bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Critical Residues in the Natural Killer (NK) Cell Receptor KIR3DS1 that Control HLA (Human Leukocyte Antigen) Binding (89.55)
Authors: O'Connor Geraldine , Yamada Eriko , Rampersaud Andy , McVicar Daniel 
Published: January 2023

Abstract
The Killer cell Immunoglobulin-like Receptor (KIR) family of NK receptors contains both activating (e.g. 3DS1) and inhibitory (e.g. 3DL1) members. Unlike 3DL1, for which binding to HLA-Bw4 has been characterized, direct binding of HLA to 3DS1 has not been observed. However both genetic studies and in vitro viral replication assays suggest that this interaction can occur and is important in the context of viral infection. 3DL1 and 3DS1 are very similar in the region predicted to interact with HLA, suggesting the subtle differences translate into dramatic functional consequences. Modeling suggests four key differences in the D1 and D2 domains likely to affect interactions with Bw4. Single substitutions in this region dramatically reduced binding by 3DL1, suggesting that any of these changes would result in a lack of binding by 3DS1. In the reciprocal experiment however, we found that reversion of single amino acid residue - position 138 (W to G) was sufficient to confer HLA-Bw4 binding to 3DS1. The HLA-Bw4 reactivity of this mutant was dependent on the residue present at other variable positions, with loss of HLA-Bw4 binding seen with double mutants carrying the 3DL1 residue at both position 138 (G) and position 199 (P). These data provide evidence for a key role for position 138 in determining the HLA binding ability and thus ligand specificity of 3DS1, while suggesting a complex interaction of the residues in this region to determine receptor reactivity and specificity.
Decreased antigen-specific responses and increased lung pathology in MRL-lpr mice following influenza infection. (92.13)
Authors: Crowe Sherry , James Judith , Anderson Jourdan , Edwards Erica 
Published: January 2023

Abstract
Influenza virus infection result in significant morbidity and mortality, especially in individuals with impaired immune systems, such as those with systemic lupus erythematosus. It is unclear, however, whether this increased morbidity is due to intrinsic immune dysfunction or immunosuppressive therapy. To address these questions we used the MRL-lpr mouse model of lupus-like disease. Following infection, MRL-lpr mice had increased weight loss and lung pathology compared to controls. These signs of increased susceptibility were not due to increased viral replication or delayed viral clearance. Splenocytes from MRL-lpr mice did, however, make significantly less TNFα and more IFNγ which might account for the increased weight loss and pathology. Both lupus-prone and control mice developed high levels of anti-influenza antibodies, but the MRL-lpr mice had significantly less antigen-specific antibodies at each time-point. MRL-lpr mice also had decreased numbers of influenza-specific CD8+ T cells. This decreased antigen-specific response and lung pathology was not due solely to the absence of the fas gene since B6-lpr mice were able to mount an immune response equivalent to that seen in B6 mice. This model will provide a unique system to dissect the immune-pathogen interaction in an autoimmune disease setting and provide valuable information on how autoimmunity impacts the development of antigen specific immunity.
Direct discovery of an influenza B peptide displayed by HLA-B*0702. (92.15)
Authors: Fogle Matthew , Wahl Angela , Bardet Wilfried , Schafer Fredda , Buchli Rico , Hildebrand William 
Published: January 2023

Abstract
Annual influenza epidemics caused by influenza A and B viruses substantially impact global public health. The proportion of infections due to influenza B fluctuates from season to season, but on average accounts for 20% of influenza cases each year. We used a direct discovery method to screen for influenza B epitopes presented by HLA-B*0702. We identified epitope TIRLVTEEL (TL9) that lies within the influenza B non-structural protein 2 (NS2) also known as nuclear export protein (NEP). The TIRLVTEEL sequence is found in 86% of influenza B strains (38 out of 44 sequences) and it is a high-affinity binder to HLA-B*0702. To test the immunogenicity of this peptide, we isolated splenocytes from influenza B-infected HLA-B*0702 transgenic mice and found that TIRLVTEEL generated a strong IFN-gamma production by ELISPOT. As three variants of this epitope occur in nature, each differing from TIRLVTEEL by a single amino acid, we tested each variant for B*0702 binding and for cross-recognition by ELISPOT. Each variant is a high affinity HLA-B*0702 binder and each stimulates IFN-gamma production. In summary, we discovered a conserved epitope within the influenza B non-structural protein 2 (NS2) or nuclear export protein (NEP) which may be a candidate for future CTL-based therapies directed towards the influenza B virus.
Influenza A infection enhances cross-priming of CD8+ T cells to cell-associated antigens in a TLR7- and type I interferon-dependent fashion (92.6)
Authors: Chen Weisan , Wei Joe , Waithman Jason , Lata Roleen , Mifsud Nicole , Cebon Jonathan , Kay Thomas , Smyth Mark , Sadler Anthony 
Published: January 2023

