bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural IgM is produced by B1a cell-derived bone marrow plasma cells that do not share a survival niche with IgG AFC. (P1467)
Authors: Reynolds Alexander , Kuraoka Masayuki , Kelsoe Garnett 
Published: January 2023

Abstract
Natural antibody makes up the majority of serum IgM and provides protection against both infection and autoimmunity. The B1 lineage is required for natural IgM, but the location and identity of the cells that secrete natural IgM are uncertain. B1-8i VHDJH knock-in mice lack virtually all B1a cells, but have normal B2 cell development and support robust splenic B2 populations. The loss of B1a cells is associated with a 10-fold reduction in serum IgM, whereas serum IgG levels are normal. We examined B1-8i mice and found a 10-fold reduction in the number of IgM AFC in the BM, while BM IgG AFC populations were normal. As B1 cells themselves do not secrete substantial amounts of antibody, our observation indicates that the BM is the major source of natural serum IgM, and that BM IgM plasmacytes require the presence of B1a cells. By FACS and histology, we determined that IgM-secreting cells in BM are CD5- CD138high and appear as differentiated plasma cells, not small B1a cells. Examination of BM revealed that while cytoplasmic IgG+ cells preferentially co-localize with eosinophils, cytoplasmic IgM+ cells do not. This localization correlated with an enhanced survival of IgG AFC, but not IgM AFC, from sorted CD138high BM cells cultured with IL-6. We propose that B1a cell-derived BM plasma cells produce natural serum IgM, and that these cells occupy a survival niche distinct from IgG AFC.
Primary repertoire expansion by junctional diversity in Bos taurus (P1445)
Authors: Liljavirta Jenni , Ekman Anna , Niku Mikael , Iivanainen Antti 
Published: January 2023

Abstract
B cell development varies significantly between species. In many domestic species fetal and neonatal gut-associated lymphoid tissue is essential for the generation of the primary antibody repertoire due to limited range of Ig genes. In fetal ruminants, the repertoire is expanded by somatic hypermutation (SHM) driven by activation-induced cytidine deaminase in the absence of external antigens. In addition to SHM also other mechanisms are likely to contribute to the repertoire expansion. Junctional diversity (JD) created during the recombination process might play a substantial role in bovine fetal IgH. To further characterize the significance of JD, we studied the tissue-specific expression of terminal deoxynucleotidyl transferase (TdT) using RT-qPCR and immunostaining. We also constructed and sequenced several IgH cDNA libraries of different tissues and analysed the junction formation between V(D)J sequences. Our work demonstrates that in fetal bovine B lymphocytes TdT is primarily expressed in the bone marrow. B lymphocytes in other lymphoid tissues did not show elevated TdT expression levels. V(D)J junctions were heterogeneous in sequence, suggesting the addition of N-nucleotides by TdT. In addition, spectratyping revealed significant differences in the distribution of CDR3 lengths between tissues. Our results suggest that along with SHM, TdT-mediated JD contributes significantly to the bovine primary antibody repertoire in fetal life.
Nr4a1 (Nur77) regulates B cell survival and activation. (P1453)
Authors: Park Kiwon , Nowyhed Heba , Hedrick Catherine 
Published: January 2023

Abstract
NR4A1 (Nur77) is a member of the NR4A family of orphan nuclear receptors that function as transcription factors. Nur77 is expressed in immune cells, including macrophages, T cells and B cells. However, the role of Nur77 in B cells is not understood. In bone marrow, Nur77 is expressed in early lymphoid precursors and is nearly absent (or maintained at low level) in Pre-pro B cells and in all stages of development through small pre B cells. However, newly formed immature B cells in bone marrow start to express low levels of Nur77 and Nur77 expression increases during transitional stages of B cell development and is maximal in mature B cells in periphery. To investigate the role of Nur77 in B cells, we compared B cell functionalities from normal C57BL/6 and congenic Nur77-deficient mice. We found that Nur77-deficient mice have significantly elevated levels of all four classes of antibodies, which implicates autoimmunity. Nur77-/- mice have 10% more BAFFR+ T1 (transitional stage 1) B cells than WT. Nur77-deficient naïve mice show a 3-fold increase of GL7+ germinal center B cells and a 60% increase of CD38hi memory B cells, compared to those from WT. Those data indicated Nur77-/- mice undergo autoimmunogenic B cells response. In addition, we found that Nur77-/- B cells that are stimulated by anti-IgM and anti-CD40 survived better than WT B cells. Our data suggest that Nur77 plays a primary role in B cell survival and activation.
CD40 exon 8 deficiency causes a novel form of immunodeficiency with hyper-IgM (P3327)
Authors: Li Yi , Li Shiwu , Wang Hai , Sun Yu , Segal Emma , Xu Yuan , Zhuang Haoyang , Han Shuhong , Sobel Eric , Satoh Minoru , Yang Li-Jun , Reeves Westley 
Published: January 2023

