bluuebunny/crossref_metadata_2025_split huggingface dataset:
CTLA4-CD28 chimeric gene modification of T cells enhances therapeutic efficacy of donor lymphocyte infusion for hematological malignancy (VAC5P.1122)
Authors: Park Hyung-Bae , Lee Ji Eun , Lee Sang , Eom Hyeon , Choi Kyungho 
Published: January 2023

Abstract
Donor lymphocyte infusion (DLI) has been used as an effective therapeutic regimen for the relapsed hematologic malignancies, such as chronic myelocytic leukemia, after allogenic bone marrow transplantation. However, therapeutic efficacy of DLI for other types of leukemia including acute lymphocytic leukemia (ALL) has been limited so far. Thus, we tested if increasing the reactivity of donor T cells by gene modification could enhance therapeutic effect of DLI in a murine model of ALL. For this purpose, we introduced CTLA4-CD28 chimeric gene (CTC28), in which the intracellular signaling domain of CTLA4 was replaced with the CD28 signaling domain, into donor T cells and evaluated the graft-versus-tumor (GVT) effect in an EL4 tumor-bearing mixed bone marrow chimera model. The modification significantly enhanced GVT effect of donor T cells. This effect was correlated with increased expansion of CD8 T cells and elimination of CD8 T cells abolished this effect. GVT effect and CD8 T cell expansion were dependent on the CTC28-modification of CD4 T cells, emphasizing the role of CD4 help in this therapeutic effect. Modified CD4 T cells not only expanded more, but also showed enhanced functional responsiveness. Modified T cell-derived IL-2 was indispensable for the GVT effect, although not required for expansion of the T cells. Thus, combined genetic modification of CD4 and CD8 donor T cells with CTC28 can be a promising strategy for enhancing therapeutic efficacy of DLI for ALL.
A novel pro-apoptotic function for Epstein-Barr virus LMP2A: increasing B cell sensitivity to Fas-mediated apoptosis via Lyn and Syk kinases (VIR1P.1136)
Authors: Swanson-Mungerson Michelle , Incrocci Ryan , Hussain Samira 
Published: January 2023

Abstract
Latent Membrane Protein 2A (LMP2A) of Epstein-Barr virus (EBV) protects B cells from many pro-apoptotic signals. LMP2A is expressed in EBV-infected B cells in the germinal center, which is a site of significant Fas-mediated apoptosis. Given that B cell receptor (BCR) stimulation protects B cells from Fas-mediated apoptosis and since LMP2A acts as a BCR mimic, we hypothesized that LMP2A would protect B cells from Fas-induced apoptosis. To test this hypothesis, LMP2A-negative and -positive B cell lines were exposed to a Fas-specific monoclonal antibody and apoptosis was assessed by Annexin V staining and PARP cleavage. Surprisingly, LMP2A-expressing B cell lines demonstrate an increased sensitivity to Fas-mediated apoptosis, due to a LMP2A-dependent enhancement in Fas expression. B cell lines harboring LMP2A mutations in either the Lyn or Syk binding site do not show an LMP2A-dependent increase in Fas levels and/or Fas-mediated apoptosis, indicating that LMP2A requires these two kinases to mediate these pro-apoptotic effects. Furthermore, experiments demonstrate that LMP2A enhances Fas-mediated apoptosis in human B cell lines in the presence of additional EBV latency proteins, indicating that LMP2A promotes Fas-dependent apoptosis in the natural context of the virus. These findings are the first to demonstrate a pro-apoptotic function of LMP2A and have implications for both EBV latency and EBV-associated malignancies.
Defining the role of CD4 T cells during acute Theiler's murine encephalomyelitis virus infection (VIR1P.1141)
Authors: Huseby April , Jin Fang , Johnson Aaron 
Published: January 2023

Abstract
Theiler’s murine encephalomyelitis virus (TMEV) infection of C57BL/6 mice has served as a model of acute neuroinflammation. Immune cells have been shown to be both pathogenic and protective during the acute stage of TMEV infection. Our lab has previously investigated the role for CD8 T cells directly interacting with virally infected neurons using confocal microscopy. Through this work, we demonstrated polarized immunological synapse formation in the CD8 T cell toward the virally infected neuron. In a subsequent study using confocal microscopy, we observed that CD4 T cells are also in tight apposition to virally infected neurons. This observation prompts an analysis to define the interaction between the CD4 T cell and the virally infected neuron. Defining the CD4 subset is a crucial first step to assessing their potential protective effector mechanisms. Future studies will investigate the role for Kupfer synapses or non-Kupfer type synapses statically and subsequent studies conducted with two-photon laser scanning microscopy (2PLSM) will allow us to measure the cell dynamics and motility, in vivo, of the immune components that contribute to the protection or pathogenesis during neuroinflammation.
Natural CD4+ T regulatory cell down-regulation of monocytic myeloid derived suppressor cell phenotypic and functional subpopulations in LP-BM5 murine retrovirus-induced immunodeficiency (VIR1P.1149)
Authors: OConnor Megan , Vella Jennifer , Green William 
Published: January 2023

