atrophy and phenotypic alterations when exposed to elevated levels of estrogen. To determine how estrogens influence the thymus and affect T cell development, estrogen receptor α (ERα) knockout (ERKO) mice were examined. ERKO mice have significantly smaller thymi than their wild-type (WT) littermates. Construction of ER radiation bone marrow chimeras indicated that the smaller thymi were due to a lack of ERα in radiation-resistant tissues rather than hemopoietic elements. ERKO mice were also susceptible to estradiol-induced thymic atrophy, but the extent of their atrophy was less than what was seen in WT mice. The estradiol-treated ERKO mice failed, however, to manifest alterations in their thymic CD4/CD8 phenotypes compared with WT mice. Therefore, ERα is essential in nonhemopoietic cells to obtain a full-sized thymus, and ERα also mediates some of the response of the thymus to elevated estrogen levels. Finally, these results suggest that in addition to ERα, another receptor pathway is involved in estradiol-induced thymic atrophy.
The Self-Directed T Cell Repertoire Against Mouse Lysozyme Reflects the Influence of the Hierarchy of Its Own Determinants and Can Be Engaged by a Foreign Lysozyme
Authors: Moudgil Kamal D. , Southwood Scott , Ametani Akio , Kim Kasey , Sette Alessandro , Sercarz Eli E. 
Published: December 2022

AbstractThe T cell repertoire is shaped by the processes of positive and negative selection. We have previously shown that mice are tolerant to a native self-Ag, mouse lysozyme (ML), but they respond vigorously when challenged with different ML peptides (“cryptic” self-determinants). In this study, we have addressed the issue of the physiological significance of both the hierarchy (dominance/crypticity) of self-determinants within ML and the anti-cryptic, self (ML)-directed T cell repertoire. Our results demonstrate that there are several ML peptides that bind well to MHC but are totally nonimmunogenic when tested for proliferative T cell response and cytokine secretion: a subset of these peptides presumably represent the originally dominant self-determinants of ML, which have rendered the T cells tolerant during thymic selection. Other ML peptides, which bind well to MHC and are immunogenic, correspond to the cryptic determinants of ML: T cells against cryptic ML determinants escape tolerance induction. Thus, the mature T cell repertoire against ML bears the direct imprint of the hierarchy of self (ML)-determinants. Interestingly, hen egg white lysozyme could prime T cells in vivo that were cross-reactive with certain cryptic ML determinants, and vice versa, without requiring any coimmunization with the foreign lysozyme and ML peptide(s). Moreover, repeated, deliberate priming and expansion of T cells by hen egg white lysozyme immunization concomitantly enhanced T cell response to such cross-reactive ML determinants. This reciprocal self-foreign determinant cross-reactivity may play a previously unrecognized, but crucial, role in the expansion and diversification of self-reactive clones in the autoimmune response.
Ligation of CD28 In Vivo Induces CD40 Ligand Expression and Promotes B Cell Survival
Authors: Yin Deling , Zhang Liying , Wang Ruoxiang , Radvanyi Laszlo , Haudenschild Christian , Fang Qiding , Kehry Marilyn R. , Shi Yufang 
Published: December 2022

AbstractFunctional activation of T cells requires ligation of Ag receptors with specific peptides presented by MHC molecules on APCs concurrent with appropriate contacts of cell surface accessory molecules. Among these accessory molecules, interactions between CD28/CTLA-4 with B7 family members (CD80 and CD86) and CD40 with CD40 ligand (CD40L) play a decisive role in regulating the progression of balanced immune responses. However, most information regarding the role of accessory molecules in immune responses has been derived in the context of signals from the TCRs. Little understanding has been achieved regarding the consequence of ligation of costimulation molecules in absence of signals from the TCR. By employing an in vivo murine system, we show, herein, that ligation of CD28 alone with anti-CD28 Abs leads to a dramatic enlargement of the peripheral lymphoid organs characterized primarily by the expansion of B cells. B cells from anti-CD28-treated mice are resistant to spontaneous and anti-IgM-induced apoptosis. These cells are also unsusceptible to FasL-mediated apoptosis. Interestingly, this in vivo effect of CD28 on B cells is largely mediated by inducing the expression of CD40L, since coadministration of a blocking Ab against CD40L inhibited CD28-mediated B cell survival and expansion. Therefore, CD28-mediated expression of CD40L may play an important role in the regulation of lymphocyte homeostasis.
Role of IL-12 in Intrathymic Negative Selection
Authors: Lúdvíksson Björn R. , Ehrhardt Rolf O. , Strober Warren 
Published: December 2022

