bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMEM16F regulates bystander TCR-CD3 membrane binding at the immunological synapse
Authors: Connolly Audrey , Panès Rébecca , Bellemare-Pelletier Angélique , Gagnon Etienne 
Published: January 2023

Abstract
The signaling cascade induced by T cell receptor (TCR) triggering has been extensively studied, but the steps separating peptide recognition from TCR phosphorylation remain elusive. In resting T cells, the TCR CD3ɛ and ζ chains dynamically associate with the plasma membrane (PM) through electrostatic interactions with anionic lipids such as phosphatidylserine (PS). Upon ligand recognition, the CD3 chains dissociate from the PM, enabling robust signaling initiation. However, the mechanisms regulating PM dissociation remain obscure. Recent studies have highlighted the role of TMEM16F, a PS-specific scramblase, in regulating TCR signaling, but the molecular steps involved in this activity have not been identified.
To study the role of TMEM16F in regulating TCR activation, we knocked-down its expression using shRNA targeting. Our results show that TMEM16F knockdown inhibited PS redistribution, which significantly reduced TCR activation. To showcase TMEM16F activity in relation to TCR signaling, we transduced T cells with a mutant form of the scramblase that constitutively redistributes PS. TMEM16F-mutant T cells showed a significant increase in proximal TCR signaling. This was directly linked with an increase in PS redistribution upon TCR engagement, which enabled the dissociation of bystander CD3ɛ chains and their participation in signaling.
Our results show that PS redistribution by way of TMEM16F activity is critical for TCR signaling. Our results also establish our ability to modulate PS redistribution by targeting TMEM16F activity in order to regulate T cell activation. These findings may ultimately lead to novel approaches enabling the modulation of TCR and other immune receptor activity in T cell-based immunotherapies.
Fibronectin Costimulation of CD40L Expression Integrates Innate and Adaptive Inflammatory Signals
Authors: Ragheb Jack , Zhang Yuxia , Bushar Nicholas , Oh Hyoungbin , Gertz E. Michael , Patnaik Anuja , Chakrabarty Sagarika , Kampen Robert , Kirk Allan D , Roberts David , Schäffer Alejandro 
Published: January 2023

Abstract
CD40 ligand (CD40L) is a well-known regulator of the adaptive immune response that induces and modulates the activation and differentiation of monocytes, dendritic cells, and lymphocytes. Less appreciated is its critical role in promoting the inflammatory response in CD40-expressing cells such as vascular endothelium. Expression of CD40L on TCR activated human CD4+ T cells is biphasic and upregulated by monocyte cell contact early and IL-2R signaling late. Here we demonstrate the existence of additional, distinct pathways that differentially regulate the expression of CD40L. We describe a novel link between vascular endothelial cell adhesion molecule 1 (VCAM-1), extracellular matrix (ECM) proteins, and CD40L expression on human CD4+T cells that constitutes an innate form of T cell costimulation modulated by the type and quantity of ECM protein present, with thrombospondin-1 inhibiting fibronectin-mediated costimulation of CD40L expression. Identification of this previously unrecognized β1 integrin pathway, which promotes CD40L expression on CD4+ T cells independently of monocytes and IL-2, provides new insights into our understanding of the potential role of CD40L in the establishment and progression of inflammatory disease.
NF-kB/mTOR/MYC axis drives PRMT5 protein induction after T cell activation
Authors: Sengupta Shouvonik , Webb Lindsay , Narvaez-Miranda Janiret , Amici Stephanie , Nagy Gregory , Guerau-De-Arellano Mireia 
Published: January 2023

