bluuebunny/crossref_metadata_2025_split huggingface dataset:
Emigration of tumor specific regulatory T cells from the bone marrow is triggered by S1P1 and correlates with their accumulation in breast tumors (TUM9P.1001)
Authors: Rathinasamy Anchana , Dettling Steffen , Ge Yingzi , Umansky Ludmila , Herold-mende Christel , Domschke Christoph , Schütz Florian , Beckhove Philipp 
Published: January 2023

Abstract
High regulatory T cell (Treg) infiltration in breast tumors is associated with reduced survival. However, the source of tumor infiltrating Treg and signals underlying their migration from lymphoid organs to the tumor tissue remain elusive. We here demonstrate that pronounced Treg infiltration in human breast tumors correlates with a selective reduction of tumor antigen specifc Treg from the bone marrow. Using MHC-II tumor peptide tetramers we furthermore show that tumor specific bone marrow Treg selectively express Sphingosine-1-phosphate receptor 1 (S1P1), the receptor that mediates cell egress. S1P1 was upregulated in Treg upon TCR stimulation mediated by bone marrow resident antigen presenting cells and triggered selective Treg but not conventional T cell migration in response to S1P gradients between bone marrow and blood which we found to be significantly increased in breast cancer patients. Taken together, our data suggests a crucial role for bone marrow antigen presenting cells in regulating the surface expression of S1P1 on tumor specific Treg in the bone marrow which may represent an important source of tumor infiltrating Treg.
Nuclear TRAF3 Inhibits CREB-mediated survival and metabolic reprogramming in B lymphocytes (TUM10P.1045)
Authors: Mambetsariev Nurbek , Lin Wai , Stunz Laura , Hanson Brett , Arkee Tina , Bishop Gail 
Published: January 2023

Abstract
TRAF3 is an adaptor protein that negatively regulates signaling through CD40 and BAFF receptor in B lymphocytes. B cells isolated from B cell conditional TRAF3-/- mice display a remarkable pro-survival phenotype compared to wild type B cells, but the mechanism for this abnormal survival is poorly understood. We find that CREB protein expression and activity - but not mRNA - were increased in TRAF3-/- B cells. Inhibition of activity of CREB and its co-activator molecule CBP attenuated the survival of TRAF3-/- B cells. Immune precipitation revealed that TRAF3 associated with both CREB and CBP preferentially in the nucleus in B cells. The TRAF-C domain was identified as necessary and sufficient for TRAF3 nuclear localization. The human TRAF3 mutant LP1 isolated from a myeloma tumor and lacking a TRAF-C domain, failed to localize to the nucleus or associate with CREB. Guided by results of microarray analysis, we found that the proteins Glut1 and Hexokinase II, two CREB targets important for glucose metabolism, were elevated in TRAF3-/- B cells and associated with enhanced glucose uptake and broad metabolic reprogramming in Seahorse extracellular flux analysis. We are currently investigating the importance of TRAF3-regulated metabolic changes to B cell survival.
Investigation of Mf-mediated suppression of B cell activation (TUM10P.1048)
Authors: Riggs James , Valiuskyte Kornelija 
Published: January 2023

Abstract
We have previously shown that C57BL/6J (B/6) peritoneal cavity (PerC) macrophages (Mfs), via IFNg-triggered iNOS expression, reduce T cell activation promoted by mitogens (ConA) or by TCR ligation (anti-CD3e, SEB, etc). We wanted to assess whether PerC B cells were also susceptible to this form of myeloid suppression. B/6 PerC B cell responses triggered by BCR {F(ab’)2 anti-IgM} and TLR4 (LPS/TLR4L) were both suppressed and could be liberated by blocking prostaglandin production with indomethacin; neutralization of IL10 also increased the LPS response. Suppression of the BALB/c (B/c) PerC B cell response to BCR ligation was similar but the TLR4 response was not suppressed. Where the addition of exogenous IL4 or IL13 suppressed the B/6 response to BCR ligation, IL4 increased this response in B/c mice. Most interestingly, the PerC B cell response to CD40 ligation was not suppressed in either strain and addition of IL10 increased this response; addition of IL4 or IL13 suppressed the B/6 response but had no impact upon B/c B cells. Concurrent CD40 and TCR ligation revealed that iNOS-mediated suppression overrides the B cell response. Considering that the high myeloid:lymphoid cell ratio found in PerC cell cultures mimics that seen in tumor microenvironments, these results serve to inform strategies designed to promote anti-cancer immunity.
IL-22+CD4+ T cells promote colorectal cancer stemness via STAT3 transcription factor activation and induction of the methyltransferase DOT1L (TUM10P.1022)
Authors: Kryczek Ilona , Lin Yanwei , Nagarsheth Nisha , Peng Dongjun , Zhao Lili , Zhao Ende , Dou Yali , Owens Scott , Zgodzinski Witold , Majewski Marek , Wallner Grzegorz , Fang Jingyuan , Huang Emina , Zou Weiping 
Published: January 2023