AbstractCytokines are central regulatory elements in peripheral lymphocyte differentiation, but their role in T cell ontogeny is poorly defined. In the present study, we evaluated the role of IL-12 in thymocyte selection more directly by determining its role in two models of in vivo negative selection. In initial studies we demonstrated that abundant intrathymic IL-12 synthesis occurs during OVA peptide-induced negative selection of thymocytes in neonatal OVA-TCR transgenic mice, and such synthesis is associated with increased IL-12R β2-chain expression as well as STAT4 intracellular signaling. In further studies, we showed that this form of negative selection was occurring at the αβTCRlowCD4lowCD8low stage and was prevented by the coadministration of anti-IL-12. In addition, the IL-12-dependent thymocyte depletion was occurring through an intrathymic apoptosis mechanism, also prevented by administration of anti-IL-12. Finally, we showed that IL-12 p40−/− mice displayed aberrant negative selection of double positive CD4+CD8+ thymocytes when injected with anti-CD3 mAb. These studies suggest that intact intrathymic IL-12 production is necessary for the negative selection of thymocytes occurring in relation to a high “self” Ag load, possible through its ability to induce the thymocyte maturation and cytokine production necessary for such selection.
Functional Synergism of STAT6 with Either NF-κB or PU.1 to Mediate IL-4-Induced Activation of IgE Germline Gene Transcription
Authors: Stütz Adrian M. , Woisetschläger Maximilian 
Published: December 2022

AbstractIg heavy chain class switching to IgE is directed by IL-4 and IL-13 by inducing transcription from the IgE germline promoter. A crucial transcription factor in this process is STAT6, which binds to a specific DNA element upon cytokine activation. In this paper it is shown that the B cell- and monocyte-specific factor PU.1 interacts with a closely spaced sequence in the human IgE germline promoter that overlaps with a previously described binding site for NFκB/rel. The authenticity of PU.1 was demonstrated by specific competition and supershifts in EMSA experiments. In addition, in vitro translated PU.1 could interact with an oligonucleotide derived from the IgE germline promoter containing the PU.1 binding site and migrated with the same mobility compared with the complex formed with nuclear extracts. Transient transfection experiments using IgE germline promoter reporter gene constructs demonstrated that mutations affecting DNA binding of PU.1 or NFκB/rel had no or little effect on IL-4 inducibility of these plasmids. However, point mutations that abolished binding of both factors abrogated cytokine inducibility. No strict spacing of the STAT6 and the composite PU.1/NF-κB elements is required for IL-4 induction. IL-4-induced STAT6 DNA binding was retained in PU.1−/NFκB/rel− double mutants. The data demonstrate that cooperation of STAT6 with at least PU.1 or NFκB/rel is necessary for IL-4-induced activation of IgE germline gene transcription.
The Human Antibody Response to Porcine Xenoantigens Is Encoded by IGHV3-11 and IGHV3-74 IgVH Germline Progenitors
Authors: Kearns-Jonker Mary , Swensson Joyce , Ghiuzeli Cristina , Chu Wilson , Osame Yuka , Starnes Vaughn , Cramer Donald V. 
Published: December 2022

