bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical Quantification of Disease Activity using Hydrophobically Modified Glycol Chitosan labeled with Near-Infrared Fluorescence in Experimental Arthritis Model (42.25)
Authors: Kang Young Mo , Park Kyeongsoon , Kang Jin Hee , Sa Keum Hee , Cho Hyung Jeong , Lee Seulki , Kwon Ick Chan 
Published: January 2023

Abstract
Objective. To investigate the quantitative analysis of disease activity using the optical imaging system with hydrophobically modified glycol chitosan labeled with Cy5.5 (HGC-Cy5.5) in animal arthritis model.
Methods. Fluorescence reflectance images were captured two hours after intravenous injection of HGC-Cy5.5 nanoprobe from the paws of collagen-induced arthritis mice. Immunofluorescence staining for F4/80 and Mac-1 molecules were performed to identify the cell types phagocytosing HGC nonoprobe, both in vivo and in vitro.
Results. In raw reflectance images, paws of the active arthritis group showed stronger fluorescence intensity than those of nonarthritis group. According to the progression of arthritis, total photon counts (TPC) increased until 5 weeks after the booster injection in parallel with the clinical arthritis index. The quantitative analysis of fluorescence intensity showed that the TPC had significant differences in methotrexate treated groups compared with an untreated group. Fluorescence microscopy demonstrated considerable accumulation of HGC-Cy5.5 within the synovial tissues, with the localization of the probe within the interstitial and a portion of cells expressing Mac-1 molecule. Macrophages differentiated with the stimulation of GM-CSF revealed conspicuous intracellular NIRF signal after two hours of incubation with the HGC-Cy5.5, with up-regulated expression of Mac-1 on the surface.
Conclusion. The present results indicate that the quantitative analysis of joint inflammation using HGC-Cy5.5 nanoprobe can provide an objective measurement of disease activity in RA.
DNA vaccine encoding spike protein of SARS-coronavirus loaded polyethylenimine elicits antigen-specific immune responses in mice immunized through intranasal route (42.8)
Authors: YUN CHEOL-HEUI , Shim Byoung-Shik , Park Sung-Moo , Han Heung Hyun 
Published: January 2023

Abstract
The spike protein (S) of severe acute respiratory syndrome (SARS) coronavirus-(CoV) is a ~180-kDa glycoprotein, which is essentially required its recognition of and binding to host receptors. It has been known that the receptor-binding motif of spike protein can produce neutralizing antibodies and therefore prevent the infection caused by SARS-CoV. Polyethylenimine (PEI) is one of the most widely used and effective nanoparticles, which have been tested for its use in the drug delivery system including DNA vaccine. In the present study, we examined the immune responses in BALB/c mice after immunized with SARS DNA vaccine in a pci-S/PEI complex form via intranasal (i.n.) route. PEI/pci-S nanoparticles showed a spherical shape with size around 194+/-99nm. The mice intranasally immunized with pci-S/PEI nanoparticles produced significantly (P&lt;0.05) higher S-specific IgA as well as B220+ cells in the lung wash than those in mice treated with pci-S alone. CD80, CD86 and Class II MHC molecules (I-Ad) were increased on pulmonary dendritic (CD11c+) cells after vaccination. The percentage of IFN-gamma, TNF-alpha, and IL-2 producing cells were also higher in PEI/pci-S vaccinated mice than in either pci-S or pci-mock treated mice. Taken together, our results showed that immunization with pci-S/PEI nanoparticles induce antigen specific humoral and cellular immune responses.
PD-1 traffics to the immunological synapse along the plasma membrane to inhibit CTL cytotoxicity and cytokine secretion (44.25)
Authors: Ahmed Fariyal , Friend Sherree , Barteneva Natasha , Lieberman Judy 
Published: January 2023

