bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue-resident memory CD8+ T cell development in the upper respiratory tract
Authors: Kost Kirsten , Michalets Sarah , Mattingly Cameron , Chen Thien Duy , Jimenez Ariana , Williams Mark , Lawrence Laurel , Kohlmeier Jacob 
Published: November 2024

Abstract
CD8+ tissue-resident memory T cells (TRM) in the upper respiratory tract (URT) limit viral replication and can prevent spread to the lower respiratory tract (LRT), which is the primary cause of morbidity and mortality after respiratory virus infection. Utilizing mouse models, our work explores the interesting dichotomy of URT CD8+ TRM development after intranasal (i.n.) priming, in which localized respiratory antigen is present, and intraperitoneal (i.p.) priming, in which URT CD8+ TRM develop without localized antigen. We explore the early kinetics of TRM formation and demonstrate through bulk RNA sequencing that URT CD8+ memory precursor TRM have unique transcriptional signatures in these distinct infection settings. Using immunofluorescent microscopy, we identify localization of URT CD8+ TRM with and without local antigen. We are currently exploring the role of CD4 T cell help and the respiratory microbiome on the development of URT CD8+ TRM in the presence and absence of local antigen. Additionally, utilizing conditional knockout mouse models, we show that cytokine signals in the URT microenvironment, namely TGF-b and IL-15, drive CD8+ TRM formation in combination with localized antigen. Our work outlines the unique requirements for URT CD8+ TRM formation in the absence of localized respiratory antigen, which can inform T cell-based vaccine strategies against respiratory viruses.
Determining the role of T follicular helper cells in a multi-antigen germinal center model
Authors: Bilanovic Jana , Jacobsen Johanne , Nakandakari-Higa Sandra , Barbulescu Alexandru , Victora Gabriel 
Published: November 2024

Abstract
High-affinity antibodies produced by germinal center (GC) B cells are a crucial line of protection from viral infections. Canonically, T follicular helper (Tfh) cells provide essential helper signals to GC B cells through cognate Tfh-B cell interactions, thereby driving the iterative cycles of GC B cell selection. While our understanding of how Tfh cell help influences GC B cell selection in single-antigen GCs has significantly increased over the last few years, less is known in the setting of multi-antigen GCs, such as those induced by Influenza infection.
Notably, during the course of Influenza infection major structural epitopes are accessible to B and T cells to various extents as either external or internal proteins. In theory, GC B cells can therefore receive help from different pools of Tfh populations, containing cells specific for the same (intramolecular) or another (linked help) antigen as the B cells.
Recently, our lab developed LIPSTIC, an enzyme-mediated, proximity-dependent intercellular labeling technique, enabling us to directly record and quantify T cell help provided to B cells in vivo. Using LIPSTIC, we are studying how T cell help varies and is distributed among different viral protein-specific GC B cells and how competition for T cell help between different B cell clones shapes the antibody repertoire against flu. Furthermore, we aim to quantify the occurrence of intramolecular and linked T cell help as well as their contribution to GC selection.
Lack of IFN-g signaling leads to enhanced susceptibility to eschar-associated scrub typhus in mice
Authors: Liang Yuejin , Wang Hui , Gonzales Casey , Sun Keer , Sun Jiaren , Soong Lynn 
Published: November 2024

Abstract
Scrub typhus is an infectious disease caused by the bacteria Orientia tsutsugamushi (Ot). Severe infection can lead to organ failure and hemorrhage, resulting in fatality without proper treatment. The mechanism of how the host innate immune system responds to this infection remains elusive. By using an intradermal (i.d.) inoculation mouse model, we found that dendritic cells (DCs) and macrophages (MФ) were the major cell subsets responsible for bacterial uptake in dermis and dissemination into draining lymph nodes (dLN), leading to a systemic infection. This process was dependent on the chemokine receptor CCR7. Interferons (IFNs) are known to play a crucial role in microbial infection defense. Our data showed that the levels of IFNs increased significantly in the skin and lymph nodes after infection. To investigate the role of IFNs in Ot infection, we i.d. infected Ifnar1- or Ifngr-deficient mice and found that the lack of IFN-γ, but not IFN-I signaling, resulted in visible skin eschar lesions, higher bacterial burdens in dLN, exacerbated systemic infection, and animal lethality. Our in vitro study demonstrated that IFN-γ restricted bacterial growth in DCs and MФ, suggesting that IFN-γ may inhibit bacterial dissemination in vivo by signaling on bacteria-carrying myeloid cells. Overall, our findings reveal a Trojan horse mechanism of bacterial transmission and highlight the crucial role of IFN-γ signaling in host protection against scrub typhus.
TLR4 dependent generation of a novel bone marrow-derived inflammatory monocyte population required for elicitation of skin contact hypersensitivity responses
Authors: Kish Danielle , Fairchild Robert 
Published: November 2024