Abstract
The initiation of anti-tumor immunity relies on DCs to cross-present cell-associated tumor antigen to CD8+ T cells due to a lack of co-stimulatory molecules on tumor cells. Innate danger signals have been demonstrated to enhance cross-priming of TCD8+ to soluble as well as virally encoded Ags, however their effect on enhancing TCD8+ cross-priming to cell-genome encoded Ags remains unknown. Furthermore, Influenza A virus has not been shown to enhance anti-tumor immunity. Using influenza-infected allogeneic cell lines, we show here that TCD8+ responses to cell-associated Ags can be dramatically enhanced due to enhanced TCD8+ expansion. This enhanced cross-priming in part involves TLR7-, but not TLR3-, mediated sensing of IAV and is entirely dependent on MyD88 and IFN signaling pathways. We also showed that the inflammasome and IFN-r did not play a role in enhancing cross-priming in our system. We further demonstrated in our ex vivo system that CD8+ DCs are the only antigen-presenting cells able to prime TCR transgenic TCD8+. Importantly, pDCs and CD8- DCs were all able to enhance such priming when provided in co-culture. These observations suggest that IAV-infection of tumor cells may facilitate improved cross-presentation of tumor Ags and may be used to augment clinical vaccine efficacy.
Experimental autoimmune uveitis in mice with defective Th1 and Th17 effector responses (93.17)
Authors: Damsker Jesse , Luger Dror , Silver Phyllis , Chan Chi-Chao , Iwakura Yoichiro , Caspi Rachel 
Published: January 2023

Abstract
Experimental autoimmune uveitis (EAU) induced in mice by immunization with the retinal antigen IRBP is a model for autoimmune uveitis in humans. Recently, we showed that Th1 and Th17 responses are redundant for induction of EAU and can substitute for each other. This study examines the effect of deficiency in both the Th1 and the Th17 signature cytokines, IFN-γ and IL-17, on susceptibility to EAU by using IL-17/IFN-double knockout (DKO) mice. Despite lack of both IFN-γ and IL-17, the DKO mice developed full-blown EAU. They exhibited enhanced Th2 responses and undiminished production of IL-22 and proinflammatory cytokines such as IL-1 and TNFα at the systemic level. At the local level, DKO eyes showed strongly elevated Th2 transcription factors, GATA-3 and c-Maf, Th2 cytokines such as IL-13 and IL-5, and eosinophil/granulocyte attracting chemokines. In keeping with this, histological analysis of diseased eyes uncovered a granulocytic/eosinophilic infiltrate in the DKO mice, rather than a lymphocytic/monocytic infiltrate typical of wild type mice. Similarly to WT mice, EAU in DKO mice was inhibited by treatment with a neutralizing Ab to TNF-alpha. Together, these findings suggest the presence of a pathogenic effector response with Th2-like characteristics that develops in the concurrent absence of IFN-γ and IL-17, in which TNF-α remains a pathogenic cytokine. Further studies using neutralizing Abs to other expressed cytokines will address their role in pathogenesis.
Antibodies elicited in response to EBNA-1 may cross-react with dsDNA. (93.29)
Authors: Yadav Pragya , Ebegbe Roland , Gottlieb Paul , Mumbey-Wafula Alice , Kaplan Atira , Spatz Linda 
Published: January 2023

Abstract
Several genetic and environmental factors have been linked to Systemic Lupus Erythematosus (SLE). One environmental trigger that has a strong association with SLE is the Epstein Barr Virus (EBV). Our laboratory previously demonstrated that BALB/c mice expressing the EBNA-1 protein, developed antibodies to double stranded DNA (dsDNA). The present study was undertaken to determine the basis for this anti-dsDNA response. We now demonstrate that BALB/c mice immunized with recombinant EBNA-1 protein develop antibodies to EBNA-1 that cross-react with dsDNA. Close examination of two monoclonal antibodies to EBNA-1 has demonstrated their reactivity with dsDNA but not unrelated proteins and absorption on dsDNA cellulose columns removes their reactivity to both dsDNA and EBNA-1. In addition, these monoclonal antibodies recognize different regions of the EBNA-1 protein suggesting that more than one epitope in EBNA-1 may be the target of antibodies that cross-react with dsDNA. These results support the association of SLE with EBV and emphasize the need to prevent EBV infection or to mask EBNA-1 protein from the immune system following EBV exposure, in order to minimize the risk of autoimmunity.
The early inflammatory response to bites of Leishmania major infected Phlebotomus duboscqi sand flies in naïve and pre-exposed mice. (94.15)
Authors: Teixeira Clarissa , Oliveira Luiz , Gomes Regis , Meneses Claudio , Elnaiem Dia-Eldim , Kamhawi Shaden , Valenzuela Jesus 
Published: January 2023