Abstract
ABSTRACT
Functional impairment of antigen-specific T cells is a defining feature of chronic HIV infection. During HIV infection, the inhibitory receptor programmed death 1 (PD-1) and its ligand PD-L1 are markedly upregulated on 'exhausted' HIV specific CD8 T cells and antigen presenting cells, respectively. PD-1 up-regulation on HIV specific CD8 T cell correlates positively with effector cell exhaustion and plasma viral loads, and inversely with CD4 T-cell count. Blockade of the PD-1/PD-L1 pathway augments some aspects of HIV-specific CD8 T cell activation, including proliferation and cytokine production. However, the underlying biology behind the workings of this described inhibitory pathway is not fully understood. I will investigate the changes in PD-1 expression and localization in response to CD8 T cell activation and study its effect on T-cell receptor signaling and effector cell functions. I hypothesize that PD-1 concentrates in the central region of the immunological synapse and undermines its stability and signaling. To test this hypothesis, I will investigate the effect on T cell signaling, proliferation, cytokine production and cytotoxicity by both over-expressing PD-1 and silencing its ligands, using RNA interference, in primary T cells and macrophages, respectively. Understanding the PD-1/PD-L1 pathway of reversible T-cell impairment may help develop novel therapeutic strategies for rescuing the function of exhausted T cells in chronic HIV infection.
Selective deficiency of STAT1 in CD4+ T cells enhances susceptibility to Leishmania major infection not by preventing induction of Th1 response, but by impairing CD4+ T cell homing (44.26)
Authors: Snider Heidi M , Bhardwaj Neeti , Barbi Joseph , Lezama-Davila Claudio M , Durbin Joan E , Satoskar Abhay R 
Published: January 2023

Abstract
We previously reported that STAT1 signaling is indispensable for host resistance against Leishmania major. In this study, we examined the role of STAT1 in lymphocytes as well as CD4+ versus CD8+ T cells in mediating immunity to L. major by performing adoptive transfers of T cells from WT and STAT1-/- C57BL/6 mice to Rag2-/- C57BL/6 mice. Rag2-/- mice reconstituted with STAT1-/- splenocytes (B cells and T cells) failed to mount an efficient Th1 response following L. major infection, produced more IL-4 and developed large lesions full of parasites. In contrast, Rag2-/- mice reconstituted with WT (STAT1+/+) splenocytes mounted a Th1 response and developed self-resolving lesions. Studies using Rag2-/- recipients that received a combination of purified CD4+ and CD8+ T cells from WT or STAT1-/- mice revealed that STAT1 in CD4+, but not CD8+ T cells was indispensable for immunity against L. major. Further studies using Thy1.1+ congenic recipients receiving WT or STAT1 Thy1.2+ CD4+ cells showed that STAT1 in CD4+ T cells was not required for Th1 differentiation and IFN-γ production during L. major infection, but was critical for migration to regional lymph nodes and the cutaneous site of infection. Together these studies indicate that STAT1 signaling in CD4+ T cells plays a critical role in immunity against L. major by controlling migration of Th1 cells to the site of infection rather than their generation.
Research Support: NIH
Promoter Complexity Model for TRIF-biased Stimulation of TLR4 by Synthetic Monophosphoryl Lipid A (44.28)
Authors: Cekic Caglar , Casella Carolyn R. , Eaves Chelsea E. , Mitchell Thomas C. 
Published: January 2023

Abstract
TLR4 uses both MyD88 and TRIF adaptors to induce inflammation and to enhance antigen presentation. Previously, we reported that the low-toxicity vaccine adjuvant monophosphoryl Lipid A (MPLA) is a TRIF-biased TLR4 agonist compared to LPS. However, not all TRIF-dependent genes were optimally induced after MPLA stimulation. Further complications were that both MPLA and LPS are heterogeneous and have several structural differences compared to each other. We now report that homogeneous preparations of synthetic MPLA (sMLA) selectively induce TRIF-dependent genes such as IFIT2 but not other TRIF-dependent genes such as IFNβ or MyD88/TRIF co-dependent genes such as COX-2 when compared to synthetic diphosphoryl Lipid A (sDLA). Consideration of the promoters for these genes revealed that IFIT2 requires fewer transcription factors for it to be active (IRF-3 and p65), whereas requirements for COX-2 and IFNβ transcription are more complex (p50/p65, AP-1, IRF-3). sMLA weakly induced signaling pathways leading to p50/p65 and AP-1 activation, but activation of IRF3 and p38 was largely unaffected. Thus, low toxicity sMLA may drive Trif-biased signaling because the promoters of its targeted genes are more likely to be 'simple', while those associated with MyD88 are more often complex. Results of this study identify a new model for TRIF-biased stimulation of TLR4 by sMLA.
This work was supported by the NIH/NIAID and the AHA.
The Programmed Death-1 and Interleukin-10 pathways play a down-modulatory role in LP-BM5 retrovirus-induced murine immunodeficiency syndrome (44.9)
Authors: Green Kathy A , Honjo Tasuku , Green William R. 
Published: January 2023

