bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invariant natural killer T (iNKT) lymphocytes promote the development of intestinal tumors (TUM2P.914)
Authors: Cardell Susanna , Wang Ying , Sedimbi Saikiran , Löfbom Linda , Porcelli Steven 
Published: January 2023

Abstract
CD1d-restricted NKT cells are known as potent regulatory cells of immune responses. Invariant NKT cells, which are activated by the artificial lipid ligand alpha-galactosylceramide, have anti-tumor functions in several murine experimental models, and iNKT cells can naturally protect against spontaneous tumors, as recently described in two different murine models. APCmin/+ mice develop intestinal tumors due to a mutation in the adenomatous polyposis coli gene, mutated in human colorectal cancer. To investigate whether iNKT cells influence tumor formation in APCmin/+ mice, this strain was crossed with Jalpha281-/- mice or CD1d-/- mice that lack iNKT cells or all NKT cells, respectively. We show that absence of iNKT cells decreased the number of tumors/polyps more than 50%, compared with the iNKT cell sufficient APCmin/+ control litter mate mice. This indicates that iNKT cells naturally promote tumor development in APCmin/+ mice. Moreover, we investigated the modulation of tumor development by iNKT cell directed therapy in preclinical studies. This study was performed by systemically activating iNKT cells with aGalCer, its TH2 skewing analogue C20:2 or the TH1 skewing analogue C-glycoside. The results revealed a decreased number of tumors after treatment with aGalCer. In contrast, in particular the TH2 skewing ligand C20:2 promoted tumor development, which suggests that iNKT cells may promote tumors through TH2 cytokines in this model.
Modeling natural killer cell responses against lung cancer (TUM2P.917)
Authors: Schmidt Leah , Jacks Tyler 
Published: January 2023

Abstract
Natural killer (NK) cells are innate lymphocytes that recognize and kill transformed and pathogen-infected cells. Thought to act as a first line of defense in immune surveillance, NK cells secrete inflammatory cytokines that stimulate adaptive immune responses. Thus, the quality of NK cell responses may impact the potency of adaptive responses against cancer and, perhaps, the efficacy of immunotherapy in individual patients. In a Kras and p53-driven model of autochthonous non-small cell lung cancer, we observe dysfunctional phenotypes in infiltrating NK cells, similar to what is seen in human disease. We have adapted this model to study NK cell responses against lung cancer in a targeted manner, by inducing expression of potent model NK cell ligands in developing tumors. Induced expression of the MCMV surface protein, m157, triggers robust lymphocytic infiltration in tumors within 6 days of induction. Infiltrates include NK cells as well as large numbers of T cells and B cells. Recruitment of T cells and B cells upon ligand induction is dependent on NK cells, and on the interaction of m157 with the Ly49H activating receptor expressed on NK cells. This work demonstrates that NK cells residing in or near established tumors can be stimulated by activating ligands, and that this stimulation leads to the recruitment of adaptive immune responses at the site of tumors. Future work will dissect the mechanisms by which activated NK cells recruit T cells and B cells to tumors.
Nk cells induce tumor cell resistance to Nk cell cytolysis (TUM2P.918)
Authors: Basse Per , Fan Ryan , Bailey Lisa , Wynn Jay , Lotze Michael 
Published: January 2023

Abstract
Live cell microscopy of murine NK cells co-cultured with tumor cells revealed substantial lysis of tumor cells by NK cells that diminished dramatically within the first few hours. The kinetics of conjugate formation and NK cell cycling between targets remained unchanged. When NK cells were re-isolated and placed in co-culture with fresh tumor cells, substantial lysis ensued, indicating that the reduction in killing was not due to exhaustion of the NK cells. When tumor cells were isolated from co-cultures and re-mixed with fresh NK cells, normal cycling and conjugate-formation with tumor cells was observed, but this rarely resulted in cytolysis. Tumor cells lost plastic-adherence and underwent replicative senescence. When removed from co-culture, most of the still viable tumor cells regained their normal adherent morphology, growth rate, and sensitivity to NK-mediated lysis. Pre-incubation of tumor cells with cell-free supernatants from NK cell or NK+tumor cell cultures reduced the killing by 60-90% compared to that of non-preincubated tumor cells. The changes in MHC expression correlated poorly with the observed changes in tumor cell resistance to NK cell-mediated cytotoxicity. Pre-incubation of tumor cells with NK cells from IFNγ-KO donors or supernatants of IFNγ-deficient NK cells did not cause MHC upregulation, but induced almost complete resistance in tumor cells to NK cell-mediated cytolysis. Both IFNγ and MHC upregulation are dispensable for the observed protection.
The complement C5a receptor facilitates cancer metastasis by altering T cell responses in metastases-targeted organs (TUM2P.883)
Authors: Sharma Sharad , Chitala Navinkumar , Vadrevu Suryakumari , Sharma Priya , Cleveland Clayton , Riediger Linley , Fairlie David , Gorczyca Wojciech , Almanza Othon , Karbowniczek Magdalena , Markiewski Maciej 
Published: January 2023

