bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-2 regulates tissue-dependent differences in CD8 T cell apoptosis during and after- viral Infection. (110.19)
Authors: Kapoor Varun , Welsh Raymond 
Published: January 2023

Abstract
Virus-specific CD8 T cell populations in lymphoid organs contract by apoptosis or by dissemination into peripheral tissues, and those residing in non-lymphoid organs, including the peritoneal cavity (PEC: peritoneal exudate cells), are more resistant to apoptosis than those in the lymphoid organs, including the spleen. We questioned whether tissue-dependent apoptotic differences in LCMV-specific T cells were due to environment factors or intrinsic stability of the CD8 T cells. The PEC environment conferred an anti-apoptotic effect, as shown by mixing PEC with excess splenic leukocytes or vice versa. This anti-apoptotic effect correlated with Stat5 phosphorylation induced by IL-2 spontaneously secreted by CD4 T cells. Spontaneous IL-2 production by CD4 T cells occurred in vivo during the contraction and the long term memory stage after LCMV infection in PEC and Fat pads, but much less so in spleen and lymph nodes. Virus-specific CD8 T cells in the PEC were also intrinsically more stable, as most had a memory precursor effector cell (MPEC) phenotype and higher expression of CD27, both correlating with decreased apoptosis. However, regardless of their phenotype, PEC CD8 T cells remained less apoptotic than their spleen cell counterparts. We conclude that long after the resolution of viral infections, IL-2-producing CD4 T cells linger in peripheral sites and locally contribute to the stability of memory CD8 T cells, thereby enhancing resistance to re-infection.
Autocrine IFN-gamma promotes limited differentiation of naïve CD8 T cells and synergizes with Type I IFN to stimulate optimal effector functions (110.5)
Authors: Curtsinger Julie , Lins Debra , Mescher Matthew 
Published: January 2023

Abstract
Autocrine IFN-gamma signaling has been shown to be important for differentiation of CD4 T helper 1 effector cells, but it has been unclear whether it contributes to CD8 T cell differentiation. We have found that naive transgenic murine OT-I CD8 T cells produce low levels of IFN-gamma shortly after stimulation with antigen and B7-1, reaching a peak within 8-12 hours. This early IFN-gamma production is distinct from effector IFN-gamma production in both timing and the amount of cytokine produced. Similar results were obtained using CD8 T cells from pmel and P14 transgenic mice. We found that early IFN-gamma contributes signals for upregulation of expression of Tbet, granzyme B, and weak cytolytic effector function. Type I IFN acts synergistically with IFN-gamma to support development of strong effector functions, while IL-12 induces optimal effector functions in the absence of IFN-gamma signaling. An early IFN-gamma signal is not sufficient to program CD8 T cells to survive in vivo and develop a memory population, nor is it necessary for IL-12- or Type I IFN-dependent programming for survival. Thus, IFN-gamma is not only an important CD8 T cell effector cytokine, it is an autocrine/paracrine factor whose contributions to differentiation vary depending on whether the response is supported by IL-12 or Type I IFN.
Role of Pax5 and YY1 in regulation of V(D)J recombination (111.1)
Authors: Malshetty Vidyasagar , Chen Jian , Hanna Mary , Cortes Patricia 
Published: January 2023

Abstract
The infinite variety of antigen-binding receptors originates from the rearrangement of B and T-cell receptor loci in a process known as V(D)J recombination. The initial site-specific DNA cleavage steps of this process are catalyzed by the lymphoid specific proteins RAG1 and RAG2. Deregulation of this process, leads to a spectrum of diseases including immunodeficiency and leukemia. These leukemias are believed to arise from RAG1/2 mediated oncogenic chromosomal translocations. The transcription factor Pax5 is critical for B cell development and is known that, it interacts with RAG1/2 and mediates V to DJ recombination. Pax5 is also been implicated in human B cell malignancies. Another multifunctional transcription factor, YY1, is known to play a role in V to DJ recombination similar to Pax5. We were able to see an interaction of YY1 with RAG1/2 and Pax5, when these proteins were over-expressed in 293T cells. When we performed a plasmid based recombination assay in presence of Pax5, YY1 or both a consistent decrease in recombination levels was observed. To elucidate the mechanism of inhibition, we analyzed the recombination intermediates and found that the initial cleavage step is inhibited by these two factors. In addition, purified Pax5 and YY1 inhibit the in vitro cleavage activity of RAG1/2 recombinase. The expression of a mutant Pax5 increased the RAG recombinase activity, suggesting the importance of these two factors in regulation of RAGs mediated recombination.
Hes1-mediated constraint of C/EBPα is essential for T-cell development (111.22)
Authors: De Obaldia Maria , Bell J. Jeremiah , Zlotoff Daniel , Sultana Dil Afroz , Bhandoola Avinash 
Published: January 2023