Abstract
We have focused on studying pathology due to the immune system's response to viral infections. In C57BL/6 mice the retroviral isolate LP-BM5 induces splenomegaly, hypergammaglobulinemia, B- and T-cell immunodeficiency, susceptibility to opportunistic pathogens, and terminal B-cell lymphomas -- a syndrome termed murine AIDS. LP-BM5 infected B6.PD-1-/- mice develop more severe splenomegaly, hypergammaglobulinemia, and immunodeficiency than infected B6 mice, and are more susceptible to lower virus dose and show exaggerated disease early post infection. Infected PD-L1-/- and B6.IL-10-/- mice, also develop exaggerated LP-BM5-induced disease, again without a significant change in retroviral load, relative to B6 mice. By reciprocal reconstitution experiments, PD-1+ B cells appear crucial in the limitation of LP-BM5 induced disease in B6 mice. LP-BM5 infected B6 mice have a macrophage/granulocyte-like subset of spleen cells which are PD-L1+, CD11b+, F4/80+, GR-1+, and IL-10 expressing; while infected PD-1-/- mice, even though showing a greater expansion of this subset, did not have an equivalent increase in IL-10 production. We conclude that PD-1/PD-L interactions and IL-10 are required in moderating the effects of LP-BM5 induced disease in B6 mice. We are continuing to define the functional role of this unique macrophage/granulocyte subset in LP-BM5-induced disease.
Redemption from Original Antigenic Sin response to influenza virus (45.1)
Authors: Kim Jin Hyang , Jacob Joshy 
Published: January 2023

Abstract
Original antigenic sin (OAS) is an inherent flaw in the immune system. Following sequential exposure to influenza viruses, the antibody response is predominantly against a prior influenza virus strain. This occurs at the expense of a response to the novel, protective epitopes in the current strain. Recently, we showed that sequential infection of mice with antigenically related strains of influenza virus, A/PR/8/34 and A/FM/1/47 led to antibody responses almost exclusively against the original antigen, A/PR/8/34. We also showed that sequential immunization with formalin-inactivated influenza viruses led to less pronounced OAS, however, memory development and recall responses were significantly compromised. The phenomenon of OAS is operational not just in mice but also in rabbits, ferrets and humans. Since OAS dampens efficacy of influenza vaccines, it is critical to develop vaccine strategies that prevent OAS. In this study, we show the host immune response can be redeemed from OAS by (a) using adjuvants such as Bordetella perutssis toxin or CpG-oligonucleotide or (b) by repeated immunization with the vaccine strain. These data indicate that while the induction of OAS might be a potential strategy by which variant influenza viruses subvert the immune system, co-administering adjuvants or expanding the memory pool of the vaccine strain represent novel approaches to prevent the effects of OAS.
Epstein-Barr Virus Latent Membrane Protein 2A protects B cells from MYC-induced apoptosis and accelerates tumor development (45.14)
Authors: Swanson-Mungerson Michelle , Bultema Rebecca , Longnecker Richard 
Published: January 2023

Abstract
Despite its initial isolation from Burkitt's lymphoma (BL) tumors over 40 years ago, the exact contribution of Epstein-Barr Virus (EBV) to BL is undefined. EBV encodes for multiple proteins in latently-infected B cells that affect B cell survival and activation. Due to the ability of one of these latency proteins, latent membrane protein 2A (LMP2A) to protect B cells from apoptosis, we tested if LMP2A protects B cells from apoptosis induced by aberrant c-MYC expression that precedes and dominates BL. We crossed LMP2A-transgenic mice (LMP2A-Tg) in which all B cells express LMP2A to a transgenic mouse that expresses a BL translocation of myc (λ-MYC-Tg mice). LMP2A protects B cells from MYC-induced apoptosis and accelerates the development of B cell lymphomas in LMP2A/λ-MYC-Tg mice. LMP2A also increases the expression of Bcl-XL in both pre-tumor B cells and tumor cells, suggesting a mechanism for LMP2A mediated B cell survival in the presence of MYC. These results support a hypothesis that EBV LMP2A promotes tumor development by protecting pre-tumor B cells that would normally apoptose after the c-myc translocation. This work is supported by Public Health Service grants CA62234 and CA73507 from the NCI.
Self-Reactive CTL Reveal a Strong Focus of the CD8+ T cell Receptor Repertoire on Self MHC (46.12)
Authors: Radhakrishnan Suresh , Hansen Michael , Pease Larry R 
Published: January 2023