Abstract
The role of complement in cancer metastasis has not yet been recognized. In addition, involvement of adaptive immunity in preventing metastasis to the vital organs is unclear. Here we show that the complement anaphylatoxin C5a receptor (C5aR) facilitates metastasis by suppressing effector CD8+ and CD4+ T cell responses in the lungs. Mechanisms of this suppression involve recruitment of immature myeloid cells co-expressing TGF-β and IL-10 to this organ. TGF- β and IL-10 favored generation of inducible T regulatory (iTreg) cells and Th2 responses that rendered CD8+ T cells dysfunctional. Importantly, pharmacological blockade of C5aR or its genetic ablation in C5aR-deficient mice prevented metastases in a syngeneic model of breast cancer. CD8+ T cell depletion abolished beneficial effect of C5aR blockade on metastasis suggesting that presence of CD8+ T cells is required for C5aR blockade-mediated protection from metastasis. These data reveal a surprising and contrasting role of C5aR-signaling in cancer metastasis that enables iTreg cell generation and suppress T cell responses. Furthermore, present study opens a new avenue for developing complement-based immunotherapies to prevent or reduce cancer metastasis.
Immunogenicity of Teffector and Treg epitopes from H7N9 avian-origin influenza: impact of cross-reactivity with the human genome (VAC2P.934)
Authors: Liu Rui , Moise Leonard , Sangare Kotou , Desrosiers Joe , Martin Bill , Groot Annie 
Published: January 2023

Abstract
Avian-origin H7N9 influenza is a novel influenza A virus (IAV) that emerged in humans in China in 2013. Using immunoinformatic tools, we found this virus has lower T cell epitope content than other IAV subtypes overall, and that some epitopes bear homology to human sequences. We hypothesized that these features may make the virus poorly immunogenic. To evaluate the reactivity of H7N9 epitopes, we synthesized four sets of H7N9 sequences with the following features: (i) unique to H7N9, (ii) cross-conserved with other IAV, (iii) cross-conserved with human genome (HG) and other IAV, and (iv) human analogs of influenza epitopes. 91% of sequences bound to at least one of five common HLA II alleles and 61% displayed strong binding. Epitopes that are conserved with other IAV induced higher IFNγ responses; conversely, epitopes that were conserved with human genome (even though equally well conserved with IAV) induced 3 fold lower IFNγ responses, similar to the level induced by H7N9 unique epitopes and to human analogs of influenza epitopes. Stimulation of human PBMCs from healthy donors with HG cross-conserved epitopes increased the frequency of CD4+CD25+FoxP3+ T cell population. Low overall T cell epitope content and the presence of HG cross-conserved H7N9 T cell epitopes that activate Tregs may explain the very low sero-conversion rates to newly developed H7HA unadjuvanted vaccines. Exploration of alternative vaccine development approaches is warranted for this new influenza virus.
Frailty correlates with age and inflammatory markers but not flu vaccine response in an older veteran cohort (VAC2P.937)
Authors: Canaday David , Oswald Douglas , Hoffman Sarah , Robinson Janet , Tumpey Terrence , Pearce Melissa , Banks Richard , Aung Htin , Burant Christopher , Higgins Patricia , Hornick Thomas 
Published: January 2023

