bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Fever on Macrophage Metabolism and Function in Young and Aged Cells
Authors: Taylor Kenneth H , Hassan Intisar , Durdik Jeannine M 
Published: August 2023

Abstract
Fever is an adaptive immune response to infections. With aging comes a rise in background inflammation that does not protect against infection. Here, we investigate the metabolism and function of macrophages at fever temperatures in a mouse cell line, in young and aged peritoneal resident macrophages, and bone marrow derived macrophages. Fever temperatures generally enhance macrophage functions although the effects are complex and dynamic. We show in the RAW264.7 murine cell line, that a raise in the baseline body temperature of 37°C to a fever temperature of 39°C increased the speed in which macrophages shift from mitochondrial oxidative phosphorylation to glycolysis. Driving this metabolic reprogramming, is the production of nitric oxide. There is also an increase in global protein synthesis and an increase in the mRNA for iNOS, the enzyme that produces NO and inflammatory cytokine production. The metabolic shift was measured via the oxygen consumption and the proton efflux rate over time. Cells were stimulated with lipopolysaccharide and/or interferon-gamma (IFNg).
Our data also shows that tissue resident PRMs from aged mice exhibit a much stronger response to fever than those of young mice, while bone marrow derived microphages (BMDM) appeared to show a similar response to that of RAW264.7 cell line. However, with the addition of a cyclooxygenase2 inhibitor to block the production of prostaglandin E2, BMDMs of aged mice show an exaggerated increase in their response to LPS+IFNg activation. This work uncovers differences in fever responses between young and aged individuals that may explain the overall outcomes of the aged to infection.
Arkansas Immunology Foundation
Role of TLR In The Cell Fate Decision of Fibroblastic Reticular Cells
Authors: Jayakumar Preethi , Jiang Ting , Hu Jiannan , Huang Hai , Deng Meihong 
Published: August 2023

Abstract
During sepsis, massive PAMPs and DAMPs are released and initiate the TLR signaling to mediate immune response and cell fate decision in cells. We have shown that Fibroblastic Reticular Cells (FRC)-based therapy improves outcome in a mouse polymicrobial sepsis model. Modulating TLR4 and TLR9 signaling in FRC regulates the efficacy of FRC-based therapy in sepsis. However, whether TLR signaling regulates FRC cell fate decision and thus affects the efficacy of FRC therapy is unknown. Here we aim to understand the role of TLR9 and TLR4 in FRC cell fate decision. FRCs were treated with or without LPS/ODN1585 for 6, 12, and 24h. To test the role of TLR4/9 in FRC proliferation, Ki67 expression was assessed using quantitative PCR and flow cytometry. To test the role of TLR4/9 in FRC cell death, the expression levels of protein related to apoptosis and necroptosis were assessed using flow cytometry and western blot. Treatment of ODN1585 decreased the expression levels of Ki67, indicating that TLR9 signaling suppressed FRC proliferation. While the expression levels of Ki67 remain at similar levels in the LPS-treated FRC as the control. Furthermore, treatment of ODN1585 drove FRC towards apoptosis cell death, evidenced by increased levels of activated caspase-3 and caspase-8. Interestingly, treatment of LPS increased the expression levels of p-RIPK1 and MLKL, suggesting that TLR4 signaling drives FRC towards necroptotic cell death. Our result indicated that TLR4 and TLR9 signaling are important for the cell fate decision of FRC. Understanding the mechanism of TLR4/9 in controlling FRC cell fate decision may help with designing new therapeutic strategies to improve the efficacy of FRC-based therapy for sepsis.
R01 AI152044
Mutating Amino Acids to Analyze the Effects on NADase Activity in Uropathogenic Escherichia coli and Acinetobacter baumannii TIR proteins
Authors: Vallejo-Schmidt Tamara E , Obiorah Trinity E , Kudjra Rachida E , Snyder Greg , Snyder Michelle E 
Published: August 2023

