bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of memory immunity to Mycobacterium tuberculosis is independent of Toll-like receptor 9 signaling (IRC9P.706)
Authors: Gopalakrishnan Archana , Dietzold Jillian , Salgame Padmini 
Published: January 2023

Abstract
Mycobacterium tuberculosis (Mtb) is known to engage Toll-like receptors (TLR) 2 and 9 on macrophages and dendritic cells to initiate an inflammatory response. Nonetheless, studies in the murine model of tuberculosis revealed minimal involvement of TLR2 and TLR9 in host resistance during acute infection. We have published that the induction of memory immunity to Mtb is not compromised in the absence of TLR2. Given that the inclusion of TLR9 ligands in vaccine preparations enhances their efficacy, we hypothesized that TLR9 adjuvanticity is necessary for the induction of memory immunity to Mtb. Mice were immunized with an Mtb auxotroph. Upon challenge with Mtb, WT and TLR9-/- immunized mice demonstrated similarly enhanced control of bacterial burden in the lungs compared to their unimmunized counterparts. The granulomatous response, IFN-gamma production and the frequency of immune cells recruited to the lungs was similar in the two genotypes. These findings indicate that the absence of TLR9 signaling during priming does not affect T cell memory response to Mtb infection. Together, our studies point that induction of effector and memory T cell responses and resistance to acute Mtb infection are independent of TLR2 and TLR9. In a recent study we showed that TLR2 signaling, although nonessential in acute infection, was critical to host resistance during chronic Mtb infection. In ongoing studies we are investigating whether TLR9, like TLR2, has a role in chronic Mtb infection.
Identifying novel regulators of TIM-3 expression in exhausted T cells (IRC9P.707)
Authors: Avery Lyndsay , Kane Lawrence 
Published: January 2023

Abstract
Chronic viral infection and the tumor microenvironment provide settings where T cells are persistently stimulated by their cognate antigen. These T cells are often ‘exhausted’ and exhibit decreased effector function and proliferative potential. Tim-3 is an inhibitory receptor upregulated on the surface of exhausted T cells, and Tim-3 blockade has shown potential for reversal of this phenotype. Understanding mechanisms that regulate Tim-3 expression and signaling can provide insight into therapeutics to rescue exhausted T cell function. Upon T cell activation, the unfolded protein response (UPR) is initiated to resolve a build-up of newly translated protein in the endoplasmic reticulum (ER). Bat3, an ER chaperone upregulated during the UPR, was suggested to be a repressor of Tim-3 cytoplasmic signaling. XBP1, a transcription factor activated during the UPR, is predicted to bind the Tim-3 gene. We aim to confirm the interaction of XBP1 with the Tim-3 gene, as well as understand its functional significance. Linking the UPR and Tim-3 could provide novel information on pathways that drive exhaustion and offer insight into therapies for diseases where chronic antigen stimulation occurs.
Protein N-myristoylation is indispensable for T-cell development and activation (LYM7P.720)
Authors: Rampoldi Francesca , Boehm Martin , Lehmann Wolf , Gröne Hermann-Josef , Porubsky Stefan 
Published: January 2023

Abstract
Protein N-myristoylation refers to an irreversible attachment of myristic acid to the N-terminal glycine of proteins. This modification promotes protein-protein and protein-membrane interactions. Thymus represents an organ with a high degree of protein N-myristoylation. Our aim was to elucidate the role of protein N-myristoylation in T-cell development and in T-cell receptor (TCR) signaling in vivo. To this end, mice with a T-cell specific deletion of both genes responsible for protein N-myristoylation (N-myristoyltransferase, Nmt, 1 and 2) were generated. Abrogation of protein N-myristoylation led to a defective maturation of thymocytes. The transition from the double negative (DN) 3 to DN4 stage and the transition from the double positive to both single positive stages were impeded. Functional analyses of T-cells deficient in Nmt1 and Nmt2 showed that N-myristoylation of the proteins Lck, Fyn and Marcks, which are involved in early and late TCR signalling events, was essential for a proper transduction of TCR signals. We could demonstrate that the absence of myristoylation caused a mislocalization and malfunction of these proteins. These findings demonstrate for the first time in vivo the indispensable role of protein N-myristoylation during T-cell development and in the transmission of TCR signals.
Therapeutic treatment with cryoablation and Meriva improves T cell responses to tumor-associated antigens and is highly effective against metastatic breast cancer (TUM2P.910)
Authors: Chandra Dinesh , Jahangir Arthee , Meheus Lydie , Rombauts Klara , Gravekamp Claudia 
Published: January 2023

