bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting gammadelta regulatory T cell recruitment for breast cancer immunotherapy (TUM2P.904)
Authors: Peng Guangyong , Ye Jian , Ma Chunling , Hsueh Eddy , Toth Karoly , Varvares Mark , Hoft Daniel 
Published: January 2023

Abstract
Immunosuppressive microenvironments induced by regulatory T cells (Treg) present a major barrier for successful anti-tumor immunotherapy. Understanding the mechanisms for the accumulation of different subtypes of Treg cells in the immunosuppressive tumor microenvironment is essential to improving cancer treatment. Enriched gammadelta1 T cell populations in tumor-infiltrating lymphocytes (TILs) suppress T cell responses and dendritic cell maturation in breast cancer, where their presence is correlated negatively with clinical outcomes. However, mechanism(s) that explain the increase in this class of gammadelta Treg cells in breast cancer patients have yet to be elucidated. In this study, we showed that IP-10 secreted by breast cancer cells attracted gammadelta Treg cells. Using neutralizing antibodies against chemokines secreted by breast cancer cells, we found that IP-10 was the only functional chemokine that causes gammadelta Treg cells to migrate toward breast cancer cells. In a humanized NSG mouse model, human breast cancer cells attracted gammadelta Treg cells as revealed by a live cell imaging system. IP-10 neutralization in vivo inhibited migration and trafficking of gammadelta Treg cells into breast tumor sites, enhancing tumor immunity mediated by tumor-specific T cells. Together, our studies show how gammadelta Treg cells accumulate in breast tumors, providing a rationale for their immunological targeting to relieve immunosuppression in the tumor microenvironment.
Investigating the mechanism underlying Ly-6A, a highly expressed protein on activated and transformed lymphocytes, induced growth inhibition and cell death in transformed T-cell lines (TUM2P.879)
Authors: Lang Melissa , Jenkins Sultan , Balzano Philip , Bamezai Anil 
Published: January 2023

Abstract
The Ly-6 family of glycosylphosphatidylinisotol proteins is excellent differentiation markers of immune cells during their development and they regulate signaling responses. Specifically, Ly-6A is up-regulated on a variety of transformed cells therefore making it a potential biomarker for cancer detection and therapy. Previous work in our laboratory revealed that a transformed CD4+ T lymphocyte cell line shows growth inhibition and apoptotic cell death when Ly-6A proteins are engaged. We have investigated whether this mechanism involves p53 protein, which is known to regulate the cell cycle, trigger growth inhibition and apoptotic cell death in several normal cell types. In cancer cells, p53 is often mutated, resulting in uncontrollable cell growth. The cell cycle is regulated by several proteins known as cyclin dependent kinases that bind cyclin proteins and usher the cell past checkpoints in the cell cycle. Therefore, we have examined the expression of relevant cell cycle and apoptotic proteins. We find that while growth inhibition and cell death in the T cell line was p53 independent, the cell cycle inhibitor gene p27 becomes significantly up-regulated. Furthermore, we extended this study beyond the analysis of one Ly-6A antibody and one T-cell line. We find that the responses were tied primarily to the extent of cross-linking with anti-Ly-6A antibody. Other transformed T-cell lines also exhibited growth inhibition and cellular death when the Ly-6A protein was engaged.
TIGIT mediated T cell exhaustion in cancer is dependent on TIGIT/CD226 interaction (TUM2P.907)
Authors: Comps-Agrar Laetitia , Johnston Robert , Hackney Jason , Yu Xin , Yang Yagai , Huseni Mahrukh , Eaton Dan , Grogan Jane 
Published: January 2023