Abstract
Little is known about how the immune system impacts human colorectal cancer invasiveness and stemness. Here we detected interleukin-22 (IL-22) in patient colorectal cancer tissues that was produced predominantly by CD4+ T cells. In a mouse model, migration of these cells into the colon cancer microenvironment required the chemokine receptor CCR6 and its ligand CCL20. IL-22 acted on cancer cells to promote activation of the transcription factor STAT3 and expression of the histone 3 lysine 79 (H3K79) methytransferase DOT1L. The DOT1L complex induced the core stem cell genes NANOG, SOX2, and Pou5F1, resulting in increased cancer stemness and tumorigenic potential. Furthermore, high DOT1L expression and H3K79me2 in colorectal cancer tissues was a predictor of poor patient survival. Thus, IL-22+ cells promote colon cancer stemness via regulation of stemness genes that negatively affects patient outcome. Efforts to target this network might be a strategy in treating colorectal cancer patients.
Recurrence of head and neck squamous cell cancer following resection may be predicted by assessment of immune infiltrates within the tumor (TUM10P.1056)
Authors: Paustian Christopher , Feng Zipei , Hulett Tyler , Moudgil Tarsem , Dubay Christopher , Campbell Mary , Welle John , Cheng Allen , Patel Ashish , Bui Tuan , Urba Walter , Leidner Rom , Bifulco Carlo , Bell Bryan , Fox Bernard 
Published: January 2023

Abstract
Tumor immune infiltrates are prognostic for many histologies, reinforcing the importance of the immune system in patient outcomes. Here we assessed a cohort of resected HPV+ and HPV- HNSCC tumors by multispectral imaging and a 770 gene digital transcript counting platform (NanoString nCounter system) that combines markers for 24 immune populations, 30 cancer antigens and relevant immune response genes. We performed IHC on FFPE and flowcytometry on enzyme-digested tumor allowing us to identify leukocyte subsets. Preliminary results show that while B cells, T cells and myeloid cells alternately predominate in different HNSCC tissue digests, NK cells rarely seen. Roughly half of our cohort has recurred at this time. Gene expression profiles indicate that tumors derived from patients with no evidence of disease contain more immune response related transcripts than tumors from patients that recur. Analysis of our discovery cohort by UPGMA hierarchical clustering indicates that the immune infiltrates in HNSCC may prove prognostic. Importantly, there are transcripts that may indicate a negative prognosis. Among these are a number of chemokines, TGFB2, the TLR4-TRIFF bridge TICAM2 and a molecule associated with anti-viral responses, IFITM1. Since these molecules constitute possible targets for therapeutic intervention, we are working to confirm their preponderance in tumors that recur by assessing a validation cohort as well as protein confirmation by IHC.
Distinct immunological activities of four variants of one mutation-generated neoepitope of a mouse fibrosarcoma (TUM10P.1023)
Authors: Brennick Cory , Duan Fei , Srivastava Pramod 
Published: January 2023

Abstract
Passenger mutations in cancer cells can give rise to mutant MHC Class I restricted epitopes, also referred to as neoepitopes. One such neoepitope, Tnpo3 (SYMLQALCI), has been described for the BALB/c Meth A fibrosarcoma, by our laboratory1. Immunization with a peptide corresponding to the Tnpo3 neoepitope elicits antigen specific CD8+ T cells, which are capable of mediating specific rejection of Meth A. Interrogating the site of mutation within the Tnpo3 neoepitope with NetMHC predicts three other variants of Tnpo3 having the same amino terminus but different carboxyl termini. Of these four Tnpo3 variants, three elicit functional CD8+ T cells upon immunization, and of these, only one elicits tumor rejection. Here, the structural and cellular immunological aspects of the differential activities of these four neoepitopes are investigated. 1Duan F, Duitama J, Al Seesi S, Ayres CM, Corcelli SA, Pawashe AP, Blanchard T, McMahon D, Sidney J, Sette A, Baker BM, Mandoiu II, Srivastava PK. Genomic and Bioinformatic Profiling of Mutational Neoepitopes Reveals New Rules to Predict Anticancer Immunogenicity." J Exp Med. 211 (2014): 2231-248. PMID: 25245761
Post-exposure treatment with neutralizing monoclonal antibodies prevents SHIV infection in infant rhesus macaques and limits establishment of latent viral reservoirs (VAC11P.1102)
Authors: Hessell Ann , Sacha Jonah , Kahl Christoph , Graham Barney , Mascola John , Haigwood Nancy 
Published: January 2023

