bluuebunny/crossref_metadata_2025_split huggingface dataset:
2D affinity measurements of primary and secondary polyclonal CD4+ effector T cells in lymphocytic choriomenengitis infection (P6121)
Authors: Andargachew Rakieb , Evavold Brian 
Published: January 2023

Abstract
T cells have been shown to undergo affinity/avidity maturation through selective expansion of higher affinity/avidity (tetramer positive) cells, resulting in the narrowing of the antigen specific repertoire over the course of primary and secondary immune responses. Using a highly sensitive two dimensional micropipette adhesion frequency assay (2D) to measure polyclonal CD4+ T cell affinities, we determined if affinity maturation occurred between primary and secondary peak effectors in lymphocytic choriomenengitis virus (LCMV) infection, and if measured affinities correlated with functional avidity. The 2D assay detected 4-5 fold more antigen specific high and low affinity cells than tetramer in both primary and secondary infection, but both 2D and tetramer indicated a 2-3 fold decrease in the frequency of LCMV specific CD4+ cells in the homologous viral rechallenge response. The range of affinities of the antigen specific repertoire was more restricted during secondary infection contracting to a narrower sixteen fold from the wider hundred fold range of the primary response. By functional avidity, secondary effectors were more sensitive to antigen despite a 3 fold decrease in their measured average affinity. Therefore, in this homologous viral rechallenge model, affinity maturation did not occur between primary and secondary effectors, and affinity did not correlate with functional avidity.
Cell intrinsic gp130 signaling is vital for virus specific CD4 T cell survival and interleukin 21 production during late stages of chronic viral infection (P6131)
Authors: Harker James , Dolgoter Aleksandr , Zuniga Elina 
Published: January 2023

Abstract
Infection with chronic viral infections such as human immunodeficiency virus-1 and hepatitis C virus significantly increases the risk of developing cancer. CD4 T cells number and function are critical in determining the outcome of chronic viral infections in both mice and humans, but little is known about the signals that promote their survival or helper functions in this highly immunosuppressive environment. Here we showed that exclusive ablation of the common interleukin-6 family co-receptor, gp130 in T cells profoundly compromised the numbers of virus-specific CD4 T cells, their differentiation into T follicular helper cells and IL-21 production at late (but not early) stages of a chronic murine viral infection. This was accompanied by a marked reduction in both virus-specific CD8 T cells and antibodies and a severe failure to control the virus. Notably, cell-intrinsic signaling by the IL-6 family cytokine IL-27 was necessary for CD4 T cell survival while IL-6 was required for optimal T follicular helper cell differentiation. Contrastingly IL-6 and IL-27 were both capable of inducing IL-21 production by virus specific CD4 T cells, but neither was essential in vivo. Our data situates direct gp130 signaling in CD4 T cells at the center of antibody and CD8 T cell mediated immune responses during an established chronic viral infection, highlighting its potential as a therapeutic target against such infections.
Competition for antigen selects T cell responses that undergo memory inflation and maintains clonal dominance during MCMV infection (P6091)
Authors: Snyder Christopher , Turula Holly , Farrington LIla , Grey Finn , Hill Ann 
Published: January 2023

Abstract
Cytomegalovirus (CMV) establishes a life-long, persistent/latent infection. Continuous immune surveillance by CMV-specific CD8+ T cells results in their accumulation over time, a process called “memory inflation”. These “inflationary” T cells migrate systemically and comprise the largest T cell populations in humans, making CMV-based vaccines attractive. Using recombinant murine (M)CMV expressing the SIINFEKL peptide, we found that SIINFEKL-specific T cells inflated at the expense of T cells specific for other MCMV-derived peptides. However, co-infecting mice with viruses expressing and lacking SIINFEKL enabled T cells with multiple specificities to inflate, implying T cell competition for antigen at the level of the infected target. Such competition was also observed among SIINFEKL-specific T cells. Adoptively transferred OT-I T cells, which have a high affinity for the SIINFEKL peptide, were preferentially enriched shortly after infection and inhibited the inflation of host-derived T cells specific for SIINFEKL. Importantly, we observed sporadic, late rejection of OT-Is as a result of minor histocompatibility differences, and only such rejection enabled host-derived T cells to inflate robustly. These data imply that relative clonal abundance is actively maintained by competition. Together, these data show that T cell competition for antigen during MCMV infection dictates which T cell responses inflate and even which clones dominate within a response.
T cell responses against structural proteins develop rapidly during acute simian varicella virus infection and are maintained during viral latency (P6133)
Authors: Haberthur Kristen , Kraft Aubrey , Meyer Christine , Asquith Mark , Dewane Jesse , Messaoudi Ilhem 
Published: January 2023