Abstract
Frailty is a geriatric syndrome associated broadly with declines in health and function in older adults. Others have reported associations between frailty and changes in immune function including increased markers of inflammation and impaired response to influenza vaccination. In the current study we have studied a cohort of 118 older veterans with a median age of 81. They underwent Fried frailty testing and received seasonal trivalent inactivated influenza vaccine with blood drawn pre- and post-vaccination. Pre-vaccination serum inflammatory markers (IL-6, TNFR1, TNFR2), anti-flu cell mediated immunity, and pre- and post-hemagglutinin inhibition (HAI) titers were determined. As has been previously described, frailty correlated with age (r=0.32 p&lt;0.001) and serum IL-6 (r=0.41 p&lt;0.001). We extend the markers of inflammation to demonstrate that frailty also correlates with TNFR1 (r=0.32 p=0.001) and TNFR2 (r=0.38 p&lt;0.001). Contrary to a prior report we did not find a correlation between frailty and change in HAI titers after vaccination. We have an estimated power from our cohort size to detect a medium effect size of 0.23. It is possible frailty had a negative effect on vaccine response, but our sample size was too small to detect it although there was not even a trend to suggest that. Therefore, we did not find reduced antibody responses after influenza specifically in the frail veterans.
Activation of the COX2/PGE2 axis by immune effector cells promotes the self-limiting nature of type-1 immunity in cancer tissues (VAC3P.939)
Authors: Wong Jeffrey , Obermajer Natasa , Edwards Robert , Bartlett David , Kalinski Pawel 
Published: January 2023

Abstract
Type-1 immune responses, mediated by IFNγ and TNFα-producing CTLs, Th1, and NK cells, are essential for effective anti-tumor immunity. Despite recent advances in the induction and stabilization of these responses by cancer immunotherapies, the clinical success of these approaches remain limited. Here, we report that the activation of type-1 immunity within the human tumor environment initiates IFNγ- and TNFα-dependent counter-regulation, driven by amplification of prostaglandin E2 (PGE2) and the key regulator of PGE2 synthesis, cyclooxygenase 2 (COX2). We demonstrate that activated NK cells and CTLs induce IFNγ/TNFα-mediated over-expression of indoleamine 2,3-dioxygenase (IDO), inducible nitric oxide synthase (iNOS/NOS2), IL-10, and COX2 by tumor-associated myeloid-derived suppressor cells (MDSCs). Importantly, this self-limiting suppressive feedback driven by type-1 immunity could be eliminated not only by neutralization of IFNγ and TNFα, the factors critically required for the anti-tumor activity of immune effector cells, but also by COX2 blockade, which counteracted the IFNγ/TNFα-driven enhancement of all other suppressive factors, amplifying the therapeutic potential of intratumoral type-1 immunity. Our data demonstrate an intrinsic mechanism underlying the self-limiting character of type-1 immunity within the human tumor environment, and provide rationale for targeting the COX2/PGE2 axis to enhance desirable type-1 responses for cancer immunotherapy.
Aberrant differentiation and exhaustion of adenovirus vaccine-elicited CD8 T cells primed in the absence of CD4 T cells (VAC3P.940)
Authors: Provine Nicholas , Larocca Rafael , Penaloza-MacMaster Pablo , Borducchi Erica , Haining W. , Barouch Dan 
Published: January 2023

Abstract
Replication-incompetent recombinant adenovirus (Ad) vectors have garnered considerable interest as candidate vaccine platforms for an array of diseases. However, the efficacy of such vaccines in settings of impaired CD4 T cell function remains poorly understood. We demonstrate that monoclonal antibody-mediated depletion of CD4 T cells prior to Ad immunization of C57BL/6 mice impaired expansion of responding CD8 T cells and led to aberrant differentiation and exhaustion. The absence of CD4 T cells resulted in a failure of antigen-specific CD8 T cells to differentiate into KLRG1hiCD127lo effector cells. This phenotypic defect corresponded to reduced ex vivo cytotoxicity and decreased expression of IFN-γ and TNF-α. Strikingly, CD8 T cells primed in the absence of CD4 T cells expressed elevated levels of the inhibitory molecules PD-1, LAG-3, and Tim-3. Consistent with this, these cells were identified as exhausted using gene expression profiling and gene set enrichment analysis. Blockade of PD-1 signaling by administration of anti-PDL-1 antibody at the time of immunization rescued expansion of antigen-specific CD8 T cells primed in the absence of CD4 T cells. This treatment also rescued differentiation into KLRG1hiCD127lo effector cells, and corrected defects in expression of IFN-γ and TNF-α. Collectively, these data suggest a novel mechanism of CD4 T cell help whereby CD4 T cells prevent the exhaustion of vaccine-elicited CD8 T cells by modulating PD-1 signaling during priming.
Dendritic cell subversion permits viral persistence (VIR1P.959)
Authors: Popkin Daniel 
Published: January 2023