Abstract
The generation of blocking antibodies against co-inhibitory receptors involved in T cell exhaustion is a recent key strategy for cancer immunotherapy. We have shown that co-blockade of TIGIT and PD-L1 results in tumor rejection by restoring the function of exhausted tumor-infiltrating CD8+ T cells. We were then interesting in deciphering the molecular mechanism of action of this anti-TIGIT blocking antibody. We hypothesized that TIGIT might inhibit a complementary co-activating receptor. Interestingly, TIGIT expression on tumor infiltrating CD8+ T cell was correlated with CD226, which binds a common receptor PVR. To better understand the relationship between these co-receptors, we utilized Time-resolved Fluorescence Resonance Energy (TR-FRET), a technology that allows for monitoring of cell surface protein interactions in real time. We showed that CD226 forms homodimers, and that co-expression of CD226 with TIGIT results in 1) the attenuation of CD226 self-association and 2) the formation of a TIGIT/CD226 complex in cis. Strikingly, anti-TIGIT antibody causes a significant decrease of the TIGIT/CD226 interaction. These observations indicate that the interaction of CD226 and TIGIT may play a central role in the antitumor effects of anti-TIGIT. Indeed, anti-CD226 antibodies blocked the ability of anti-PD-L1/anti-TIGIT to inhibit tumor growth in mice. Altogether, these results depict a close relationship between TIGIT and CD226 in CD8+ mediated T cell exhaustion.
Control of in situ pathogenic effector T cell activities by PD-1-PDL1 interaction in the lung during respiratory syncytial virus infection (VIR2P.1019)
Authors: Yao Shuyu , Jiang Li , Du Jianguang , Zhou Baohua , Braciale Thomas , Sun Jie 
Published: January 2023

Abstract
RSV infection is the most common cause of lower respiratory diseases in infants and young children. It is believed that over-exuberant inflammatory responses are mainly responsible for the disease development. Here, we seek to define host factors that can dampen over-reactive pulmonary inflammation and injury during RSV infection. We have identified that the co-inhibitory receptor PD-1 is up-regulated on pulmonary effector T cells in RSV infected mice and infants. Importantly, acute blockade of PD-1 ligand (PD-L1) function in vivo resulted in the development of excessive pulmonary inflammation and severe host diseases. Using the in vivo and in vitro cytokine staining assays, we found that PD-L1 blockade specifically enhanced the in situ inflammatory activities (i.e. release of inflammatory cytokines) of effector T cells in the lung. Interestingly, we showed that PD-L1 expression is mainly restricted to the monocyte derived dendritic cell (Mo-DC) population in the lung, and that an axis, involving with type I and II interferons (IFN), STAT1 and IRF1, is critical for the induction of PD-L1 expression on Mo-DCs. Collectively, these data suggest that IFN-dependent PD-L1 expression on respiratory DCs is critical to inhibit the pathogenic activities of tissue effector T cells, thereby suppressing the development of excessive pulmonary inflammation and lung injury during RSV infection. Our study also opens the door for novel strategies to treat sever RSV infection.
Impaired CD8+ T cell responses to influenza infection in neonatal mice are due to the immature T cell receptor repertoire (VIR2P.1020)
Authors: Carey Alison , Gracias Donald , Thayer Jillian , Hope Jennifer , Mueller Yvonne , Katsikis Peter 
Published: January 2023

Abstract
To understand the role of virus antigen-specific CD8+ T cell responses in neonates during respiratory viral infection, we developed a model where 3-day old C57Bl/6 mice were infected intranasally with influenza type A virus strain A PR/8/34 (H1N1). When these neonatal mice are infected with influenza virus they mount a greatly reduced and delayed lung NP(366-374)-specific primary CD8+ T cell response. To investigate what was responsible for the reduced response, we performed adoptive transfers of TCR-transgenic OVA(257-264)-specific (OT-I) CD8+ T cells into hosts infected with recombinant influenza virus WSN-OVA, which expresses the OVA(257-264) peptide. These studies revealed that naïve adult OT-I cells expand equally well in neonatal and adult hosts, which excludes the neonatal environment as an inhibitor of the CD8+ T cell response. When naïve neonatal OT-I cells were transferred into neonatal and adult hosts, these neonatal OT-I cells expanded equally as well as adult OT-I cells, excluding an intrinsic defect in the neonatal CD8+ T cells. These studies demonstrate that the TCR repertoire of neonates is responsible for reduced CD8+ T cell immunity in neonates, not a suppressive environment or intrinsic signaling defects. Finally, despite impaired primary response, animals primed as neonates exhibited normal secondary responses to influenza virus. These findings raise important issues that need to be taken into consideration for vaccination of neonates.
T cell promiscuity between susceptible MHC alleles potentiates autoimmune diabetes (HUM3P.259)
Authors: Chow I-Ting , Gates Theresa , McGinty John , Mai Duy , Papadopoulos George , Torres-Chinn Nadia , James Eddie , Greenbaum Carla , Nepom Gerald , Kwok William 
Published: January 2023