AbstractPreformed and induced Ab responses present a major immunological barrier to the use of pig organs for human xenotransplantation. We generated IgM and IgG gene libraries established from lymphocytes of patients treated with a bioartificial liver (BAL) containing pig hepatocytes and used these libraries to identify IgVH genes that encode human Ab responses to pig xenoantigens. Genes encoded by the VH3 family are increased in expression in patients following BAL treatment. cDNA libraries representing the VH3 gene family were generated, and the relative frequency of expression of genes used to encode the Ab response was determined at days 0, 10, and 21. Ig genes derived from the IGHV3-11 and IGHV3-74 germline progenitors increase in frequency post-BAL. The IGHV3-11 gene encodes 12% of VH3 cDNA clones expressed as IgM Abs at day 0 and 32.4–39.0% of cDNA clones encoding IgM Abs in two patients at day 10. IGHV3-11 and IGHV3-74 genes encoding IgM Abs in these patients are expressed without evidence of somatic mutation. By day 21, an isotype switch occurs and IGHV3-11 IgVH progenitors encode IgG Abs that demonstrate somatic mutation. We cloned these genes into a phagemid vector, expressed these clones as single-chain Abs, and demonstrated that the IGHV3-11 gene encodes Abs with the ability to bind to the gal α (1,3) gal epitope. Our results demonstrate that the xenoantibody response in humans is encoded by IgVH genes restricted to IGHV3-11 and IGHV3-74 germline progenitors. IgM Abs are expressed in germline configuration and IgG Abs demonstrate somatic mutations by day 21.
An Antibody-Avidin Fusion Protein Specific for the Transferrin Receptor Serves as a Delivery Vehicle for Effective Brain Targeting: Initial Applications in Anti-HIV Antisense Drug Delivery to the Brain
Authors: Penichet Manuel L. , Kang Young-Sook , Pardridge William M. , Morrison Sherie L. , Shin Seung-Uon 
Published: December 2022

Abstract
In the present study a novel Ab-avidin fusion protein has been constructed to deliver biotinylated compounds across the blood brain barrier. This fusion molecule consists of an Ab specific for the transferrin receptor genetically fused to avidin. The Ab-avidin fusion protein (anti-TfR IgG3-CH3-Av) expressed in murine myeloma cells was correctly assembled and secreted and showed both Ab- and avidin-related activities. In animal models, it showed much longer serum half-life than the chemical conjugate between OX-26 and avidin. Most importantly, this fusion protein demonstrated superior [3H]biotin uptake into brain parenchyma in comparison with the chemical conjugate. We also delivered a biotinylated 18-mer antisense peptide-nucleic acid specific for the rev gene of HIV-1 to the brain. Brain uptake of the HIV antisense drug was increased at least 15-fold when it was bound to the anti-TfR IgG3-CH3-Av, suggesting its potential use in neurologic AIDS. This novel Ab fusion protein should have general utility as a universal vehicle to effectively deliver biotinylated compounds across the blood-brain barrier for diagnosis and/or therapy of a broad range of CNS disorders such as infectious diseases, brain tumors as well as Parkinson’s and Huntington’s diseases.
Binding of Longer Peptides to the H-2Kb Heterodimer Is Restricted to Peptides Extended at Their C Terminus: Refinement of the Inherent MHC Class I Peptide Binding Criteria
Authors: Hörig Heidi , Young Aideen C. M. , Papadopoulos Nicholas J. , DiLorenzo Teresa P. , Nathenson Stanley G. 
Published: December 2022

Abstract
MHC class I molecules usually bind short peptides of 8–10 amino acids, and binding is dependent on allele-specific anchor residues. However, in a number of cellular systems, class I molecules have been found containing peptides longer than the canonical size. To understand the structural requirements for MHC binding of longer peptides, we used an in vitro class I MHC folding assay to examine peptide variants of the antigenic VSV 8 mer core peptide containing length extensions at either their N or C terminus. This approach allowed us to determine the ability of each peptide to productively form Kb/β2-microglobulin/peptide complexes. We found that H-2Kb molecules can accommodate extended peptides, but only if the extension occurs at the C-terminal peptide end, and that hydrophobic flanking regions are preferred. Peptides extended at their N terminus did not promote productive formation of the trimolecular complex. A structural basis for such findings comes from molecular modeling of a H-2Kb/12 mer complex and comparative analysis of MHC class I structures. These analyses revealed that structural constraints in the A pocket of the class I peptide binding groove hinder the binding of N-terminal-extended peptides, whereas structural features at the C-terminal peptide residue pocket allow C-terminal peptide extensions to reach out of the cleft. These findings broaden our understanding of the inherent peptide binding and epitope selection criteria of the MHC class I molecule. Core peptides extended at their N terminus cannot bind, but peptide extensions at the C terminus are tolerated.
Tumor Regression After Adoptive Transfer of Effector T Cells Is Independent of Perforin or Fas Ligand (APO-1L/CD95L)
Authors: Winter Hauke , Hu Hong-Ming , Urba Walter J. , Fox Bernard A. 
Published: December 2022