Abstract
Multiple sclerosis (MS) is a debilitating autoimmune disease of the central nervous system (CNS) mediated by CD4+ T cells. Clinical data has provided evidence that MS patient T cells display an activated or memory phenotype and genome-wide association studies (GWAS) have identified single nucleotide polymorphisms linked to NF-kB complex and MYC genes in MS patients. These data imply a role for TcR (T cell receptor) signaling pathways in MS. PRMT5 is the major type II arginine methyltransferase catalyzing the symmetric dimethylation of histones and other proteins. Our lab has recently reported PRMT5 plays a crucial role in inflammatory T cell expansion and EAE disease. From cancer studies, we are aware of links between NF-kB/MYC signaling and PRMT5 induction. Here, we unravel the impact of NF-kB/MYC pathways in T cell PRMT5 expression and pathogenic T cell responses. We used naïve and memory mouse Th1/Th2 CD4+T cells as models to identify mechanisms controlling PRMT5 protein expression in initial and recall T cell activation. Naïve (initial) mouse T cell activation resulted in NF-kB-dependent transient Prmt5 transcription and NF-kB, mTOR and Myc-dependent PRMT5 protein induction. Recall activation in memory T cells showed rapid induction of PRMT5 protein expression, supported by both transcription and loss of Prmt5-targeting miRNAs. These results highlight the importance of the NF-kB/mTOR/MYC axis in PRMT5-driven pathogenic T cell expansion and may guide targeted therapeutic strategies for MS.
Deciphering liver environmental signaling pathways for Kupffer cell identity
Authors: Sakai Mashito , Troutman Ty Dale , Seidman Jason S. , Ouyang Zhengyu , Spann Nathanael J. , Abe Yohei , Ego Kaori , Bruni Cassi M. , Schlachetzki Johannes C. M. , Nott Alexi , Bennett Hunter , Chang Jonathan , Vu BaoChau T. , Pasillas Martina , Link Verena M. , Texari Lorane , Heinz Sven , Glass Christopher K. 
Published: January 2023

Abstract
Functional specialization of tissue resident macrophages occurs through environmental signals controlling activity and/or expression of transcription factors. Kupffer cells are resident macrophages in the hepatic sinusoids and have critical roles in the innate immune response and iron metabolism. Here, we characterize transcriptomic and epigenetic changes in repopulating liver macrophages following acute Kupffer cell depletion as a means to infer signaling pathways and transcription factors that promote Kupffer cell differentiation. Nr1h3 encoding LXRα is rapidly and highly induced in repopulating liver macrophages, suggesting its induction plays a crucial role in Kupffer cell differentiation. Restricted deletion of Nr1h3 in Kupffer cells reveal that it is required for shaping the Kupffer cell-specific enhancer landscape. Further, we obtain evidence that combinatorial interactions of DLL4 and TGF-β/BMP produced by sinusoidal endothelial cells and endogenous LXR ligands are required for the induction and maintenance of Kupffer cell identity. DLL4 regulation of RBPJ through Notch signaling plays a key role in activating poised enhancers to rapidly induce LXRα and other Kupffer cell lineage-determining factors. These factors in turn reprogram the repopulating liver macrophage enhancer landscape to converge on that of the original resident Kupffer cells. Using molecules which mimic these liver environment signals, we show that it is possible to induce Kupffer cell-specific genes in mouse bone marrow progenitor cells and human monocytes in vitro. Collectively, these findings provide a framework for understanding how macrophage progenitor cells acquire tissue-specific phenotypes.
Loss of miR-146a skews the dendritic cell milieu in favor of CD8a+CD103+ cross-presenting migratory dendritic cells and reduces production of IL-27
Authors: Flynn Patrick A , Lind Evan F 
Published: January 2023

Abstract
miR-146a is a micro-RNA that acts on transcripts upregulated in response to LPS induced TLR4 signaling. Activation of TLR4 results in maturation and survival of dendritic cells (DCs) to activate T cells in the spleen. Interestingly, little is known how miR-146a regulates DC phenotype/function and whether it has direct effects on the regulation of effector T cell function. To probe this question, we utilized a miR-146a knockout mouse model to study both DCs and lymphocytes. Splenocytes were analyzed by multi-parameter flow cytometry and we found that miR-146a mice had a greater population of cross-presenting CD8a+CD103+ DCs compared to wild-type mice. T cells from miR-146a mice had increased CD44 and CD69 expression, and decreased CD62L expression. Bone marrow derived DCs (BMDCs) were sorted (via multi-parameter flow cytometry) and subjected to RNA isolation and transcript analysis. BMDCs lacking miR-146a had 2.5-fold higher IL1R2 and 1.3-fold higher STAT1 transcript levels in addition to 13 increased genes. Supernatants from control and miR-146a knockout BMDCs were analyzed in vitro for a cytokine profile. In the presence of LPS, miR-146a knockout BMDCs had decreased IL-27 protein concentration compared to control mice. Our data indicate that the lack of miR-146a results in a skewing of DC subsets to favor CD8a+CD103+ DCs who are known to excel at cross-presentation and migrate through tissues. RNA transcript analysis suggests spontaneous maturation of the DCs from miR-146a knockout mice. IL-27 signaling in DCs has been shown to limit TH1 responses in mice. Our data suggest that miR-146a is important for regulation of IL-27 signaling in DCs. We are now using a collagen induced arthritis model to further understand the role of miR-146a in DCs.
Serum amyloid A promotes LPS clearance and attenuates LPS-induced tissue injury
Authors: Ye Richard Dequan , Cheng Ni , Liang Yurong , Du Xiaoping 
Published: January 2023