Abstract
Major histocompatibility complex (MHC) genes, also known as human leukocyte antigen (HLA) genes in humans, are the prevailing risk factors in multiple autoimmune diseases, including multiple sclerosis (MS), autoimmune diabetes (type 1 diabetes or T1D), and rheumatoid arthritis (RA), yet MHC-linked susceptibility is not fully understood. In T1D, HLA-DQ8trans (DQ8trans), a trans-complementary molecule encoded by DQA1*0501 (HLA-DQ2α) and DQB1*0302 (HLA-DQ8β), confers exceptionally high risk. In contrast to the notion that DQ8trans expands a unique pathogenic T cell repertoire due to its trans-complementary nature, here we report a high degree of epitope overlap between DQ8trans and another high-risk allele, HLA-DQ8 (DQ8; DQA1*0301/DQB1*0302).T cells specific for shared islet-epitopes are cross-reactive to both molecules. Cross-reactivity is driven mainly by the shared β-chain and is observed ex vivo in polyclonal T cell populations in T1D patients. Stronger disease-associated responses to cross-reactive epitopes are elicited by DQ8trans, as the HLA-DQ2 α-chain enhances peptide-MHC-TCR interaction.These results suggest that a functional epistatic interaction between DQ8 and DQ8trans promotes the pathogenesis of T1D and provide an important general mechanism whereby disease risk may be altered primarily byT cell promiscuity among susceptible HLA haplotypes.
Intracisternally localized lupus serum IgG induces meningitis (HUM3P.245)
Authors: Deng Guo-Min , Sun Lingyun , Liao Xiang , Xie Chang-hao 
Published: January 2023

Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by high autoantibody levels and multiorgan tissue damage, including brain. Headache in SLE patients is frequent clinical manifestations and its etiology and pathogenesis remains unclear. We hypothesized that lupus serum containing high levels of IgG induces meningitis. Information from the analyzed 150 lupus patients demonstrates higher levels of IgG in CSF from lupus patients with headache than that without headache. There is meningitis in brain of MRL/lpr mice. We have intracisternally injected mice and rats with serum from patients with SLE, health individuals, lupus prone mice and normal mice , and found meningitis induced only by serum from lupus patients and lupus prone mice. Meningitis induced by lupus serum appeared 12 h and peaked 3 days after injection. Deleted the monocyte/ macrophage abrogated meningitis but lack of lymphocyte did not affect the development of meningitis induced by lupus serum. Specific interactions with vascular selectin expression and depletion of complement system led to a significant amelioration of meningitis. Depletion of IgG from lupus serum reduced meningitis suggests that IgG is important contributor in lupus serum-induced meningitis. Intracisternally lupus serum may trigger development of hippocampus neuron apoptosis. This study proves that lupus serum IgG induces meningitis, which is important mechanism of headache of lupus patients.
Biomimetic lipid nanoparticles as treatment for bacterial sepsis (HUM4P.275)
Authors: Foit Linda , Thaxton C. 
Published: January 2023

Abstract
Sepsis describes a spectrum of potentially fatal medical conditions caused by the inflammatory response of the human body to an infectious insult. Due to significant morbidity and high mortality, new treatments are urgently needed specifically targeting the cause of sepsis. Gram-negative sepsis is elicited by lipopolysaccharides (LPS). Recognition of these bacterial cell wall components by TLR4 and accessory proteins leads to activation of complement and coagulation systems and the release of pro-inflammatory agents. Human high-density lipoproteins (hHDL) can bind LPS and reduce its levels in the blood. However, remodeling and depletion of HDL during sepsis impairs HDLs’ immune-protective capacity. Thus, we sought to design nanoparticles (NP) that mimic hHDL in shape and surface chemistry, yet exceeded its LPS-binding properties and boosted LPS detoxification. Convincingly, our data show that HDL-like NPs effectively reduce the LPS-induced production of cytokines in human monocytic cell lines and in whole human blood. Our NPs, but not hHDL, exert their immune-protective function at low nM concentrations when stimulated with LPS concentrations above those levels reported in sepsis patients. Further, our NPs are non-immunogenic and non-toxic to target cells. As such, our NPs have the great potential for an LPS antidote that rapidly detoxifies LPS in the blood, drastically inhibits the release of inflammatory mediators, and constitutes a highly effective treatment for sepsis.
Dexamethasone suppresses of IL-33-mediated mast cell activation in vitro and in vivo (HYP4P.314)
Authors: Paranjape Anuya , Chernushevich Oksana , Ryan John 
Published: January 2023

