bluuebunny/crossref_metadata_2025_split huggingface dataset:
miR-150 differentially regulates the development of NK and NKT cells via targeting the transcription factor c-Myb (153.37)
Authors: Bezman Natalie , Chakraborty Tirtha , Pellerin Alex , Bender Timothy , Lanier Lewis 
Published: January 2023

Abstract
Natural killer (NK) and Natural killer T (NKT) cells are important in host defense against pathogens, as well as for the initiation of adaptive immune responses. We and others have recently showed that miRNAs play important roles in NK and NKT cell development, maturation and function, but the roles of specific miRNAs are still lacking. Here we show that modulation of miR-150 expression levels has a differential effect on NK and NKT cell development. Mice with a targeted deletion of miR-150 have an impaired, stem cell-intrinsic defect in their ability to generate mature NK cells. Conversely, a gain-of-function miR-150 transgene promotes the development of NK cells, which display more mature phenotype and produce higher amounts of IFNγ following activation. In contrast, we find that overexpression of miR150 results in a substantial reduction of iNKT cells in the thymus and from the peripheral lymphoid organs. The transcription factor c-Myb has been shown to be a direct target of miR150, and we propose that miR-150 controls the development of NK and NKT cell lineages by targeting c-Myb. Our findings of the increased NK cell and decreased NKT cell frequencies in c-Myb heterozygous bone marrow chimeras are consistent with this hypothesis.
IL-7 receptor expression defines a human common lymphoid progenitor in cord blood lymphopoiesis (153.4)
Authors: Payne Kimberly , Baez Inneavely , Milford Terry , Weldon Abby , Francis Olivia , Sinisa Dovat , Su Rui-jun 
Published: January 2023

Abstract
Expression of the IL-7 receptor alpha (IL-7R) is a distinguishing feature of common lymphoid progenitors (CLP) in mice. Human B cell development has been thought to differ from that in mouse with respect to the requirement for IL-7. Our previous studies show that IL-7 plays a critical role in human B cell production (J Immunol. 2009, 182:4255). Here we use IL-7R expression to identify a human CLP population that can be generated from hematopoietic stem cells (HSCs) in umbilical cord blood (CB). Following two weeks of co-culture with primary human bone marrow (BM) stroma, CB CD34+ cells give rise to a CD34+CD19-IL-7R+ progenitor population that is absent from fresh, uncultured CB. IL-7R+ progenitors make up ~17% of the CD19-CD34+ cells present in culture at 2 weeks. A similar IL-7R+ human progenitor population is generated in the BM of immunodeficient mice following transplant with human CD34+ CB cells. FACS-sorted CD34+CD19-IL-7R+ progenitors produced in co-culture or in the human-mouse xenograft model give rise to CD19+ B cells and CD56+ NK cells in bulk and single cell culture, but lack myeloid potential in CFU assays and when transplanted into immunodeficient mice. Ongoing experiments will evaluate the T lineage potential of IL-7R+ progenitors in the human-mouse xenograft model. These data will be important for developing therapies to accelerate and enhance lymphoid reconstitution from HSCs in CB, a hematopoietic source used increasingly for stem cell transplant.
Over expression of Foxn1 in the bone marrow prevents age-associated perturbations in the expansion and survival of T cell progenitors (153.6)
Authors: Zook Erin , Zhang Shubin , Witte Pamela , Le Phong 
Published: January 2023

Abstract
The thymus requires continuous seeding of progenitors from hematopoietic stem cells (HSC) in bone marrow (BM) for naïve T cell production. HSC give rise to multipotent progenitors (MPP) and their progeny common lymphoid progenitors (CLP); however, MPP are the predominant source of early T cell progenitors (ETP) in the thymus. ETP, HSC, MPP and CLP decline with age, culminating in reduced naïve T cell production. We reported that the age-associated decline in ETP is abrogated in K14-Foxn1 transgenic mice (Foxn1Tg). Here, we show that Foxn1 is expressed in BM and its expression was 98-fold higher in Foxn1Tg. Foxn1 transgene expression increased endogenous Foxn1 mRNA levels by 18- to 24-fold; Foxn1 positive cells were readily detected in the BM. We found that HSC number was 2-fold higher in young Foxn1Tg versus wild type (Wt). HSC and MPP numbers declined in aged Wt but not in Foxn1Tg. A higher percent of HSC was in S,G2/M; further, HSC and MPP in subGo from Foxn1Tg were respectively 3-fold and 4-fold reduced, suggesting inhibition of cell death. In contrast, CLP frequency was 4-fold less in young Foxn1Tg. A higher number of the committed T cell progenitors (CTP) with a 2-fold increase in S,G2/M fraction were found in young Foxn1Tg versus Wt. Our data provide evidence linking Foxn1 to the development of T cell progenitors in the BM and thymus, suggesting that increased expression could limit the decline in naïve T cell production with age.
The anti-viral and signal-3 effects of Type-I interferons exert opposing effects on clonal expansion of CD8 T cells during West Nile Virus infection (154.13)
Authors: Bhaumik Siddhartha , Thomas Sunil , Moguche Albanus , Wijaranakula Michael , Kaja Murali-Krishna 
Published: January 2023