Abstract
We have developed a unique pre-clinical SHIV/macaque model with the potential to address translational implications of early intervention in mother-to-child-transmission (MTCT). Based on prior passive studies in this model, we hypothesized that very early therapeutic treatment with potent NmAbs would limit or ablate establishment of viral reservoirs in babies born to HIV-infected mothers. Fourteen one-month-old rhesus macaques were inoculated orally with SHIVSF162P3. Cocktails of NmAbs PGT121 and VRC07-523 were prepared for subcutaneous passive transfer. A control group of two animals did not receive NmAbs. Beginning at 24 hours (1 day) post SHIV exposure, NmAbs were delivered subcutaneously and repeated at days 4, 7, and 10. Blood samples monitored for plasma viral load (PVL) and transferred NmAb kinetics. Cell-associated viral loads (CAVL) were measured in PBMC and in tissues at necropsy. Animals were followed for 24 weeks to assess PVL, PBMC-based CAVL, and T and B cell responses. Controls were infected by three d.p.i. NmAb-treated infants had undetectable PVL with no evidence of CAVL in PBMC or tissue samples at necropsy. ICS was used to detect Gag and Vif T cell responses. No anti-SHIV T cell responses were detected in lymphocytes isolated from inguinal lymph nodes at week 20 or in necropsy tissue samples. Results indicate early therapeutic treatment with a cocktail of potent NmAbs can prevent infection and limit the establishment of latent viral reservoirs.
Isolation of Dengue neutralizing antibodies from single cell sorted human antigen specific memory B cell cultures (VAC11P.1107)
Authors: Cox Kara , Tang Aimin , Chen Zhifeng , Horton Melanie , Meschino Steven , Yan Hao , Wang Xin-Min , Dubey Sheri , DiStefano Daniel , Vora Kalpit 
Published: January 2023

Abstract
Monitoring antigen-specific memory B cells and the antibodies they encode is important for understanding the specificity, breadth and duration of immune response to an infection or vaccination. The antibodies isolated could further help design vaccine antigens for raising relevant protective immune responses. However, developing assays to measure and isolate antigen specific memory B cells is technically challenging due to the low frequencies of these cells that exist in the circulating blood. Here we describe a method to develop a direct flow cytometric assay for the detection of Dengue envelope-specific memory B cells using a Dengue envelope specific mouse hybridoma line. We used this flow cytometry assay and a cultured B ELISPOT assay to enumerate Dengue-envelope specific B memory cells from a cohort of Dengue seropositive donors. Furthermore, we were able to culture the single sorted Dengue-envelope specific memory B-cells and differentiate them into plasma cells using cell lines expressing CD40L. The culture supernatants were assayed for antigen binding and the ability of the antibodies to neutralize the cognate dengue virus. Moreover, we successfully isolated the heavy and light Ig sequences and expressed them recombinantly as full length antibodies to reproduce the activity seen in culture supernatants. In conclusion, we have established a robust methodology to enumerate antigen-specific memory B-cells and assay their encoded antibodies for functional characterization.
Antibody-mediated toxin aggregation correlates with the ability of heterodimeric camelid antibodies to passively protect mice against ricin (VAC11P.1108)
Authors: Herrera Cristina , Tremblay Jacqueline , Shoemaker Charles , Mantis Nicholas 
Published: January 2023

