bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of CD8+ T cells in the Development of Oral Tolerance (B14)
Authors: Arnaboldi Paul M. , Roth-Walter Franziska , Mayer Lloyd 
Published: January 2023

Abstract
The role of CD4+ vs. CD8+ T cells in the generation of low dose oral tolerance is still controversial. To address the roles of these cells in the setting of an intact immune system C57BL/6 mice were fed PBS, OVA, or molar equivalents of MHC Class I (SIINFEKL) or MHC Class II (OVA(323–339)) peptides by gastric lavage followed by immunization with OVA in both hind-leg footpads. Mice were sacrificed and cells from the spleen and draining lymph nodes were restimulated in-vitro with OVA. Mice fed OVA or SIINFEKL before OVA immunization displayed significantly reduced cell proliferation and cytokine (IFN-γ and IL-2) production compared to mice fed PBS. In contrast, feeding OVA(323–339) prior to OVA immunization resulted in elevated levels of IFN-γ and IL-2 upon in-vitro restimulation. However, tolerance was achieved if mice were both fed and immunized with OVA(323–339). The induction of cytokine mRNA (IFN-γ, TGFβ and IL-10) in jejunum, ileum, Peyer’s patches and spleen was then assessed 6h after feeding OVA or peptides. IFN-γ and IL-10 were induced in the jejunum and ileum but not PPs with either OVA or peptides but these cytokines were only seen in the spleen after OVA or OVA(323–339) feeding. These results suggest that the stimulation of CD8+ T cells in the intestine following antigen feeding may be a key step in the induction of low dose oral tolerance.
Analysis of dendritic cell maturation following respiratory infection with vaccinia virus (B140)
Authors: Beauchamp Nicole Marie , Alexander-Miller Martha , Alexander-Miller Martha 
Published: January 2023

Abstract
Poxvirus infections have the potential to induce significant pathology. Clearance of these infections requires the generation of a potent adaptive immune response. A key contributor to this process is the dendritic cell (DC). Using a recombinant vaccinia virus (VV) expressing enhanced green fluorescent protein (eGFP), infected DCs were tracked following respiratory infection. CD8+ and CD8− subsets of DCs harvested from the mediastinal lymph node (MLN) and lung were analyzed for the expression of eGFP and the maturation markers CD80 and CD86. EGFP+ cells were found within both subsets. Although the absolute number of eGFP+ CD8+ DCs was lower, on average, than the eGFP+ CD8− DCs, they were similarly infected on a percentage basis. EGFP+ cells appeared to undergo maturation, showing increased expression of CD80 and CD86. These results suggest that following infection of the respiratory tract, VV has the ability to provide a maturation signal to infected DC. As a result these cells may contribute directly to the elicitation of a T cell response.
This work was supported by NIH grant P01 AI60642.
Lewis Lung Carcinoma-derived CCL22 recruitment of T regulatory cells (B148)
Authors: Mailloux Adam William , Lathers Deanne M R , Young M Rita I 
Published: January 2023

Abstract
Two aspects of cancer progression that contribute to malignancy are the ability of the tumor to metastasize to remote locations in the body, and the ability to evade effective host anti-tumor immune responses. It has been shown that T regulatory cells (Treg) can inhibit immune effector cell function and aid in anti-tumor immune evasion. Several types of tumors have elevated Treg numbers, and it is believed that tumors may actively recruit these cell types. Treg migration is induced by several chemokines and their receptors such as CCL22 and CCR4. Here, we use flow cytometry to analyze CCR4 expression on T cell populations and show that Tregs express more CCR4 than any other T-cell type. We also used ELISA to compare CCL22 secretion levels in normal and Lewis Lung Carcinoma (LLC) bearing lung tissue. While high basal levels of CCL22 are secreted from normal lung tissue, even higher levels are secreted by LLC bearing lung tissue. In addition, we used media conditioned on these tissues in transwell migration assays to measure preferential Treg chemoattraction. Normal lung tissue induced high levels of selective Treg chemoattraction, while LLC bearing lung selectively attracted even greater numbers of Tregs. These data suggest that normal lung tissue may be able to recruit elevated levels of immune inhibitory Tregs through the secretion of CCL22 prior to metastasis, and that once LLC metastasis occurs, both CCL22 and Treg levels increase even further.
Long-term inhibition of tumor growth by T cells targeting cancer stroma alone: persistent elimination of tumor-promoting myeloid suppressor cells (B149)
Authors: zhang bin , zhang Yi , Schietinger Andrea , Bowerman Natalie , Fu Yang-Xin , Kranz David , Rowley Donald , Schreiber Hans 
Published: January 2023