Abstract
Pre-exposure to uninfected sand fly bites (USFB) protects against Leishmania major infection. Little is known about the initial immune response responsible for this protection. During blood feeding, the insect sand fly inoculates Leishmania parasites into the skin alongside saliva. Here, we explore the early inflammatory response in the skin of pre-exposed (PE) mice challenged with L. major-infected P. duboscqi flies. The relative expression of cytokines and chemokines by skin cells were investigated 2- 48h post-infection using a macroarray (Oligo GEArray®). There is a rapid and strong early expression of inflammatory genes in PE compared to naive mice following challenge. Two to twelve hours post-infection, naïve mice showed an increased expression of MCP-1, MCP-3 and eotaxin that attract macrophages and granulocytes while PE mice upregulated TCA-3, BRAK and I-TAC related to migration of NK cells, macrophages, granulocytes and activated T cells. Characterization of leukocytes by FACS 24-48h post-infection showed a significantly increased recruitment of neutrophils, NK cells, macrophages and CD4+ cells in PE mice. PE mice also presented a higher frequency of IFN-γ producing CD4+ and NK cells 24h post-infection. This suggests that induced cytokines and chemokines are altered by pre-exposure to USFB. Thus, protection from Leishmania infection observed in PE mice may result from Th1 priming by an anti-saliva immunity that acts in concert with a modulated innate immune response.
Repercussions of Brucella metabolic activity on protection against virulent Brucella melitensis challenge in mice. (94.17)
Authors: Magnani Diogo , Harms Jerome , Durward Marina , Splitter Gary 
Published: January 2023

Abstract
Brucella spp are highly infective human intracellular pathogens that cause the most prevalent worldwide zoonotic disease, with over 500,000 human infections yearly. No human vaccine exists. Since killed and subunit vaccines present limited efficacy and live attenuated strains retain unacceptable levels of virulence, optimal design for a brucellosis vaccine requires a non-living vaccine that confers effective immunity against Brucella infected cells. Because host cell infection requires synthesis and secretion of new antigens, we hypothesized that bacterial metabolic activity generates the antigenic and adjuvant environment required for efficient triggering of protective responses. Here, we demonstrate that inactivation of B. melitensis by γ-irradiation inhibited its replication capability, yet retained live-Brucella protective features. Irradiated Brucella possessed transcriptional and oxidation-reduction activity, persisted in macrophages, generated antigen-specific cytotoxic T cells and protected mice against virulent bacterial challenge, without signs of residual virulence. In conclusion, pathogen metabolic activity has a positive role in shaping protective responses, and the generation of inactivated yet metabolically active microbes is a promising strategy for safely vaccinating against intracellular organisms like B. melitensis.
Role of hypoxia induced autophagy in the resistance of tumor cells to CTL-mediated specific lysis. (95.11)
Authors: Noman Muhammad , Janji Bassam , Moer Kris , Pierson Sandrine , Buart Stéphanie , Berchem Guy , Mami-Chouaib Fathia , Chouaib Salem 
Published: January 2023