Abstract
Contact hypersensitivity (CHS) is a CD8 cell mediated response to hapten skin sensitization and challenge. Hapten-primed CD8 cell infiltration into the skin challenge site during elicitation of CHS requires infiltration of a novel population of Gr-1+ CXCR2+ cells that express FasL and perforin. The goal of the current studies was to further characterize these myeloid-derived cells and to determine mechanisms generating the cells in the bone marrow during elicitation of CHS. The cells were purified from the bone marrow of hapten sensitized mice 2 hrs after hapten challenge by depletion of CD3+, B220+, NK1+, F4/80+, and class II MHC+ cells. Flow cytometry analyses indicate &gt;90% of the remaining bone marrow cells were CD11c+, Ly6C+, CCR2+, expressing FasL+ and perforin. This cell population was at low numbers in the bone marrow of naïve mice but increased to peak numbers 2 hrs. after hapten challenge of sensitized WT and Rag-/- mice as well as T-cell depleted WT. Generation of these cells was absent in hapten sensitized and challenged TLR4-/- mice. Currently, we are using spectral flow cytometry to focus on sensitization induced differences in hematopoietic progenitor cell populations in the bone marrow of TLR4-/- compared to WT mice. These results indicate that generation of bone marrow-derived Ly6C+ CXCR2+ FasL+ cells in response to inflammation requires TLR4 signaling that occurs independently of T cell activation.
The source of TAFA4 and its role in CNS immune cell recruitment during neuroinflammation
Authors: Tso Hwa-Sung , Yeh Xin-Mei , Wu-Hsieh Betty A , Miaw Shi-Chuen 
Published: November 2024

Abstract
TAFA4, also known as Fam19a4, has been reported to be secreted by C-low-threshold mechanoreceptors (C-LTMRs) and alleviate mechanical pain hypersensitivity. However, its immunological function in the central nervous system (CNS) remains incompletely understood. Our study aims to elucidate the wider source of TAFA4 in the CNS and its role in CNS inflammation. We generated lines of TAFA4-knockout (KO)-reporter mice, wherein the TAFA4 gene is deleted and replaced with a membrane-bound green fluorescent protein (GFP) and secretable nano-luciferase. We discovered that TAFA4 expression extended beyond C-LTMRs, encompassing neurons in the habenula-fasciculus retroflexus, hypothalamus, and olfactory bulb. Notably, the kinetics of TAFA4 expression followed a decreased trend during EAE-induced inflammation by nano-luciferase assay. Furthermore, we showed that mice with TAFA4 deficiency exhibited diminished immune cell infiltration and reduced demyelination in the spinal cord after EAE induction. These results underscore the involvement of TAFA4 in pro-inflammatory responses during EAE pathogenesis. Additionally, we showed that TAFA4 acted with chemoattractant properties towards M1 macrophages and neutrophils but not T cells by trans-well analysis. In summary, our study revealed the diverse sources of TAFA4 within the CNS and unveiled its inflammatory role during EAE inflammation. We propose that TAFA4 is potentially involved in CNS immune cell recruitment and inflammation.
Combination Therapy Blocking TNF Superfamily Members 14 and 15 Reverses Pulmonary Fibrosis
Authors: Steele Hope , Cheng Jason , Willicut Ashley , Dell Garrison , Ghastine Andrew , Nguyen Xinh-Xinh , Feghali-Bostwick Carol , Croft Michael , Herro Rana 
Published: November 2024