Abstract
The growth of solid tumors depends on tumor stroma. Targeting tumor stromal cells might provide an effective strategy to inhibit tumor growth. A single adoptive transfer of CD8+ T cells which only recognize tumor-Ag-loaded stromal cells, but not the cancer cells because of MHC restriction, caused a long-term equilibrium between tumor growth and elimination. The T cells persistently destroyed at least two subpopulations of myeloid-derived suppressor cells (MDSCs) in the tumor stroma: CD11b+ F4/80+ and CD11b+ Gr1+ cells. Using high affinity TCR tetramers, we found that both subpopulations captured tumor Ag from surrounding cancer cells. Epitopes on the captured Ag make these cells targets for Ag-specific T cells. These two subpopulations suppressed T cell proliferation and promoted tumorogenesis. By adding Gr1+ immature myeloid cells that expressed irrelevant MHC-I molecules, T cell-mediated inhibition of tumor growth was abrogated. Therefore, recognition and elimination of these MDSC by T cells may significantly contribute to effective control of tumor growth. These findings indicate targeting MDSCs by T cells may complement conventional cancer treatments.
Small molecular MHC-loading enhancers (MLE) amplify immune responses by targeting pocket 1 of class II MHC proteins (B150)
Authors: Gupta Shashank , Hoepner Sabine , Dickhaut Katharina , Rupp Bernd , Kühne Ronald , Freund Christian , Jung Günther , Falk Kirsten , Roetzschke Olaf 
Published: January 2023

Abstract
We have shown that certain organic compounds can amplify immune responses by catalyzing the peptide-loading of human class II MHC molecules. Notably, the effect was evident only for an allelic subset of HLA-DR molecules expressing glycine at the dimorphic position b86. The residue forms the floor of the conserved pocket P1, which is located in the peptide binding site of MHC molecule. The transient occupation of this pocket by adamantane derivatives stabilizes the peptide-receptive conformation, permitting rapid antigen loading. On ‘adamantyl-susceptible’ MHC molecules these structural transitions are detectable by conformation-specific antibodies. As ‘MHC-loading enhancer’ (MLE) these compounds may be useful molecular tools to amplify the immune response. In experimental tumour models MLE compounds have already been successfully used as ‘adjuvant’ to enhance the CD4+ T cell response against several tumour antigens. The observation, however, that the ligand repertoire can be affected through polymorphic sites may also imply that environmental factors could modulate allergic or autoimmune reactions by this mechanism. Preliminary in vitro data with the celiac disease associated HLA-DQ2 and in vivo data obtained in the MS animal model EAE suggest that MLE compounds could act as risk factors acting in a strictly allele-selective manner.
Interleukin-12 initiates an immune response that leads to tumour rejection (B151)
Authors: Nelles Megan Elizabeth , Labbe Alain , Walia Jagdeep , Jia Lintao , Furlonger Caren , Nonaka Takahiro , Medin Jeffrey A. , Paige Christopher J. 
Published: January 2023

Abstract
Immunotherapies are developed based on the notion that cancer cells can be targeted and eliminated by an appropriately stimulated immune system. Integral to both the innate and acquired immune systems, cytokines are ideal candidates for use in immunotherapy. We have developed two systems of interleukin-12 (IL-12) therapy, in a murine model, that elicit protective immune responses against the acute lymphoblastic leukemia (ALL) cell line, 70Z/3. The first system involves direct injection of IL-12, and the second is a tumour cell-mediated approach. Initially we found that direct delivery of low doses of IL-12 is sufficient to elicit a long-term protective immune response against an established tumour burden, mediated by both CD4+ and CD8+ T cells. Based on this knowledge, we created a lentiviral vector expressing murine IL-12, and transduced 70Z/3 cells to obtain IL-12 secreting tumor cells. We demonstrated that anti-tumour immunity in the second model is long lasting but is primarily dependent on the CD4+ T cell subset alone. Our results highlight that the mode of IL-12 delivery has a distinct impact on the immune response that is initiated and can lead to tumour clearance by way of disparate mechanisms. Furthermore, we demonstrate some of the underlying conditions within the tumour microenvironment that may have resulted in these differential outcomes.
Induction of active autoimmunity to the murine CD20 extracellular domain protects mice from tumor challenge in a model of B cell lymphoma. (B158)
Authors: Oscherwitz Jon , Gribbin Thomas , Cease Kemp Bailey 
Published: January 2023