Abstract
Ricin belongs to the A-B toxin family that also includes Shiga and cholera toxins. While immunity to ricin is antibody (Ab)-mediated, it is unclear what functional qualities of Abs are associated with immunity to ricin, considering that Abs with potent toxin-neutralizing activity (TNA) in vitro are not always protective in vivo. We recently produced a collection of alpaca heavy-chain only Abs (VHHs) specific for ricin’s enzymatic (RTA) and binding (RTB) subunits. To better define the attributes associated with immunity to ricin, we engineered VHH homodimers and heterodimers and characterized them in vitro and in vivo. Dimeric VHHs had 10-fold improved binding affinities for ricin and had 2-3 times increased TNA as compared to their monomeric constituents. However, neither improved affinity nor increased TNA correlated with a VHH’s ability to protect in vivo. Instead, immunity was associated with heterodimers composed of an RTA and an RTB monomer in which at least one had TNA. Analytical ultracentrifugation showed that all five protective heterodimers identified in this study promoted ricin aggregation in solution. The same five VHHs also prevented ricin from binding to cell surfaces in vitro. We propose that toxin aggregation and/or inhibition of attachment are likely key determinants of antibody-mediated protective immunity to ricin and possibly other A-B family members.
Preliminary assessment of hepatitis B-specific cellular immunity amongst a longitudinal vaccine cohort demonstrates evidence of natural exposure. (VAC11P.1110)
Authors: Simons Brenna , Spradling Philip , Zanis Carolyn , Choromanski Tammy , Case Samantha , Bruce Michael , Bruden Dana , Murphy Trudy , Knall Cindy , McMahon Brian 
Published: January 2023

Abstract
Duration of protection after hepatitis B (HB) vaccination is unknown; therefore, we examined humoral and cellular immunity among persons living in an area endemic for HBV, 30 years post-vaccination. Measurement of antibody to hepatitis B surface antigen (anti-HBs) indicated 51% (n=217) of persons retained anti-HBs titer ≥10mIU/mL. However, of persons who lost anti-HBs (&lt;10mIU/mL) and received a booster dose, 89% responded. Our objective was to conduct a preliminary comparison of cellular and humoral immunity characteristics between persons who retained (n=28) anti-HBs levels ≥10mIU/mL and those who did not (n=18). Immune cell frequency was assessed by flow cytometry (B cell, T cell, memory, Treg, PD-1, CD57, NK/NKT). PD-1hiCD3+ lymphocytes were significantly increased (p = 0.047) in persons who maintained anti-HBs titer ≥10mIU/mL. Peripheral Blood Mononuclear Cells (PBMC) were stimulated directly ex vivo with whole HB Core Antigen or HB Surface Antigen and assessed for cytokine response. Results indicated no significant difference in the magnitude of HB Surface Antigen-specific responses in persons who maintained anti-HBs ≥10mIU/mL and those who did not. HB Core Antigen-specific TNFα responses were significantly higher (p=0.01) in persons who had lost anti-HBs titer. The observed cellular responses to HB Core suggest natural exposure amongst the cohort. Understanding cellular immunity afforded by the HB vaccine is critical to determining long-term protection.
A broadly protective anti-influenza neuraminidase monoclonal antibody (VAC11P.1100)
Authors: Hashem Anwar , Doyle Tracey , Li Changgui , Van Domselaar Gary , Wang Junzhi , Hurt Aeron , Brown Earl , Li Xuguang 
Published: January 2023

Abstract
Hemagglutinin (HA) and neuraminidase (NA) are the major surface glycoproteins of influenza viruses and the main targets of vaccine-induced antibodies (Abs). While several broadly neutralizing anti-HA Abs can cross-protect against diverse influenza subtypes, NA-specific Abs could only protect partially against strains from the same subtype. Through comprehensive bioinformatics analyses of all publicly available influenza A and B NA sequences, we found a universally conserved 9-mer peptide (ILRTQESEC) amongst all influenza NA proteins (amino acids 222-230). Growth kinetics of recombinant viruses with single alanine substitutions within this epitope proved its crucial roles in viral fitness and replication. Importantly, a monoclonal Ab (HCA-2 mAb) raised against this sequence showed broad in vitro inhibition against multiple strains from all influenza A NA subtypes (N1-N9) and influenza B lineages. It also provided in vivo heterosubtypic protection against lethal doses of H1N1 and H3N2 strains. Amino acid residues I222 and E227, located in close proximity to the active site, were found to be indispensable for inhibition by HCA-2 mAb. These findings reveal the essential role of this highly-conserved sequence in NA function and viral replication and show that it is sufficiently exposed to allow access of inhibitory Abs during the course of infection. Thus, it could represent a potential target for novel antivirals or vaccines against diverse strains of influenza A and B viruses.
Immune checkpoint blockade activates effective anti-tumor immunity in an orthotopic model of glioblastoma (VAC12P.1119)
Authors: Klein Sarah , Gokhale Praful , Jones Kristen , Saur Amy , Rodig Scott , Liao Xiaoyun , Kohl Nancy , Reardon David , Freeman Gordon 
Published: January 2023