Abstract
West Nile Virus (WNV) is a neurotropic positive stranded RNA virus, which affects central nervous system in a fraction of infected humans in several continents, including North America. In concert with innate responses both antibody and T cell mediated immunity play an important role in conferring protection against WNV. While the importance of type-I IFN-I (IFN-I) signaling on WNV-specific innate immunity is well documented, it remains unclear whether and what effects IFN-I have on WNV-specific adaptive response. Using a murine foot pad infection model of WNV infection here we asked two questions: (1) what happens to virus-specific CD8 T cell responses if the infected host is devoid of IFN-I signaling, (2) what happens to virus-specific CD8 response if only CD8 T cells lack IFN-I signaling. We found that lack of IFN-I signaling in the host results in exaggerated CD8 clonal expansion whereas lack of IFN-I signaling exclusively in CD8 T cells results in diminished clonal expansion. Our results together, suggest INF-I mediated innate viral control and the ability to provide signal-3 exerts opposing effects on CD8 T cell expansion during West Nile Virus infection.
2P imaging reveals that PD-1 blockade promotes clearance of a persistent viral infection by overriding prolonged T cell engagement (154.18)
Authors: Zinselmeyer Bernd , Heydari Sara , Nayak Debasis , McGavern Dorian 
Published: January 2023

Abstract
The recent demonstration of improved anti-viral T cell function following PD-1 blockade is a finding of great clinical importance that can benefit patients with persistent infections and cancer. Presently, it is not clear how blockade of this inhibitory pathway improves the function of exhausted T cells. Infection of mice with an immunosuppressive strain of LCMV is a well described paradigm to study T cell exhaustion. In this study we sought novel insights into the mechanisms of T cell exhaustion and recovery during persistent infection by simultaneously imaging CD8 and CD4 T cell responses using two-photon microscopy in the spleen. To define the motility parameters associated with immune exhaustion, we compared anti-viral T cell dynamics during an acute versus a persistent LCMV infection. Analyses of T cells in these two distinct environments revealed that exhaustion during viral persistence is associated with prolonged TCR signaling and cellular arrest in the splenic marginal zone and red pulp - two regions with abundant LCMV antigen and elevated levels of PD-L1.
Coordinated regulation of PD-1 gene expression and nuclear localization during virus-specific memory CD8+ T cell differentiation (154.20)
Authors: Sacristan Catarina , Youngblood Ben , Xu Jean , Shipper Katelyn , Skok Jane , Boss Jerry , Ahmed Rafi , Dustin Michael 
Published: January 2023

Abstract
Mechanisms that mediate changes in transcriptional regulation during differentiation of long-lived memory T cells during infection remain poorly understood. During chronic viral infection, CD8 T cell differentiation yields a unique transcriptional profile: T-cell exhaustion. The suboptimal effector function of exhausted cells is partly due to sustained expression of the inhibitory receptor PD-1. Using the lymphocytic choriomeningitis virus mouse model of infection, we examined pdcd1 (PD-1) gene regulation at different stages of T cell differentiation. Changes in gene expression are associated with cell-type specific profiles accompanied by distinct patterns of locus conformation and positioning of a gene relative to specific nuclear compartments (e.g. recruitment to nuclear lamina indicating silencing). We hypothesized that pdcd1 epigenetic programming and nuclear localization were coupled to viral persistence and T cell differentiation. Using DNA-FISH, we report a significant decrease in the % of pdcd1 alleles recruited to nuclear lamina in exhausted cells relative to other CD8 T cell subsets from infected mice. Reduced recruitment to nuclear lamina was consistent with upregulated expression of PD-1 mRNA and protein, and with loss of PD-1 DNA methylation in exhausted cells. Our findings contribute to the understanding of the molecular pathways mediating T cell memory and exhaustion, and may provide insight into the use of therapeutic strategies to resolve chronic infections.
CD4 regulatory T cells control CD8 T cell responses to human herpesvirus 8 lytic and latency proteins (154.28)
Authors: Lepone Lauren , Rappocciolo Giovanna , Piazza Paolo , Jais Mariel , Jenkins Frank , Rinaldo Charles 
Published: January 2023