Abstract
Cryoablation of tumors involve the insertion of a probe into a tumor nodule to administer tissue-ablative cold temperatures. Its mechanism of action has been attributed to the mechanical forces of crystallization, the osmotic changes due to crystallization, and the ischemic effects of microvascular injury. This leads to immunogenic tumor cell death resulting in cross presentation of tumor-associated antigens (TAA) of the cryo-killed tumor cells by antigen-presenting cells (APC) to the immune system. This in turn leads to the recruitment of TAA-specific T cells, which are powerless because of the strong immune suppression in the tumor microenvironment. We found that Meriva, a Curcumin derivate with high bioavailability, reduced immune suppression by IL-6, resulting in the activation of T cell responses to TAA Mage-b and Survivin (highly expressed by tumors and metastaess), and a nearly complete elimination of metastatic breast cancer (4T1 model) when combined with Cryoablation. In addition, the overall survival of mice that received Cryoablation and Meriva was significantly increased compared to the saline group. Our results demonstrate that Meriva is a potent agent to reduce immune suppression by IL-6 and to stimulate TAA-specific T cells in a tumor microenvironment. Moreover, Meriva might be useful in other combination therapies that induce immunogenic tumor cell death like adriamycin or radiation, or with vaccines that are hampered by immune suppression in the TME.
Qualitative and quantitative effects of 4-1BBL in boosting pre-existing influenza immunity (VAC2P.923)
Authors: Zhou Angela , Wagar Lisa , Wortzman Michael , Watts Tania 
Published: January 2023

Abstract
Influenza virus induces an acute respiratory infection responsible for up to 500,000 annual deaths, primarily in older persons. CD8+ T cells against conserved influenza proteins confer heterotypic protection, potentially providing a “universal vaccine.” However, live infection only transiently boosts influenza-specific T cell memory, and immunity further declines with age. To improve the longevity of T cell memory, we investigated the effects of stimulating the TNFR-family member 4-1BB. To mimic vaccination of previously flu-immune adults, mice were infected with influenza A/HK-X31 and boosted intranasally one-month later with control replication-deficient adenovirus or adenovirus encoding influenza nucleoprotein (NP) alone (Ad-NP) or NP with 4-1BBL (Ad-NP-4-1BBL). 4-1BBL dramatically enhanced NP-specific CD8+ T cell responses at a dose where Ad-NP had minimal effects. 4-1BBL induced a remarkably long-lived effector-memory population that protects mice against lethal challenge into old age (&gt;1 year old). Increasing the Ad-NP dose did not replicate these effects, and instead caused partial functional exhaustion. Preliminary analysis indicates that the 4-1BBL-induced effector memory T cells have increased expression of IL-7R as well as the transcriptional factor TCF-1 and an increased ratio of T-bet to Eomesodermin. Thus, 4-1BBL in a vaccine vector administered in flu-immune mice induces a potentially unique protective subset of memory CD8+ T cells.
A cationic lipid-DNA complex adjuvant (JVRS-100) enhances the immunogenicity and cross-protective efficacy of influenza pre-pandemic H5N1 vaccine in ferrets (VAC2P.931)
Authors: Liu Feng , Tumpey Terrence , Sun Xiangjie , Fairman Jeff , Levine Min , Katz Jacqueline , Lu Xiuhua 
Published: January 2023

Abstract
Highly pathogenic avian influenza A H5N1 viruses continue to pose a public health threat. Adjuvants are needed to improve the immunogenicity of H5N1 vaccine in humans. JVRS-100 is a cationic lipid-DNA complex adjuvant. We investigated the immunogenicity and cross-protective efficacy of JVRS-100-adjuvanted H5N1 (clade 2.2) vaccine in ferrets. Four weeks after the first vaccination, significantly higher levels of serum hemagglutination-inhibition (HI), neutralizing and H5 IgG antibody were detected in ferrets immunized with adjuvanted vaccine compared to the unadjuvanted vaccine group. Following a second dose of JVRS-100 adjuvanted vaccine, cross-reactive HI antibody titers of ≥40 were detected against viruses from multiple H5N1 clades. Ferrets were challenged with a high lethal dose of heterologous H5N1 virus (clade 2.1.3.2) 2 months after the second vaccination. Ferrets that received JVRS-100 adjuvanted vaccine had significantly reduced virus titers in the nasal washes and were completely protected from severe disease and death. In contrast, ferrets that received unadjuvanted vaccine had high viral titers through day 6 and 3 of 6 animals succumbed to the lethal infection. Our results indicate that the addition of JVRS-100 to H5N1 vaccine enhanced immunogenicity and cross-protection against lethal H5N1 virus disease in ferrets. JVRS-100 warrants further investigation as a potential adjuvant for use in human vaccination against avian influenza viruses with pandemic potential.
Sphingosine kinase 1 and its role in modulation of anti-tumor T-cell responses (VAC3P.951)
Authors: Thyagarajan Krishnamurthy , Al-Khami Amir , Ponnusamy Suriyan , Guo Beichu , Ogretmen Besim , Mehrotra Shikhar 
Published: January 2023

