bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of immunoglobulin heavy chain intronic enhancer Eμ in cell selection at the pre-B to immature B cell transition (P1437)
Authors: Peng Cheng , Eckhardt Laurel 
Published: January 2023

Abstract
We previously described an Eμ-dependent checkpoint for allelic exclusion, operating at the pre-B to immature B cell transition. We now show that Eμ functions at this transition to ensure that Igμ levels, and consequently B cell receptor (BCR) levels, reach a threshold required for positive selection into the immature B cell pool. We find that Ig-mediated signalling is reduced in pre-B cells expressing an Eμ-deficient IgH allele, as is the size of the emerging immature B cell compartment. Some Eμ-deficient B cells break the rules of allelic exclusion as “double-producers” to achieve higher BCR levels. We previously showed that B cells expressing only the Eμ-deficient allele underwent heightened light-chain editing, consistent with the hypothesis that deficient BCR signals were driving further light chain gene rearrangements in search of an IgH/IgL combination with superior signalling properties. In the current study, we tested this by providing Eμ-deficient mice with a pre-assembled VL gene. As predicted, both heavy chain allelic exclusion and the size of the immature B cell pool were affected. In addition, we found that the double-producers in allelic exclusion-defective mice include a subpopulation in which the BCR generated from the Eμ-deficient allele is autoreactive. These results demonstrate that Igμ levels in developing B cells have an important impact on the breadth of the BCR repertoire, the maintenance of allelic exclusion, and the emergence of autoimmune B cells.
Bcl-xL protects from UPR-associated apoptosis during plasma cell differentiation. (P1457)
Authors: Gaudette Brian , Iwakoshi Neal , Boise Lawrence 
Published: January 2023

Abstract
Understanding factors that control plasma cell survival is important for the development of therapeutic approaches to diseases including multiple myeloma and autoimmune disorders. Plasma cell differentiation requires activation of the unfolded protein response, a set of signaling pathways in which prolonged activation leads to apoptosis in other cell types. Plasma cells activate this pathway during differentiation suggesting compensatory survival signals are activated. Consistent with this hypothesis, we found that LPS-driven differentiation protects Bcl1 cells against tunicamycin-activated ER stress-induced death. LPS plus cytokine-induced differentiation was associated with an increase in Bcl-xL expression accompanied by a decrease in Mcl-1 or Bcl-2 in Bcl1 cells and primary B cells respectively. Moreover, differentiation-induced protection against ER stress was shown to be Bcl-xL-dependent as tunicamycin-induced death was restored by the addition of the Bcl-xL/Bcl-2 inhibitor, ABT-737. Importantly, we also showed that during differentiation, Bcl1 cells and primary B cells are Bcl-xL-dependent as ABT-737 resulted in significant apoptosis in the absence of any additional death signal. Finally, we found that differentiation was accompanied by a change in Bim binding from primarily Mcl-1 and/or Bcl-2 to Bcl-xL in differentiating cells. These data demonstrate that Bcl-xL induction protects from death signals activated during plasma cell differentiation.
Long-lived plasma cells in the spleen (P1472)
Authors: Bohannon Caitlin , Joshy Jacob 
Published: January 2023

Abstract
Immunological memory can last a lifetime, in large part due to the antigen-specific antibodies continuously secreted by long-lived plasma cells. Though a great deal of attention has been given to long-lived, IgG-expressing plasma cells within the bone marrow microenvironment, other long-lived plasma cell populations are also found within the secondary lymphoid organs. We sought to characterize the splenic plasma cell populations in comparison to those found in the bone marrow and explore to what extent they contribute to serological memory, hypothesizing that this niche may play a significant role in immune memory. Surprisingly, our initial findings showed a large population of IgM-secreting, long-lived plasma cells dominating the splenic niche in murine models. These plasma cells persisted for the lifetime of the animals. Here we demonstrate how these splenic IgM plasma cells compare to bone marrow resident IgG PCs and explored the factors that contribute to their homing.
Constitutive AKT activation impairs B cell homeostasis and class switch recombination (P1443)
Authors: Hoevelmeyer Nadine , Cox Eva Maria , Wunderlich Frank Thomas , Waisman Ari 
Published: January 2023