Abstract
Glioblastoma presents a formidable obstacle for developing immunotherapeutic strategies due to a highly immunosuppressive systemic and micro-environment. Antibody blockade of co-inhibitory receptors CTLA-4 and PD-1 has been shown to overcome immunosuppression in clinical trials of various solid tumors. We evaluated the anti-tumor efficacy of murine antibodies targeting CTLA-4 and/or PD-1 in the GL261 orthotopic, immunocompetent mouse model of glioblastoma. We observed tumor regression and long-term survival in 15% and 50% of mice treated with anti-CTLA-4 or anti-PD-1 as single agents, respectively. Combination therapy resulted in 75% of animals surviving long-term and tumor-free. Importantly, similar efficacy was observed with both early (day 7) or late (day 14) onset of treatment, thus this therapeutic strategy was effective on established tumors. Furthermore, resistance to tumor re-challenge demonstrated the generation of immunological memory in treated mice. Upon investigating the systemic and tumor immunological profile, we discovered that combination therapy increased CD8+ and NK effector cells and decreased suppressive immune cells at the tumor site and draining lymph node. In addition, combination therapy increased the serum levels of various monocyte chemo-attractant chemokines involved in immune activation. Our data provide strong support for the evaluation of immune checkpoint blockade in glioblastoma patients, and predicts potential prognostic serum biomarkers.
Anti-CD25 antibody and denileukin diftitox deplete regulatory T cells in ID8 ovarian cancer equally, but αCD25 promotes more T cell cytotoxicity that correlates with better survival (VAC12P.1112)
Authors: Drerup Justin , Liu Aijie , Hurez Vincent , Curiel Tyler 
Published: January 2023

Abstract
In ovarian cancer (OC) regulatory T cells (Tregs) block anticancer immunity, suggesting Treg depletion could be beneficial. In our phase 2 denileukin diftitox (DDT) trial we found no clinical efficacy in 19 OC patients despite Treg depletion. αCD25 depletes Tregs but reportedly only works as cancer prophylaxis. We found that αCD25 did not treat subcutaneous B16 mouse melanoma whereas DDT did, and both reduced Tregs equally. We further show that in intraperitoneal ID8 challenge, αCD25 depletes Tregs in ascites and strikingly extends survival better than DDT, the first demonstration that αCD25 is effective cancer treatment (vs prophylaxis). Treg suppression of T cell proliferation in vitro from ID8-bearing mice was equal after DDT or αCD25. DDT and αCD25 could thus target or modulate Treg subsets or other immune cells differentially, as neither is Treg-specific. Despite reduced clinical efficacy, DDT increased beneficial IFN-γ+CD4+ and ID8-specific CD8+ T cells and NK cells in ascites better than αCD25, but also increased pro-tumorigenic IL-17+ and TNF-α+ CD4+ T cells, whereas αCD25 did not. αCD25 increased numbers of ascites GzB+CD107a+CD8+ T cells whereas DDT did not, suggesting increased cytotoxicity that could explain better clinical efficacy. These observations show that Treg depletion agents available for clinical use have distinct effects on antitumor immunity, help define clinical indications for αCD25 versus DDT and identify responsive cancers or anatomic compartments.
Strong systemic cancer immunostimulatory therapies cause stress-induced acute thymic involution (VAC12P.1114)
Authors: Sckisel Gail , Mirsoian Annie , Tietze Julia , Monjazeb Arta , Blazar Bruce , Wiltrout Robert , Murphy William 
Published: January 2023

Abstract
Agonistic immunotherapeutic regimens are being increasing applied in cancer. The thymus, and therefore naïve T cell output, is highly sensitive to stress environments. We therefore investigated thymic function following stimulatory cancer regimens (CpG, high-dose IL-2, anti-CD40) and found that acute thymic involution (TI) occurred in young mice within days of treatment initiation and recovered by two weeks post treatment cessation. Acute TI was hallmarked by a spike in systemic corticosterone levels and adrenalectomy prevented the involution suggesting it was mediated by glucocorticoids. Cancer patients are typically aged and, with obesity being a major risk factor, becoming increasingly obese as well. Both aging and obesity are associated with premature immune senescence, notably chronic TI. Data investigating the recovery from acute TI in the context of ongoing chronic TI are lacking since the vast majority of preclinical models involve the use of young mice (2-4ms). Treatment of obese and aged mice also resulted in acute TI. Using a congenic bone marrow adoptive transfer model, we tracked thymic recovery across young lean, obese, and aged models to show that recovery differed in magnitude and quality of T cells in the obese and aged. These data have profound implications for the long term risks of delayed thymic recovery and naïve T cell output which can increase susceptibility to infections in aged and obese cancer patients following systemic immunostimulatory regimens.