Abstract
Mouse CD8+ T cells can be activated to lyse targets expressing self class I molecules more potently than allogeneic targets. Self-reactive CTL express IL-17 and can be enriched following intracellular staining. Such CTL lyse targets in an MHC restricted fashion. This recognition is independent of the bound peptides, as demonstrated by cold-target inhibition studies. Activation of OT-1 transgenic T cells using traditional APC results in peptide specific CTL recognition, stimulation of the same T cells induces peptide independent, yet Kb-restricted recognition, irrespective of whether RAG sufficient or deficient mice were used. Self-reactive CTL efficiently lyse targets expressing wild type Kb or Kb-mutants with amino acid substitutions on the β-strands of the antigen binding groove, but not mutants with substitutions on the α1 and α2 helices, suggesting self MHC recognition is mediated by interactions of the CDR1 and CDR2 regions of the TCR with the α-helices of the class I molecules, and not by bound peptides. The ability of CTL to react in an MHC restricted, yet peptide independent, manner raises important questions about the nature of TCR-MHC interactions. We propose a novel "pre-positive selection" check point in thymic development and in peripheral T cell activation in recruitment of TCR-MHC complexes at the immunological synapse during T cell activation and homeostatic recognition.
A novel subset of T helper cells promotes immune responses by producing GM-CSF (46.13)
Authors: ZHANG JIMIN , Devadas Satish , Liu Catherine , Shi Yufang 
Published: January 2023

Abstract
T helper cells are critical for maintaining proper immune responses. Yet, they have an undefined relationship with one of the most potent immune stimulatory cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF). Although produced locally, GM-CSF can act in a paracrine fashion to recruit circulating neutrophils, monocytes and lymphocytes to enhance their functions in host defense and inflammatory processes. By depleting major cytokines during CD4+ T cells differentiation in vitro, we obtained a novel subset of T helper cells, which produce large amounts of GM-CSF, but little of the cytokines produced by other T helper subsets. Through GM-CSF, these cells promoted cytokine production by Th1, Th2, Tc1, Tc2 and naïve T cells. Anti-GM-CSF antibody supplementation abolished the cytokine augmentation properties of the cells. Interestingly, dendritic cells (DC) differentiated with GM-CSF alone significantly upregulated DC-SIGN, a DC receptor that is critical in DC adhesion, migration, and activation of primary T cells. Furthermore, these cells are prone to AICD and express elevated levels of pro-apoptotic proteins, such Bid and Bim. Inhibitors of FasL, TRAIL, caspase 8 or granzymes could not block their AICD. Thus, ThGM cells are a novel T helper population that produces GM-CSF, exhibits great susceptibility to apoptosis, and plays an important role in regulating immune responses.
Development of CD4 T cells from Human Hematopoietic stem Cells in a Lentiviral-engineered Stromal Culture (46.15)
Authors: Patel Ekta  S , Chang Lung Ji 
Published: January 2023

Abstract
Hematopoietic precursor/stem cells (HPCs) are progenitors to all functional immune cell lineages. We established a novel stromal cell line expressing (Delta-like 1) DL1, interleukin-7 (IL-7), and FMS-like tyrosine kinase 3 Ligand (Flt3-L) and demonstrated efficient differentiation and expansion of early T cells from adult CD34+ HPCs. However, continuous IL-7 signaling led to the production of immature CD8+ T lymphocytes at the expense of CD4+ T lymphocytes. It is known that the developing double positive T cells shut down IL-7 mediated signaling and require TCR signaling for survival and positive selection. We hypothesize that IL-7 inhibits the TCR signaling event required for positive selection. We found that by removal of IL-7, followed with CD3/CD28 stimulation, the early T cells were able to differentiate into mature single positive CD4 T cells expressing CD3, CD28, and TCRαβ. This can also be demonstrated by bypassing TCR signaling through stimulation with PMA/ionomycin. When further stimulated, these in vitro derived CD4+ T cells differentiated into various T helper subtypes and produced effector cytokines including IL-2, IFN-γ, and IL-17. This novel culture system can greatly facilitate the study of late T cell development and has potential for immunotherapeutic applications.
Supported by Vectorite Biomedica Inc. and Yongling Foundation.
LFA-1 signaling plays an important role in effector and memory CD8+ T cell survival via TNF receptor/ligand family-activated Bcl-2 apoptosis pathway and Caspase cascade (46.19)
Authors: Xiang Jim 
Published: January 2023