Abstract
The serine/threonine kinase AKT controls not only cellular metabolism, cell survival and proliferation but is also an important regulator for peripheral B cell maturation especially representing a critical check point in phases of proliferation and differentiation. In this study we investigated the role of constitutive AKT activation in B cell development and maturation through the use of a mouse strain allowing for the conditional expression of a N-terminally myristoylated AKT (ROSA-AKT-C) in cell types that express the Cre recombinase. The myristoylation signal recruits AKT-C to the plasma membrane where AKT becomes constantly phospho-activated. This mouse was crossed to CD19 Cre mice leading to the B cell specific overexpression of AKT-C (AKTBOE). AKTBOE mice displayed splenomegaly compared to control mice as a result of increased absolute numbers of not only B cells but also T cells, neutrophiles, monocytes and mature macrophages. Interestingly, in these spleens, a B cell specific loss of CD23 expression was observed. Of note, B cells isolated from AKTBOE mice did not form germinal centers and were not able to class switch in vitro and in vivo. The investigation of immunoglobulin titers by ELISA revealed reduced IgM, and almost no IgG1, IgG2a, IgG3 and IgA serum levels. Thus, the B cell specific overexpression of AKT-C underlines its importance in B cell maturation, homeostasis and class switch recombination.
PR1-CTL directly sort-purified from umbilical cord blood lymphocytes reduce human AML in vivo. (P4360)
Authors: St. John Lisa , He Hong , Ruisaard Kathryn , Ma Qing , Shpall Elizabeth , Karen Clise-Dwyer , Molldrem Jeffrey 
Published: January 2023

Abstract
Adoptive transfer of leukemia specific CTL could prove to be a valuable tool in the prevention and/or treatment of relapse after SCT. In line with this, we chose to examine the use of PR1-specific CTL derived from UCB as a means of adoptive immunotherapy for leukemia. PR1, a 9 amino acid, HLA-A2-restricted self-peptide is well established as a dominant LAA. While cells specific for PR1 are present in the peripheral blood of healthy adults at extremely low frequencies (0.0005 to 0.05% of CD8+ T cells), we have found that the frequency of PR1-CTL in UCB is significantly higher ranging from 0.007 to 0.345% (mean 0.117%; n=57) of CD8+ cells. We hypothesized that these cells could be isolated directly from UCB via cell sorting and used in the prevention or treatment of leukemia. CD8 enriched cells were sorted and then activated ex vivo with anti-CD3/anti-CD28/IL-2. Sorted, activated cells were infused into a cohort of NSG mice with established leukemia. In three separate, but comparable, experiments the frequency of leukemia cells in the bone marrow of mice receiving PR1-specific CTL was reduced by 27% (range 21%-32%) compared to those receiving no treatment, and 23% (range 4%-47%) compared to those receiving non-specific CD8+ cells. The reduction of leukemia cells in the blood was even more pronounced with a 47% (range 45%-61%) decrease compared to the level seen in mice receiving PBS alone, and 58% (range 48%-68%) compared to mice receiving non-specific CD8+ cells.
Assessing natural telomerase activators (P4342)
Authors: Valenzuela Hector , Burguez Clarissa , Chikami Kristin , Cruz Manuel , Rinaldi Domenico 
Published: January 2023

Abstract
Telomeres are DNA-protein complexes at the ends of chromosomes that shorten during cell division, an occurrence that causes cellular senescence. Telomere shortening is offset by the action of a reverse transcriptase enzyme called telomerase, which can extend the DNA strands at the ends of chromosomes and delay cellular senescence. These observations have lead investigators to search for methods of stimulating telomerase activity in the hopes of delaying cellular senescence and extending cellular function. Currently, there are natural compounds proven to activate telomerase activity, i.e., TA-65 and TAT2. Both compounds are extracts from the plant Astragalus membranaceus, which is commercially available. Different formulations for Astragalus membranaceus can be obtained. The objective of this research was to compare two products, TA-65 and HTA (both extract of Astragalus membranaceus) for their ability to activate telomerase activity and their affect on cellular growth on both CD4 and CD8 T cell cultures. The results of our study indicate that TA-65 was able to induce telomerase activity 1.4-3.3x fold relative to controls, whereas HTA showed increases in telomerase activity up to 1.3x-fold only in two donors but did not reach statistical significance. In addition we demonstrate that T cells treated with TA-65 had increase cell growth within 7 days of culturing, again HTA also showed increases in cell growth but did not reach statistical significance.
Transcriptome analysis of N. meningitidis PorB as an adjuvant in a multi-injection vaccination schedule (P4494)
Authors: Platt Andrew , Mosaheb Munir , Gower Adam , Wetzler Lee 
Published: January 2023