Abstract
Dexamethasone, a synthetic member of the glucocorticoid class of steroid drugs is known for its immunosuppressant and anti-inflammatory effects. Mast cells, critical effectors of allergic disease, can be activated by IL-33, a pro-inflammatory member of the IL-1 family. We found that Dexamethasone potently suppresses IL-33-stimulated cytokine secretion by mouse mast cells. We similarly found that Dexamethasone treatment in vivo reduced IL-33-mediated cytokine production and neutrophil infiltration in the murine peritoneum. We compared the activation status of signaling proteins during IL-33 stimulation, and found that Dexamethasone pretreatment significantly reduced Erk phosphorylation. However, we also observed that Dexamethasone-mediated suppression occurred when it was added simultaneously with IL-33, suggesting that inhibition occurrs even prior to Erk blockade. The effect of Dexamethasone on IL-33 stimulated NFkB-mediated gene transcription is currently under investigation. Our data show that Dexamethasone, a well-established therapy for inflammatory disease, can suppress IL-33-mediated mast cell activation, and may therefore be effective for treating diseases now being attributed to IL-33 effects.
CXCR2 is a critical mediator of Brucella-induced articular inflammation (INC4P.335)
Authors: Skyberg Jerod , Lacey Carolyn , Keleher Lauren , Brown Charles 
Published: January 2023

Abstract
Osteoarticular complications are the most common focal manifestation of brucellosis in humans. Little is known about the pathology of osteoarticular brucellosis due to the lack of relevant models. However, we recently reported that ablation of IFN-γ in mice results in articular inflammation during infection with Brucella melitensis. Here, we show that adaptive immune cells are dispensable for Brucella-induced articular inflammation. Wild-type, µMT-/-, and Rag1-/- mice all developed articular inflammation at a similar rate and severity when infected with B. melitensis and depleted of IFN-γ. In addition, minimal levels of cytokines associated with T cell responses were detected in arthritic joints. However, we found increased numbers of neutrophils and macrophages in joints from mice with Brucella-induced arthritis. In addition, the concentration of CCR2 and CXCR2 ligands, was strikingly enhanced in Brucella-infected joints. Interestingly, CXCR2-/-, but not CCR2-/- mice, displayed markedly lower joint inflammation relative to wild-type mice when infected with B. melitensis and depleted of IFN-γ. Collectively, these results show that chemokines, such as CXCR2 ligands, are important mediators of Brucella-induced articular inflammation while adaptive immune cells are not required. Therefore, the targeting of CXCR2 and/or other chemokine receptors may have potential as a complementary antibiotic therapy for the resolution of Brucella-induced arthritis.
Toxoplasma gondii elicits a phagocytosis dependent pro-inflammatory cytokine response in human primary myeloid cells (INC4P.327)
Authors: Tosh Kevin , Singer Steven , Sher Alan , Jankovic Dragana 
Published: January 2023

Abstract
Toxoplasma gondii is an intracellular protozoan parasite and the etiological agent of toxoplasmosis, a disease seen in immunocompromised individuals such as HIV patients. Studies in murine models have shown that the innate immune response depends on the MyD88-dependent pattern-recognition receptors, TLR11 and TLR12. Thus, mice deficient in TLR11/12 rapidly succumb to acute infection due to uncontrolled parasitemia. While these findings highlighted a critical role for the innate recognition of toxoplasma, they also reveled a major gap in translation to clinical disease since humans do not express TLR11 or TLR12. In order to address how human innate immune cells detect and respond to T. gondii, we infected primary human monocytes, dendritic cells and monocyte-derived macrophages with T. gondii. We found that while all three cell-types become infected and support parasite replication, only monocytes and DC produce significant levels of TNFα and p40 IL-12. Although infection with live parasites was required for an optimal response, we demonstrated that parasite invasion was dispensable while phagocytosis of parasites by monocytes and dendritic cells was necessary for cytokine production. Upon sort-purification, we found that the minor CD16+ monocyte subsets produced the majority of the cytokines in response to infection. Taken together, these results suggest that human monocytes utilize a distinct recognition system from mice that requires phagocytosis of live T. gondii.
Limiting cholesterol biosynthesis acts as a danger signal that engages STING-dependent inflammation (INM2P.349)
Authors: York Autumn , Tong Ann-Jay , Argus Joseph , Gray Elizabeth , Wu Nicholas , Zhen Anjie , Kitchen Scott , Smale Stephen , Stetson Daniel , Bensinger Steven 
Published: January 2023