Abstract
Varicella zoster virus (VZV) is the etiological agent of varicella and herpes zoster. Clinical observations suggest that successful control of VZV during both primary infection and reactivation is mediated by cellular rather than humoral immunity. Numerous studies have characterized T cell responses directed against select VZV open reading frames (ORF), but a comprehensive analysis of the T cell response to the entire VZV genome has not yet been conducted. We have shown that intrabronchial inoculation of young rhesus macaques with simian varicella virus (SVV), a homolog of VZV, recapitulates the hallmarks of acute and latent VZV infection in humans. In this study, we characterized the specificity of T cell responses during acute and latent SVV infection. We identified several SVV ORFs targeted by T cell responses in majority of animals examined during both acute and latent infection. We show that structural proteins are targeted by both CD4 and CD8 T cells, and immediate early/early viral proteins are primarily targeted by CD8 T cells. Also, while both CD4 and CD8 T cell responses are detected during acute SVV infection, latent infection elicits primarily CD8 T cell responses. These results suggest that CD4 T cell immunity may wane faster than CD8 T cell immunity. Given the close genome relatedness of SVV and VZV, our studies highlight immunogenic ORFs to be further investigated as potential components of second-generation VZV vaccines designed to boost T cell immunity.
Pro-apoptotic Bim regulates NK cell contraction and the generation of the NK memory pool following viral infection (P6106)
Authors: Min-Oo Gundula , Bezman Natalie , Madera Sharline , Sun Joseph , Lanier Lewis 
Published: January 2023

Abstract
Apoptosis is critical in lymphocyte development and homeostasis; moreover, this pathway eliminates activated lymphocytes and prevents immune pathology during viral infection. Pro-apoptotic factor Bim controls LCMV-specific T cell contraction and the formation of memory T cells. Natural killer (NK) cells also undergo antigen-driven expansion to become long-lived memory cells after mouse cytomegalovirus (MCMV) infection. Bim expression is decreased in memory NK cells; therefore, we examined the role of Bim in regulating the MCMV-driven memory NK pool. Ly49H+ Bim-/- NK cells respond similarly to wild-type cells early after MCMV. However, following the m157-driven expansion phase, Bim-/- Ly49H+ NK cells show impaired contraction and significantly outnumber wild-type cells by day 14. Importantly, the inability to reduce the Ly49H+ effector pool leads to a larger Bim-/- NK memory subset; these Bim-/- memory cells display a less mature phenotype (CD11blo,CD27hi) and lower levels of NK memory markers, KLRG1 & Ly6c. Furthermore, compared to wild-type memory NK cells, Bim-/- cells are functionally impaired in response to receptor-mediated stimulation, despite equal responses in naïve cells. These results suggest that apoptosis of antigen-specific effector NK cells is critical in generating a potent memory pool. Further studies are required to elucidate the mechanisms that drive apoptosis in most activated NK cells, but spare a small subset to become long-lived memory cells.
The inhibitory receptor NKG2A on NK cells controls CD8+ T cell responses to hepatic viral infection (P6109)
Authors: Krueger Peter , Hahn Young 
Published: January 2023

Abstract
NKG2A is an inhibitory receptor expressed on a variety of liver lymphocytes, including NK and activated CD8+ T cells. NKG2A recruits the phosphatase SHP1 and inhibits signaling cascades necessary for immune cell activation when bound to its ligand, the nonclassical MHC-I Qa1b/Qdm complex. Elevated NKG2A expression on circulating NK cells is associated with chronic hepatitis C virus infections in humans; however, the impact of NKG2A+ NK cells in host immunity and chronic infections has not been elucidated. Using NKG2A-/- mice infected with adenovirus-ova, we have observed that loss of NKG2A signaling on NK cells leads to an increase of antigen-specific CD8+ T cell numbers with enhanced IFNγ production in the liver, but not the spleen, from days 6 through 40 post infection. Importantly, intrinsic NKG2A signaling on CD8+ T cells does not appear to control their proliferation or IFNγ expression. Furthermore, blockade of NKG2A-Qa-1b interaction on NK cells by the administration of Qa1b neutralization antibody or NK cell depletion prior to infection leads to increased hepatic CD8+ T cell numbers, suggesting NK cells are actively dampening CD8+ T cell cellularity and functions. Taken together, these results indicate that NK cell-mediated NKG2A signaling plays a pivotal role in controlling CD8+ T cell responses to hepatic viral infection.
IL-15 mediated NK cell responses during rhinovirus infection requires type I interferon signalling (P6111)
Authors: Jayaraman Annabelle , Johnston Sebastian , Bartlett Nathan 
Published: January 2023