Abstract
Vaccines play an integral role in the fight against infectious diseases. Most current vaccines, however, were developed empirically, both in their formulation and schedule. A deeper understanding of the regulatory pathways involved in both adjuvanted vaccines and multi-injection schedules would contribute greatly to the rational design of future vaccines. Here we report a microarray analysis study of a 3 injection vaccination using Neisseria meningitidis PorB as a vaccine adjuvant and an Ova antigen in a murine model. We observe that the kinetics of the response in a number of gene sets is accelerated, with maximal expression after the second vaccination, rather than the third, in the adjuvanted vaccine. We also observe a recruitment of a number of innate inflammatory pathways, with adjuvanted vaccines eliciting more robust gene expression. Main effects and interactions between the antigen and adjuvant were determined, in particular as related and antibody production. In this report we demonstrate that the inclusion of PorB as an adjuvant into the formulation of a vaccine significantly alters the kinetics and nature of the immune response at a deep transcriptional level. This may provide meaningful implications for the rational design of future adjuvanted vaccines.
Comprehensive mapping of SIVmac239 envelope antigenic determinants recognized by specific polyclonal antibodies in vaccinated and/or infected macaques (P4503)
Authors: Guo Jia , Zuo Teng , Cheng Lin , Sun Caijun , Chen Ling , Zhang Linqi , Chen Zhiwei 
Published: January 2023

Abstract
The RV144 trial in Thailand has demonstrated a modest level of protection against HIV infection, which was likely related to V2-binding antibodies. Along with several HIV bnAbs identified recently, it is of great importance to understand the major differences between vaccination and infection in eliciting humoral immune responses. We adopted a robust mapping technique for quantitative measurement of antigenic domains of entire SIV env displayed on the yeast. The finding of reactive determinants ranges from 30 to 240 amino acids, which allows some conformational domains being evaluated as a major technical improvement. The antigen profile of all the tested sera shared two dominant domains: V1V2 stem of gp120 and ecto-gp41 region. A major distinct domain, however, was identified near the V3 loop and the main CD4 binding region which was only recognized by the effective immunized serum but not of the non-effective immunized one. Notably, binding titer of V1V2 antibodies is significantly different between the two vaccination groups, suggested a likely role of these antibodies in controlling viral replication. Unexpectedly, the anti-V1V2 antibody responses were shifted to the ecto-gp41 region when infected macaques developed AIDS. In conclusion, our findings have significant implications to help understanding the humoral immunity against neutralization-resistant SIVmac239 infection and simian AIDS, and to guide rational vaccine immunogen identification and design.
Inflammatory responses in mice exposed to various doses of TiO2 nanoparticles (P5084)
Authors: Strecker Ronald , Sharma Nilesh 
Published: January 2023

Abstract
Application of TiO2 nanoparticles has increased tremendously in recent years. Consumer products containing a significant amount of these nanoparticles range from paints, plastics, papers, tooth paste, food colorants, cosmetics, sunscreens to medicine pills and beverages. Ti is generally considered biologically inert, but Ti-nanoparticles were observed to cause significant toxicity including DNA damage in recent studies. In this study, C57-BL6/J mice were administered intraperitoneally TiO2 rutile crystals (30-50nm) at the rate of 333 and 1332 mg/kg body weight. Serum levels of proinflammatory cytokines, chemokines and angiogenesis growth factors (IL-1a, IL-1b, IL-6, TNFα, IFN-γ, IL-2, Rantes, G-CSF, GMCSF, MCP-1 VEGF, EGF, IGF-1and Leptin) were determined. The majority of cytokines or growth factors in exposed mice were not significantly different than in vehicle control, but VEGF level was, approximately, 50% reduced in mice exposed to the high dose, relative to control. Mice belonging to this group also demonstrated a significant decrease in the body weight, and an increase in their liver weight. The study on transcriptional activation of the related cytokine genes is in progress.
Anti-obesity effect of Sargassum muticum (Yendo) Fensholt in high fat diet-induced obese mice (P5092)
Authors: Ahn Eun-Kyung , Lee Jung A , Ko Hye-Jin , Hong Seong Su , Oh Joa Sub 
Published: January 2023