Abstract
Currently, anti-inflammatory drugs fail to reduce pulmonary fibrosis in the clinic and there is an urgent unmet need to develop novel anti-fibrotic drugs capable of reversing disease. Our lab has identified two novel mediators of pulmonary fibrosis belonging to the tumor necrosis factor superfamily (TNFSF), LIGHT (TNFSF14) and TL1A (TNFSF15). Here, we show LIGHT and TL1A receptor are both significantly elevated in patient pulmonary fibrosis biopsies as compared to healthy control lungs. Using gain of function studies, we found that LIGHT and TL1A can drive airway remodeling independently of one another and that these TNFSF members synergize to maximize airway inflammation and fibrosis. We show that the combinatorial blockade of LIGHT and TL1A limits TGFb-driven profibrotic effects on fibroblasts in vitro. Moreover, LIGHT and TL1A stimulation of human epithelial cells and fibroblasts reveal distinct fibrotic and inflammatory signatures, including redundant, additive, and synergistic profibrotic activities. Importantly, using antagonistic reagents to neutralize both LIGHT and TL1A signaling in combination post-disease onset, we observe a significant decrease in collagen deposition and smooth muscle hypertrophy in a bleomycin model of pulmonary fibrosis as opposed to respective monotherapies. The implication of this work highlights a therapeutic need of concomitantly targeting LIGHT and TL1A to treat pulmonary fibrosis disorders in humans.
Novel loss of function mutations in the death domain of tumor necrosis factor superfamily receptor 1A (TNFRSF1A) in children with systemic juvenile idiopathic arthritis (sJIA)
Authors: Cruz Anthony , Nakano Hiroto , Chou Sophia , Krantz Marisa , Fu Tianmin , Felicelli Christopher , Wu Hao , Ombrello Michael 
Published: November 2024

Abstract
Systemic juvenile idiopathic arthritis (sJIA) is an inflammatory disease characterized by recurring fevers, arthritis, and hyperinflammation, but the etiology is unknown. Using family- and population-based sequencing approaches, we have identified several novel TNFRSF1A mutations. These include 2 mutations in the death domain (DD) of TNFR1 (P367S; E398K) and 1 that leads to truncation of the TNFR1 protein (K203X), fully eliminating the DD and intracellular domains. Protein modeling predicts that E398K will reduce the strength of TNFR1-TNFR1 interactions, while P367S will alter TNFR1-TRADD binding. Using flow cytometric Förster resonance energy transfer (FRET) analysis, we studied TNFR1 DD-mediated interactions. As predicted, interactions between E398K and both WT TNFR1 and TRADD are reduced, as is the interaction of P367S with TRADD. Further, proximal signaling complex formation is reduced in mutant-transfected cells by immunoprecipitation. Consistent with this, cell death is reduced in cells harboring TNFR1 mutants, while overexpression of mutant TNFR1 in NFkB reporter Jurkat cells reveals abrogated TNF responses. Analysis of soluble TNFR1 released into the supernatant of transfected cells shows K203X is released in a greatly enhanced manner unique to this mutation. Overall, we show that these mutations confer muted TNFR1 responses upon stimulation. Future studies will explore the mechanisms through which these loss of function mutations lead to an inflammatory phenotype.
GITRL expressed by regulatory B cells is the key to expanding T-regulatory cells to the level required to ameliorate autoimmunity
Authors: Gurski Cody , Khalil Mohamed , Beltrame Angela , Burns Robert , Dittel Landon , Sommers Kelli , Dittel Bonnie 
Published: November 2024

Abstract
CD4+Foxp3+ T regulatory cells (Treg) are well characterized for their role in controlling autoimmunity. We have previously shown that mice deficient in B cells (μMT) have significantly reduced Treg and cannot recover from the mouse model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), demonstrating a regulatory role for B cells in immune tolerance. Using B cell depletion strategies and phenotyping, we discovered B cell IgD Low (BDL) regulatory B cells that when adoptively transferred into μMT mice increased Treg numbers and drove EAE recovery. BDL activity was found to be dependent upon glucocorticoid-induced tumor necrosis factor receptor-related protein ligand (GITRL), which engages GITR on Treg inducing their proliferation. To investigate whether BDL activity could be enhanced, B cell-specific GITRL transgenic (tg) mice were obtained. These mice had three-fold more Treg than WT mice consistent with attenuated EAE. Adoptive transfer of GITRLtg BDL into μMT mice did not increase Treg numbers nor reduce EAE severity as compared to WT BDL. Here we posit that sustaining elevated Treg numbers is required to ameliorate EAE to clinical scores below that of WT, as seen in GITRLtg mice. This holds translational implications for many autoimmune diseases for which Treg cell therapies have been proposed. New approaches must be examined to not only increase Treg in autoimmune patients, but also to retain these levels over longer periods of time.
Intranasal and Intramuscular Immunization with a Universal Influenza A Virus Vaccine Induces Distinct and Protective Immune Responses in Mice
Authors: Zhang Alicia (Wanyue) , Li Sean 
Published: November 2024