Abstract
Toll/interleukin-1 receptor/resistance protein (TIR) domains are crucial components in the innate immune system. In mammalian cells, TIR domains are found in Toll-like receptors (TLRs) which activate innate immune responses upon recognition of pathogen-associated molecular patterns and danger-associated molecular patterns. In contrast, TIR domains in prokaryotic cells may be linked to bacterial evasion of the innate immune system. To evade immune system defenses, Uropathogenic E. coli utilize TIR domains, like TcpC, to inhibit TLR signaling pathways. TcpC also has NADase activity which could have a role in immune evasion; we are interested in identifying amino acids important for TcpC’s NADase activity. Previously, we were able to determine that a conserved amino acid, glutamate, is important for NADase activity and that a conserved aspartic acid was crucial for NADase functionality for the additional bacterial TIR protein found in bacteria Acenitobacter baumanii (AbTIR). We hypothesized that the conserved aspartic acid may play a role in TcpC NADase activity. To support our hypothesis, we created an aspartic acid (D) to alanine (A) mutation using site-directed mutagenesis, tested to see if the mutation in TcpC affected NADase activity, and compared the effect of the TcpC DA mutation with the DA mutation from AbTIR. Results show that the DA mutants lost NADase activity, suggesting that the conserved aspartic acid is important for NADase activity in both TcpC and AbTIR. By determining which amino acids are critical for NADase activity, we can use this information for drug development for diseases that might be associated with TIR activity and innate immune evasion.
Funded by NIH R25Act GM058264
Differential regulation of natural killer cells by tumor necrosis factor receptors 1 and 2
Authors: McCulloch Timothy R , Rossi Gustavo Rodrigues , Lam Allie , Wong Joshua , Kane Lawrence P , Herold Marco , Wells Timothy , Souza-Fonseca-Guimaraes Fernando 
Published: August 2023

Abstract
Tumor necrosis factor (TNF) is a key cytokine across homeostasis, health, and disease. However, the role of TNF is often dichotomous in that it is critical for protective anti-microbial and anti-tumour responses, yet it is also a major player in immune dysfunction and immune-related pathology. Surprisingly, while the effects of TNF on myeloid responses are well studied, how TNF impacts lymphocyte responses is yet to be elucidated. This is particularly the case for natural killer (NK) cells, innate lymphoid cells which play a key role in immune protection against both cancer and infection. To address this knowledge gap, we have generated novel transgenic mouse models which lack the receptors for TNF (TNFR1 and/or TNFR2) specifically on NK cells, allowing us to precisely dissect how TNF directly regulates NK cell function and survival, along with the relative importance of each receptor. Using single cell RNA sequencing among other techniques, we have discovered TNF regulates expression of co-inhibitory receptors on NK cells, including Tim3 and TIGIT, through both TNFR1 and TNFR2. In models of infection and cancer we have found that TNFR1 plays an inhibitory role through depletion of NK cells, leading to increased disease burden. Conversely, TNFR2 plays a protective role through maintenance of optimal NK function and cytokine production, promoting disease control. This ongoing work establishes the importance of TNF in the regulation of NK cell function, which could have significant clinical implications.
Myeloid PTEN inhibits innate host defense during methicillin-resistant Staphylococcus aureus-induced sepsis
Authors: Faneuff Eden , Shili Cedrick , Kim Min Joo , Salina Ana , Penteado Leticia , Blackman Amondrea , Serezani C Henrique 
Published: August 2023

Abstract
Sepsis is defined as life-threatening organ dysfunction and damage caused by an aberrant host immune response to systemic infection. Due to the abundant production of different classes of inflammatory mediators, investigating the role of endogenous proteins that influence multiple signaling pathways might provide important clues in understanding sepsis pathogenesis. Phosphatase and tensin homolog (PTEN) is a protein/lipid phosphatase, tumor suppressor, and a negative regulator of the PI3K/AKT/mTORC pathway. PTEN inhibits FcR-mediated phagocytosis, bacterial killing, and the expression and actions of the Toll-IL1R (TIR) adaptor MyD88. Whether PTEN influences the outcome of Methicillin-resistant Staphylococcus aureus (MRSA) infection remains to be determined. Given the pleiotropic effects of this phosphatase on both antimicrobial response and TLR activation, we hypothesize that PTEN is a key signaling intermediate that perturbs cellular function and increases organ damage in sepsis. Our data showed that MRSA infection increased PTEN expression in the murine kidney and PTEN deletion in myeloid cells (PTENΔmyel) decreases MRSA loads and kidney abscess area compared to PTENfl/fl mice. PTENΔmyel leads to increased neutrophil but not monocyte/macrophage migration to the kidney. Furthermore, infected PTENΔmyel show reduced IL-1β and TNF-α in the kidney. In vitro data demonstrate that PTEN−/− macrophages have increased phagocytosis and reactive oxygen species production. These data indicate that during MRSA-induced sepsis, PTEN expression in myeloid cells increases the inflammatory response while decreasing antimicrobial effector functions in the kidney.
NIH R01 HL124159-09 NIH T32AI138932-03
Spleen tyrosine kinase inhibition restores neutrophil homeostasis in COVID-19
Authors: Wigerblad Gustaf , Warner Seth , Ramos-Benitez Marcos , Kardava Lela , Tian Xin , Mao Rui , Reger Robert , Chakraborty Mala , Wong Susan , Kanthi Yoghandra , Suffredini Anthony , Dell’Orso Stefania , Brooks Stephen , King Christopher , Shlobin Oksana , Nathan Steven , Cohen Jonathan , Moir Susan , Childs Richard , Kaplan Mariana J , Chertow Daniel , Strich Jeff 
Published: August 2023