Abstract
Rhinoviruses (RV) are a global burden on respiratory health, particularly for those with chronic respiratory diseases such as asthma. The lack of treatments for RV-induced diseases inspires further studies into immune mechanisms of disease. IL-15 and NK cells are critical for defence against many viruses, however their role during RV infections has not been defined. Hypothesis IL-15, induced by type I interferons (IFNs), is critical for NK cell responses in the lungs during RV infection. Aims Use mouse models of RV infection with modulation of IL-15 or type I IFN signalling and assess airway inflammation and viral load. Results RV-1B infection induced upregulation of IL-15 gene and protein expression at day 1 in lung tissue (2.5-fold P&lt;0.001) and was proceeded by an activated (increased CD69, GranzymeB and IFN-γ expression) NK cell response in the lungs at days 2-4. Neutralisation of airway IL-15 with a monoclonal antibody at the time of infection inhibited NK and CD8+ T cell responses. In type I IFN receptor knockout mice, deficient RV-induced IL-15 expression (P&lt;0.01) was associated with deficient NK and CD8+ T cell responses and increased viral load. This study demonstrates the necessity of type I IFN signalling for increased IL-15 expression during RV infection, which is important for NK and CD8+ T cell antiviral responses. These data identify type I IFNs and IL-15 as potential therapeutics to prevent/treat RV-induced diseases such as asthma exacerbations.
Optimal germinal center B cell activation and T-dependent antibody production is dependent on Complement Receptor 1 (P1461)
Authors: Donius Luke , Orlando Christopher , Handy Jennifer , Weis Janis , Weis John 
Published: January 2023

Abstract
Rapid identification of antigens during a primary immune response requires timely detection, opsonization, and delivery to immune follicles for B cell activation. Evidence demonstrates complement sequestration of antigen is important for efficient detection and antibody production by B cells. Follicular dendritic cells (FDC), which promote B cell activation and maturation by organizing germinal centers and retaining antigen, as well as B cells, are exclusive expressers of the Complement Receptor 2 (Cr2) gene products Cr1 and Cr2. We show here that Cr1 is the nearly exclusive product of the Cr2 gene on FDC and, in contrast, Cr2 is the predominant product on B cells. Consistent with FDC restricted expression of Cr1, immunization of Cr1 deficient (Cr1KO) mice demonstrated deficiencies in antibody and B cell responses to T-dependent but not T-independent (TI) antigens. Cr1KO mice exhibit a reduction in antigen specific IgM and IgG3 during primary immunization with TNP-KLH, and do not generate activated germinal center B cells as readily as wildtype mice in response to sheep red blood cell. Cr1KO mice generate effective immunity to Streptococcus pneumoniae, which typically is controlled by TI induced antibody against the bacterial polysaccharide capsule. In total the results of this study define a specific role for Cr1 in B cell germinal center maturation, and defines the Cr1KO mouse as a new tool for studying activation of B cells during primary immune responses.
The role of NCOR co-repressors in lymphocyte development and function (P1471)
Authors: Manlove Luke , Farrar Michael 
Published: January 2023

