bluuebunny/crossref_metadata_2025_split huggingface dataset:
The increased permeability and inflammatory response of porcine intestinal epithelial cells caused by Escherichia coli and Salmonella enterica Typhimurium infections are mitigated by bovine colostrum
Authors: Blais Mylene , Bouchard Michael , Touchette Vincent , Asselin Claude , Lessard Martin 
Published: January 2023

Abstract
Gastroenteric infections caused by Escherichia coli and Salmonellaenterica Typhimurium are the source of important losses in porcineindustry. The use of antibiotics in piglets’ food to improve post-weaning performances and prevent enteric infections is raising many concerns, leading the governments to call for finding alternatives that contribute to enhance gut health and resistance to infections. Bovine colostrum is loaded with bioactive pro-immune components that could mediate anti-microbial activities. Therefore, we tested the effect of complete defatted bovine colostrum (BC), as well as bovineserocolostrum and casein fractions (SC and CAS respectively) on porcineintestinal epithelial cell (IPEC J2) in response to the two enteric pathogens. Bothpathogens increased the cell monolayer permeability 4h following the infection, as determined by TEER assays. BC treatment prevented the monolayer disruption caused by both pathogens, while SC only prevented the one caused by Salmonella. After 2h of incubation, the expression of IL8, IL6, TNFA, CCL20, CXCL2 and CXCL10 was increased by bothpathogens, while IL1B, CCL5 and SAA2 were only induced by Salmonella, as measured by Q-PCR. BC and SC reduced the induction of IL8, CCL20 and CXCL2 genes by E. coli(p&lt;0,05). Both BC and SC reduced the expression of IL6 and CCL20 genes by Salmonella (p&lt;0,05), while only BC reduced the induction of IL8, IL6, CCL20, IL1B, SAA2 (p&lt;0,05) and TNFA (p&lt;0,1). Altogether, these results show that the complete form of bovine colostrum can reduce both E. coli and Salmonella infections of porcineintestinal epithelial cells and could be a good alternative to antibiotics in order to control these infections.
Trehalose-6-phosphate synthase-deletion in Cryptococcus neoformans elicits rapid innate fungal clearance from the lungs with early neutrophil accumulation
Authors: Xu Jintao , Reynolds Mack , He Xiumiao , Gao Xueli , Ivey Michael , Kolbe Jess , Lopez Raphael , Mechler Claire , Perfect John , Olszewski Michal A 
Published: January 2023

Abstract
Clearance of the invasive fungus Cryptococcus neoformans (Cn) infection requires T-cell immune responses and individuals with impaired adaptive immunity are highly vulnerable to Cn infection. The innate immune response thus may be the only functional arm against the expansion of pathogens in patients with severe T cell deficiencies. Accordingly, targeting pathways responsible for Cn-evasion of early innate defenses could rapidly resolve Cn-disease in immunocompromised patients.
Trehalose-6-phosphate synthase (TPS1), a fungal enzyme for trehalose sugar synthesis absent in mammal, was recently identified as a key virulence gene. Using a mouse model of pulmonary Cn infection, we found that TPS1-deficient Cn (tps1Δ) elicits rapid clearance by the host. Within 72 hours, tps1Δ was either completely cleared or reduced by 5 orders of magnitude, while WT-Cn expanded in the lungs of infected mice. Mechanistically, we found that rapid tps1Δ clearance was associated with early neutrophils recruitment and induction of neutrophils - recruiting CXCL1 and CXCL2. Notably, this occurred without improved Cn-killing by macrophages. Tps1Δ stains were rapidly cleared from CD4+ T cell depleted mice that receive anti-CD4 antibody treatment, suggesting that Tps1Δ clearance is independent of host adaptive immunity. Furthermore, our in vitro killing assay showed that tps1Δ was more vulnerable to neutrophils killing compared to WT strain. Together, our data revealed that cnTPS1 contributes to early innate immune evasion by inhibiting neutrophil recruitment and killing. We identify TPS1-interception as an important therapeutic strategy to both compromise the microbe fitness and to enhance efficiency of the innate defenses in C.n elimination.
Bacteria in human intestine contribute to mucosal immune function in utero
Authors: Rackaityte Elze , Halkias Joanna , Fukui Elle M , Mendoza Ventura , Crawford Emily D. , Fujimura Kei , Burt Trevor , Lynch Susan V 
Published: January 2023