Abstract
Objectives: CD8 T cells likely play an important role in controlling human herpesvirus 8 (HHV-8) infection, the cause of Kaposi's sarcoma (KS). However, these T cell responses are non-robust compared to other herpesviruses, suggesting that they could be under tight control by regulatory T cells (Treg). Methods: HLA A*0201 pentamer complexes for 2 lytic and 3 latency protein epitopes of HHV-8 and polyfunctional flow cytometry were used to detect HHV8-specific CD8 T cells in blood. The effect of Treg was examined by depleting CD4+CD25High cells. Results: Direct staining of PBMC with pentamer complexes showed a frequency of antigen-specific CD8 T cells from 0.02% to 0.2%. This presence of HHV-8-specific CD8 T cells contrasted with low HHV-8 T cell polyfunctional reactivity, suggesting a regulatory suppression. Indeed, removal of Treg enhanced CD8 T cell responses to HHV-8 epitopes. This was not related to proportional increases in number of CD8 T cells after Treg removal. The frequency of T cells specific for HHV-8 lytic antigens was greater than for latent antigens, and this effect was greater when Treg were removed. Conclusions: Treg suppress CD8 T cell responses to HHV-8 lytic and latency antigens. The involvement of CD8 T cells and Treg in control of HHV-8 infection has implications for development of vaccines to prevent KS.
CD11b+Ly6C+ cells, myeloid-derived suppressor cells, activated following Theiler’s virus infection (154.3)
Authors: Olson Julie , Glazer Alex 
Published: January 2023

Abstract
Theiler’s murine encephalomyelitis virus (TMEV) infection of susceptible mice leads to a persistent infection of the microglia/macrophage population in the central nervous system (CNS). The persistent infection leads to the development of a chronic progressive demyelinating disease associated with a myelin- specific CD4+ T cell response. We recently determined that the predominant innate immune cells infiltrating into the CNS following TMEV infection are CD11b+Ly6C+ cells. CD11b+Ly6C+ cells are immature myeloid cells that exit the bone marrow without maturing. Therefore, we wanted to determine the function of these cells during TMEV infection. CD11b+Ly6C+ cells isolated from the CNS during TMEV infection expressed high levels of IL-10 and iNOS and low levels of IL-12, and expressed low levels of costimulatory molecules and MHC class II. The CD11b+Ly6C+ cells were a stable population in the CNS throughout TMEV infection. Most importantly, CD11b+Ly6C+ cells isolated during TMEV infection suppressed both CD4+ T cell and CD8+ T cell responses against virus antigens. Furthermore, depletion of Ly6C+ cells during TMEV infection lead to increased T cell responses associated with increased expression of IFNγ, IL-12, and IL-17 in the CNS and lead to decreased virus load in the CNS. These results suggest that CD11b+Ly6C+ cells generated after TMEV infection are myeloid- derived suppressor cells that suppress T cell responses and may contribute to persistent virus infection in the CNS.
Up-regulation of programmed death ligand 1 expression on human plasmacytoid dendritic cells by viral stimulation (154.31)
Authors: Patel Meher , Dai Jihong , Fitzgerald-Bocarsly Patricia 
Published: January 2023