AbstractThe adoptive transfer of tumor-specific effector T cells can result in complete regression and cure mice with systemic melanoma, but the mechanisms responsible for regression are not well characterized. Perforin- and Fas ligand (APO-1/CD95 ligand)-mediated cytotoxicity have been proposed as mechanisms for T cell-mediated tumor destruction. To determine the role of perforin and Fas ligand (FasL) in T cell-mediated tumor regression in a murine melanoma model, B16BL6-D5 (D5), we generated D5-specific effector T cells from tumor vaccine-draining lymph nodes of wild type (wt), perforin knock out (PKO), or FasL mutant (gld) mice and treated established D5 metastases in mice with the same genotype. Effector T cells from wt, PKO and gld mice induced complete regression of pulmonary metastases and significantly prolonged survival of the treated animals regardless of their genotype. Complete tumor regression induced by PKO effector T cells was also observed in a sarcoma model (MCA-310). Furthermore, adoptive transfer of PKO and wt effector T cells provided long-term immunity to D5. Therapeutic T cells from wt, PKO, or gld mice exhibit a tumor-specific type 1 cytokine profile; they secrete IFN-γ, but not IL-4. In these models, T cell-mediated tumor regression and long-term antitumor immunity are perforin and FasL independent.
TNF Is Essential for the Cell-Mediated Protective Immunity Induced by the Radiation-Attenuated Schistosome Vaccine
Authors: Street Miyoko , Coulson Patricia S. , Sadler Clare , Warnock Lorna J. , McLaughlin Deborah , Bluethmann Horst , Wilson R. Alan 
Published: December 2022

AbstractC57BL/6 mice exposed to the radiation-attenuated schistosome vaccine exhibit high levels of protective immunity. The cell-mediated pulmonary effector mechanism involves IFN-γ-producing CD4+ T cells in a focal response around challenge larvae. IFN-γ can promote production of TNF and can synergize with this cytokine in its actions on responder cells. We have examined whether TNF plays a role in lung phase immunity to schistosomes using mice with a disrupted gene for TNFRI (TNFRI−/−). The most dramatic finding was that the schistosome vaccine elicited no protection whatsoever in these mice. However, this could not be attributed to a lack of responder cells, because more lymphocytes were lavaged from the airways of TNFRI−/− than wild-type mice. Furthermore, CD4+ T cells were equally represented in airway populations from the two groups and produced IFN-γ upon Ag stimulation in vitro. In contrast, pulmonary macrophage function was defective in TNFRI−/− mice, as indicated by a failure to up-regulate inducible NO synthase mRNA. Histopathological analysis revealed that focal infiltrates were of similar size and cell composition in the two groups but that more parasites were free of foci in the TNFRI−/− mice. These animals had a greatly impaired IgG response to schistosomes, which may explain their lack of residual protection due to Ab in a situation where cell-mediated immunity is disabled. We suggest that the absence of protective immunity could result from a retarded build-up of leukocytes around migrating lung worms and/or a deficit in accessory cell function within a focus, both of which would permit parasite escape.
Activated Lymphocytes Promote Endothelial Cell Detachment from Matrix: A Role for Modulation of Endothelial Cell β1 Integrin Affinity
Authors: Phan Cecile , McMahon Alan W. , Nelson Randall C. , Elliott John F. , Murray Allan G. 
Published: December 2022