Abstract
Sphingosine kinase 1(Sphk1) is a key enzyme in sphingolipid metabolism that is involved in the production of sphingosine-1-phosphate (S1P). S1P controls many cellular processes such as cell proliferation, migration and cytokine production. We sought to address the role of Sphk1 in regulating T cell responses to a tumor specific ‘self’ antigen gp100, in a mouse model of melanoma by generating TCR transgenic mice pMel on Sphk1 deficient background. We found that Sphk1-/-pMel mice showed reduced tumor progression on subcutaneous administration of B16-melanoma. Tumor progression was slower when T-cells from Sphk1-/-pMel mice were adoptively transferred to treat Rag-/- mice with established subcutaneous tumors. There was an increased infiltration of Sphk1-/-pMel T-cells at the tumor site as compared to pMel cells. This suggests that loss of Sphk1 from T-cells enhanced their ability to target the tumor site. We also found TGF-β mediated suppression of IFN-γ secretion was poorer in Sphk1-/- T-cells suggesting better functionality of effector T cells infiltrating the tumor site. A comparative evaluation of T cells from WT and Sphk1-/-pMel showed similar cell surface markers, activation status and proliferation and Tc1 cytokine response. However, we found that Sphk1-/- T-cells showed greater IL-17 secretion. It is possible that the enhanced anti-tumor T cell immunity noticed in Sphk1-/- mice is dependent on the innate Tc17 phenotype and lesser susceptibility to suppression.
Interferon-α augments the clinical efficacy of regulatory T cell depletion in ovarian cancer through direct and indirect T cell effects (VAC3P.941)
Authors: Thibodeaux Suzanne , Hurez Vincent , Wall Shawna , Pandeswara Sri Lakshmi , Sun Lishi , Daniel Benjamin , Liu Aijie , Wood Leslie , Zou Weiping , Curiel Tyler 
Published: January 2023

Abstract
Tregs blunt anti-tumor immunity, and their depletion effectively treats tumor in mouse cancer models. However, Treg depletion in human trials is only partially effective. In our phase II ovarian cancer trial, denileukin diftitox (DT) effected significant Treg depletion in blood and the tumor microenvironment but did not produce significant clinical efficacy. Interferon-α is not an effective ovarian cancer treatment, but we show here that it significantly augments immune and clinical DT-mediated Treg depletion efficacy in human ovarian cancer. In a mouse ovarian cancer model, DT modestly improved anti-tumor immunity and survival. Interferon-α alone did not alter Treg numbers or function, but boosted CD8+ T cell anti-tumor immunity. Interferon-α plus DT significantly prolonged mouse survival over either individual agent. Using type I IFNR-/- mice that cannot mediate interferon-α signals, we showed that interferon-α directly boosted CD8+ T cell function independent of CD4+ T cell help, and in combination with DT reduced Treg function (without further numerical reduction) through indirect effects on tumor microenvironmental dendritic cells. When three ovarian cancer patients failed DT alone, two experienced immunologic and clinical benefit by adding pegylated interferon-α2a, with manageable toxicities. These studies demonstrate novel immune and clinical interferon-α anti-cancer benefits that augment Treg depletion using FDA-approved agents for rapid clinical translation.
LPS and HIV-1 induce a mature phenotype in human plasmacytoid dendritic cells and enhance their programmed death ligand-1 expression (VIR1P.970)
Authors: Patel Meher , Dai Jihong , Singh Sukhwinder , Fitzgerald-Bocarsly Patricia 
Published: January 2023