Abstract
Hypoxia is a hallmark of solid tumors. We have recently demonstrated that exposure of tumour targets to hypoxia inhibits CTL induced autologous target cell lysis. Such inhibition is correlated to the cooperative induction of pSTAT3 and HIF-1α. Recent studies show that autophagy plays an important role in protecting cells against hypoxic stress, but the relationship between hypoxic stress and autophagy remains unclear. Here, we provide evidence that hypoxia-dependent impairment of tumor susceptibility to CTL-mediated cell lysis is associated with the induction of autophagy in tumor cells. Interestingly, inhibition of autophagy by targeting Beclin-1 or ATG-5 was sufficient to restore hypoxic tumor susceptibility to CTL and to inhibit the hypoxia-dependent phosphorylation of STAT3 on tyrosine-705 residue (pSTAT3). Furthermore, we show that the inhibition of pSTAT3 in hypoxic Atg5 or beclin-1-targeted tumor cells involves the degradation or the inhibition of the Src family protein kinase by a mechanism that involves the Ubiquitin Proteasome System (UPS). Overall, our data identify a new mechanism of pSTAT3 degradation by cooperate regulation of autophagy and the UPS under hypoxic stress. To our knowledge, this study establishes for the first time a novel functional link between hypoxia induced autophagy and tumour susceptibility to CTL-mediated lysis and highlight the use of autophagy inhibitors in immunotherapy for modulating tumor cell resistance to CTL-mediated lysis.
Simvastatin induces ER stress and p53-mediated apoptosis via eIF2α (95.12)
Authors: Lee Sang Kyu , Lim Ho Yong , Kim Young Sang 
Published: January 2023

Abstract
In addition to cholesterol lowering effect, statins have pleiotropic effects including cytotoxicity to cancer cells. In this study, we investigated the signaling pathways leading to apoptosis induced by simvastatin. Simvastatin induced apoptosis was accompanied by stabilization and translocation of p53 and Bax to mitochondria. The stabilization and the translocation of Bax were alleviated in p53 knockdown MethA and p53-/- HCT116 cells, suggesting p53-dependence of Bax translocation. Simvastatin also induced cardinal features of ER stress; phosphorylation of PERK, eIF2α, and JNK, up-regulation of CHOP and Grp78, and activation of caspase-12. Salubrinal, an inhibitor of dephosphorylation of eIF2α, sustained phosphorylation of eIF2α, suppressed the simvastatin-induced apoptosis, and reduced the stabilization and translocation of p53 and Bax. SP600125, a JNK kinase inhibitor, did not affect the apoptosis and the translocation of p53 and Bax in the condition. Furthermore, PERK knockdown or over-expression of a mutant form of eIF2α (Ser51/Ala) sensitized MethA and HCT116 cells to the simvastatin-induced apoptosis. Over-expression of the eIF2α-mt also enhanced the stabilization of p53 and Bax in response to simvastatin. These results indicate that the PERK-eIF2α axis is involved in stabilization and translocation of p53 and Bax to mitochondria, and eIF2α plays an essential role in induction of ER stress-mediated apoptosis by simvastatin.
Contribution of MyD88 to the tumor exosome-mediated induction of myeloid derived suppressor cells (MDSC) (95.16)
Authors: Liu Yuelong , Xiang Xiaoyu , Zhuang Xiaoying , Zhang Shuangyin , Liu Cunren , Cheng Ziqiang , Michalek Sue , Grizzle William , Zhang Huang-Ge 
Published: January 2023

Abstract
Tumor cells released membrane microvesicles - exosomes, can stimulate inflammation through MDSC, and then promote tumor growth by activating immunosuppressive networks. MyD88 is a cytoplasmic adaptor molecule essential for inducing inflammation via the TLR receptors. Very little is known about whether tumor exosome-mediated induction MDSCs and tumor growth is regulated through MyD88. In this study, we observed that mice pretreated with tumor exosomes had a significant acceleration of tumor metastasis in the lung. Tumor metastasis correlated significantly with an increase in recruitment of more MDSCs in the lung of B6 mice pretreated with tumor exosomes. These effects were blunted when MyD88 KO mice were pretreated with tumor exosomes. MDSCs induced by tumor exosomes and isolated from WT B6 mice are also more potent in inhibition of T cell activation and induction of IL-6 and TNF-α than MDSCs isolated from the lung of MyD88 KO mice via activation of the Stat3 pathway. Our in vitro data further support that addition of tumor exosomes to bone marrow derived CD11b+Gr-1+ cells isolated from WT B6 mice results in producing more cytokines, including TNF-α, IL-6 and the chemokine CCL2, than CD11b+Gr-1+ cells isolated from MyD88 KO mice. Less CCL2 in lung was observed in MyD88 KO mice pretreated with tumor exosomes than that in WT mice. Together these data demonstrate a pivotal role for MyD88 in tumor exosome-mediated induction of IL-6, TNF-α, expansion of MDSCs and tumor metastasis.
Murine AIDS and the role of PD-1, PD-L1 and IL-10 in the development of LP-BM5 retrovirus induced CD11b+GR-1+ suppressor cells. (98.26)
Authors: Green Kathy , Green William 
Published: January 2023