Abstract
Persistent viral infections share the ability to combat the normally protective function of dendritic cells (DC). We and others postulate that DC inhibition is necessary for viruses to persist in spite of an adaptive T cell response (e.g. HIV, HBV, and HCV). However, resolving whether viral subversion of DC (directly or indirectly) actually permits systemic viral persistence in vivo has not been determined. We developed a model system that allows us to inhibit viral replication in specific cell types to answer this question. We used cell-specific genetic deletion of the host site-1 protease (S1P) to determine a requirement for DC infection in viral persistence. The host site-1 protease (S1P) is required for replication of lymphocytic choriomeningitis virus (LCMV) and other hemorrhagic arenaviruses in addition to HCV replication. We deleted S1P in DC (S1PDCnull) to selectively eliminate viral replication in DC. Three weeks post LCMV infection, S1PDCnull mice had NO detectable viremia in contrast to &gt;5 logs of infectious virus present in WT controls. Thus, productive infection of DC was required for viral persistence. This genetic deletion occurs in &lt;1% of the cells LCMV infects. Thus, overall viral loads were equivalent during the 1st week of infection between WT and S1PDCnull mice. However, S1PDCnull mice possessed more polyfunctional T cells which we reason led to a rapid loss of viral persistence.
Using public T cell responses to predict cytomegalovirus infection status in silico (VIR1P.1004)
Authors: Emerson Ryan , Rieder Mark , Carlson Christopher , Gravley Jenna , Hansen John , Robins Harlan 
Published: January 2023

Abstract
The ability of a host’s adaptive immune system to address an incipient infection relies on the previous existence of T cells which have randomly generated an appropriate antigen-specific T cell receptor (TCR). The nature of V(D)J recombination ensures that despite the enormous space of potential TCRs, there are many TCR specificities that are common in the naïve T cell repertoires across individuals. Hence, many pathogenic antigens are known to induce a “public” T cell response, in which the same functional TCR is found to be immunodominant in multiple individuals. Despite historical limitations on sequencing depth and the limited size of investigational cohorts, previous work on public T cell responses has identified many individual examples of public T cell responses to diseases including CMV, EBV, influenza and others. Using high-throughput TCRβ sequencing, we performed deep characterization of the TCR repertoires of 650 healthy subjects (356 CMV- and 294 CMV+) to enable massively parallel discovery of public T cell responses to CMV. We have identified in one experiment hundreds of CMV-associated public T cell responses. Using cross-validation, we demonstrate that taken collectively public T cell responses to CMV contain enough information to predict CMV status in new subjects using TCR sequencing alone, showing for the first time that assaying the host adaptive immune system could be a valid diagnostic strategy in the context of infectious disease.
IFNγ protects neonatal neuronal precursor cells during measles virus infection of the brain (VIR1P.1007)
Authors: Fantetti Kristen , O'Donnell Lauren 
Published: January 2023

Abstract
In the developing brain, self-renewing neural stem/progenitor cells (NSPC) differentiate into neurons or glia. NSPC survival and differentiation can be altered by neurotropic viruses and by the anti-viral immune response. We hypothesize that interferon-gamma (IFNγ), a pro-inflammatory cytokine required for non-cytolytic clearance of many neurotropic viruses, alters NSPC proliferation and cell fate in measles virus (MV)-infected neonates. Two transgenic mouse lines were used: CD46+ express human CD46, a receptor for MV, under the neuron-specific enolase promoter, thereby restricting MV infection to mature neurons; CD46+/IFNγ-KO lack IFNγ. In our model, NSPCs are not infected, allowing us to evaluate the impact of solely the immune response on NSPCs. Flow cytometry and western blot were used to quantify effects on cell number and IFNγ-mediated signaling, respectively. Mice were mock- or MV-infected on postnatal day 2 and sacrificed 3, 7, and 10 days post-infection. Whole brain isolates were double-labeled with BrdU and markers for NSPCs (nestin), early neuronal lineage (CD24), and glial lineage (GFAP, O4). CD24+ cells showed the greatest cell loss at 7 dpi in both genotypes. NSPCs were reduced in CD46+/IFNγ-KO mice at 3 and 7 dpi, but unaffected in CD46+ mice. Thus, IFNγ may protect against NSPC, but not neuronal, loss. Current experiments aim to address the cell fate of NSPCs exposed to the antiviral immune response and define mechanisms of NSPC loss in CD46+/IFNγ-KO neonates.
Altered lipid metabolism influences course of hepatitis C virus infection and hepatocyte cytokine production (VIR1P.1011)
Authors: Narayanan Sowmya , Hoehn Kyle , Kenwood Brandon , Nieh Albert , Tosello-Trampont Annie , Davis Christine , Caldwell Stephen , Hahn Young 
Published: January 2023