Abstract
Notch signaling in the thymus induces expression of T-cell genes and discourages progenitors from adopting alternative fates. Recent work has suggested that T-cell progenitors arrive at the thymus with T and non-T (B, NK) lymphoid potential as well as dendritic cell potential and a degree of myeloid potential; however, the importance of actively repressing alternative gene expression programs in T-cell development has not been adequately addressed. To examine the role of Notch-mediated gene repression in T-cell development, we used mice deficient for the Notch target and transcriptional repressor Hes1. We found that Hes1-deficient progenitors failed to make normal numbers of T-cells upon culture with Notch ligands, but instead failed to downregulate the myeloid transcription factor C/EBPα and gave rise to increased numbers of Mac1+ myeloid cells. To test whether the primary role of Hes1 in T-cell development is to repress expression of the myeloid transcription factor C/EBPα, we deleted floxed alleles of C/EBPα in Hes1-deficient progenitors using a retroviral Cre recombinase and co-cultured transduced progenitors with Notch-ligand expressing stromal cells. We found that deletion of C/EBPα restored T-cell development in Hes1-deficient progenitors. These results establish that an essential function of Hes1 is to constrain progenitors from activating myeloid lineage programs early in T-cell development.
IL-33-induced hematopoietic stem and progenitor cell mobilization and anti-fungal activity in mice (111.24)
Authors: Kim Wonyoung , Kim Juyang , Le Hongnga , Kim Hyunju , Cho Hong , Kwon Byungsuk 
Published: January 2023

Abstract
IL-33 has been implicated in the pathogenesis of asthma, atopic allergy, anaphylaxis and other inflammatory diseases by promoting the production of pro-inflammatory cytokines and chemokines or Th2 immune responses. In this study, we investigated the role of IL-33 in hematopoietic stem and progenitor cell (HSPC) mobilization and host anti-fungal response in mice that received autologous HSPC transplantation. IL-33 induced HSPC mobilization through increasing vascular cell CXCL1 and CXCL2 productions. IL-33-mobilized HSPCs were capable of homing to and of long-term reconstitution in the BM of irradiated recipients. Immune cells derived from these recipients had normal anti-fungal activity. When injected after IL-33-mobilized HSPC transplantation, IL-33 had an additional protective effect against lethal Candida albicans infection. The anti-fungal effect of IL-33 was due to the rapid recruitment of neutrophils to the infection site via release of CXCR2 chemokines in peritoneal cavity and blood and prevention of CXCR2 down-regulation induced by Toll-like receptor (TLR) signaling in neutrophils and their enhanced phagocytic activity. The ability of IL-33 to promote HSPC mobilization and host anti-fungal activity represents a previously unrecognized role of IL-33 in innate immunity. These properties of IL-33 have clinical implications in hematopoietic stem cell transplantation.
Endogenous mouse mammary tumor viruses influence the development of thymic αβ NKT cells and innate CD8+ T cells (111.26)
Authors: Holt Michael , Punkosdy George , Blain Melissa , Glass Deborah , Lozano Mary , Dudley Jaquelin , Shevach Ethan 
Published: January 2023

Abstract
Mounting evidence has demonstrated the presence of a population of thymic CD8+ T cells that share phenotypic and functional similarity to “innate-like” or “memory-like” T cells. Innate CD8+ T cells have increased expression of CD44, CD122, and Eomesodermin (Eomes), as well as the capacity to rapidly produce interferon (IFN)-γ upon stimulation. In addition to several gene-deficient models, including KLF2-, Itk-, and Id3-deficient mice, innate CD8+ T cells have also been documented in naïve BALB/c mice. The development of such cells is dependent on the production of interleukin (IL)-4 from an expanded population of αβ or γδ NKT cells expressing the transcription factor promyelocytic leukemia zinc finger (PLZF). Interestingly, this innate phenotype among CD8+ T cells is lost in congenic BALB/c mice lacking all endogenous mouse mammary tumor proviruses (BALB/Mtv-null). In the absence of endogenous Mtv proviruses, the expression of CD44, CD122, CXCR3, and Eomes, as well as the production of IFN-γ, was greatly reduced among thymic CD8+ T cells. The loss of this innate CD8+ T cell population in BALB/Mtv-null mice correlated with a reduction in PLZF+, IL-4 secreting αβ NKT cells within the thymus compared to wild type BALB/c. Our findings suggest a potential Mtv-mediated role in modulation of thymic αβ NKT cell development that subsequently influences the generation of innate CD8+ T cells.
Does androgen signaling cause thymic involution? (111.34)
Authors: Cooper John , Bryson Jerrod , Li Jie , Narayan Prema , Manley Nancy 
Published: January 2023