Abstract
Aberrant immune activation and immune exhaustion are features characteristic of chronic HIV infection. Elevated plasma LPS levels resulting from disruption of gut mucosal integrity during HIV infection have been implicated as a major factor contributing to immune activation. In chronic HIV-1 infection immune exhaustion molecules PD-1 and its ligand PD-L1 negatively regulate the function of exhausted CD8 T cells. The pDC constitute only a minor portion of the PBMC population, but are crucial contributors to the innate as well as adaptive immune response. We have confirmed our previous results that pDC express low levels of TLR4 and respond to LPS. We undertook this study to examine the influence of LPS on virally stimulated pDC maturation and PD-L1 expression and mechanisms thereof. In order to do so we primed pDC with LPS prior to stimulation with HIV. We observed that LPS enhanced HIV-1-induced pDC maturation (CD83 and CD40 expression) and PD-L1 expression. PD-L1 was up-regulated on mature pDC specifically by LPS and HIV combination treatment versus individual treatment with LPS or HIV. The combination treatment specifically induced co-expression of PD-L1 with positive co-stimulatory molecule CD86 but not CD80. Additionally, LPS enhanced CD4 expression on pDC but depressed HIV-1 induced CXCR4 and CCR5 expression. Together, these results indicate that in response to HIV stimulation, pDC adopt a tolerogenic phenotype (i.e. PD-L1-positive) and LPS helps drive this.
Galectin-3 translocates to virological synapse and promotes HIV-1 transfer (VIR1P.1000)
Authors: Chen Huan-Yuan , Wang Sheng-Fan , Hsu Daniel K Hsu , Chen Yi-Ming Arthur , Liu Fu-Tong 
Published: January 2023

Abstract
Galectin-3 contains β-galactoside-binding domain and is mainly expressed in immune cells and epithelial cells. Galectin-3 is known to play regulatory roles in the immune system to defend against pathogens. Previous studies showed that Alix is a host factor employed by HIV-1 for its replication. Here, we report that galectin-3 is another such factor. We have reported that galectin-3 is translocated to the immunological synapse and affects T cell cytokine production. We have now studied the role of galectin-3 in the virological synapse (VS). Our data showed that HIV-1 infection induces galectin-3 expression in primary CD4 T cells. Immunofluorescence imaging showed that galectin-3 is translocted to the virological synapse and co-localized with Gag and Env at the cell-to-cell junction of HIV-1-infected cells. We have studied the effects of galectin-3 in the VS by using fluorescent-tagged HIV-1 and incubation of fluorescent-labeled T cells with galectin-3 knockeddown (KD). Our analysis indicates that HIV-1 transmission efficacy is significantly attenuated in galectin-3 KD cells comparing to galectin-3-expressing wild type cells. Our analysis also shows that Alix plays a role in promoting cell-to-cell transfer of HIV-1. Further analysis indicate that effects of galectin-3 in effector cells is likely more important than expression of galectin-3 in target cells. We conclude that endogenous galectin-3 translocates to VS and promotes cell-to-cell viral transfer upon HIV-1 infection.
IFNγ attenuates of yellow fever virus 17D vaccine strain in vivo and its implication for severe adverse events (VIR1P.966)
Authors: Lam Long Kwan Metthew , Watson Alan , Klimstra William , Ryman Kate 
Published: January 2023

Abstract
The yellow fever virus (YFV) vaccine strain 17D elicits long-lasting immunity against wild-type YFV infection. The success of 17D has led to vaccine candidates using 17D as a vector to deliver heterologous antigen against other pathogens. However, the attenuation mechanism for 17D remains elusive and reports of rare but potentially lethal severe adverse events (SAE) post-vaccination raise questions about the continued use of 17D. Type I IFN receptor-deficient mice (AB6) are susceptible to subcutaneous infection with WT virus and display clinical signs of disease similar to humans whereas 17D infection is self-limiting. In mice lacking both type I and type II IFN receptors (AGB6), 17D results in a lethal infection, suggesting that the vaccine virus is attenuated by IFNγ. Intact IFNγ responses restrict 17D replication to lymphoid organs whereas 17D spreads viscerally and neuroinvades leading to paralysis in the absence of IFNγ. Interestingly, IFNγ production is largely restricted to draining lymph nodes (DLN) but antiviral gene induction is observed globally. In the presence of IFNγ, we observe more robust expression of MIG, MCP-1 and IFIT1, indicative of potential downstream effectors against 17D. We are investigating the DLN immune infiltrates and identifying the IFNγ producing cells. Our data suggest that host-specific variations in the IFNγ signaling network may increase susceptibility to SAE following vaccination.
NK cells modify anti-influenza CD8 T cell responses and memory formation (VIR2P.1014)
Authors: Rose David , Tompkins Stephen , Tripp Ralph , Klonowski Kimberly 
Published: January 2023