Abstract
CD20 is a mostly B-cell restricted differentiation protein with a 40 amino acid extracellular domain (ECD) that has proven to be a clinically effective target for passive antibody therapy of B cell malignancies. Though there is interest in developing a mouse model to study the induction of active immunity to CD20, the CD20 ECD has significant secondary and tertiary structure which make it difficult to target with peptides. Our lab designs and studies the immunogenicity of recombinant immunogens which display peptides as tandemly repeated sequences. To target the CD20 ECD, we constructed and expressed a recombinant immunogen displaying six tandemly repeated copies of the N terminus of the murine CD20 ECD. Immunization of two inbred and one F1 strain of mice, and outbred rabbits, all led to the induction of antibodies reactive with the CD20 C-terminal peptide sequences by ELISA and more importantly, with native CD20 on the cell surface of the murine B cell lymphomas, A20 and 38-C13, by flow cytometry. The CD20-specific rabbit serum was also effective at immunoprecipitating CD20 from A20 cell lysate. Lastly, two independent experiments demonstrated that immunization of mice with the CD20 immunogen led to significant protection from a lethal challenge with the 38-C13 murine B cell lymphoma. Long term follow up of survivor mice demonstrated significant diminution of their auto antibody responses and no gross abnormalities.
Expansion of Functional Polyclonal Human T-regulatory Cell Lines Using Artificial Antigen Presenting Cells and Rapamycin. (B159)
Authors: Golovina Tatiana , Mikheeva Tatiana , Shan Xiaochuan , Suhoski Megan , Riley James , June Carl 
Published: January 2023

Abstract
T-regulatory CD4+CD25+ T lymphocytes play a central role in regulating immune response and preventing autoimmunity. There is a broad spectrum of potential clinical applications of expanded T-regs including but not limited to treatments of graft versus host disease, transplant rejection, and type I diabetes.
K562 cell line with stable expression of lentivirus-introduced CD64 and CD86 markers (KT64/86) and loaded with anti-CD3 antibodies was used to expand human CD4+CD25 high T lymphocytes. Though in several occasions stimulation of CD4+CD25high cells with KT64/86 only resulted in production of functional T-regulatory cells, only when antibiotic rapamycin was added to the cultures, functional Tregs were produced in 100% of stimulations. These cells were also active in vivo in reversing GVHD in NOG mice. Total CD4 lymphocytes grown in the presence of rapamycin though suppressive in vitro were not able to reverse GVHD in mice.
Substitution of CD86 with CD80 resulted in a less potent Tregs. Addition of certain members of TNF receptor family such as CD70, OX40 ligand or 4-1BB ligand to KT64/86 cells, had different effects on expansion of Treg cell lines. While CD70 addition did not show any impact, 4-1BB and OX-40 ligands in most cases stimulated growth of T-regulatory cell lines but at the same time in most cases also attenuated their activity.
The project is supported by JDRF Collaborative Center for Cell Therapy grant to C.J.
Mechanisms Study on Tolerogenic Dendritic Cells Induced by Apoptotic Cells (B161)
Authors: Ren Guangwen , Das Gobardhan , Zhang Liying , Roberts Arthur I , Shi Yufang 
Published: January 2023

Abstract
Apoptosis plays a pivotal function in maintaining the homeostasis of the immune system. Our previous experiments have demonstrated that i.v. administration of apoptotic cells of donor origin significantly prolonged the survival of allograft. However, the mechanism was unknown. In this report, we found that dendritic cells (DCs) play an important role in apoptotic cells-mediated immunosuppression. DCs fed with apoptotic lymphocytes (DCaps) down-regulated expression of MHC class II and costimulatory molecules CD80, CD86, as well as producing less IL-6, IL-12 and TNFalpha, but more IL-10. When DCaps were presented with antigen and then injected into the footpad of syngenic mice, they induced a much weaker immune response in draining lymph nodes compared to normal DCs. However, DCaps exhibited much less suppressive effect in ex vivo stimulation for CD4+ T cells in the presence of anti-CD3 when compared with the in vivo model. Surprisingly, the mixture of both normal DCs and DCaps could strikingly suppress T cells proliferation ex vivo. Further studies on the mechanisms of the helper role of normal DCs toward DCaps to get the immunosuppressive effect will strengthen the understanding of apoptotic cells-mediated immune tolerance.
Expression of TLR2 and TLR4 in Preterm Baboon Lung (B165)
Authors: Awasthi Shanjana , Cropper Jodie 
Published: January 2023