Abstract
Pathology due to the immune system’s response to viral infections often represents a delicate balance between inhibition of viral pathogenesis and regulation of protective immunity. In susceptible C57BL/6 mice the murine retroviral isolate LP-BM5 induces splenomegaly, hypergammaglobulinemia, B-and T-cell immunodeficiency, increased susceptibility to opportunistic pathogens and terminal B-cell lymphomas. We have reported that B6.PD-1 and B6.IL-10 knockout(k.o.) mice are more susceptible to LP-BM5-induced disease than wild-type (w.t.) C57BL/6 mice. By reciprocal reconstitution experiments, comparing w.t. vs. PD-1 k.o. sources of the requisite cells for LP-BM5 pathogenesis - CD4 T and B cells, PD-1+ B cells appear crucial in the normal limitation of LP-BM5 induced disease in B6 mice. Recent studies have shown: 1) LP-BM5 infected PD-L1 k.o. mice also develop more severe splenomegaly, hypergammaglobulinemia, and immunodeficiency than infected B6 mice 2) CD11b+GR-1+ spleen cell subsets, from LP-BM5 infected w.t., IL-10 k.o., PD-1 k.o. and PD-L1 k.o. mice are all suppressive in in vitro LPS proliferation assays with suppression most complete for IL-10 k.o. and PD-1 k.o. derived cells. Experiments in progress include: 1) adoptive transfer to define the crucial cell subset required for PD-L1 normal limitation of LP-BM5 induced disease and 2) phenotypic and mechanistic further characterizing CD11b+GR-1+ LP-BM5 induced suppressor cells.
A novel MHC class Ib-mediated immune surveillance mechanism detects the absence of ERAAP (100.16)
Authors: Nagarajan Niranjana , Gonzalez Federico , Shastri Nilabh 
Published: January 2023

Abstract
Immune surveillance mechanisms detect failures in vital parts of the host immune system, such as in the antigen processing pathway. The ER aminopeptidase associated with antigen processing, ERAAP, is an essential component of the antigen processing pathway, and is required to generate the final peptides presented by MHC class I molecules. It has been unclear how the immune system detects deficiencies in ERAAP function, and here we describe a potential mechanism to do so. Non-classical MHC class I, or MHC class Ib, molecules present novel peptides in ERAAP-deficient cells, and elicit potent CD8 T cell responses in wild-type mice. Using these CD8 T cells as a probe, we identified a novel peptide presented by Qa-1b. FL9-Qa-1b-specific CD8 T cells can be readily detected in naïve mice and constitute a substantial fraction of the anti-ERAAP-/- immune response in wild-type mice. Additionally, WT CD8 T cells detect and eliminate MHC class Ib-expressing ERAAP-deficient cells. Therefore, we suggest that presentation of the FL9 peptide by Qa-1b molecules is a surveillance mechanism for detecting inhibition of ERAAP function.
GILT regulates CD4+ T cell tolerance (100.28)
Authors: Rausch Matthew , Metzger Todd , Anderson Mark , Hastings Karen 
Published: January 2023

Abstract
Regulating the balance between T cell activation and tolerance is essential for stimulating an anti-tumor immune response and in controlling autoimmunity. We have shown that gamma-interferon-inducible lysosomal thiol reductase (GILT) is required for efficient MHC class II-restricted processing of an epitope from the melanoma antigen tyrosinase-related protein 1 (TRP1). Using CD4+ TRP1-specific T cell receptor transgenic mice, here we demonstrate a novel function for GILT in the regulation of TRP1-specific T cell tolerance. TRP1-specific T cells are centrally deleted in mice expressing both GILT and TRP1 on the RAG-/- background. In contrast, CD4+ T cells develop in the absence of either GILT or TRP1. GILT’s role in central tolerance is supported by GILT and TRP1 expression in thymic stromal cells. Although TRP1-specific CD4+ T cells escape thymic deletion in the absence of GILT, they are tolerant to TRP1 and do not induce vitiligo. TRP1-specific T cells from GILT-deficient mice initially divide in response to antigen, but fail to produce substantial levels of IFN-γ and IL-2. Tolerance is partially mediated by CD25+Foxp3+ regulatory T (Treg) cells. There is an increased percentage of TRP1-specific Treg cells in GILT-deficient compared to TRP1-deficient mice, and Treg cell depletion allows GILT-deficient TRP1-specific CD4+ T cells to induce vitiligo. These studies highlight a critical role for GILT in shaping the CD4+ T cell repertoire.