Abstract
Spleen tyrosine kinase (SYK) is a novel therapeutic target that inhibits neutrophil and macrophage activation in coronavirus disease 2019 (COVID-19). Fostamatinib, a SYK inhibitor, was studied in a phase 2 placebo-controlled randomized clinical trial and was associated with improvements in many secondary end points related to efficacy. Here, we used a multiomic approach to evaluate cellular and soluble immune mediator responses of patients enrolled in this trial. We demonstrated that SYK inhibition was associated with reduced neutrophil activation, increased circulation of mature neutrophils (CD10+CD33−), and decreased circulation of low-density granulocytes (LDG) and polymorphonuclear myeloid-derived suppressor cells (HLA-DR–CD33+CD11b−). Additionally, LDG transcriptional profiles were distinct in COVID-19 compared to during autoimmune conditions. Together, these data suggest that SYK inhibition may mitigate proinflammatory neutrophil cellular and soluble mediator responses thought to contribute to immunopathogenesis of severe COVID-19.
This work has been funded in part by the Intramural Research Program of the NIH Clinical Center (NIHCC) including a Research Award for Staff Clinicians (FY2020/FY2021), NHLBI, National Institute of Allergy and Infectious Diseases (NIAID), and National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAIMS)
IL-4 RECEPTOR SIGNALING REGULATES LUNG MACROPHAGES DURING HELMINTH COINFECTION RESULTING IN ENHANCED GAMMAHERPESVIRUS PERMISSIVENESS
Authors: Petrellis Gerogios , Rolot Marion , Preure Amira , Wathieu Caroline , Dougal Annette , Chetty Alisha , Chariot Alain , Horsnell William , Dewals Benjamin G 
Published: August 2023

Abstract
Helminth infection conditions lung macrophages in the long term, but little is known about how helminths affect lung macrophage responses to respiratory viral coinfection. Experimental helminth infection of BALB/c and C57BL/6 mice revealed an increased type 2 airway inflammation in C57BL/6 mice that was associated with pronounced phenotypic changes in lung macrophages. These changes consist of a disappearance reaction of SiglecF+ alveolar macrophages (AlvMs) and a concomitant recruitment of monocyte-derived macrophages. Monocyte-derived macrophages replenish macrophages in the airways and lung, as shown with Ms4a3TdT reporter mice, and have a distinct profile to tissue resident macrophages. Competent IL-4Rα responsiveness or intra-tracheal instillation of recombinant IL-4 or IL-13 reproduced the contraction of AlvMs and recruitment of monocyte-derived macrophages, while anti-IL13 antibody treatment impaired the phenotypic changes post helminth infection. Helminth infection of C57BL/6 mice resulted in enhanced permissiveness to subsequent infection with murid gammaherpesvirus 4 (MuHV-4) during the acute stage of the infection in vivo with viral early tropism mainly restricted to AlvMs. AlvMs isolated from helminth-infected C57BL/6 mice appear more permissive ex vivo to MuHV-4. This enhanced permissiveness of AlvMs after helminth infection was dependent on direct IL-4Rα signalling. Thus macrophages-specific IL-4Ra signalling is required for the observed macrophage phenotypic changes and renders AlvMs more permissive to gammaherpesvirus infection.
Supported by FNRS-ASP
Vδ1+ and Vδ2+ gamma delta T cell subsets exert distinct functional profiles with aviremic HIV infection and aging
Authors: Smith Erika L , Belkina Anna C , Snyder-Cappione Jennifer 
Published: August 2023