Abstract
The related co-repressors NCOR1 and NCOR2 interact with transcription factors required for lymphocyte development and function. To examine the role of NCOR2 in lymphocytes, we generated CD4-Cre x Ncor2FL/FL and Mb1-Cre x Ncor2FL/FL mice. Deletion of Ncor2 in T cells had a modest effect on T cell development. Specifically, in mixed bone marrow chimeras comparing Ncor2-deficient versus wild type T cells, we observed that loss of Ncor2 impairs the Double Positive to Single Positive transition, suggesting an effect on positive or negative selection. We are currently generating CD4-Cre x Ncor1FL/FL x Ncor2FL/FL mice to determine whether NCOR1 and NCOR2 play partially redundant roles in thymocyte development. In addition, we are examining the impact that NCOR2 deficiency has on T cell function. Unlike T cell development, deletion of Ncor2 alone in B cells led to a dramatic reduction in mature B cells at the T2 to mature B cell transition. We are currently characterizing NCOR2 at the molecular level to determine how NCOR2 modulates transcription and B cell development. Finally, we are generating Mb1-Cre x Ncor1FL/FL and Mb1-Cre x Ncor1FL/FL x Ncor2FL/FL mice to assess redundancy between the NCOR1 and NCOR2 proteins in B cell development. We suspect that NCOR1 and NCOR2 may have redundant roles in modulating transcription in lymphocytes, and that ablation of both co-repressors will lead to pronounced developmental blocks in both B and T lymphocytes.
Human CARD11 deficiency causes profound combined immunodeficiency (P3325)
Authors: Warnatz Klaus , Baerbel Keller , Buchta Mary , Kienzler Anne-Kathrin , Elpeleg Orly , Somech Raz , Cohen Sivan , Shachar Idit , Miosge Lisa , Schlesier Michael , Fuchs Ilka , Enders Anselm , Eibel Hermann , Grimbacher Bodo , Stapansky Polina 
Published: January 2023

Abstract
Patients with primary immunodeficiency present an excellent opportunity to understand the role of specific molecules in the human immune system. Recently we had the chance to investigate a young girl with a complete CARD11 deficiency due to a homozygous deletion of exon 21. Clinically the child presented with increased susceptibility to respiratory tract infections at 6 months, before she was diagnosed at 13 months with Pneumocystis jirovecii revealing her combined immunodeficiency. The immunological characterization showed severe hypogammaglobulinemia, but normal T-, B- and NK-cell numbers. While there were only subtle changes in the T cell compartment, B-cell differentiation was blocked at the transitional stage. In the absence of CARD11 protein expression activation of the canonical NF-κB pathway after antigen receptor or PMA stimulation was abrogated, while CD40 signaling in B cells was preserved. CARD11 deficient T cells were severely impaired in the up-regulation of ICOS, OX40, cytokine production and proliferation after TCR stimulation. On B cells BAFF receptor expression was reduced and after activation ICAM1 and CD25 were not induced while CD86 induction was comparable to control cells. Immunoglobulin production was intact after anti-IL-21/CD40L stimulation, demonstrating that plasma cell differentiation was not dependent on intact CARD11. Thus CARD11 plays a crucial, non-redundant role in the antigen specific immune response in humans.
Autoimmune susceptibility gene critically influences CD39 T cell expression and function in modulating human inflammation (P3313)
Authors: Moncrieffe Halima , Ursu Simona , Pesenacker Anne , Gordon-Smith Sophie , Zheng Dongling , Wedderburn Lucy 
Published: January 2023

Abstract
Background: Purinergic signaling is an important mechanism of immunomodulation. The ectoenzyme CD39 is a key regulator of extracellular ATP levels and catalyses hydrolysis of ATP to AMP. The A allele of the CD39 SNP rs10748643 is associated with both susceptibility to the autoimmune condition Crohn’s disease and low CD39 RNA transcript expression levels in HapMap transformed immune cell lines. Aim: To investigate the association between CD39 genetic polymorphism, protein expression and function in human healthy and autoimmune arthritis inflamed tissues. Results: We demonstrate increased CD39 protein on T cells in the human inflamed arthritis joint compared to peripheral blood. SNP rs10748643 AA individuals had a greatly reduced CD39 T cell expression and ATPase capacity compared to GG individuals (p&lt;0.001). An electrophoretic mobility shift assay revealed a decrease in nuclear protein-DNA complex with rs10748643 AA probe compared to the GG probe. Bioinformatic analysis revealed AA individuals had ablation of an Sp1 transcription factor binding site, previously shown to be important in CD39 upregulation. Discussion: This is the first study to show how a specific SNP genotype, previously found in increased frequencies in patients with Crohn’s autoimmune disease and associated with reduced CD39 mRNA expression, is associated with functional modulation of the immune system.
In vivo trafficking, persistence and efficacy of Lewis-Y chimeric antigen receptor T cells in patients with Lewis-Y positive acute myeloid leukaemia (P4354)
Authors: Neeson Paul , Ritchie David , Khot Amit , Peinert Stefan , Tai Tsin , Honemann Dirk , Gambell Peter , Westerman David , Westwood Jennifer , Scott Andrew , Kravets Lucy , Dickinson Michael , Trapani Joseph , Smyth Mark , Darcy Phillip , Kershaw Michael , Prince H. 
Published: January 2023