Abstract
Lipopolysaccharide (LPS) is a major microbial mediator of inflammation and is responsible for sepsis resulting from Gram-negative bacterial infections. LPS is an external factor that induces robust expression of serum amyloid A (SAA), a major constituent of the acute-phase proteins in vertebrates, but the relationship between SAA expression and LPS-induced tissue inflammation and injury remains unclear. We constructed transgenic mice expressing human SAA1 under an inducible promoter. These mice were partially protected against lung inflammatory response caused by systemic LPS administration and by cecal ligation and puncture (CLP). Interestingly, transgenic SAA1 expression did not attenuate TNFα-induced lung inflammation and injury. Further experiments identified SAA1 binding to LPS to form a complex that promoted LPS uptake and clearance by macrophages. This effect could be disrupted by a peptide derived from SAA1, and blockade of SAA1-LPS interaction markedly reduced the protective effect of SAA1 and exacerbated inflammation in both the transgenic mice and wildtype mice treated with LPS or CLP. These findings demonstrate that acute-phase SAA expression provides innate protection against LPS-induced inflammation and tissue injury in mice.
B cell recruitment to the intestine critically depends on GATA3- and RORgt-mediated development of NKp46 negative innate lymphoid cells
Authors: Zheng Mingzhu , Mao Kairui , Li Dan , Fang Difeng , Lyu Jun , Zhu Jinfang (Jeff) 
Published: January 2023

Abstract
The isolated lymphoid follicles (ILFs) enrich for B cells, most of which are conventional B cells, however, how they are recruited into and remain in intestine is not fully understood. Here, we show that in the small intestine lamina propria (siLP) of the Gata3f/f-VavCre mouse strain, in which no T cells and very few innate lymphoid cells (ILCs) are present, B cells were also largely absent, despite B cells were normal in number in the spleen of these mice. Mixed bone marrow chimera experiments showed that Gata3-deficient B cells were able to migrate to the siLP. Normal intestinal B cells were found in Tcra−/− mice excluding the possibility of T cell contribution to B cell recruitment. Bone marrow reconstitution of various donors into Gata3f/f-VavCre mice indicated that ILCs were involved in B cell migrating into small intestine LP. Further immunofluorescent analyses using RorcGFP/GFPand Gata3f/f-Rorc-Cre mice implicated that deficiency in NKp46 negative ILC3s, presumably the lymphoid tissue inducers, was responsible for impaired B cell recruitment. In summary, our findings suggest that NKp46 negative ILC3-mediated formation of tertiary lymphoid structures such as ILFs is required for B cell recruitment and/or retention in the small intestine.
IL-12 signaling drives the differentiation and function of a TH1-derived TFH1-like cell population
Authors: Powell Michael Duane , Read Kaitlin , Sreekumar Bharath , Oestreich Kenneth J. 
Published: January 2023

Abstract
CD4+ T follicular helper (TFH) cells play key roles in the generation of humoral immunity, as they provide T cell help to B cells that ultimately results in the production of pathogen-specific antibodies. A subset of TFH cells that shares features with TH1 cells, referred to as (TH1)-biased TFH (TFH1) cells, has recently been shown to play key roles in responses to chronic infections including HIV and malaria, as well as the onset of some autoimmune diseases. Despite the apparent importance of these cells to comprehensive immune responses and human health, many questions remain regarding their origin, including the molecular mechanisms that regulate their differentiation. Here, we describe a population of TH1-derived TFH1-like cells that produce both the TH1 cytokine interferon-γ and the TFH-associated cytokine interleukin-21 (IL-21). Interestingly, this TFH1-like population exhibits increased B cell helper activity compared to IL-6 derived TFH-like cells. We further demonstrate that IL-12 signaling is required for both the differentiation and functional properties of the TFH1-like cell population. Specifically, IL-12-dependent activation of STAT4, and unexpectedly STAT3, result in both the upregulation of the TFH lineage-defining transcription factor Bcl-6, as well as the increased production of IL-21. Finally, we show that IL-12 signaling is required for TFH1-like cell expression of Icos, a receptor that is critical for the ability of T cells to provide help to B cells. Taken together, our findings provide potential insight into the genesis and regulatory requirements of recently described TFH1 cells with emerging roles in human health and disease.
Gene Expression Profiling of TRIM Family in Individuals with Latent versus Active Tuberculosis and Reveals Potential Biomarkers for Diagnosis
Authors: Li Chuanyou 
Published: January 2023