Abstract
In this study, we investigated the ethanol extract of Sargassum muticum (Yendo) Fensholt (ESMF) attenuate high-fat-diet-induced obesity in 57BL/6 mice. The mice were maintained on a normal diet (ND), high-fat-die (HFD) and Oral administration of ESMF with HFD for 6 weeks. ESMF administration with HFD significantly decreased the body weight gain, fat tissue content and serum total cholesterol and triglyceride levels in comparison with the HFD group. The food intakes among the groups did not show significant changes but ESMF administration groups observed significant reduction energy efficiency ratio (EER) values in comparison with the HFD group. ESMF administration with HFD induced a significant decrease in lipid droplet accumulation in the liver tissue. We demonstrated the ESMF elevated AMPK phosphoryation and activation of ACC phosphorylation in a dose-dependent manner. Our findings suggest that ESMF may be anti-obesity effect on HFD-induced mice through activating AMPK pathway.
Crucial role for non-tissue macrophages in the development of TSLP-mediated airway inflammation (P6243)
Authors: Lai Jen-Feng , Thompson Lucas , Ziegler Steven 
Published: January 2023

Abstract
Allergic asthma is a common chronic Th2-driven airway inflammatory disease. TSLP is an epithelium-derived cytokine recognized as a potent factor in the development of asthma. TSLP is known to influence the function of dendritic cells to enhance Th2 T cell responses, however many of the mechanisms underlying TSLP-induced airway inflammation remain undefined. In addition to dendritic cells, the lung tissues include other MHC class II-expressing phagocytic populations which may influence T cell responses. Among these potential antigen-presenting cells are macrophage subsets (including CD11c+ SiglecF+ F4/80+ resident tissue macrophages and CD11c-lo CD11b+ F4/80+ non-tissue macrophages) which can comprise up to 10% of hematopoietic cells in the lung during airway inflammation. Here we demonstrate that these pulmonary macrophage populations express the TSLP receptor and non-tissue macrophages are rapidly recruited to the lung tissue in response airway priming in the context of TSLP. Blockade of CCR2- and/or CX3CR1-dependent recruitment of non-tissue macrophages diminishes eosinophilic allergic airway inflammation and expression of type II inflammatory genes. These finding suggest a crucial role for non-tissue macrophages in the development of TSLP-mediated airway inflammation. By elucidating the cellular mechanisms of airway inflammation, this data will contribute to more effective therapeutic approaches for treatment of asthmatic disease.
P300, but not PCAF, collaborates with IRF-1 in stimulating TRIM22 expression, that is independent on its histone acetyltransferase activity (P6336)
Authors: Xiong Sidong , Gao Bo , Xu Wei 
Published: January 2023

Abstract
TRIM 22 plays an important role in IFNs-mediated antiviral activity. We previously demonstrated that IRF-1 was crucial for constitutive and IFNs-induced TRIM22 expression. Here, we further investigated the molecular mechanisms of IRF-1 in promoting TRIM22 expression. Using in vitro DNA affinity binding assay and in vivo chromatin immunoprecipitation assay, we found that IFN-γ stimulation significantly enhanced the binding of p300 and PCAF, but not other co-activators such as GCN-5, SRC-1 and ACTR, to the 5’ extended IFN-stimulating response element-containing region of TRIM22 promoter together with IRF-1. Overexpression and knockdown analysis demonstrated that it was p300, but not PCAF, that functioned as a transcriptional co-activator of IRF-1 in IFN-γ-mediated TRIM22 production. Further study revealed that p300 mainly participated in the IRF-1-mediated TRIM22 expression by recruiting RNA polymerase II to TRIM22 promoter, and this effect was independent on its histone acetyltransferases activity. Our study indicated that p300 might serve as a bridge between IRF-1 and the basal transcriptional apparatus in TRIM22 induction.
TLR2 is essential for immunity against lethal herpes simplex virus encephalitis (P6346)
Authors: Kollias Christina , Jennings Stephen 
Published: January 2023

Abstract
HSV-1 infection of the CNS is a serious condition. Both virus-mediated neurotoxicity and bystander inflammation contribute to pathology. Understanding the mechanisms responsible for limiting invasion and controlling overactive CNS inflammation are essential for disease prevention/treatment. Multiple cell types express TLR2, which recognizes HSV-1 glycoproteins and leads to inflammatory cytokine production. We assessed the role of TLR2 in a natural lip infection model and showed that KO mice are more susceptible to CNS infection and mortality. The KO mice displayed faster invasion, elevated viral spread, and overactive inflammatory responses in the nervous system. HSV-1 infection of the CNS drove migration of peripheral WBCs to both the WT and KO brains, therefore we were unable to discern their contribution toward mortality. Analysis of DC, NK and T cell activation and function showed these cell types were not responsible for the phenotype. These data suggested a nervous system TLR2+ cell type was essential for protection. To assess the role of TLR2 specifically within the CNS, we infected mice intracranially, however, both groups succumbed to a low dose of the McKrae strain of virus. In summary, TLR2 is critically important for controlling the level of HSV-1 that spreads to the CNS, and once the virus accesses the brain, TLR2-independent responses contribute to the heightened inflammation observed in the KO animals. We aim to identify the responsible TLR2+ cell type.
Antigen-dependent and independent NKT cell responses to microbes. (P4379)
Authors: Tyznik Aaron , Verma Shilpi , Holzapfel Keli , Hogquist Kristin , Benedict Chris , Kronenberg Mitchell 
Published: January 2023