Abstract
The function of exhausted CD8 T cells in chronic HIV-1 infection is negatively regulated by the PD-L1/PD-1 pathway resulting in suppression of specific anti-viral T cell responses. Blockade of this pathway reconstitutes T cell function and enhances antiviral immune responses. In HIV-infected individuals, increased PD-L1 (B7-H1) expression on APCs correlates directly with viral load, indicating a potential effect of the virus on PD-L1 expression. However, the mechanisms of PD-L1 up-regulation in these settings are not well understood. In this study, we investigated how PD-L1 expression is regulated in human pDCs. We found PD-L1 expression on pDC was up-regulated with different viral stimulations including HSV, Sendai virus, Influenza virus and both live and AT-2 inactivated HIVMN. PD-L1 levels were differentially regulated by stimulation with different viruses. In comparison with these virus stimulations, TLR9 ligands CpGA and-B were less efficient at inducing PD-L1 expression. TNF-α and IL-6 had no influence on PD-L1 although IFN-α had a moderate effect on it, indicating that up-regulation of PD-L1 on pDC was specifically a primary response to viral stimulation. Furthermore, we observed that LPS enhanced virus-induced PD-L1 expression on pDC, suggesting potential involvement of LPS in the up-regulation of PD-L1 in chronic HIV-1 infection. Taken together, our results suggest a potential role for up-regulation of PD-L1 expression on pDC in HIV-induced immune exhaustion.
Novel approaches to improve influenza and cytomegalovirus vaccines (155.25)
Authors: Fischer David , Sundick Roy 
Published: January 2023

Abstract
Cytokines have been extensively used as adjuvants in vaccines. However, several factors limit their use including diffusion from antigen, short half-lives and production costs. To address this, we developed a technology that efficiently produces inactivated, whole-virus influenza vaccine bearing membrane-bound cytokines. Tethering the cytokine to the antigen of interest keeps the adjuvant in close contact with the antigen ensuring that immune cells recruited by the adjuvant react with the antigen as well. Influenza can be used to test this model since it has two surface proteins with conserved signal sequences that direct these proteins to the infected cell surface where they are picked up budding virions. Cytokines can be fused to these signal sequences producing viral particles that will then contain an attached cytokine adjuvant. Trials using IL2 and GMCSF have shown this method may be effective at increasing seroconversion rates. IL4 and complement factor C3d are also being tested as adjuvants in this system. This platform can also be used to deliver and enhance immunogenicity of antigens from other viruses. The cytomegalovirus surface protein gB can be anchored to influenza virions using conserved signal sequences. We hypothesize that delivery of gB via an influenza virion, with or without a bound adjuvant will result in enhanced immune responses.
Modification of VRC01 for enhancing half-life and ADCC activity (155.39)
Authors: Ko Sung-Youl , Kuo Timothy , Blumberg Richard , Nabel Gary 
Published: January 2023

Abstract
Several studies have demonstrated that increased binding of IgG to hFcRn extended the half-life of antibody in serum. In addition, the Fc region of IgG binds to FcγRIIIa, mediating ADCC. Modification for hFcRn and FcγRIIIa may negatively affect their functions respective to the other. Here, to increase the potency and duration of VRC01, a broadly neutralizing antibody to HIV gp120, we have combined hFcRn-binding enhancing mutations (QL, LS, A, AAA and YTE) with ADCC enhancing mutations (DE and DLE) to improve in vivo activity. We demonstrated that all of the mutants have Ag binding affinities similar to VRC01 wild type (WT), indicating that the neutralizing activities are likely maintained with these mutants. All mutants except mutant group A have increased binding to hFcRn at both pH6.0 and pH7.4 compared to VRC01 WT. Using a transcytosis assay, we showed that DE-QL and DE-LS mutants had increased transport across epithelial cells compared to others in the DE mutant groups. ADCC enhancing mutations recovered the loss of ADCC acitivities and FcγRIIIa binding affinity associated with hFcRn-binding enhancing mutations. Unlike other mutations tested, a single LS mutant has FcγRIIIa binding and ADCC activity similar to VRC01 WT. The combined DE-LS and DLE-LS mutants showed increased functional activity in transcytosis and ADCC assays. Taken together, the DE-LS or DLE-LS mutants were able to enhance both half-life and effector functions in vitro.
Synthetic LbL nanoparticle vaccines containing the chemokine mimic epitope of RSV-G protein and a CD8 epitope of RSV-M2 protein elicit broad-based cellular and humoral responses (155.7)
Authors: Powell Thomas , Boyd James , Jacobs Andrea , Palath Naveen , DeRome Mary , Tang Jie , Cardenas Edwin , Harcourt Jennifer , Haynes Lia , Anderson Larry , Tripp Ralph 
Published: January 2023