Abstract
Tripartite motif (TRIM) protein family plays important regulatory roles in innate immune and inflammatory responses. Their dysregulation causes several diseases classified as virus infective diseases, cancers, immunological diseases, neuropsychiatric disorders, or developmental disorders. Nevertheless, the role and function of many members of TRIM family in tuberculosis (TB) remains largely unknown. Our study employed qRT-PCR to first profile the mRNA expression levels of 72 members of TRIM family in patients with active TB, latent tuberculosis infection (LTBI) and healthy individuals. Our results revealed a panel of TRIM genes markedly downregulated in patients with active TB when compared to LTBI subjects and healthy controls. Subsequently, in vitro cell infection experiment identified that some differentially expressed TRIM genes were specifically linked to Mtb infection. More importantly, we established the potential use of these dysregulated TRIM genes as biomarkers for the diagnosis of active TB from LTBI or healthy controls.
Incorporation of genetic diversity provides protection from cerebral malaria in Mus musculus
Authors: Cornwall Douglas , Evavold Brian D 
Published: January 2023

Abstract
Since their creation over a century ago inbred mouse strains have been the workhorse of immunology and due to their reduced biological variability have led to countless biological breakthroughs. However, this reduced variability by its very nature is not necessarily representative of a genetically diverse (outbred) population. Here we try to understand how increased genetic diversity in the Mus musculus system may lead to more protective immunity, through a heightened but not over reactive response. Breeding together wild derived mice, that have been maintained for genetic diversity, and C57Bl/6 mice we are able to look at how the incorporation of diversity into the host genome can alter known C57Bl/6 immune function. The F1 mice from the cross are infected with the well characterized pathogen system Plasmodium bergehi ANKA, which induces cerebral malaria and death of C57Bl/6 animals in ~6 days post infection. In contrast, we show a large reduction of virulence in the F1 mice (&lt;5% morbidity) that corresponds with differential immune response allowing for suppression of disease. Furthermore, F1 mice appear to produce a more controlled reaction that promotes the differentiation of more memory-like cells and fewer effector-like cells. These data suggest that the incorporation of genetic diversity into the C57Bl/6 inbred animal model system drastically alters Plasmodium infection outcome.
Short- and long-term impact of prebiotic supplementation during infancy on immune activity in Wistar rats
Authors: Jeffrey Michael P , Clarke Sandra T , Krysa Nicole , Brooks Steve P.J. , Kalmokoff Martin L , Green Judy , Matias Fernando , Green-Johnson Julia May 
Published: January 2023