Abstract
Hepatitis C virus (HCV) is remarkably efficient in establishing persistent infection leading to the development of chronic inflammatory liver diseases. Lipids play a central role in regulating inflammatory responses and are necessary for the replication and assembly of HCV. Fatty acids are the building blocks of lipids and are synthesized via a rate-limiting step catalyzed by the enzyme acetyl-CoA carboxylase (ACC). To determine the role of lipid synthesis in regulating innate inflammatory responses and HCV biogenesis, we examined the effect of ACC inhibition on HCV replication and cytokine production. Inhibition of ACC decreases intracellular viral RNA in Huh7.5.1 cells infected with JFH-1, a genotype 2a strain of HCV. Surprisingly, ACC inhibition slightly decreases IL-1β transcription and results in comparable production of IL-8, IL-13, and IP-10 in HCV-infected hepatocytes relative to vehicle controls. Further studies using electron and fluorescent microscopy demonstrate a reduction in the number of lipid droplets, which was accompanied by an accumulation of viral protein. These data highlight the paradoxical immune response of HCV-infected hepatocytes, where the continued accumulation of viral antigen fails to stimulate synthesis of inflammatory cytokines. The potential role of lipids in dampening immune responses in HCV-infected hepatocytes may provide an important link between host factors driving infection and suppression of immune responses in chronic infection.
Sialic acid binding preference of influenza A viruses regulates pathological leukocyte recruitment (VIR2P.1012)
Authors: Obar Joshua , Zickovich Julianne , Graham Amy 
Published: January 2023

Abstract
Influenza A virus (IAV), a seasonal respiratory pathogen, has a high capacity to cause pandemic infections resulting in severe lung pathology. Multiple studies using pathological IAV strains have demonstrated the importance of macrophages and neutrophils, but whether the pathological inflammation induced by different IAV isolates is identical has not been directly compared. Here we demonstrate that while both A/WSN/33 (WSN) and A/PR/8/34 (PR8) influenza viruses cause significant immunopathology in mice the inflammatory milieu differs between the two isolates. Specifically, PR8 infection was associated with greater neutrophil recruitment and CCL4 and CXCL2 expression; in contrast, WSN infection was associated mast cell activation, recruitment of a unique Ly6ghigh Ly6chigh monocyte population, and elevated levels of IFNα, G-CSF, and CCL2. One difference between WSN and PR8 is their hemaggultinin molecules preferentially bind to α2,6- and α2,3-linked sialic acids, respectively. Using a recombinant WSN strain whose sialic acid binding preference is switched to α2,3-linkages, we observed minimal mast cell activation and a switch to a more neutrophilic inflammation. Thus, sialic acid binding preference of IAV isolates has clinically important alterations to the inflammatory cascade(s) activated. These findings have important implications for our ability to therapeutically target the host inflammatory response to limit morbidity following influenza virus infection
Respiratory syncytial virus (RSV)-specific cell-mediated immune responses in human peripheral blood (VIR2P.1025)
Authors: Kim Young-In , Harrison Lisa , DeVincenzo John 
Published: January 2023

Abstract
Respiratory syncytial virus (RSV) is the leading cause of respiratory tract infections and hospitalization in infants, but no vaccine exists, primarily because the immune response is poorly understood and immune correlates of protection have not been adequately defined. Antiviral lymphocytes, along with secreted immunoglobulins (Ig) are likely the most important components of effective anti-RSV immunity RSV-specific assays to quantify the effective cell-mediated immune response to naturally-occurring RSV infections are imperative. We therefore quantified IFN-γ secreting human peripheral blood mononuclear cells (PBMCs) with and without stimulation by whole RSV from different clades, and with highly purified RSV-peptide pools. PBMCs from donors demonstrated between-donor variable levels of immune response to the RSV peptide pools and the whole virus preparations. Robust IFN-γ T-cell responses were observed at 72 hours in all PBMCs, thus allowing a single time point assay evaluation. Higher responses were seen in the CD4+ population of PBMCs compared to the CD8+ population. Responses of CD8+ PBMCs to whole virus preparations and to mock infection control preparations were similar and responses to RSV peptide pools were not statistically significant from the negative peptide control. IFN-γ based ELISPOTS and FACS assays are promising tools to quantify RSV-specific T-cell-mediated immune responses in human blood.