Abstract
The thymus is the main source of naïve T cell output. As the body ages, the thymus undergoes involution, causing a drop in naïve T cell availability in the peripheral T cell pool. The molecular mechanisms underpinning thymic involution are not well characterized. However, androgen signaling has been associated with involution based on increases in thymus size and thymocyte number in both sex steroid ablated (SSA) mice and those lacking functional androgen receptor (Ar). However, to date there is no clear cellular target or mechanism by which androgen signaling affects involution. The available data consistently point to a thymic stromal target as the major site of androgen action in the thymus. Among these stromal cell types, thymic epithelial cells (TECs) express Ar and have been shown to increase proliferation and production of specific effectors such as CCL25 in response to castration. We have used a Cre-LoxP strategy to selectively delete Ar in TECs. Evaluations of these mice present compelling evidence that TECs are directly involved in androgen signaling within the thymus. While TEC-selective Ar deletion does cause increased thymus size and thymocyte numbers, these mice differ in several ways from previous reports on global Ar deletion or SSA, leading to the possibility that current models of the role of androgens in postnatal thymus may need to be re-evaluated.
STAT3 and STAT5 guide key transcriptional and epigenetic responses during dendritic cell development (111.37)
Authors: Li Haiyan , Yang Cliff , Nallaparaju Kalyan , Zhang Huiyuan , Liu Yong-Jun , Goldrath Ananda , Watowich Stephanie 
Published: January 2023

Abstract
STAT proteins regulate homeostatic development of dendritic cells (DCs), yet information about their role in demand situations and their mechanisms of action remains limited. We found that STATs control cytokine-driven production of plasmacytoid (pDCs) and conventional DC (cDC) subsets in vivo. In DC progenitor cultures, STATs induce expression of the transcriptional regulators E2-2/Tcf4 and Id2, which have essential and distinct activities in pDCs, CD8α+ and CD103+ cDCs. Tcf4 is stimulated by Flt3 ligand- (Flt3L) activated STAT3. Id2 is induced by Flt3L or GM-CSF; both cytokines utilize C/EBPβ while GM-CSF also employs STAT5. These results are consistent with previous reports that Flt3L regulates pDCs, CD8α+ and CD103+ DCs while GM-CSF is required for the development of CD103+ DCs in skin and peripheral lymph nodes. The status of promoter chromatin modifications suggests pDC-restricted access for Tcf4 and an open configuration for Id2. These epigenetic marks are influenced by STATs independent of Tcf4/Id2 mRNA expression. Thus, our results reveal mechanisms by which STAT3 and STAT5 control the transcriptional networks that define pDC and cDC lineages.
Analysis of Hematopoietic Stem Cell populations in control and autoimmune mouse strains. (111.48)
Authors: Elia Jeanne , Chronopoulou Efthalia , Carson Christian 
Published: January 2023

Abstract
Hematopoietic stem cells (HSC) are cells capable of self renewal and multilineage differentiation. Flow cytometry is often used to isolate very pure populations of HSC. To successfully isolate live HSC using FACS, cells are typically identified using a combination of cell surface markers, a dye or both. Several methods have successfully been used for the isolation of these cells in mice, including KLS (c-kit/Sca-1/Lineage negative), side population (Hoechst Red vs. Hoechst Blue), and more recently the SLAM panel (CD150+/CD48-/CD41-). It has been demonstrated that transplantation of all these cell populations results in bone marrow reconstitution in lethally irradiated mice. Using combinations of these signatures, we examined various mouse strains to determine whether there were strain-specific differences in the HSC populations. Specifically, we isolated HSCs by FACS from two control (C57BL/6 and Balb/C) and two autoimmune (SJL and NZB) strains. The data suggest that certain signatures are more suitable for the isolation of prospective HSC populations from certain strains of mice and that the HSC compartment is variable is size from strain to strain. In addition we will discuss interesting findings with respect to expression of these markers in the spleens of the different strains.
Regulation of B lymphopoiesis by Zinc Finger Protein 521 (ZFP521) (111.9)
Authors: Lei Hong , Lukin Kara , Rodriguez Valerie , Straign Desiree , Feeney Ann , Warming Søren , Hagman James 
Published: January 2023