Abstract
Natural Killer (NK) cells are part of the first line of defense against viral infection as they quickly mobilize and eliminate infected cells independent of prior activation. However, recent evidence also suggests that NK cell activity can influence subsequent adaptive immune responses via contact dependent and independent interactions with APCs and effector T cells. Despite the importance of NK cells in coordinating these early responses, little is known regarding how this NK cell-mediated tuning regulates long-term anti-viral immunity. Using an antibody depletion method, we studied how loss of NK cells impacts the formation and maintenance of influenza-specific memory CD8 T cells. We find that in the absence of NK cells, there are increased numbers of influenza-specific CD8 T cells at the peak of the response and persisting into memory, with a skewed memory phenotype apparent earlier than observed in non-depleted mice. Loss of NK cells also reduced levels of lung-derived IFNγ and indoleamine 2,3-dioxygenase (IDO), known T cell modulators. Moreover, the anti-influenza response after heterologous challenge was also altered in the NK cell depleted cohort. Together these data suggest that NK-derived IFNγ may regulate local immunity by suppressing anti-viral memory CD8 T cell development. Importantly, loss of NK cell-derived signals has long-term consequences suggesting that differential regulation of NK cell activation should be considered in rational vaccine design.
The role of unanchored polyubiquitin chains and the TRIM E3-ubiquitin ligase family of proteins in the innate immune response to influenza virus infection (INM3P.402)
Authors: Rajsbaum Ricardo , Bharaj Preeti , Ellis Jane , Versteeg Gijs , Schmid Sonja , Maestre Ana , Belicha-Villanueva Alan , Patel Jenish , Morrison Juliet , Giuseppe Pisanelli Giuseppe , Miorin Lisa , Martínez-Romero Carles , Laurent-Rolle Maudry , Moulton Hong , Stein David , Fernandez-Sesma Ana , tenOever Benjamin , Garcia-Sastre Adolfo 
Published: January 2023

Abstract
Intracellular innate immune responses are essential to protect host cells against pathogens. Upon infection, pattern recognition receptors detect incoming microbes and trigger downstream signaling pathways leading to production of antiviral type-I interferons (IFNs).These signaling pathways are regulated by different posttranslational modifications including the ubiquitin (Ub) system. Proteins covalently attached to K48-linked polyUb are targeted for degradation by the proteasome, whereas protein modification with K63-linked polyUb may have non-proteolytic activating functions. Unanchored Ub chains that are not covalently attached to any protein are also important for kinase activation. Tripartite motif (TRIM) proteins, which function as E3-ubiquitin ligases, have been implicated in antiviral activity. We found that TRIM6 is important in the synthesis of unanchored K48-linked polyUb chains, which activate the IKKε kinase for STAT1 phosphorylation and induction of an antiviral response. These polyUb chains and IKKε interact in vivo in an IFN-I signaling dependent manner upon virus infection in mice. To better understand the physiological role of unanchored polyUb during virus infection, we developed a system to isolate ubiquitin-interacting proteins from the lungs of influenza-infected mice. Using a proteomics approach we identified new cellular factors that interact with unanchored polyUb chains in vivo and may be involved in the innate immune antiviral response.
The tumor suppressor PTEN enforces Treg stability in control of TH1 and TFH cell responses (IRC7P.427)
Authors: Shrestha Sharad , Yang Kai , Guy Cliff , Vogel Peter , Neale Geoffrey , Chi Hongbo 
Published: January 2023

Abstract
Regulatory T cells (Tregs) suppress CD4+ T cell responses during homeostasis and inflammation to prevent autoimmunity and other immune disorders. Although the transcriptional and epigenetic programs regulating Treg function have been extensively studied, the signaling and metabolic pathways underlying Treg stability and function are not fully understood. In this study, we determined the role of the phosphatase PTEN in Tregs. We found that specific depletion of Pten in Tregs results in excessive TH1 and T follicular helper cells (TFH) responses, associated with elevated germinal center (GC) B cells and spontaneous development of autoimmune and lymphoproliferative disease in vivo. Interestingly, the exaggerated TFH and GC responses and autoimmune symptoms are reduced when IFNγ expression is abrogated in mice containing Pten-deficient Tregs. Thus, the uncontrolled TH1-mediated inflammation in these mice drives aberrant TFH responses and autoimmune and lymphoproliferative disease. Mechanistically, we linked PTEN to mTORC2-mediated control of transcriptional and metabolic programs that enforce Treg stability and function. Consistent with this notion, deletion of Rictor, the obligate component for mTORC2, restores Treg function and stability in the absence of Pten. Together, these results establish that Tregs rely on the PTEN-mTORC2 axis to maintain their stability and suppressive activity in controlling TH1 and TFH cell responses.