Abstract
Immunomodulatory cellular subsets, including myeloid derived suppressor cells (MDSCs) and T regulatory cells (Tregs), contribute to the immunosuppressive tumor microenvironment and have been targets of immunotherapy, but their role in retroviral-associated immunosuppression is less understood. Due to known crosstalk between Tregs and MDSCs in the tumor microenvironment, it is of interest to look at the interplay between these immune cells during LP-BM5-induced murine AIDS. Following in vivo natural Treg (nTreg) depletion, and subsequent LP-BM5 retroviral infection, enriched MDSCs from infected nTreg-depleted mice exhibit increased suppression of T cell, but not B cell, responses, as compared to MDSCs derived from non-depleted LP-BM5-infected controls. MDSCs from LP-BM5-infected nTreg-depleted mice also display altered phenotypic subsets, which correlate with functional differences. In addition, LP-BM5-induced MDSCs modulate in vitro Treg phenotype and function. These collective data highlight an antagonistic relationship between MDSCs and Tregs, and may provide insight into the immunotherapeutic targeting of these cells during retroviral infection.
High avidity and functionality of virus-specific CD8 T cells associated with protection during HCV reinfection (VIR2P.1168)
Authors: Boisvert Maude , Abdel-Hakeem Mohamed , Bruneau Julie , Soudeyns Hugo , Shoukry Naglaa 
Published: January 2023

Abstract
The majority of acute hepatitis C virus (HCV) infection (75%) leads to chronicity and liver diseases. While 25% of infected individuals can naturally clear the infection, long-term protection is elusive and reinfection can occur. We have previously showed that protection from viral persistence upon HCV reinfection correlates with expansion of HCV specific T cells with increased breadth. Viral persistence was associated with limited expansion of virus specific T cells. CD8 T cell receptor (TCR) repertoire analysis showed that clonotypes associated with protection upon reinfection are recruited from the memory population, with focusing of the repertoire. We hypothesized that protective immune memory response is associated with selection of T cell clonotypes with the highest TCR avidity and a polyfunctional profile. We FACS sorted HCV-specific CD8 T cells to generate individual clones representative of clonotypes of high, medium or low frequency in the TCR repertoire. Tetramer titration assay showed that the TCR avidity correlated with the clonotype expansion in vivo upon reinfection. All clones showed a polyfunctional profile but the main function varied between clones. In conclusion, our results suggest that the main determinant for the expansion of memory HCV specific CD8+ T cells during HCV reinfection was the TCR avidity. The results of this study have implications for the development of vaccination regimens to boost generation and selection of such clonotypes.
HLA-F and MHC open conformers in a novel HIV-1 immunization strategy
Authors: Geraghty Daniel , Gooodridge Jodie P , Wang Kevin , Burian Aura , McNevin John , McElrath Margaret J , Lee Ni 
Published: January 2023

Abstract
HLA-F is expressed as a protein independent of bound peptide or b2-microglobulin and surface expression is upregulated in dendritic cells, monocytes and most lymphocyte subsets upon activation. Classical MHC class I (MHCI) is also expressed on proliferating lymphoid cells as so-called ‘open conformers (OCs)’, in addition to the ubiquitously expressed form complexed with peptide and b2-microglobulin. Previous studies showed that HLA-F binds most MHCI proteins as open conformers without peptide but not as peptide bound complex. These studies were extended to show that both HLA-F and MHCI OC are ligands for a specific subset of killer Ig-like receptors (KIRs). The HLA-F/MHCI physical interaction was further implicated in the function of HLA-F and MHCI open conformers in a general mode of exogenous MHCI antigen uptake and antigen presentation by activated immune cells that differs from the canonical MHCI endogenous antigen presentation. We are currently testing the hypothesis that antigen entry is governed by a synergy between specific structural characteristics of the exogenous antigen and the MHC-I allele types of target cells. New evidence is presented using HIV-1 p24 gag derived long polypeptides suggesting a requirement for HLA class I peptide epitope specificity in antigen uptake, upstream of antigen presentation, which subsequently can be presented by either or both of MHCI and MHCII. These experiments suggested that the physical proximity of HIV-1 class I and class II peptide epitopes within a p24 polypeptide can govern antigen presentation of epitopes through either MHCI or MHCII or both. A goal is to manipulate these features in designing effective immunogens for directed stimulation of antigen-specific host responses.
Proteasomal degradation by irreversible binding of Nedd8.
Authors: Vijayasimha Kartikeya , Palmer Amy , Dolan Brian P 
Published: January 2023