Abstract
Populations of gamma delta T cells exert different effector function profiles (inflammatory (Th1/Th17) vs. immunoregulatory (Th2/Treg)) in response to non-antigen specific signals in a microenvironment. The nature of gamma delta T cell lineage commitment versus functional capacity at the single cell level is unclear. Also, gamma delta T cells are implicated as drivers of the chronic inflammation found with normal aging and ART-suppressed HIV infection; however, the precise subsets involved in this phenomenon are currently unknown. To address these questions, we optimized a 31-color Intracellular Cytokine Staining (ICS) panel enabling measurement of 10 cytokines, as well as Ki67, granzyme B, and CD107a for use with PBMC from participants of a HIV and Aging cohort. Multi-variate analysis (opt-SNE) of the collected dataset revealed striking differences in the overall functional potential of the V delta 1 (Vδ1) and V delta 2 (Vδ2) subsets, with many Vδ1+ cells not producing any of the cytokines measured. Distinct differences of both the Vδ1+ and Vδ2+ subsets were found between the HIV infected and age-stratified subject groups. Individual gamma delta T cells with a ‘Th0’ phenotype, producing both Th1 and Th2 lineage cytokines, were present in both Vδ1+ and Vδ2+ subsets. Also, HIV+ subjects lacked Vδ2+ cells expressing CD107a, indicating a specific defect in the cytotoxic function of this subset with HIV infection. Further investigation of gamma delta T cell functions and phenotypes could provide new insight into the biology of this unique T cell population and reveal novel therapeutic targets.
Supported by a grant from NIH (R01AG060890-01)
C-type lectin receptor dysregulation in HIV and Mycobacterium tuberculosis co-infection
Authors: Browning Sarah , Paez Reina , Endsley Mark A , Naqvi Kubra , Huante Matthew B , Chauhan Sadhana , Gelman Benjamin , Endsley Janice J 
Published: August 2023

Abstract
Infection with Mycobacterium tuberculosis (Mtb) is a serious and potentially life-threatening condition, especially in people with HIV (PWH). According to the WHO, there were 10.6 million new tuberculosis (TB) cases in 2021, and 700,000 of those cases were among PWH. Macrophages are a host cell for both pathogens and play an important innate immune role in determining the outcome of disease. C-type lectin receptors (CLR) are pattern recognition receptors (PRR) abundantly expressed on the macrophage surface that orchestrate the innate immune response to microbial insults. We previously identified a role for the macrophage galactose-type lectin receptor (MGL) CLR in protection against TB. In subsequent studies, we observed suppression of MGL in tissues of HIV-infected decedents and in human macrophages following in vitro infection with HIV. In human THP-1 cells and a humanized mouse model, we observe that HIV infection markedly impairs activation of MGL by mycobacteria in comparison to other CLRs with defined roles in antimycobacterial immunity including DC-SIGN and Dectin 1. We further determine roles for TLR2/6 heterodimer, TLR4, and TGF-β signaling pathways for transcriptional regulation of MGL. Importantly, these pathways have roles in innate immunity and pathogenesis following Mtb or HIV infections. These findings advance our understanding of MGL regulation as part of the CLR repertoire, as well as its role in the response to Mtb and to Mtb/HIV co-infection.
NIH R31AI138328, R61AI138328
Monocyte-derived IL-6 Programs Microglia to Rebuild Damaged Brain Vasculature
Authors: Choi Bo-Ran 
Published: August 2023

Abstract
Cerebrovascular injury (CVI) is a common pathology caused by infections, injury, stroke, neurodegeneration, and autoimmune disease. Rapid resolution of a CVI requires a coordinated innate immune response. In this study, we sought mechanistic insights into how CNS infiltrating monocytes program resident microglia to mediate angiogenesis and cerebrovascular repair following intracerebral hemorrhage. In the penumbrae of human stroke brain lesions, we identified a subpopulation of microglia that express VEGFA. These cells, termed repair associated microglia (RAM), were also observed in a rodent model of CVI and co-expressed IL-6Ra. Cerebrovascular repair did not occur in IL-6 knockouts or in mice lacking microglial IL-6Ra expression, and single cell transcriptomic analyses revealed faulty RAM programming in the absence of IL-6 signaling. Infiltrating CCR2+ monocytes were the primary source of IL-6 following CVI and were required to endow microglia with proliferative and pro-angiogenic properties. Faulty RAM programming in the absence of IL-6 or inflammatory monocytes resulted in poor cerebrovascular repair, neuronal destruction, and sustained neurological deficits that were all restored via exogenous IL-6 administration. These data provide a molecular and cellular basis for how monocytes instruct microglia to repair damaged brain vasculature and promote functional recovery after injury.
Mycobacterium tuberculosis infection of human neural progenitor cells alters their functions
Authors: Thanthrige Thiunuwan Priyathilaka , Herbath Melinda , Laaker Collin James , Schwartz Michael , Lebakken Connie , Fabry Zsuzsanna , Sandor Matyas 
Published: August 2023