Abstract
The ZFP521 (Evi3/ZNF521/EHZF) transcription factor has been identified as an inhibitor of Early B cell factor 1 (EBF1), which is essential for B cell lineage specification and commitment. ZFP521 contains 30-zinc finger (ZF) domains, including C-terminal ZF’s that bind to EBF1. However, whether ZFP521 is required for appropriate B cell development and function has not been addressed. We demonstrated that Zfp521 transcripts correlate inversely with Ebf1 transcripts. Zfp521 transcripts are expressed at the highest levels in pre-pro-B and pro-B cells and decrease progressively with differentiation. In contrast, Ebf1 transcripts are detected only weakly in pre-pro-B cells and are increased at later stages in the bone marrow. In 3-wk old Zfp521 knockout (KO) mice, pre-pro-B and pro-B cells are increased substantially, while late pro-B, pre-B and immature B cells are reduced significantly. Re-circulating mature B cells accumulate prematurely in the bone marrow of Zfp521 KO mice relative to WT mice. We are addressing two possible models in these mice. ZFP521 may modulate EBF1 function through direct protein:protein interactions. Alternatively, because ZFP521 is itself a DNA-binding protein, ZFP521 may direct transcription of cognate target genes independently of EBF1. We obtained evidence that ZFP521 co-occupies functional promoters with EBF1 in pro-B cells. This indicates that ZFP521 regulates B cell development through interactions with EBF1 on target genes.
Characterization of live, attenuated rubella viral vectors expressing SIV Gag or HIV MPER determinants (113.16)
Authors: Berkower Ira , Ni Yisheng , Virnik Konstantin 
Published: January 2023

Abstract
Infection with HIV or SIV can elicit potent and broadly reactive neutralizing antibodies against HIV, as well as disease modifying CTL against SIV. In order to elicit similar responses by vaccination, we have developed live attenuated rubella viral vectors to express HIV and SIV antigens. Safety and immunogenicity of rubella vaccine is well known; it elicits mucosal immunity, and one dose protects for life (against rubella). We have identified two insertion sites, in the nonstructural (ns) and structural regions, where foreign genes can be expressed without affecting viral growth. We have made 15 vectors expressing HIV MPER and SIV Gag antigens containing multiple CTL epitopes. Inserts at the ns site were expressed as rubella early genes. Inserts at the structural site were over-expressed as late genes and processed with the structural polyprotein. Some of the structural inserts were incorporated into virions and displayed on their surface. The vector should be safe, since loss of the insert would revert to the vaccine strain. We are using rubella because it grows well in rhesus macaques, which provide a good model of immunogenicity and protection against SIV or SHIV challenge. In preliminary studies, one of the vectors is growing in vivo, and it has elicited antibodies to the vector. These vectors will be useful in determining the role of a live vector in eliciting protective immunity and for optimizing its use in a prime and boost strategy.
Engineered microneedle arrays for transcutaneous HIV vaccine delivery (113.17)
Authors: DeMuth Peter , Huang Bonnie , Min Younjin , Hammond Paula , Irvine Darrell 
Published: January 2023

Abstract
Microneedle skin patches represent a promising approach for safe, convenient, and rapid delivery of vaccines and therapeutics to the skin through pain-free disruption of the stratum corneum to access epidermal and dermal immune-competent cell populations. We have developed a ‘nano-layer’-coated microneedle (MN) delivery platform in which vaccines/therapeutics encapsulated in surface coatings on biodegradable polymer MNs are rapidly delivered upon application to the skin of mice. Layer-by-layer deposition of plasmid DNA (pDNA) and nucleic acid TLR agonists together with biodegradable polymers on the surface of microneedle arrays gave thin coatings with tunable dosages of vaccine cargo and vaccine release rates. Following application of coated MN arrays to the skin of mice for ~5 min, intact film coatings were rapidly implanted in the skin for sustained release of vaccine components over time. Microneedle delivery of DNA vaccines encoding SIV-gag proteins induced 5-fold increased antigen-specific T-cell expansion and generation of serum IgG titers 5-fold in excess of that observed for traditional i.m. or i.d. immunizations; further, responses obtained with MN delivery were quantitatively similar to those observed for i.m. delivery with in vivo electroporation. MN delivery also induced enhanced generation of long-lived memory T-cells. Together these results demonstrate the potential for MN delivery to improve vaccine performance in the context of HIV immunization.
HIV-Env protein subunits containing native gp41 and gp120 in immunoreactive form are enriched by DC-SIGN lipoparticles. (113.22)
Authors: Vyas Girish , Stoddart Cheryl Stoddart , Killian Michael , Brennan Todd , Goldberg Tiffany , Ziman Alyssa , Bryson Yvonne 
Published: January 2023