Abstract
A large fraction of endogenous antigenic peptides presented by the major histocompatibility complex-1 (MHC1) is thought to be generated by rapid proteasomal degradation of newly synthesized defective ribosomal products (DRiPs). Poly-ubiquitination is responsible for the proteasomal degradation of a majority of intracellular proteins. However, recent data demonstrate that the inhibition of poly-ubiquitin chain assembly itself does not fully inhibit DRiP presentation, thus indicating the involvement of other players. We therefore suspected that other ubiquitin-like (UBL) molecules may be involved in antigen presentation. A recently described chemical inhibitor of the UBL termed Neural precursor cell expressed, developmentally down-regulated 8 (Nedd8) conjugation was used in conjunction with a cell-based assay to measure direct antigen presentation. Inhibition of Nedd8 conjugation led to a striking decrease in presentation of peptides derived from DRiPs, but not from peptides derived from retired forms of the same model antigen. To determine if Nedd8 conjugation to a substrate led to proteasomal-mediated degradation, we created a mutant form of Nedd8, which substituted the three of the four C-terminal glycine residues to alanine and thus inhibited the processing of Nedd8 into its active form. When fused to GFP, we found the mutant Nedd8 led to a rapid, proteasomal mediated destruction of the fusion protein. Wild-type Nedd8-GFP fusion protein was processed as expected and protein detection was not detected. Here we show a mechanism of proteasomal degradation mediated directly by Nedd8 conjugation, and a possible role for Nedd8 in the MHC1 presentation pathway.
TLR9 is indispensable for MR1-mediated bacterial antigen presentation
Authors: Liu Jianyun , Brutkiewicz Randy Richard 
Published: January 2023

Abstract
Mucosal-associated innate T (MAIT) cells are conserved T cells that express a semi-invariant T cell receptor (TCR; Vα7.2 in human and Vα19 in mice). The development of MAIT cells requires the antigen (Ag) presenting major histocompatibility complex (MHC)-related molecule, MR1, as well as commensal bacteria, because germ-free or MR1-deficient animals have few MAIT cells. B cells were the first identified (and the most prominent) antigen presenting cells (APCs) for MAIT cells. Previous studies have shown that MR1 is ubiquitously expressed, but is mostly localized in the cytosol. B cells normally express very few MR1 molecules on the cell surface. Upon a bacterial infection, MR1 translocates to cell surface with loaded Ag, interacts with the invariant TCRα and activates MAIT cells. However, it remains unknown how MR1 molecules are processed and loaded with bacterial Ag in APCs. We have found that treating B cells with a TLR9 agonist CpG increases MR1 surface expression. The upregulation of surface MR1 was blocked by protein transport inhibitor Brefeldin A, suggesting that endocytic trafficking stimulated by TLR9 activation is important for the surface expression of MR1 in B cells. Further, knocking-down TLR9 expression by shRNA reduces MR1-mediated activation of MAIT cells. Overall, our results indicate that TLR9 is important for MR1-mediated bacterial Ag presentation. Further studies are needed to elucidate how TLR9 controls MR1 endocytic trafficking and bacterial Ag processing and/or loading onto MR1.
Rab43 facilitates cross-presentation of cell-associated antigens by CD8a+ dendritic cells
Authors: Theisen Derek J , Kretzer Nicole , Tussiwand Roxane , Briseno Carlos , Grajales-Reyes Gary , Wu Xiaodi , Durai Vivek , Albring Jorn , Bagadia Prachi , Murphy Theresa , Murphy Kenneth M 
Published: January 2023