Abstract
Respiratory infections can cause significant morbidity and mortality in prematurely delivered babies. The increased susceptibility of preterm babies to infection is related to immaturity of the immune system. The Toll-like receptors (TLR) are expressed by antigen-presenting cells and play a key role in recognition of pathogens and regulation of immune response. However, their role in preterm babies is not well-understood. In this study, we investigated the expression of TLR2 and TLR4 proteins in lung tissues of fetal (delivered at 125, 140, 175 days of gestation age, dGA; complete term 185 days) and naturally-infected, prematurely delivered (125dGA ventilated with PRN O2) baboons. The expression of TLR2 and TLR4 was studied at protein level by Western blotting using anti-human-TLR2 and TLR4 antibodies. We found that the expression of TLR2 and TLR4 protein increased with the gestational age; the expression was found low in lung tissues of 125dGA baboon which increased to adult level at 175dGA. But in the lung tissues of naturally-infected preterm baboons, the protein levels of both TLR2 and TLR4 were significantly increased as compared to non-infected controls. Our results suggest that the expression of TLR2 and TLR4 is developmentally regulated and it may play a significant role in regulation of immune responses during infection in preterm babies.
Research Support by American Lung Association
NK Cells Lyse T Regulatory Cells in Human Infection with An Intracellular Pathogen (B167)
Authors: Roy S , Barnes P , Garg A , Wu S , Weis S , Rajavelu P , Cosman D , Vankayalapati R 
Published: January 2023

Abstract
Previously we found that regulatory T cells (CD4+CD25+Foxp3+ cells, Tregs) expand in response to M.tuberculosis (M. TB) through mechanism that depend on prostaglandin E2 production. In the current study, we determined the role of NK cells in regulating Tregs expansion in human M. TB infection. M. TB whole cell lysate (TB lysate) resulted in regulatory T cell expansion (15.33±1.02% vs 1.5±0.22%, P&lt;0.001). Addition of monokine-activated NK cells (IL-12, IL-15 and IL-18) markedly inhibited Treg expansion (6.2±1.2% vs 15±1.5%, P&lt;0.001) but freshly isolated NK cells had no effect. NK cells activated with TB lysate-stimulated monocytes also reduced Tregs expansion (13.2±0.3% to 3.4±1.4%, P&lt;0.001) confirming the physiological relevance of this effect. Reduced Tregs expansion was not due to inhibition of PGE2 production or because of IFN γ. Monokine activated NK cells lysed TB lysate-expanded Tregs, but not freashly isolated Tregs (% specific lysis of 21±3% vs 1±1% P&lt;0.001), nor T regs depleted T cells. Anti-NKG2D and anti-NKp46 reduced the % specific lysis of expanded Tregs from 22±3% to 7±3% and 8±3%, respectively (P&lt;0.001) but abs to CD16, DNAM-1, and 2B4 had no effect. NKG2D ligand, ULBP1 expression was markedly upregulated on expanded T regs, compared to T regs depleted cells ( 31±5% vs 2.1 ±0.4%, P=0.002) and freshly isolated Tregs (4.6±1.1%). Anti -ULBP1 significantly inhibited the NK mediated lysis of expanded Tregs (specific lysis of 27±4% vs 9±2%, P&lt;0.001) but abs to ULBP2, ULBP3 and MICA/B had no effect. These finding suggest that NK cells reduce the frequency of M.TB-expanded T regs by direct lysis.
Purine nucleosides downregulate innate immune function and arrest apoptosis in teleost fish leucocytes (B168)
Authors: Salinas Irene , Esteban Maria Angeles , Meseguer Jose 
Published: January 2023

Abstract
Adenosine and other purines are naturally present in the cell environment and exert a general protective role of organs and tissues following injury or stress. Moreover, adenosine is a key regulator of immune responses in higher vertebrates; inhibiting phagocytosis, regulating cytokine secretion and generation of oxygen metabolites. It also affects proliferation, survival and apoptosis of different cell types. We aimed to study purinergic nucleotides are able to i) downregulate in vitro innate immune responses and ii) modulate apoptosis in teleost fish leucocytes.
Experiment 1:
Head kidney leucocytes (HKL) from 6 specimens were incubated or with A or CHA (0.1, 1, 10 100μM) for 30, 120 or 360 min in 96-well plates. Phagocytosis, respiratory burst, peroxidase content and natural cytotoxic activity were measured. CHA significantly decreased phagocytic activity and respiratory burst at the highest assayed concentration.
Experiment 2:
106 HKL were dispensed into 48-well culture plates. 250μl of A or CHA (200μM) or sRPMI (negative control) or 1μg/ml staurosporine (positive control) were added to each well in triplicate. Apoptosis after 30min, 24h or 48h was assessed by a double staining flow cytometry assay using fluorescein diacetate and propidium iodide. Both A and CHA reduced apoptosis in HKL’s cultures after 24h. By analysing the different subpopulations, it was observed that only apoptosis of lymphocytes was significantly inhibited.
Conclusions:
teleost innate immune functions are regulated by purine nucleosides.apoptosis was not induced but arrested by A and CHA in seabream HKL cultures after 24h.
The roles of CARD9 in immune responses against intracellular bacterial infection (B170)
Authors: Zhang Yongliang , Hsu Yen-Michael S. , Dong Chen , Lin Xin 
Published: January 2023