AbstractIn vivo, MHC class I-restricted injury of allogeneic tissue or cells infected by intracellular pathogens occurs in the absence of classical cytolytic effector mechanisms and Ab. Modulation of the target cell adhesion to matrix may be an additional mechanism used to injure vascular or epithelial cells in inflammation. We studied the mechanisms of human umbilical vein endothelial cell (EC) detachment from matrix-coated plastic following contact by concanamycin A-treated lymphocytes as an in vitro model of perforin-independent modulation of EC basement membrane adhesion. Human PBL were depleted of monocytes, stimulated, then added to an EC monolayer plated on either fibronectin or type I collagen matrices. Activated, but not resting, PBL induced progressive EC detachment from the underlying matrix. Injury of the EC monolayer required direct cell contact with the activated lymphocytes because no detachment was seen when the PBL were placed above a Transwell membrane. Moreover plasma membranes prepared from activated but not resting PBL induced EC detachment. Adherent EC stimulated with activated PBL did not show evidence of apoptosis using TUNEL and annexin V staining at time points before EC detachment was observed. Finally, neither the matrix metalloproteinase inhibitors o-phenanthroline and BB-94 nor aprotinin blocked EC detachment. However, activation of EC β1 integrin using mAb TS2/16 or Mg2+ decreased EC detachment. These data indicate that cell-cell contact between activated PBL and EC reduces adhesion of EC to the underlying matrix, at least in part by inducing changes in the affinity of the endothelial β1 integrin.
Cutting Edge: Ig Heavy Chain 3′ HS1–4 Directs Correct Spatial Position-Independent Expression of a Linked Transgene to B Lineage Cells
Authors: Chauveau Christine , Jansson Emmelie Å. , Müller Susanne , Cogné Michel , Pettersson Sven 
Published: December 2022

Abstract
The Ig H chain locus is regulated by a set of cis-acting elements. Hypersensitive sites (HS) located 3′ of the IgH, HS1–4, has been suggested to act as a locus control region (LCR) in cell lines. To assess the proposed role of HS1–4 acting as an LCR, we generated transgenic mice harboring a VH promoter-β-globin reporter gene linked to the Ig H chain HS1–4 3′regulatory sequences. Transgene expression is strictly confined to B lymphocytes, with no detectable expression outside the B cell lineage in all transgenic founder lines. Furthermore, reporter gene activity is integration independent but not copy number dependent. Thus, additional sequences are required to allow the HS1–4 regulatory region to act as a classical LCR in mice. Our data are discussed in the context of tissue-specific gene expression in B lineage cells.
Cutting Edge: Cross-Talk Between Cells of the Innate Immune System: NKT Cells Rapidly Activate NK Cells
Authors: Carnaud Claude , Lee Daniel , Donnars Olivier , Park Se-Ho , Beavis Andrew , Koezuka Yasuhiko , Bendelac Albert 
Published: December 2022

Abstractα-Galactosylceramide (α-GalCer) is a glycolipid with potent antitumor properties that binds to CD1d molecules and activates mouse Vα14 and human Vα24 NKT cells. Surprisingly, we found that, as early as 90 min after α-GalCer injection in vivo, NK cells also displayed considerable signs of activation, including IFN-γ production and CD69 induction. NK activation was not observed in RAG- or CD1-deficient mice, and it was decreased by pretreatment with anti-IFN-γ Abs, suggesting that, despite its rapid induction, it was a secondary event that depended on IFN-γ release by NKT cells. At later time points, B cells and CD8 T cells also began to express CD69. These findings identify a high-speed communication network between the innate and adaptive immune systems in vivo that is initiated upon NKT cell activation. They also suggest that the antitumor effects of α-GalCer result from the sequential recruitment of distinct innate and adaptive effector lymphocytes.
Cutting Edge: KAP10, a Novel Transmembrane Adapter Protein Genetically Linked to DAP12 but with Unique Signaling Properties
Authors: Chang Chiwen , Dietrich Jes , Harpur Ailsa G. , Lindquist Jonathan A. , Haude Anja , Loke Y. W. , King Ashley , Colonna Marco , Trowsdale John , Wilson Michael J. 
Published: December 2022

AbstractTransmembrane adapter proteins are a class of molecules that mediate signals from an extracellular receptor to the cytoplasm of the cell. We have cloned a novel transmembrane adapter protein called KAP10, a ∼10-kDa protein that is encoded within 100 bp of the DAP12 locus on human chromosome 19. KAP10 is predominantly expressed in immune cells, including NK cells, T cells, and monocytes. We show that KAP10, unlike other transmembrane adapter proteins, binds phosphatidylinositol-3 kinase following phosphorylation of a cytoplasmic YINM motif, which results in activation of Akt. In addition, we identify KAP10 as being able to bind the adapter protein Grb2. Based on our data, we suggest that this molecule is involved in stimulation and costimulation in cells of both myeloid and lymphoid origin.