Abstract
We have studied the antigen-dependent and independent roles of natural killer T cells (NKT cells) in the protective response to microbes. For mouse cytomegalovirus (MCMV), a β herpes virus infection, we establish that NKT cells are important for host protection. Using Nur77-GFP mice, a sensitive reporter for TCR stimulation, and other methods, we observe that rapid induction of IFNγ secretion by NKT cells induced by viral infection is independent of TCR triggering, in vitro or in vivo. Furthermore, compared to natural killer (NK) cells, NKT cells have a different requirement for APC-derived cytokines for optimal induction of IFNγ, being more dependent on IL-12. The different requirements for APC-derived cytokines suggest that there are nonredundant roles for NK and NKT cells in the innate response to viral infections. In contrast, during Streptococcus pneumoniae infection, a microbe that expresses known NKT cell lipid Ags, NKT cells rapidly expressed GFP as well as IFNγ following infection in Nur77-GFP reporter mice, suggesting a TCR-foreign lipid mediated activation. In conclusion, our data show that NKT cells mediate host protection against diverse infections by antigen-dependent and independent means.
Ets-1 interacts with NRON complex and facilitates the nuclear entry of NFAT (P6335)
Authors: Tsao Hsiao-Wei , Tai Tzong-Shyuan , Tseng William , Ho I-Cheng , Miaw Shi-Chuen 
Published: January 2023

Abstract
NFAT transcription factors are critical for the expression of IL-2 by Th cells. In resting Th cells, NFATs are phosphorylated and trapped in cytoplasm by NRON complex. Calcium dependent signals downstream of TCR lead to dephosphorylation of NFATs and disassembly of NROM complex, releasing NFAT into nucleus to transactivate IL-2. However, how the assembly and disassembly of NRON complex is regulated is not fully understood. Here we report that Ets-1, the prototype of the ETS family of transcription factors was critical for the expression of IL-2 in primary human Th cells. A sizable fraction of nuclear Ets-1 quickly exited nucleus in response to calcium dependent signals and interacted with protein components of NRON complex. Ets-1 deficiency resulted in impaired nuclear entry of NFAT proteins and their recruitment to the IL-2 promoter. To the best our knowledge, Ets-1 is the first transcription factor that is known to facilitate nuclear entry of NFAT proteins by interacting with NRON complex.
Cellular expression of the alarmin IL-33 in acute skin inflammation (P6337)
Authors: Sundnes Olav , Loos Tamara , Khnykin Denis , Rankin Andrew , Sponheim Jon , Pflanz Stefan , Haraldsen Guttorm 
Published: January 2023

Abstract
Background: IL-33, a recently described member of the IL-1-family, is an important player in a variety of inflammatory settings and is thought to be released from damaged or necrotic cells. Little work has so far been published on the cellular expression and regulation of IL-33 in inflammatory lesions. Results: In normal mouse skin IL-33 showed a nuclear expression in non-proliferating keratinocytes (Ki67-) and periglandular myoepithelial cells. After injection with Staphylococcus aureus (6h i.d.) we observed that nuclear IL-33 disappeared from keratinocytes in the center of the lesion and instead appeared in fibroblasts at the periphery. The keratinocyte layer remained intact and expressed nuclear HMGB1, revealing no evidence of overt necrosis at this time point, thus indicating possible secretion. Wound lesions of the ear showed a similar picture at the margins. At later time points IL-33 reappeared in keratinocytes, initially in a hyperproliferative, multilayer structure in which IL33 and Ki-67 remained minimally co-localized. Similarly, in cultured human keratinocytes there was constitutive expression of nuclear IL-33 in non-proliferating cells and in contrast to endothelial cells, expression levels appeared unaffected by cell density or pro-inflammatory activation (TNF-a or IL1b) Conclusion: The regulation of IL-33 in keratinocytes appears to involve molecular signals different from the regulation seen in vascular endothelial cells and deserves further investigation.