Abstract
Mucosal immunity influences host-microbial interactions and is evident in the human fetal intestine by 11–14 weeks of gestation; the developing intestine is populated by lymphoid aggregates, memory T cells and dendritic cells capable of responding to microbial stimuli. However, whether intestinal encounters with viable microbes occur in utero and shape immune maturation has not been investigated. Here, we identified subsets of fetal meconium relatively enriched in Lactobacillus or Micrococcaceae, using culture-independent methods, which related to divergent epithelial cell layer transcriptomes and proportions of lamina propria PLZF+ CD161+ CD4+ T cells in paired intestinal samples. Mimicking conditions in the fetal intestine permitted isolation of viable Lactobacillus and Micrococcus strains from fetal meconium. In contrast with phylogenetically related reference strains, fetal isolates utilized placental hormones for growth, remained viable within antigen presenting cells, and exhibited species-specific capacity to promote immune homeostasis. Fetal Lactobacillus isolates reduced activation of antigen presenting cells, while the Micrococcus isolate induced IL-10 production in antigen presenting cells and inhibited IFNγ production by memory PLZF+T cells. Fetal isolates were identified as strains of Lactobacillus jensenii or Micrococcus luteus by whole genome sequencing, with the latter encoding strain-specific genes for intracellular survival, immune modulation, and steroid uptake. These data suggest that pre-natal immunity is influenced by bacterial exposure in the fetal intestine, identifying a previously unknown component of human mucosal immune development.
NKT cells induce IgG1 class switch against C. difficile carbohydrate antigens and enhance immunity against a live pathogen challenge
Authors: Lang Mark L , Lang Gillian A , Amani Souwelimatou Amadou , Shrestha Binu , Shadid Tyler , Gillaspy Allison F , Ballard Jimmy D 
Published: January 2023

Abstract
All clinical Clostridioides difficile strains identified to date express a surface capsule-like polysaccharide structure known as polysaccharide II (PSII). The PSII antigen is immunogenic and when conjugated to a protein carrier and induces a protective antibody response in animal models. Given that CD1d-restricted Natural Killer T (NKT) cells promote antibody responses, including those against carbohydrates, we tested the hypothesis that immunization with PSII and a CD1d-binding glycolipid adjuvant could lead to enhanced protection against a live C. difficile challenge. We purified PSII from a clinical isolate of C. difficile and immunized B6 mice with PSII alone or PSII plus the CD1d-binding glycolipid α-galactosylceramide (α-GC). PSII-specific IgM and IgG3 titers were evident in sera from immunized mice, but the inclusion of α-GC led to additional isotype switch and production of IgG1. Enhanced protection against C. difficile disease was achieved by inclusion of the α-GC ligand and was associated with reduced bacterial numbers in fecal pellets. In contrast, NKT-deficient Traj18−/− mice were not protected by the PSII/α-GC immunization modality. These results indicate that α-GC-driven NKT cells stimulate a protective IgG1 response directed at the C. difficile PSII antigen. This study suggests that NKT activation represents a pathway for additional B cell help that could be used to supplement existing efforts to develop a C. difficile vaccine.
Alveolar macrophage dysfunction and increased PD-1 expression during chronic SIV infection of rhesus macaques
Authors: Hunegnaw Ruth , Mushtaq Zuena , Enyindah-Asonye Gospel , Hoang Tanya , Robert-Guroff Marjorie 
Published: January 2023

Abstract
HIV infected individuals have been shown to be predisposed to pulmonary infections even while receiving anti-retroviral therapy. Alveolar macrophages (AMs) play a critical role in innate immunity of the lung, but their functional and immunological attributes after infection remain contradictory. Here, we use flow cytometry and phagocytosis assays to document phenotypic and functional responses of SIV infected rhesus macaque AMs. We assessed AMs by sampling bronchoalveolar lavage (BAL) from acute through chronic phases of SIV infection and compared these to BAL samples taken from naïve macaques. We found that expression of pro-inflammatory cytokines TNF-□, IL-6, IL-1β and the chemokine RANTES by AMs drastically increased at 2 weeks post-infection compared to naïve animals (p&lt;0.0001 for all) and was quickly followed by a significant drop as infection progressed into the chronic phase of infection. We further show that AMs from chronically infected macaques have diminished capacity to perform SIV-specific antibody-dependent phagocytosis (ADP). Moreover, SIV infection was associated with reduced AM FcγRIII expression, which negatively correlated with viral load (r=−0.6819; p=0.0013). Importantly, PD-1 was shown to be expressed on AMs and showed a strong trend toward correlation with plasma viral load (r=0.8266; p=0.0583), indicating that similar to T-cells, PD-1 expression on AMs may also be associated with disease progression. These findings provide new insight into the dynamics of SIV infection leading to AM dysfunction and alteration of pulmonary innate immunity. Our results suggest new pathways to exploit in developing therapies targeting pulmonary disease susceptibility in HIV-infected individuals.
In vivoeffectsof α4β7 blockade on size of viral reservoirs in SIV-infected rhesus macaques
Authors: XU HUANBIN 
Published: January 2023