Abstract
Second generation chimeric antigen receptor (CAR) T cells were used to treat patients with acute myeloid leukemia (AML) in a phase I clinical study. Autologous T cells were genetically modified to express a CAR which re-directed T cell effector function to the LeY tumor associated carbohydrate antigen on AML cells. CAR-T cell therapy safety, AML disease response, and CAR-T cell trafficking and persistence post-infusion were investigated. Five patients received GMP grade CAR-T cells (LeY-T). Post infusion, no patients experienced grade 3 or 4 toxicities. Patient AML responses to LeY-T cell infusion included a transient cytogenetic response and a reduction in peripheral blood leukemic blast count. In all patients, LeY-T cells trafficked thru peripheral blood, and persisted in the bone marrow. In one patient, leukemia cutis was associated with trafficking of the LeY-T cells to the skin at sites of AML blast infiltration. Despite LeY-T cells being present at the disease site, relapse with LeY-expressing AML blasts occurred in all patients (range 29 days to 23 months) post-infusion. Further studies indicated LeY-T cell CAR expression was downregulated post-infusion in vivo, this was also observed post-LeY antigen exposure and long term culture in vitro. This study provides important safety and feasibility data to support the application of CAR-T cell therapy to treat AML. Furthermore, we provide a potential mechanism for tumor escape from LeY-T cell surveillance in vivo.
Differential signaling responses may promote proliferation and survival of chimeric antigen receptors linked to 4-1BB:CD3ζ. (P4356)
Authors: Posey Avery , Kawalekar Omkar , June Carl 
Published: January 2023

Abstract
Chimeric antigen receptors have been explored clinically with more disappointments than successes. T lymphocytes modified with CARs bearing the CD137 (4-1BB) costimulation domain have been successful in patients with acute and chronic leukemia. We hypothesized that the initial signaling events after CAR-target ligation might identify mechanisms responsible for prolonged persistence in vivo. Human T cells were electroporated with mRNA to express anti-mesothelin chimeric antigen receptors containing either the CD28:CD3ζ domains, 4-1BB:CD3ζ domains or CD3ζ domain alone. CAR T cells expressing the 28ζ domains showed a rapid calcium flux after stimulation with surrogate antigen (mesothelin-Fc fusion protein) that was similar to TCR stimulation via endogenous CD3ζ, but no detectable calcium flux was observed for BBζ or ζ alone CARs. BBζ and ζ alone CARs showed a similar calcium response to 28ζ CAR T cells when stimulated with OKT3. 28ζ CAR T cells also show an intense increase in both proximal and distal phosphoproteins, compared to a moderate increase from BBζ and ζ alone CARs. Here we report that CARs containing 28ζ demonstrate accelerated signaling compared to BBζ and ζ only CARs. These results may have implications for sustainability and effectiveness of CAR-T cells in future clinical studies.
T-bet dictates CD8+ T cell tolerance versus immunity following antigen recognition (P4368)
Authors: Jackson Stephanie , Yuan Jinyun , Berrien-Elliott Melissa , Meyer Jennifer , Teague Ryan 
Published: January 2023

Abstract
Efforts to overcome tolerance to improve adoptive immunotherapy for cancer have been hindered because the T cell intrinsic pathways that regulate whether tumor/self-reactive T cells are directed toward tolerance versus immunity remain largely undefined. Our lab studies a murine model of tolerance in which adoptively transferred tumor/self-reactive CD8+ T cells undergo multiple rounds of division following engagement of tumor/self-antigen, but fail to produce effector molecules and are progressively deleted without providing anti-tumor immunity. Here, we demonstrate that T cells engaging antigen within this tolerizing environment fail to express the T-box transcription factor, T-bet, which is induced under immunizing conditions. We further establish that restoring T-bet expression in these T cells within the tolerizing environment by vaccination with Listeria monocytogenes corresponds with their acquisition of effector function and the prolonged survival of leukemia-bearing hosts. Utilizing T-bet deficient T cells, we confirmed that T-bet is required for this rescue of effector function and for therapeutic anti-tumor immunity within a tolerizing environment. We are now utilizing T cells with constitutive T-bet expression to determine if T-bet alone is sufficient to overcome tolerance. Our results identify T-bet as a CD8+ T cell-intrinsic regulator of effector responses within a tolerizing environment and have important implications for immunotherapy in patients with cancer.