Abstract
Introduction: The germinal center (GC) reaction generates switched memory B cells and plasma cells. Mutation of CD40L or other genes involved in the GC reaction causes hyper-IgM syndrome (HIM). Hypothesis: We evaluated a 56-year-old woman who had an immunological phenotype resembling HIM but only mild immunodeficiency. The age, gender, and clinical presentation were not readily explained by known HIM mutations and we hypothesized that the patient might have a novel mutation. Method: The patient’s immune function was evaluated and CD40 DNA/RNA sequences were determined. The patient’s CD40 cDNA lacking exon 8 (Δexon8) was cloned and transfected into 293 cells. Signaling downstream of CD40 was assessed. Results: By flow cytometry, the patient’s peripheral blood lacked switched memory B cells. The patient mounted a robust IgG response to tetanus toxoid immunization, but antibody levels dropped precipitously suggesting that there was a problem generating long-lived plasma cells. Although CD40 expression was mildly decreased, cDNA sequences showed a deletion of the entire exon 8 of CD40 in 67% of her cDNA clones. This was rare in controls. Expression of CD40-Δexon8 in 293 cells resulted in surface expression of CD40, but signaling downstream of CD40 upon sCD40L stimulation was impaired. Conclusion: This patient has a novel immunodeficiency syndrome due to deletion of exon 8 of CD40, which encodes a cytoplasmic domain critical for signal transduction.
Deep sequencing of the IgH locus in CVID reveals global alterations in central and peripheral B cell development (P3329)
Authors: Simchoni Noa , Roskin Krishna , Boyd Scott , Cunningam-Rundles Charlotte 
Published: January 2023

Abstract
Common Variable Immunodeficiency (CVID) is the most common clinically important primary immune deficiency, affecting roughly 1:25,000 persons and characterized by hypogammaglobulinemia and loss of specific antibody (Ig) production. The causes are poorly understood, but defective B cell activation has been demonstrated. Examining the Ig repertoires of patients could help elucidate early and late B cell maturation. Rearranged Ig heavy chains were sequenced on the Roche 454 for 78 well-characterized patients, with or without non-infectious complications, and 27 healthy controls. Reads were parsed into component genes and structural segments using the iHMMune-align algorithm. Comparison of the repertoires was done in R, or with a combination of SQL and Prism. CVID subjects consistently showed altered central B cell development, with fewer in-frame sequences (85 v 86%, p&lt;0.01), shorter in-frame CDR3 segments (48.1 v 49.6bp, p&lt;0.0001), and VDJ recombination biased away from nontemplated and towards germline-encoded nucleotides. Peripheral somatic hypermutation was also defective in CVID, with fewer mutations both overall (0.6 v 1.5% of V bases, p&lt;0.0001) and in mutated sequences (3.1 v 5.8%, p&lt;0.0001), and fewer in-frame mutated sequences (83.4 v 89.2%, p&lt;0.0001). CVID subjects with &lt;0.55% circulating isotype switched memory B cells showed more severe defects. Defective B cell activation has been shown in CVID; here we demonstrate intrinsic differences in early B cell development.
Sub-phenotypes of Systemic Lupus Erythematosus are associated with genetic sequence polymorphisms in the IRF5-TNPO3 region of chromosome 7 (P3317)
Authors: Zoller Erin , Kottyan Leah , Hawtrey Samantha , Kaufman Kenneth , Harley John 
Published: January 2023