Abstract
Cellular viral reservoirs are rapidly established upon HIV/SIV infection, which persist throughout viral infection, even under long-term antiretroviral therapy (ART). Recent studies report α4β7 blockade in vivo could preserve mucosal CD4+ T cells, and control persistent viral infection in SIV-infected macaques. In this study, we investigated the effects of early administration with α4β7 antagonist (antibody against α4β7 or small-molecule dual inhibitor TR-14035) for the prevention of infection, and for reducing cellular reservoirs in systemic and lymphoid tissues post SIV infection. Rhesus macaques (Macaca mulatta, RMs) were intravenously (i.v.) inoculated with 100 TCID50 SIVmac251, then administrated a single i.v. dose of anti-α4β7mAb one week prior to SIV inoculation and another 3 weeks post SIV inoculation, or orally treated with TR-14035 for two weeks beginning on the day of SIV inoculation. Our results indicated that early α4β7 blockade did not result in viral containment or reduction of the reservoir size post SIV infection. Plasma viral loads and cell-associated SIV DNA/RNA levels in blood and lymphoid tissues in treated animals were similar to untreated cohorts. Interestingly, TR-14035, a dual inhibitor for α4β7 and α4β1, resulted in persistently higher viremia throughout infection, and more rapid disease progression when administrated in the acute stage of SIV infection.

Conclusions
These findings suggest that α4β7 blockade alone may not effectively control viral infection, replication, and dissemination and reservoir establishment in HIV/SIV infection. Its usage for potential preventive or/and therapeutic strategies in combined with ART requires further investigation.
Uncharted Territory: The CD4+ T cell response to human metapneumovirus
Authors: Lamens Kristina D , Rogers Meredith C , Tometich Justin T , Hand Timothy W , Williams John V 
Published: January 2023

Abstract
Human metapneumovirus (HMPV) is a leading cause of lower respiratory tract infection in pediatric and immunocompromised populations. Clearance of respiratory viruses including HMPV relies primarily on the destruction of infected cells by cytotoxic CD8+ T cells. However, signals provided by CD4+ helper T cells significantly impact the magnitude and effectiveness of CD8+ T cells. Using a mouse model of acute infection, we performed an in-depth analysis of CD4+ helper T cells in the immune response to HMPV. We identified and validated an immunodominant CD4+ T cell epitope in C57BL/6 mice and constructed the first MHC-II tetramer for HMPV. Kinetic analysis showed that the percentage of CD44+tetramer+ cells in the lung peaked at day 10 post-infection. Ex vivo peptide stimulation of pulmonary T cells revealed that most virus-specific CD4+ T cells produced IFNγ, followed by a small but consistent population of IL-17a producing cells. To determine the contribution of CD4+ T cells in the primary immune response to HMPV, CD4+ T cells were antibody-depleted prior to infection. Depletion of CD4+ T cells exacerbated infection-induced CD8+ T cell impairment, led to enhanced PD-1 expression on virus-specific CD8+ T cells, and delayed viral clearance. Next, global PD-1−/− mice were infected with HMPV to further explore the role of PD-1. Both CD4+ and CD8+ T cells displayed improved functionality in HMPV-infected PD-1−/− mice, suggesting that PD-1-mediated impairment following respiratory virus infection affects CD4+ as well as CD8+ T cells. Further characterization of virus-specific CD4+ helper T cells, their regulation by PD-1, and their role in CD8+ T cell impairment will provide new insights that aid in the design of effective vaccines against HMPV.
Eosinophils undergo temporally regulated phenotypic and physiologic changes during influenza A virus infection
Authors: Samarasinghe Amali , Tiwary Meenakshi , LeMessurier Kim 
Published: January 2023