Abstract
Central nervous system tuberculosis (CNS-TB) is the most dangerous form of extrapulmonary tuberculosis. However, the current understanding of infectious mechanisms and anti-mycobacterial immunity within the brain parenchyma is limited due to the absence of an ideal human CNS-TB model. In this study, we developed a novel human in vitro model for the study of CNS-TB by infecting 3D neural organoids and 2D neural progenitor cells (NPC) with Mycobacterium tuberculosis (Mtb). Here we report that the subset of the NPC population can be phagocytized by the apoptotic cell binding receptors. Internalized Mtb bacilli, co-localized within late endosomal and phagolysosomal compartments as well as in the cytoplasm of the NPCs. Mtb infection of NPC induced an elevated cell death and limited proliferation of the infected NPCs Additionally a strong type-1 interferon (IFN) responses were detected in Mtb-infected NPCs by the RNA-sequencing and by immunohistochemistry. We demonstrated that the treatments with anti-IFNα neutralization antibodies could partially rescue Mtb-induced NPC death and proliferation defects. Our findings suggest that these novel neural organoids and NPC-based in vitro platforms provide a new platform for elucidating CNS-TB pathogenesis and can be ultimately used for testing novel anti-mycobacterial treatment strategies for the human CNS-TB.
“Supported by grants from NIH (R56AI162164-01)
LXR Signaling Mediates Protection from Bacterial Toxins
Authors: Lee Minsub S , Sammarco Alessandro , Su Baolong , Williams Kevin , Fong Loren , Tarling Elizabeth , Scumpia Philip O , Bensinger Steven 
Published: August 2023

Abstract
Necrotizing fasciitis (NF) is an aggressive skin and soft tissue infection characterized by massive tissue destruction. Current treatment strategies are limited to aggressive and repeated surgical debridement, coupled with systemic antibiotics. Thus, new therapeutic approaches that preserve tissue integrity would be beneficial. Cholesterol-dependent cytolysins (CDCs) are toxins produced by select gram-positive microbes implicated in NF. CDCs recognize cholesterol in membranes of cells for pore formation and subsequent cellular and tissue damage. Recently, we have shown that interferon signaling is able to protect cells from CDCs via reprogramming cholesterol homeostasis. This observation led to us to ask if pharmacological targeting of cholesterol metabolism provide similar protection. Liver X Receptor (LXRs) are key transcriptional regulators of cholesterol metabolism. We find that pharmacological LXR activation protects mice from Streptolysin O (SLO)-induced tissue damage. LXR stimulation in various cell types, such as macrophages, neutrophils, and endothelial cells induced resistance to CDCs by abrogating the ability of CDCs to directly bind to cholesterol in the plasma membrane. Ongoing mechanistic studies are investigating which metabolic pathways induced by LXRs (e.g., cholesterol efflux, biosynthesis, import, or trafficking) are responsible for the protective effects. Translationally, LXR stimulation may serve as an adjunctive therapeutics for necrotizing fasciitis and other CDC-mediated pathologies (e.g., pneumonia, pharyngitis, and septic cardiomyopathy).
P01 HL146358
Viral immunology in the context of COVID-19
Authors: Sika-Paotonu Dianne 
Published: August 2023

Abstract
Early into the COVID-19 pandemic, countries in the Pacific Region worked hard to keep the SARS-CoV-2 virus outside their borders, until COVID-19 vaccines could be developed. Even before made readily available, COVID-19 vaccines became the subject of widespread speculation, misinformation and disinformation, with some of these efforts targeted to the Pacific Region. The demand for appropriate and effective scientific communication efforts suddenly increased. Areas of immunological focus pertaining to the SARS-CoV-2 virus and the COVID-19 vaccine needed clarification for the general public and lay audiences everywhere. Efforts to communicate complex immunological based content pertaining to the SARS-CoV-2 virus in particular while in various degrees of lockdowns became more reliant upon online platforms. Prior to the widespread use of Rapid Antigen Testing for COVID-19, one of the many areas of interest was the PCR testing methodology for COVID-19 which also became a focus of mis/disinformation in the Pacific Region. The purpose of this work was to apply an approach for countering mis/disinformation about the SARS-CoV-2 virus in particular, with a strong focus on the immunological aspects through an online Pacific Fono (gathering) to support appropriate scientific communication. Participants gave positive feedback, indicating this approach was relevant, helpful, with requests for more Pacific Fono. This work showed that an appropriate, contextualised scientific focus upon the immunological aspects of the SARS-CoV-2 virus and COVID-19 vaccines, could help counter mis/disinformation efforts against COVID-19 vaccines.
Wellington School of Medicine & Health Sciences, University of Otago