Abstract
Batf3-dependent classical dendritic cells (cDCs) are essential for cross-presentation and clearance of intracellular pathogens through priming of CD8 T cells. By analyzing differences in gene expression between cDC subsets we identified vesicular transport molecules unique to cross-presenting dendritic cell subsets. RAB43, a GTPase that is localized to the golgi, is selectively expressed in Batf3-dependent CD8a+ and CD103+ cDCs and was highly conserved between mouse and human. Mice with germline and conditional Rab43 deletions are viable and fertile with normal hematopoiesis. However, mice lacking Rab43 showed reduced cross-presentation of cell-associated, but not soluble, antigens both in vitro and in vivo. Bone-marrow derived DCs (BMDCs) from Rab43 deficient mice show normal cross-presentation efficiency, suggesting that Rab43 is involved in optimizing cross-presentation in vivo through a pathway unique to CD8a+ DCs.
A Sec22b knockout mouse offers novel insights into the molecular mechanisms of crosspresentation
Authors: Wu Shin-Rong Julia , Johnson Claire , Zajac Cynthia , Sun Yaping , Mathewson Nathan , Toubai Tomomi , Oravecz-Wilson Katherine , Khoriaty Rami , Ginsburg David , Reddy Pavan 
Published: January 2023

Abstract
Crosspresentation critically contributes to the adaptive immune response to tumors and viral infection by presenting extracellular antigen on MHC I to activate CD8 T cells. However, its molecular regulation is poorly understood. Using in vitro shRNA-mediated knockdown (KD) methods, another group had shown that Sec22b, an ER-SNARE, specifically regulates crosspresentation. Thus, we tested the hypothesis that Sec22b would mediate crosspresentation in vivo. We generated DC-specific Sec22b knockout (KO) mice, which have an intact, functional immune system. After adoptively transferring OT-I T cells into these mice, then injecting with soluble OVA i.p., we analyzed OT-I T cell proliferation to measure crosspresentation. Surprisingly, we saw no difference in OVA crosspresentation by KO versus FL mice. This observation was verified in vitro using KO DCs from BM and spleen crosspresenting soluble and insoluble OVA. We concluded Sec22b is not necessary for crosspresentation, invalidating our hypothesis. However, we were able to reproduce the reduced crosspresentation by shRNA-mediated KD of Sec22b. Intriguingly, when we treated KO BMDCs with the same Sec22b-targeting shRNA, we again observed reduced crosspresentation comparable to that seen in shRNA-treated WT BMDCs. This suggested the shRNA mediates crosspresentation through its effects on an off-target gene. RNAseq data on shRNA-treated BMDCs provided a candidate list of potential crosspresentation mediators. Our data demonstrates that (a) Sec22b is not necessary for crosspresentation, (b) there may be a novel critical mediator of crosspresentation targeted by the shRNA, and (c) extrapolating mechanisms or phenotypes based on KD studies alone must be done with caution.
γδ T cells can play a role in provoking an inflammatory attack on the cornea
Authors: O’Brien Rebecca L , Yang Zhifang , Huang Yafei , Loomis Josh , Owen Amie L , Born Willi K H 
Published: January 2023

Abstract
Ocular immune privilege results from a complex set of mechanisms that together prevent immunogenic inflammation, but still allow the eye to deal with potentially infectious agents in a localized way that does not compromise vision. Failure of immune privilege can unleash a damaging autoimmune attack on the eye. γδ T cells have been found to be important for these processes in a number of different systems. In mice of the C57BL/10 background (B10), we have previously shown that γδ. T cells help prevent the spontaneous development of keratitis, an inflammation of the cornea that B10.TCRδ −/− mice are highly prone to develop, particularly the females. Paradoxically, B10 mice that can produce γδ T cells but not αβ T cells also develop keratitis at a high rate. We recently found that Vγ4+ cells from the spleens of keratitic B10.TCRβ−/− mice, but not Vγ1+ cells, can adoptively transfer the disease to normally keratitis-resistant B10.TCRβ−/−δ−/− hosts. Immunofluorescence staining of corneal whole mounts from B10.TCRβ−/− mice revealed that Vγ4+ cells infiltrate the keratitic corneas, and show a strong bias to secrete IL-17. In contrast, Vγ1+ cells were more rare in the keratitic corneas and did not produce IL-17. The majority of the γδ T cells in keratitic corneas were Vγ1-negative, Vγ4-negative, and Vγ7-negative, however, and did not produce IL-17. We hypothesize that although some γδ T cell subsets protect against autoimmune attack on the cornea, certain Vγ4+ γδ T cells instead promote keratitis by infiltrating the corneas and secreting IL-17, which attracts and mobilizes neutrophils, resulting in tissue damage.
The TAM receptors Axl and Mer play a joint-specific protective role in experimental arthritis
Authors: Waterborg Claire Elisabeth Joyce , Través Paqui González , Zagórska Anna , Lemke Greg , Beermann Silke , van de Loo Fons Adrianus 
Published: January 2023

Abstract

Introduction
Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by an unrestrained inflammatory response in synovial joints. One family of tyrosine kinase receptors involved in anti-inflammatory feedback mechanism are Tyro3, Axl and Mer (TAM). The plasma level of the TAM receptor ligand Gas6 is significantly reduced in RA patients suggesting this feedback mechanism is impaired in RA. We investigated the individual role of each TAM receptor in experimental arthritis.