Abstract
The aim of this study was to examine short-term and long-term effects of early administration of two dietary oligosaccharide supplements, fructooligosaccharide (FOS) and galactooligosaccharide (GOS) on innate immune parameters in infant Wistar rats. A second aim was to compare the impact of these supplements between sexes. Infant rats were gavaged orally on post natal days (PND) 6–16 with either FOS or GOS solution (0.075 g/50 μL), or with glucose (0.375 g/50 μL) or no gavage as controls while being maintained on an AIN-93G diet post-weaning (n = 8 per treatment/sex). Immune impacts at PND-16 and PND-70 were determined by immunophenotyping via flow cytometry and analyses of whole blood ex vivo TLR ligand responses at PND-70. At PND-16, percentages of CD103+ Dendritic cells (DC) were higher in MLN (P &lt; 0.003) and spleens (P &lt; 0.008) of FOS-treated rats (P &lt; 0.003). At PND-70, CD103+ were unaffected but FOS supplementation had differential effects on MLN and spleen γδ-T cell populations in females versus males. Unstimulated whole blood cultures from rats fed GOS produced less CINC-1 than other treatments (P &lt; 0.02, 57.5 ± 21.6 pg/mL). GOS-fed rats also had lower CINC-1 production in response to TLR2 (Pam3Cys, P &lt; 0.02) and TLR4 (lipopolysaccharide, P &lt; 0.01) stimulation, and produced less IL-1β after TLR4 stimulation (P &lt; 0.05) than rats from all other treatments. Males produced more IL-10 than females after TLR4 stimulation regardless of treatment (P &lt; 0.001, 72.6 ± 11.6 vs. 40.9 ± 8.2 pg/mL). Overall, these results suggest limited impact of early administration of prebiotic supplements FOS and GOS on immune development, with GOS having some long-term potential to modulate TLR2 and TLR4 ligand responses.
Immunization with Leishmania major centrin knock-out (LmCen
−/−
) parasites induces skin resident memory T cells that plays a role in protection against wild type infection (LmWT)
Authors: Ismail Nevien , Karmakar Subir , Bhattacharya Parna , Dey Ranadhir , Nakhasi Hira L 
Published: January 2023

Abstract
Leishmaniasis is a vector-born disease transmitted through sand fly bite with no available vaccine. Vaccination through leishmanization with Leishmania major has been used successfully but is not safe. Recently, we have demonstrated immunization with live attenuated LmCen−/− parasite protects against Leishmaniasis via induction of host cellular immunity. Resident memory T cells (TRMs) are considered the first line of defense against infections invading the host through epithelial barrier. We evaluated the generation and function of skin TRMs post LmCen−/− immunization, compared to that generated by LmWT healed mice. We examined chemokine receptors controlling the generation and survival of skin TRMs, as well as effector and recruitment function of those cells post challenge with WT parasites. We observed that expression of CXCR6 and CXCR3 was significantly higher on T cells from spleens and lymph nodes of immunized mice, compared to those from healed mice. At 15 weeks post immunization, the skin of immunized mice had significantly larger population of TRMs compared to healed mice. In addition, epithelial cytokine production, such as IL-15, IL-33 and TNFa was significantly higher in the skin of immunized mice. Upon virulent challenge, immunofluorescent labeling of skin sections showed rapid recruitment of more T cells in the immunized mice compared to healed mice. IFNγ production by skin TRMs post challenge was significantly higher in immunized mice compared to healed mice. Taken together, these results show that immunization with live attenuated parasites is safer than Leishmanization. In addition, it generates large functional population of skin TRMs which play an important role in protection against the Leishmania infection.
Acute congenital Toxoplasma gondii infection alters fetal hematopoiesis via interferon-gamma
Authors: Apostol April , Jensen Kirk , Beaudin Anna E 
Published: January 2023

Abstract
In adulthood, infection drives cytokine-mediated inflammation that can directly influence hematopoietic stem and progenitor cell (HSPC) function and differentiation, but the effects of maternal infection on the trajectory of fetal hematopoietic and immune cells have not been elucidated. Toxoplasma gondii is a TORCH pathogen that can be vertically transmitted upon acute infection during pregnancy, with dire consequences for the developing fetus. Maternal IFNγ production during congenital infection is required to prevent vertical transmission and promote parasite clearance, but at the cost of lowered birth weights and premature abortion. Here, we investigated the effects of acute congenital toxoplasmosis on fetal hematopoiesis. Our examination of fetal hematopoiesis in response to maternal T. gondii infection of varying virulence revealed that discrete HSPC populations, including subsets of fetal hematopoietic stem cells, B1 precursors, and myeloid progenitors are fundamentally altered in response to congenital toxoplasmosis. To assess the ability of IFNγ to mediate these observed changes and directly cross the placental barrier, we performed epistatic crosses of mice deficient for IFNγ receptor. Our results indicate that maternal IFNy produced in response to T. gondii infection may drive observed changes to the fetal HSPC compartment and that fetal HSPCs respond directly to maternal sources of IFNγ in a manner distinct from adult HSPCs. Ongoing experiments attempt to resolve the mechanisms by which vertical transmission and maternal inflammation perturb the establishment of the fetal immune system, and the direct role of IFNγ in mediating these phenomena.