Abstract
Systemic Lupus Erythematosus (lupus) is a systemic autoimmune disorder with a strong genetic etiology. A recent fine-mapping study of the IRF5-TNPO3 lupus association revealed two genetic effects that independently increase lupus risk. We tested the hypothesis that variants in the IRF5-TNPO3 region are also associated with the clinical presentation of lupus. We performed a case-only sub-phenotypic association study using 101 genetic variants in the IRF5-TNPO3 region that were genotyped in 8,395 lupus patients across four ancestral populations. In Europeans Americans with lupus, the age-of-onset (p-value=2.44x10-16, OR=0.68) and the presence of anti-Ro (p-value=2.09x10-7, OR=0.67) and anti-dsDNA (p-value=4.15x10-7, OR=0.75) autoantibodies are associated with genetic variants in the IRF5-TNPO3 locus. In a step-wise logistic regression analysis of age-of-onset, variants are associated in both the IRF5 promoter and the independent genetic effect spanning IRF5 and TNPO3. In contrast, the presence of anti-Ro and anti-dsDNA autoantibodies is only associated with genetic variants in the IRF5 promoter. No other sub-phenotypic analysis in any ancestry demonstrated association after permutation tests were applied to correct for multiple hypothesis tests. In conclusion, genetic variants in the two genetic effects of the IRF5-TNPO3 locus independently affect the age-of-onset and production of anti-dsDNA and anti-Ro autoantibodies in European American lupus patients.
4-1BBL costimulation enables CD4 T cells expressing a CD28/zeta chimeric antigen receptor to eliminate aggressive leukemia. (P4338)
Authors: Condomines Maud , Zhao Zeguo , Wang Xiuyan , Kloss Christopher , Davila Marco , Sadelain Michel 
Published: January 2023

Abstract
Adoptive T-cell therapy using chimeric antigen receptor (CAR) engineered T cells is a promising cancer treatment. First generation CARs include an scFv targeting a surface antigen and the CD3ζ chain to direct tumor cell killing. CAR transduced T cells however need appropriate costimulation to proliferate and persist. Here we assessed in a B-cell leukemia xenograft model, the anti-tumor activities of human T cells transduced with an anti-CD19 CAR harboring the zeta chain alone (19z1+), fused to the CD28 or 4-1BB cytoplasmic domain (1928z+), (19BBz+), along with 4-1BBL (19z1-4-1BBL+), or with CD28 and 4-1BBL (1928z-4-1BBL+). We observed total tumor regression in NALM-6 bearing NSG mice treated with 1928z-4-1BBL+ T cells and no or partial regression in the other T-cell groups, as measured by bioluminescence imaging. 1928z-4-1BBL+ T cells showed the highest bone marrow accumulation and persisted the most. Experiments utilizing purified T cell subsets revealed that naïve and central memory 1928z-4-1BBL+ CD4+ T cells are sufficient to trigger leukemia eradication and are necessary to support CD8+ T-cell in vivo expansion. 1928z-4-1BBL+ CD4+ T cells displayed reduced apoptosis and increased cytotoxicity compared to 1928z+ CD4+ T cells. Thus, constitutive 4-1BBL expression and CAR-mediated CD28 signaling afforded the most efficient costimulatory combination to generate long-lived T cells capable of eradicating aggressive leukemia.
CAR mediated redirection of Teff and Treg cells for the treatment of cancer and autoinflammation (P4340)
Authors: Eshhar Zelig , Waks Tova , Globerson-Levine Anat , Blat Dan 
Published: January 2023

Abstract
T cells expressing chimeric, antibody based receptor (CART cells or T bodies) recognize their target and execute their destined function in none MHC restricted manner. Effector T bodies lyse their target and secrete effector cytokines whereas regulatory T cells produce suppresive cytokines. In an attempt to optimize the performance of Teff and Treg T bodies, we used murine models with spontanous or induced pathology; mammary cancers in the HER2NG mice, over expressing Her2/neu, or the CEABAC transgenic mice expressing low levels of CEA in its colon. In the first system we found that i.v. injections of Her2/neu Teff T bodies delayed the apperance of mammary tumors. When injected to tumor bearing mice, Tbodies accumulated in the mammary lesion. Yet, to eradicate the tumors, repeated injections were needed. A single intratumoral injection of Teff T bodies rejected large tumors, nevertheless, most tumors relapsed. In the second system, naïve Tregs were modified to express a CEA-specific CAR and transferred into colitic CEA transgenic mice. Colitis was induced by azoxymethane-DSS that develop colitis and later on colorectal tumors. The other colitis model was induced by i.v.injection of CEA-specific Teff T bodies. The adoptive transfer of the Treg T-bodies markedly reduced the severity of colitis as monitored by endoscopy. Moreover, in the AOM-DSS model CEA-Treg T-bodies significantly decreased the subsequent tumor burden.
Novel immunotherapy for AML using DNT cells (P4348)
Authors: Zhang Li , Li Xujian , Schuh Nicholas , Joe Betty , Allen Christopher , Chen Claire , Der Sandy , Minden Mark , Dick John , Schuh Andre 
Published: January 2023