Abstract
Pathogen invasion alters host lipid metabolism, however the mechanisms underlying this remain poorly understood. Here, we show that transcriptional repression of cholesterol and fatty acid biosynthesis is driven by TRIF-dependent danger signals. Unexpectedly, decreasing cholesterol biosynthesis induces type I interferon (IFN)-mediated inflammation in the absence of conventional danger signals, resulting in resistance to pathogens. Spontaneous induction of inflammation was traced to a reduction in cellular cholesterol levels, and normalizing cholesterol attenuated IFNb and interferon stimulated gene expression. Epistasis studies indicate that the Stimulator of Interferon Genes (STING) links cellular cholesterol balance to type I IFN-mediated inflammation. These findings reveal that perturbing cholesterol homeostasis acts as an independent “danger” signal sensed by host defense machinery, and provides mechanistic insights as to how lipid metabolism influences inflammation.
Vibrio cholerae ghosts elicit the production of soluble immunostimulatory factors and prevent development of Chlamydia infection (INM3P.408)
Authors: Stevens Mumbi , McKeithen D. , Martinez O. , Igietseme J , Eko Francis , Black C , He Q , Ananaba G 
Published: January 2023

Abstract
Infections by the obligate intracellular pathogen Chlamydia trachomatis cause infertility in women of childbearing age. Currently infections caused by the pathogen are treated with antimicrobial therapy. Bacterial ghosts offer a cost-effective, long-term, protective therapy as vaccine delivery vectors. In the present study we tested the hypothesis that factors contained in culture supernatant exhibit anti-chlamydial activity. THP-1 monocytes were differentiated into macrophages (Mdm) by incubating with phorbol myristate acetate (PMA). Activated Mdm were pulsed with Vibrio cholerae ghosts (VCG) for 24 h, followed by the addition of murine splenocytes for an additional 48 h. After 72 h the supernatant was collected and assayed for cytokine concentration. Samples presented observable levels of immunostimulatory factors necessary for containing or clearing infections with chlamydia. Following these assay results, Chlamydia pneumonia (MoPn) elementary bodies (EBs) were suspended in VCG-pulsed THP-1 Mdm supernatant (conditioned media) and used to culture HeLa cells. As a positive control, MoPn was suspended in Earle’s MEM - a medium used for HeLa cell culture. Immunostimulatory factors contained in the conditioned media prevented the development of Chlamydia infection forming units (5.87%) vs. our positive control (94.1%). These results indicate that immunostimulatory factors induced by VCG confer protective immunity against the development cycle of Chlamydia.
The role of the novel ion channel TRPM7 in B cell activation (IRM12P.655)
Authors: Treanor Bebhinn , Krishnamoorthy Mithunah , Schmitz Carsten , Perraud Anne-Laure 
Published: January 2023

Abstract
The process of B cell spreading and the formation of signalling BCR microclusters are critical to the effective activation of B cells. These processes are dependent on the actin cytoskeleton; however the molecular pathways leading to reorganization of the actin cytoskeleton upon B cell encounter with membrane-bound antigen are poorly understood. Recent work has highlighted a potential role for the novel ion channel protein Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) in actomyosin reorganization. Intriguingly, this protein also contains a kinase domain, and thus, TRPM7 may play an important role in receptor-mediated signal transduction by phosphorylating downstream effector molecules. Interestingly, studies in B cells have implicated TRPM7 kinase in the regulation of phospholipase C (PLC), a key BCR signalling molecule and critical regulator of B cell spreading and the formation of BCR microclusters. Here, we show that TRPM7 plays a critical role in the early events of B cell activation through both its ion channel and kinase functions. B cells deficient in TRPM7 or expressing a point mutation which abolishes phosphotransferase activity show increased antigen accumulation and prolonged BCR signalling. Our data suggests this is likely due to altered actomyosin organization and defective antigen internalization.