Abstract
Eosinophils are traditionally known for their antiparasitic responses and as biomarkers of allergic diseases, including asthma. Using our model of asthma and influenza (AF) co-morbidity wherein disease outcomes varied by the presence of eosinophils in the airways, we determined that eosinophils played a dynamic antiviral role during influenza A virus (IAV) infections mainly by regulating CD8+ T cell immunity. We have also found that eosinophils in different niches including bone marrow, lymphoid organs, and lungs, undergo distinct immunophenotypic changes depending on the disease state in mice with asthma, influenza, or AF co-morbidity. Therefore, we hypothesized that eosinophil activation and migratory capacity are temporally regulated during IAV infection and that these changes in eosinophils are sensitive to the environment. Virus-exposure resulted in the upregulation of ICAM-1, CD69, and CD11b and downregulation of CD62L on eosinophils within 20 minutes. This expression pattern was temporally regulated suggestive of their ability sense IAV and alter functional responses such as migratory potential. Furthermore, mice infected with eosinophil pre-exposed IAV had a significantly reduced viral burden in the lungs. Eosinophils prevented IAV-induced cytopathology on lung epithelial cells when co-cultured directly or separated by transwell. In addition, eosinophil recipient IAV-infected mice showed no damage to the bronchial airway epithelium. Cumulatively, these data suggest a direct antiviral role for eosinophils through self-activation, reducing virus infectivity, and protecting the respiratory barrier from virus-induced damage further establishing an antiviral role for eosinophils in allergic airways.
Unmasking a killer: discovery of a gene that controls the pathogenic activation of CD8 T cells in Type 1 diabetes
Authors: Ye Cheng , Serreze David V , Chen Yi-Guang , Driver John P 
Published: January 2023

Abstract
CD4 T cell help is critical for the activation of autoreactive CD8 T cells that cause most β-cell destruction in type-1 diabetes (T1D). We previously identified a 10 Mb C57BL/6 (B6)-origin recessive Idd susceptibility locus on chromosome 11, designated Idd32 that controls whether CD4 T cells cause pathogenic CD8 T cells to undergo activation or become tolerized. To identify the underlying gene, we adoptively transferred CD8 T cells transgenically expressing the diabetogenic AI4 T cell receptor into B6 mice expressing the NOD-derived H2g7 MHC haplotype (B6.H2g7) and one of 9 different NOD-derived segments of the Idd32 interval. This reduced the interval to a &lt;520 kb region containing 18 polymorphic genes. To test these candidate genes (Δ) we used the CRISPR/Cas9 system to generate two sets of F1 strains: (B6.H2g7.Idd32NOD/NOD.Δ−/− x B6.H2g7)F1 and (B6.H2g7.Idd32NOD/NODx B6.H2g7)F1 that were monitored for T1D development after infusing them with AI4 T cells. We found that F1 mice lacking the NOD allele of the sialic acid transferase gene St6galnac1 (B6.H2g7.Idd32NOD/NOD. St6galnac1−/− x B6.H2g7)F1, but not other candidates, developed T1D. Furthermore, CD4 T cells from these mice strongly promoted diabetogenic AI4 T cell activation when co-transferred into NOD.Rag1−/− mice. In contrast, CD4 T cells from St6galnac1-intact (B6.H2g7.Idd32NOD/NODx B6.H2g7)F1 mice suppressed AI4 activation and T1D development. In summary, we have identified a novel, recessively-acting T1D susceptibility gene hidden in the normally T1D-resistant B6 mouse strain, with striking effects on pathogenic CD8 T cell activation. Our results may aid the screening of humans at future risk for T1D as well as provide a target for possible disease interventions.
Intranodal dendritic cell relocalization during inflammation impacts T cell immunity
Authors: Leal Joseph M. , Olin Brandy , Gerner Michael Y 
Published: January 2023