Abstract
LFA-1 signaling is required for CD8+ T cell priming and cytolytic activity. However, its role for effector and memory CD8+ T cell survival in transition and maintenance phase is elusive. We adoptively transferred ovalbumin (OVA)-pulsed dendritic cell (DCOVA)-stimulated effector CD8+ T cells or purified OVA-specific memory CD8+ T cells into wild-type C57BL/6 or CD54 gene knockout (CD54-/-) mice. We assessed CD8+ T cell survival kinetics and molecular mechanisms responsible for LFA-1 signaling defect-induced T cell apoptosis by flow cytometric and Western-blotting analysis. We found that transferred OVA-specific effector and memory CD8+ T cell survival significantly decreased (p&lt;0.05) in transition and maintenance phase in CD54-/- mice due to increased T cell apoptosis, compared to C57BL/6 mice. Increased CD8+ T cell apoptosis is initiated via altered gene expression in TNF receptor/ligand (TNFR/L) (up-regulation of Fas and down-regulation of CD27, CD30 and 41BB), Bcl-2 (down-regulation of proapoptotic Bid, anti-apoptotic Bcl-2 and Bcl-XL and up-regulation of apoptotic Bax) and Caspase (down-regulation of pro-Caspase 8 and up-regulation of cleaved Caspase 3 and 7) families, and in survival signals (down-regulation of IL-15R). Therefore, LFA-1 signaling plays an important role in effector and memory CD8+ T cell survival via TNFR/L family-activated Bcl-2 apoptosis pathway and Caspase cascade.
Stability of peptide:MHCII complexes determines clonal CD4+ T-cell selection (46.4)
Authors: Hausl Christina , Ferrante Andrea , Gorski Jack , Malherbe Laurent 
Published: January 2023

Abstract
Antigen-specific CD4+ T-cells are major regulators of adaptive immune responses. Interactions between TCR and peptide-MHCII complexes are critical for the selection and expansion of these cells. The role of peptide-MHCII stability in CD4+ T-cell selection, however, has not been reported yet. We used altered peptide ligands (APL) which displayed different stabilities in complex with MHCII. Mice were immunized with the APLs and draining lymph nodes were analyzed. Although the accumulation of antigen-specific CD4+ T-cells was similar, we found that the repertoire of T-cells selected was different among the APLs. Single cell sorting of antigen-specific CD4+ T-cells and sequencing of their TCR alpha- and beta-chains revealed that high stability complexes selected a broad and mainly private repertoire of CD4+ T-cells. Low stability complexes on the other hand selected a more focused and public repertoire. Our findings suggest that peptide-MHCII stability is a critical parameter in the selection of CD4+ T-cells during adaptive immune responses.
This study is partly supported by FWF - Austrian Science Fund (Erwin Schroedinger Fellowship).
Resistance of Th17 cells to Activation-Induced Cell Death (47.13)
Authors: Yu Xue-Zhong , Iclozan Cristina , Yang Xuexian , Anasetti Claudio , Dong Chen , Yu Yu 
Published: January 2023

Abstract
Peripheral T cells undergo apoptosis induced by repeated TCR stimulation, known as activation-induced cell death (ACID), which plays an important role in T-cell tolerance. AICD in CD4 T helper (Th) cells including Th1 and Th2 effectors has been extensively studied. Recently, IL-17-producing CD4+ T cells (Th17 cells) have been identified as a unique Th subset, but the susceptibility and underneath molecular mechanism of AICD in Th17 effectors have not been defined. In this study, we found that Th17 cells were significantly less susceptible to AICD upon TCR restimulation compared to Th1 cells. The resistance was confirmed on pure Th17 cells by gating on CD4+RFP+ cells that were polarized from CD4 naïve T cells from il17f/rfp knock-in mice. Furthermore, the resistance of Th17 cells to AICD was also observed when Th17 cells were co-cultured in vitro or co-injected in vivo with Th1 cells. To explore the molecular mechanism, we found that Th17 cells were defective in FasL expression and in caspase activation, but highly expressed anti-apoptotic protein c-FLIP. After knocking down c-FLIP with its specific siRNA, Th17 cells re-expressed FasL and underwent rapid apoptosis upon TCR restimulation. In conclusion, Th17 cells are resistant to AICD likely because the high level of c-FLIP prevents Fas-mediated apoptosis. The resistance of Th17 cells to AICD reveals additional mechanism to explain the high pathogenicity of Th17 cells in autoimmune diseases, and may also provide a rationale to generate tumor-specific Th17 cells for adoptive cell immunotherapy.