Abstract
Acute myeloid leukemia (AML) is the most common form of adult acute leukemia with very poor survival due to high relapse rates after chemotherapy. New therapeutic approaches that can effectively prevent relapse are needed. Human CD56-CD3+CD4-CD8- double negative T cells (DNTs) are a small subset of peripheral T cells. We have developed a protocol enabling ex vivo expansion of DNTs from both healthy donors and AML patients and showed recently that these DNTs have potent anti-leukemia activity in vitro. Here we further characterized the anti-leukemia properties of DNTs in vivo using a murine xenograft model. Following infusion into NSG mice, human DNTs proliferated and persisted for at least 14 days, and were detectable in spleen and bone marrow. DNTs did not kill normal bone marrow cells in vitro or in vivo. Unlike infusion of CD4+ or CD8+ T cells, DNT infusion did not cause graft-vs-host disease. Pre-treatment of AML blasts with allogeneic DNTs in vitro led to a 4-fold reduction in subsequent engraftment of CD45+CD33+ AML blasts in NSG mice. Further, infusion of DNTs expanded from an AML patient resulted in a 75% reduction in autologous CD33+ and CD34+ leukemia cell engraftment in NSG mice. These studies demonstrate that expansion of DNTs to therapeutic quantities is possible and that DNTs may be used as a novel immunotherapy to reduce AML burden by targeting primary leukemic blasts and potentially leukemic stem cells.
Human blood Tfh cells (P4534)
Authors: Crotty Shane , Locci Michela , Havenar-Daughton Colin , Kroenke Mark , Haddad Elias 
Published: January 2023

Abstract
Follicular helper (Tfh) CD4 T cells are the specialized T cells for B cell help, required for development of germinal centers and most B cell memory. T cell help is frequently a limiting factor for these processes. Therefore understanding Tfh cells is important for developing rational vaccine strategies. Tfh cells are also potentially extremely useful biomarkers in human vaccine clinical trials as predictors of long-term humoral immunity. We have therefore pursued an understanding of the phenotype, transcription factors, and functions of Tfh cells in humans. CXCR5+ CD4 T cells are present in human blood, and constitute ~20% of CD45RO+ cells. There are differences of opinion as to whether these “blood Tfh” are memory cells or not. We have performed a series of experiments subsetting the blood CXCR5+ cells into 4 groups based on differential expression of Tfh associated surface markers. Gene expression profiling indicates that one of the four groups is the most related to active Tfh in human lymphoid tissue. All four populations have significant gene expression differences from CXCR5lo memory CD4 T cells in blood. Furthermore, a series of functional studies indicates that these four subsets of CXCR5+ cells differ in their capacity to help B cells. We are assessing whether long term memory cells are present in one or more of these blood Tfh subpopulations. These studies examining the functions and ontogeny of blood Tfh cells are important for the field of vaccine design.
A novel platform to generate peptoid-based mimetic vaccines (P4504)
Authors: Case Allison , Desmond Angela , Yi Kate Jiyeun , Chakravarty Pavitra , Smallshaw Joan , Collins Angela , Dye Kelly , Mapes Kelly , Ruback Steve , Yang Jue , Tran Helen , Connolly Michael , Zuckermann Ronald , Chirayil Sara , Luebke Kevin , Astle John , Reddy M. , Kodadek Thomas , Vitetta Ellen 
Published: January 2023

Abstract
The aim of this research is to generate vaccine candidates for any virus for which a neutralizing monoclonal antibody exists without prior knowledge of the protective epitope. We have developed a platform to generate such vaccine candidates and are working on a device to automate their identification. The platform consists of libraries of B cell epitopes prepared by displaying peptoid sequences on beads, screening with neutralizing monoclonal antibodies to select peptoids bound by the antigen binding site of the monoclonal antibody, and retaining the antibody-bound peptoids with protein G dynabeads and a magnet. Peptoids are similar to peptides but with the R group attached to the nitrogen instead of the carbon. They are haptens that can be attached to protein carriers to elicit anti-peptoid antibody responses. We have conducted platform optimization and proof-of-principle testing using FLAG peptide and anti-FLAG monoclonal antibody. We then applied the optimized platform to screen peptoid libraries with monoclonal anti-FLAG and identified two potential mimetics. Mice immunized with the peptoids have made FLAG peptide-reactive antibodies, thereby demonstrating proof of concept. Implementation of this platform with neutralizing monoclonal antibodies we have in hand against HIV, West Nile virus and hepatitis C virus can identify potential mimetic vaccine candidates without prior knowledge of important epitopes, and could represent an entirely new way to generate safe vaccines.
Mechanisms of soluble program death 1 fusion DNA vaccine with antigen-specific enhanced adaptive immunity (P4497)
Authors: Zhou Jingying , Cheung Allen , Tan Zhiwu , Chen Zhiwei 
Published: January 2023