Abstract
Influenza infections cause more than half a million deaths annually. Despite the prevalence of influenza vaccines, the vaccine efficacy varies widely (19-54%) due frequent mutations of the viral genome, a problem exacerbated by cross-species transmission. Although intranasal (IN) administration could enhance effectiveness, most current vaccines are intramuscular (IM) due to limited understanding of the IN mechanism. This study aims to compare the mechanism of protection conferred by an IN or IM delivered universal influenza vaccine. We designed a vector expressing a conserved antigen, the nucleoprotein (NP), fused with CD40 ligand, acting as both a targeting ligand and a molecular adjuvant. Only IN vaccinated mice were protected against H1N1, H3N2, and a highly pathogenic and transmissive H5N1 avian strain, showing high antibody levels and distinct cytokines along the respiratory tract. To further characterize the cell-mediated response, IN or IM vaccinated animals were treated with an agonist for sphingosine-1-phosphate receptors, inhibiting lymphocyte egress. After the treatment, only IN was protective against the viral challenge, indicating that IN induced a potent local cell-mediated defense without circulating lymphocytes. Further flow cytometric analysis revealed that IN induced proliferative tissue-resident T cells in the lungs. These findings suggest that IN vaccination induces superior cross-subtype protection by stimulating robust mucosal immunity.
The role of B cell and microglial BTK signaling in the pathogenesis of experimental autoimmune encephalomyelitis.
Authors: Ogbaslase Abraham 
Published: November 2024

Abstract
Bruton’s tyrosine kinase (BTK) is a key signaling molecule expressed in B cells and microglia. While the contribution of BTK signaling in B cells to the pathogenesis of multiple sclerosis has been explored to some degree, the involvement of microglial BTK signaling to disease remains largely uncharacterized. We hypothesize that BTK signaling regulates features of microglia and B cells that drive disease progression in experimental autoimmune encephalomyelitis (EAE). Using a global-BTK KO model we have found that BTK deletion confers a protective effect against the development of EAE. Additionally, in our CD79-cre conditional KO system, deletion of BTK reduces the ability of B cells to serve as antigen presenting cells and dampens T cell responses following EAE induction. Within the central nervous system of BTK KO mice there is a reduction in B cell expression of MHC II and co-stimulatory molecules as well as a reduction in the frequency of overall CD4 (p = 0.0079, n ≥ 13) and effector CD4 (p = 0.0857, n ≥ 13) T cells compared with WT. Additionally, BTK KO mice produce less anti-rodent MOG antibody in comparison to BTK-replete controls. We have also observed that the protective effect of BTK deletion is only partially driven by BTK signaling in B cells, leading us to explore microglial contribution to disease pathogenesis. Induction of EAE in a CX3CR1-cre-ert2 conditional knock-out system will determine the contribution of microglial BTK signaling to disease pathogenesis.
BCLAF1 is a novel regulator of fetal and adult hematopoietic stem cell function
Authors: Crowley Stephanie , White Lynn , Yang Wei , Li Yanan , Wu Jun , Schmidt Haley , Magee Jeffrey , Bednarski Jeffrey 
Published: November 2024

Abstract
Hematopoietic stem cells (HSCs) adapt to blood production and maintenance needs of a developing organism. Mouse fetal liver HSCs undergo rapid perinatal proliferation and possess high repopulation capacity. Adult HSCs establish residence in the bone marrow and lose repopulation capacity with age. This shift is characterized by epigenetic and transcriptional cues. The objective of our study is to determine the developmental context-dependent role for BCLAF1 in HSC function. Conditional loss of BCLAF1 results in a reduction of fetal HSCs that persists into adulthood, while induced deletion of BCLAF1 in adult mice does not affect HSC numbers. These results suggest the context of fetal liver HSC development may exacerbate effects of BCLAF1 loss. In competitive transplant models, we have found that both fetal and adult BCLAF1-deficient HSCs have significantly reduced repopulation capacity. CITEseq of fetal Vav-Cre:Bclaf1fl/fl hematopoietic cells reveals a reduction in long-term repopulating HSCs and elevated AP-1 gene expression. Consistent with these results, in vitro HSC differentiation culture assays demonstrate that BCLAF1-deficient HSCs have increased myeloid differentiation. Current BCLAF1 CUT&RUN sequencing experiments on fetal and adult HSCs will define specific changes in DNA-binding patterns of BCLAF1 over development. Collectively, these results suggest that BCLAF1 acts in fetal and adult HSCs to transcriptionally restrain AP-1 activity and promote HSC function.
Conditionally immortalized cell lines with mast cell potential
Authors: Salehi Faraz , Redecke Vanessa , Häcker Hans 
Published: November 2024