Methods
The KRN serum transfer model of arthritis was induced by two intraperitoneal injections of arthritic K/BxN serum in TAM receptor single gene knock-out mice (Tyro3−/−, Axl−/−, Mer−/−) and wild-type (WT) mice. Ankle joints were macroscopically scored for 7 days and knee and ankle joints were taken at the end of the experiment for histology and immunohistochemistry.

Results
Mer−/− mice had an increased macroscopic ankle score until day 4 whereas Axl−/− mice had an enhanced macroscopic score from day 4 until the end of the experiment. Histology of the ankle joints showed significantly increased arthritis pathology in Axl−/− mice compared to WT. In contrast, enhanced macroscopic score and arthritis pathology in the knee joints of Mer−/− mice was observed. Both in ankle and knee joints, no protective or aggravating role of Tyro3 was seen. To explain the discrepancy of Axl involvement between ankle and knee, we looked for Axl expression in synovium of naïve mice. The lining layer of ankle synovium was completely Axl-positive whereas only mild expression in the knee joints was observed.

Conclusion
These findings identify the TAM receptors Axl and Mer as important protective players in arthritis in addition to being expressed in a joint-specific manner.
Plasmacytoid dendritic cells in late-stage lupus mice defective in producing IFN-α
Authors: Liao Xiaofeng , Li Song , Settlage Robert E , Sun Sha , Ren Jingjing , Reihl Alec , Zhang Husen , Karyala Saikumar , Reilly Christopher , Ahmed S Ansar , Luo Xin M 
Published: January 2023

Abstract
Plasmacytoid dendritic cells (pDCs) are professional type I IFN producers believed to promote lupus. However, questions exist about whether they function at the same level throughout the course of lupus disease. We analyzed high-purity pDCs sorted from lupus mice. Although pDCs produced a large amount of IFN-α during disease initiation, those sorted from late-stage lupus mice were found to be defective in producing IFN-α. These pDCs expressed an increased level of MHC, suggesting a functional drift to Ag presentation. We examined the potential mechanism behind the defect and identified a novel transcriptional factor, Foxj2, which repressed the expression of several genes in pDCs, but not IFN-α. Dysregulation in pDCs appears to be predisposed, because they exhibited an altered transcriptional profile before the onset of clinical signs. Our results suggest that pDCs do not function the same throughout the disease course and lose the ability to produce IFN-α in late-stage lupus mice.
The gut microbiome influences arthritis development in IIJ mice
Authors: Paras Tyler M , Percival Frank , McQuade Eileen 
Published: January 2023

Abstract
Inherited Inflamed Joint (IIJ) mice spontaneously develop inflammatory arthritis at an early age. The gut microbiome has been implicated in several murine models for inflammatory arthritis, however the role of the microbiome in IIJ arthritis is unknown. The purpose of this study was to determine whether the gut microbiome affects arthritis development in IIJ mice and characterize the microbiome of IIJ mice in various age and disease states using next generation sequencing techniques. Pre-arthritic (pAR) IIJ mice were treated with water containing neomycin, ampicillin, vancomycin, and metronidazole for 5 weeks. Disease onset and severity was scored based on swelling of the large joints throughout the treatment period. Antibiotic treatment delayed disease onset and reduced disease severity in IIJ mice. Additionally, the IIJ gut microbiome in pAR, 5 week old arthritic mice (AR), and age matched controls (pN and NAR, respectively) were characterized using MiSeq sequencing of 16S rRNA amplicons. pAR mice were enriched with an unclassified member of the Clostridiales, whereas pN mice were dominated with species from the S24-7 family and Bacteroides, both members of the Bacteroidetes. Differences between the bacterial communities of experimental groups were apparent from the non-metric multidimensional scaling (NMDS) plots, but were not significant by PERMANOVA. Together these results suggest that the gut microflora of IIJ mice increase host susceptibility to inflammatory arthritis, which may be mediated by a unclassified member of the Clostridiales. Classical triggers of the innate immune system are also being investigated for effects on arthritis incidence and severity.