Abstract
Conventional dendritic cells (cDCs) are the critical antigen-presenting cells that initiate adaptive immunity in response to external inflammatory stimuli. We have previously shown that LN-resident cDC2s, a DC subset critical for generating CD4 T cell responses, reside in regions highly proximal to the lymphatic sinuses, enabling superior acquisition of draining soluble and particulate antigens. However, given that this peripheral positioning is distal from the deep LN paracortex and the T cell zone, we hypothesized that for optimal generation of adaptive immunity, LN-resident cDC2s must migrate intranodally from peripheral sites into the deep T zone in order to engage in cognate DC-T cell interactions during priming. Here, we show that s.c immunization with TLR-agonists, as well as infection with West Nile Virus, induces rapid relocalization of cDC2s into the deep T zone of the LN. This cDC2 relocalization requires Type 1 interferon in some, but not all, adjuvant immunizations, and is predominantly driven by increased CCR7 expression on cDCs after maturation. When lacking CCR7, LN-resident cDC2s failed to reposition to the T cell zone across multiple adjuvant comparisons, and this in turn led to a marked reduction in the activation and proliferation of CD4+ T cells. A decrease in the differentiation of Tfh cells was also observed, suggesting a possible impact on humoral immunity. Collectively, this work identifies a novel CCR7-mediated spatial reorganization of LN-resident cDC2s during inflammation, independent of peripheral migratory DCs, and its role in the generation of adaptive immunity.
CXCL9/10 producing cell clusters optimize Th1 cell positioning for interaction with antigen presenting cells
Authors: Negatu Seble G , Prizant Hen , Fowell Deborah J 
Published: January 2023

Abstract
Intracellular pathogen clearance is dependent on successful T cell mediated immunity. Th1 cells must localize to the site of infection to be activated into IFN-γ producing effector T cells. How Th1 cells find and interact with antigen presenting cells (APC) in infected tissues is poorly understood. Preliminary data using intravital imaging and the REX3 mouse, in which CXCL9 and CXCL10 producing cells express red and blue fluorescent proteins (RFP/BFP) respectively, suggest that CXCL9/10-producing cells form dense perivascular clusters that attract and arrest CXCR3+ Th1 cells. We hypothesize that these CXCL10+ cell clusters are enriched for APC that optimize Th1 cell activation and IFN-γ production. To determine the phenotype of the immune cells within the chemokine-producing clusters we crossed the REX3 mouse with a photoactivatable green fluorescent protein (PA-GFP) mouse. This will enable selective labeling of cells within chemokine-rich clusters prior to flow cytometry. Using precise multiphoton delivery of 830 nm light, we have successfully photoactivated the CXCL10+ clustered regions in the inflamed ear and have developed a flow cytometry panel to distinguish between macrophages, cDCs, and monocyte-derived cells that may be positioned within or outside these chemokine-clusters. Additionally, we will determine if these cell clusters enhance Th1 function by sorting photoactivated (in clusters) and non-photoactivated (outside clusters) Th1 cells from the inflamed ear and analyzing IFN-γ expression. Understanding how Th1 cells are positioned and activated at sites of inflammation will allow the field to boost responses to infectious agents and therapeutically attenuate Th1 responses in autoimmunity.
Multi-parametric Cell-Based Inflammation Assays for Cytokines and Cell Surface Antigens
Authors: Cromwell Evan , Cho Byungrae , Hoxha Ori , Bristol Neil , Olsen Cathy , Sirenko Oksana 
Published: January 2023

Abstract
Macrophages and vascular cells upregulate expression of cytokines and adhesion molecules in response to inflammation stimuli. Monitoring these molecules can provide a physiological read-out for inflammation. We present results from a multiparametric assays that used a combination of low-volume ELISA for secreted cytokines and automated cell imaging for cell surface markers to evaluate the effect of different mediators on inflammatory response with two cell models. First, human monocytic THP-1 cells were differentiated to macrophages and activated by LPS. Phenotypic changes in cell morphology were quantified by cell area and number of adherent cells using TL imaging. Secretion of IL-8, IL-1β and TNF-α was quantified by an automated low-volume ELISA (PuMA System). Second, primary human umbilical vein endothelial cells (HUVEC) were stimulated with inflammation cytokines (TNF-α, IFN-γ, and IL-1β), then PuMA System was used to quantify amount of MCP-1, IL-8, and IL-6 in cell supernatants. Expression of adhesion molecules VCAM and HLADR was quantified by measurement of total fluorescence from antibody-stained cells using an ImageXpress Pico system. Concentration dependent inhibition of inflammation by the compounds AG126 and MG132, SB202190 and PDTC were measured and EC50s calculated. Clear differences in cytokine expression were seen between the compounds consistent with reported mechanism of actions of the kinase inhibitors. The combination of imaging and microfluidic-based assays provides an efficient multiparametric assay system that can test the efficacy of anti-inflammatory compounds versus toxicity and provide insight into their MoA by selective inhibition of markers triggered by different signaling pathways.