Abstract
CARD9 is an adaptor molecule containing an N-terminal Caspase Recruitment Domain (CARD) and a C-terminal Coiled-coil domain. Previous study showed that it activated NF-κB transcription factor when overexpressed in cell line. In order to understand the role of CARD9 in immune responses, we created and analyzed CARD9 deficient mice. We found that p38 activation was selectively defected in CARD9 deficient macrophages in responses to bacterial and viral mimetics-induced signaling pathways. Macrophages from the CARD9 deficient mice produced significantly decreased amount of proinflammatory cytokines in response to components of intracellular microbial pathogens. Furthermore, in response to Listeria moncytogenes infection, CARD9 deficient mice were impaired in innate immunity and failed to activate anti-bacterial clearance. Together, our data demonstrated that CARD9 plays an essential and selective role in immune responses against intracellular bacterial infection.
Tobacco Smoke Exposure Disrupts CCL20 Production and Antimicrobial Activity by Respiratory Epithelial Cells. (B173)
Authors: Crane-Godreau Mardi A , Maccani Matthew A. , Eszterhas Susan K , Fiering Steven N. 
Published: January 2023

Abstract
The mechanism whereby tobacco smoke (TS) exposure increases the risk of infection is unknown. We tested the hypothesis that exposure to TS suppresses production of respiratory tract CCL20, a defensin-like antimicrobial peptide characterized primarily as a chemokine. When nasal washes from human subjects exposed to TS within the last two years were compared to nasal washes from individuals not exposed for more than 20 years, the latter had approximately six times more CCL20 than the former. In studies of polarized human bronchial epithelial cells (Beas-2b) grown in antibiotic-free media, CCL20 was released preferentially to the apical surface of the cell cultures. When cells were treated with tobacco smoke extract (TSE), CCL20 mRNA and secreted protein levels decreased by approximately half. In bacterial survival assays conducted with apically-collected conditioned media, media collected from TSE-treated cells killed significantly fewer CFU than media from non-TSE-treated cells; assays conducted with media treated with anti-CCL20 antibody resulted in abolition of its bacteriocidal activity. Statistically similar results were obtained in assays using rhCCL20 instead of apical media. These results demonstrate that TS exposure disrupts important antimicrobial activity and signaling by respiratory epithelial cells, a condition which may lead to increased susceptibility to infection.
Functional Implication of BAFF Synthesis and Release in Gmix-stimulated Microglia (B174)
Authors: Kim Kwang Soo , Jou Ilo , Park Sang Myun 
Published: January 2023

Abstract
BAFF (B-cell activating factor) is a recently identified member of TNF ligand superfamily that plays a critical role in B cell differentiation, survival, and regulation of immunoglobulin production. It exerts its effect by binding to three receptors: BAFF-R (BAFF receptor), TACI (transmembrane activator and CAML interactor), and BCMA (B-cell maturation antigen) which was known to be primarily expressed in B-lineage cells.
In this present study, we examined whether or not BAFF is also expressed in microglia and the synthesis and release of BAFF is regulated by stimuli. BAFF is expressed and released in primary rat microglia as well as BV-2 cells, mouse microglial cell line and the expression and release of BAFF is increased by Gmix-stimuli in microglia. The expression and release of BAFF is regulated by JAK-STAT, especially STAT1 and STAT3-dependent signaling pathway. Interestingly, SP600125, and SB203580, inhibitors of p38 and JNK, respectively, did not inhibit BAFF expression, but inhibit the release of BAFF by soluble form. It suggested that p38 and JNK signaling pathway regulate the release, not the synthesis of BAFF in microglia.
In BV-2 cells, only BAFF-R is expressed in cytoplasm and cell-surface. However, in primary rat microglia of microglia, BAFF-R and TACI are expressed in cytoplasm and cell-surface. Recombinant BAFF increases cytokines release, especially, IL-6 and IL-10 in primary rat microglia as well as BV-2 cells. It was suggested that BAFF, secreted by microglia may play important roles in CNS inflammation through regulating microglia as well as infiltrated B cells.