Abstract
Prior to the establishment of definitive hematopoiesis, mast cells (MCs) derived from the yolk sac and fetal liver colonize diverse tissues, maintaining a presence throughout life. Following the establishment of definitive hematopoiesis, hematopoietic stem cells from the bone marrow (BM) also contribute to the MC pool. The diverse origins and tissue-resident nature of MCs complicate their study. Therefore, a system facilitating the expansion of MC progenitors and their controlled differentiation becomes crucial. This report outlines the development of conditionally immortalized MC progenitor cell lines based on two tissue sources, i.e. mouse fetal liver and adult bone marrow. To obtain cell lines, retroviral vectors encoding an estrogen-regulated Hox gene were introduced into progenitor cells derived from both tissues. These transduced cells can be expanded in their non-differentiated state for extended periods and upon estrogen removal, these cells differentiate into MCs in the presence of IL-3 and SCF. Resulting mast cells are functionally comparable to BM-derived MCs, initiating degranulation upon IgE cross-linking. Likewise, these MCs express MC-specific proteases such as chymase 1 and MCPT4. In conclusion, our findings highlight the efficacy of estrogen-regulated Hox genes in targeting MC progenitors in both fetal liver and adult BM. The established cell lines serve as reliable tools for studying MC biology, ontogeny and, possibly, disease conditions, such as allergies.
Chaotic hematopoiesis in homeostasis
Authors: Jia Dongya , Mukherjee Ratnadeep , Altan-Bonnet Grégoire 
Published: November 2024

Abstract
Hematopoiesis is a highly dynamical and stochastic process, challenging classical models of homeostasis. By number, there are around 330 billion cells turning over every day in a human body and 86% of which being blood cells. Clinical studies of leukemia and neutropenia patients suggested that multiple blood cell types are vibrantly fluctuating with large yet controlled variation. Yet the establishment and dynamics underlying homeostasis in the hematopoietic system remains elusive.
We integrated high-dimensional cytometry (mass and spectral cytometry) with mathematical modeling, and performed both cross-sectional study (n=39) and longitudinal study (n=10) of healthy mice. We found that all cell types exhibit large variations of cell numbers (10-100-fold-change in general) in bone marrow, blood and spleen. We showed that the time-series of leukocyte population size (B cells, neutrophils etc.) all exhibit chaotic behaviors i.e. the leukocyte population size demonstrated a strong sensitivity to initial conditions, and a broad spectrum of characteristic timescales of fluctuations. Using mathematical modeling, we accounted for the emergence of chaotic dynamics and predicted that accumulation of B cells (akin to lymphoma development) would transition the blood cell dynamics from chaos to oscillations (as observed for leukemia patients). Such model challenges our textbook understanding of homeostatic hematopoiesis, opening new avenues of research for immunotherapeutic manipulations.
LMAN1 promotes enhanced Alternaria alternata-induced airway hyperresponsiveness through alteration of alveolar macrophage and ILC2 populations
Authors: Sauber Faith , Swaby Lindsay , Zhang Bin , Tigno-Aranjuez Justine 
Published: November 2024

Abstract
Current biologics often fail to effectively manage symptoms in severe allergic asthmatic patients, necessitating the exploration of novel therapeutic approaches. Our laboratory has recently identified LMAN1 as a novel regulatory cell surface receptor for house dust mite (HDM). Binding of LMAN1 to HDM allergens was found to depend on mannosylation, suggesting a potential broader role of this receptor in the recognition of other highly mannosylated allergens such as molds. Alternaria alternata is a ubiquitous mold often associated with severe asthma. Whether LMAN1 can also act to regulate responses to Alternaria, remains to be explored. We demonstrate that the immunodominant Alternaria allergen Alt a 1 can also bind to purified Fc-LMAN1, indicating potential involvement of this receptor. Thus, we subjected both WT and LMAN1 knockout mice to an Alternaria alternata-induced asthma model. The absence of LMAN1 resulted in a substantial increase in airway hyperresponsiveness (AHR) compared to WT animals. Interestingly, changes in AHR did not correlate with enhanced eosinophilia but, instead, went hand in hand with a reduction in alveolar macrophages and an increase in type-2 innate lymphoid cells. Work is currently ongoing to further investigate the cellular and molecular mechanisms underlying these findings. This discovery highlights LMAN1 as a promising target for innovative therapeutic interventions.