Abstract
We prepared infection-free HIV-1 envelope proteins (HIVenv) from genetically homogeneous R5-HIV-1 occurring in plasma (PHIV) of donors before anti-HIV response. Such an immunogen could elicit broadly neutralizing antibodies (bnAb) against viruses transmitted in humans. PHIV was co-cultured with PBMCs and virions from culture supernatants were isolated by ultracentrifugation, and purified to remove contaminating microvesicles with anti-CD45. Membrane cholesterol was extracted with beta-cyclodextrin (BCD) to permeabilize virions and expel p24, RT and virion RNA, removable by 100kD Centricon. The residual host/viral DNA/RNA were hydrolyzed with protease-free Benzonase (BZ) and filtered through 30kD Centricon to obtain mHIVenv. This was tested for infectivity by PBMC cocultures, by inoculating SCID-hu Thy/Liv mice, and by EM for virions. Immunometric analyses of mHIVenv bound to DC-SIGN lipoparticles was done with anti-gp41 (1240) and anti-gp120 (b12) MoAb. A prototype HIV-1280 isolate after inactivation by BCD-BZ yielded mHIVenv with residual 0.28% p24 and retention of 91.9% gp120, and HIV RNA reduced by 7.4 logs. The mHIVenv proved noninfectious in vitro and in vivo and showed no virion particles by EM. The mHIVenv bound to DC-SIGN lipoparticles through gp120 revealed noncovalently bound gp41, with relative luminescence paralleling that of gp120. Infection-free mHIVenv protein subunits concentrated on DC-SIGN lipoparticles fulfil the need for an HIV vaccine candidate.
Adjuvant-dependent cytokine profiles in the context of a DNA prime-protein boost HIV vaccine (113.23)
Authors: Buglione-Corbett Rachel , Pouliot Kim , Marty-Roix Robyn , West Kim , Wang Shixia , Lien Egil , Lu Shan 
Published: January 2023

Abstract
Heterologous prime-boost vaccination approaches have emerged as a promising strategy to generate protective immunity against a variety of pathogens in animal and human studies. Our previous studies demonstrated that HIV-1 gp120 DNA vaccine prime-protein boost elicits improved neutralizing antibody responses. To understand the mechanisms that regulate the immune responses in prime-boost vaccination strategy, current studies were designed to define the cytokine profiles associated with different adjuvants used in such regimens. A polyvalent vaccine DP6-001, including gp120 antigens from 5 different primary viral isolates, was used as the model vaccine. Any influence of endotoxin associated with DNA plasmid preparation was first excluded, as regular DNA preparations did not elicit different immune response when tested in vivo against endotoxin-free DNA preparations. Next we studied the effects of several adjuvants, QS-21, alum, and MPL, on the immunogenicity of DP6-001 in a mouse model. gp120-specific antibody and T cell responses, and innate cytokine production, were monitored at time points after immunizations and at termination. Our results indicate that different adjuvants may generate unique cytokine profiles and improve the immunogenicity of DP6-001. This study may provide valuable information in selection of an adjuvant for inclusion in future prime-boost vaccination strategies, with the goal of enhancing immunogenicity while minimizing reactogenicity.
Influenza virus-like particle vaccination boosts CD8 T cell immunity (113.28)
Authors: Hemann Emily , Song Jae-Min , Kang Sang-Moo , Legge Kevin 
Published: January 2023

Abstract
Influenza virus-like particles (VLPs) have been demonstrated to provide protection against lethal influenza A virus (IAV) infections in mice following a single, intranasal (i.n.) vaccination. Previous work has demonstrated that VLP administration leads to an increase in virus-specific IgG production. However, the effect of VLP vaccination on the influenza-specific CD8 T cell response remains unknown. Given the important role of CD8 T cells in viral clearance, we determined the role of vaccine-induced CD8 T cell immunity in influenza VLP-mediated protection. Our results demonstrate that the HA533-specific CD8 T cell response is significantly boosted in the lungs, spleens and lung-draining lymph nodes of VLP-vaccinated mice following IAV challenge. Further, adoptive transfer of CL4 (HA533-specific) T cells and serum from VLP-vaccinated mice improved mortality following lethal infection compared to transfer of T cells or serum alone. Together, our results suggest that memory CD8 T cell responses contribute to the protection mediated by influenza VLP vaccination and support the potential use of VLPs as an effective influenza vaccine candidate.