Abstract
Nanoparticle vaccines synthesized via layer-by-layer (LbL) fabrication were loaded with designed peptides representing epitopes of the attachment (G) and matrix (M2) proteins of respiratory syncytial virus. The CX3C chemokine mimic epitope of RSV-G has been proposed to contribute to inflammatory responses post-challenge while CD8+ T-cell responses against RSV M2 have been shown to limit the severity of infection and inflammatory pathology. Both monovalent designs (G or M2) and multivalent designs (G+M2) were tested. Mice immunized with RSV-G nanoparticles produced antibody responses that recognized the CX3C epitope only in its folded conformation and not in a linearized state. The same sera also bound native RSV-G protein, inhibited binding of RSV-G protein to the CX3CR1 chemokine receptor, and inhibited migration of human leukocytes toward RSV-G protein. Mice immunized with RSV M2 nanoparticles generated CD8+ T-cell responses and in vitro CTL activity against M2-labeled target cells. The multivalent vaccines containing both G and M2 elicited higher antibody responses to RSV-G and, surprisingly, more potent cellular responses against RSV-M2. These novel nanoparticle vaccines are currently being tested for the induction of neutralizing antibody responses and protection from viral challenge. If successful, the LbL nanoparticle fabrication strategy will provide an innovative approach to formulating safe and effective subunit vaccines for respiratory pathogens including RSV.
Programming of antigen-specific CTLs from induced pluripotent stem cells for tumor protection (156.1)
Authors: Lei Fengyang , Haque Rizwanul , Song Jianxun 
Published: January 2023

Abstract
Generation of highly reactive antigen(Ag)-specific CTLs derived from induced pluripotent stem(iPS) cells can provide an unlimited source of functional CTLs that can be used for adoptive immunotherapy. The iPS cell-derived T cells have the advantages of averting potential immune rejection, as well as circumventing ethical and practical problems associated with other types of stem cells. Previously we demonstrated that iPS cells are able to differentiate into progenitor T cells in vitro by the stimulation of Notch ligand Delta-like 1 (DL1) over-expressed on OP9 bone marrow stromal cells. Full maturation of iPS cells was observed upon adoptive transfer into RAG1-deficient mice. Here we show that iPS cells differentiate into functional CTLs in vivo after over-expressing MHC I-restricted Ag-specific T cell receptors (TCRs). In this study, murine iPS cells are genetically modified with OVA specific, MHC-I restricted TCR (OT-I) by retroviral transduction. We demonstrate that after adoptive transfer into recipient mice, the majority of OT-I/iPS cells undergo differentiation into CD8+ CTL. In vivo developed TCR-transduced iPS cells are able to respond to ex vivo peptide stimulation and secrete IL-2 and IFN-γ. Moreover, adoptive transfer of TCR-transduced iPS cells results in the infiltration of OVA-reactive CTLs into tumor tissues and protection of animals from tumor challenge. Our results provide a novel approach for generating Ag-specific T lymphocytes for T cell-based therapies.
Modulating therapeutic antitumor T cell immunity with MicroRNAs (156.21)
Authors: Rutkowski Melanie , Nesbeth Yolanda , Toraya Seiko , Scarlett Uciane , Jacobs Ana , Conejo-Garcia Jose 
Published: January 2023

Abstract
MicroRNAs are attractive candidates for enhancing the therapeutic effectiveness of adoptive T cell therapy, although overcoming tumor-induced immunosuppression in the tolerogenic ovarian cancer microenvironment remains a formidable barrier. We hypothesized that over-expression of miR181a in adoptively transferred tumor-reactive T cells would result in sustained anti-tumor immunity within the tolerogenic ovarian tumor microenvironment. To test this, congenic tumor-reactive T cells were intraperitoneally injected into mice bearing established transplantable ovarian tumors. Twelve and 26 days post-transfer, RNA was isolated from sorted peritoneal host or transferred CD4 and CD8 T cells. Contrary to our initial hypothesis, miR181a expression was significantly and exponentially greater in transferred CD4 and CD8 T cells, compared to host-derived T cells at these temporal points during which the function of transferred T cells was impeded by the tolerogenic microenvironment. This suggested an unexpected negative role for miR181a in the context of T cell immunotherapy. To confirm these findings, T cells over-expressing miR181a were adoptively transferred into tumor-bearing mice and survival was monitored. Compared to mice receiving either non-transduced or control-vector transduced T cells, mice treated with T cells over-expressing miR181a had significantly reduced survival, supporting the novel finding that miR181a may have a negative role in adoptive T cell immunotherapy.