Abstract
Previously a well-defined dendritic cell (DC)-targeting strategy of anti-DEC205 based vaccine shows highly enhanced CD4+ T cell immunity. We have demonstrated that a DNA vaccine with soluble (s)PD1 fused with HIV-1 p24 antigen can greatly enhance p24-specific humoral and cellular immune responses in mice by targeting DCs. Consequently, we compared the efficacies of the two vaccines in our system and found that sPD1-based DNA vaccination induced higher functional CD8+ T cell responses. Although the binding and uptake of encoded fusion proteins are similar between sPD1-p24 and anti-DEC205-p24 in DCs in vitro, transfer of DCs pulsed with these proteins into mice resulted in the sPD1-p24 group eliciting higher IFN-γ releasing CD8+ T cells. These data suggests that different mechanistic pathways exist between the two DC-targeting strategies. We examined the route of antigen processing/presentation by confocal microscopy and found that sPD1-p24 protein co-localized to both Rab14 and Lamp1 endosomal compartments used for MHC class I and II presentation, respectively, while anti-DEC205-p24 was only found in the latter. In addition, sPD1 DNA vaccination resulted in draining lymph node DCs with elevated CD40 and MHC class II expression with higher production of IL-12 compared to anti-DEC205. The mechanism of sPD1-based vaccination in enhancing CD8+ T cells immunity is likely dependent on DC-targeting and activation, production of Th1 cytokines and antigen cross-presentation.
The impact of IL-4 on the CD8 T cell response to infection (P4483)
Authors: Hamilton Sara , Lee June-Yong , Lee You Jeong , Hogquist Kris , Jameson Stephen 
Published: January 2023

Abstract
IL-4 influences the development of memory-phenotype, IFNγ-producing, CD8 T cells and plays a critical role in the generation of antigen-specific memory cells during liver-stage malaria infection. Elevated IL-4 levels, which can be efficiently created by treatment with IL-4 cytokine-antibody complexes (IL-4C), enhances the number of CD8 memory T cells displaying high expression of CXCR3 and Eomes, but low levels of T-bet. This is in contrast to treatment with IL-2 cytokine-antibody complexes (IL-2C) that generate T-bet high, Eomes and CXCR3 low, and granzyme B expressing cells. IL-2C and IL-4C also caused differential responses to an acute pathogen. Whereas IL-2C treatment of naïve C57BL/6 mice produced a significant improvement in clearance of Listeria monocytogenes(LM) infection, IL-4C failed to have an effect, despite a large expansion of the CD8 memory pool. Interestingly, BALB/c mice, which are known as a “Type-2” or naturally IL-4 high mouse strain, demonstrated better clearance of LM after IL-4C treatment. This suggests that depending on the mouse strain, there may be intrinsically different CD8 T cell signals generated in response to γc cytokines, with global functional consequences for the host. Future studies will explore both the functional significance of IL-4 at different stages of the CD8 T cell response to LM and malaria and ask whether IL-4C treatment is able to augment immunity.
The Ron receptor tyrosine kinase, macrophage heterogeneity and obesity associated disease. (P5070)
Authors: Hankey Pamela , Yu Shan 
Published: January 2023

Abstract
Macrophages play a central role in the progression of obesity associated disease. Macrophages are generally classified into two distinct programs, termed M1 and M2 macrophages, polar ends of a spectrum of potential macrophage activation states. The ability to tip the balance of macrophage activation away from inflammatory M1 cells and toward a reparative M2 phenotype could be beneficial in the treatment of chronic inflammation associated with obesity. The Ron receptor is expressed on tissue resident macrophages and plays a critical role in suppressing inflammation while promoting hallmarks of M2 macrophage activation. Here we show that Ron plays a protective role in the progression of atherosclerosis and hepatic steatosis in obese animals, associated with decreased inflammatory cytokine expression and decreased lipid deposition in these tissues. In lean animals, Ron is highly expressed on resident macrophages in adipose tissue. Upon weight gain, the expression of Ron is decreased and there is shift in the relative percentages of M1/M2 cells in Ron deficient mice, favoring an inflammatory environment. The percentage of Ron+ cells was also reduced in the liver and atherosclerotic plaques, while pro-inflammatory cytokine expression in isolated macrophages was enhanced in the absence of Ron. We predict that Ron is a potential marker for reparative macrophages and that the gene expression profile of macrophages from obese animals will correlate with Ron expression in these cells.