bluuebunny/crossref_metadata_2025_split huggingface dataset:
Airway Prevotella promote TLR2-dependent neutrophil activation and rapid clearance of Streptococcus pneumoniae from the lung
Authors: Clark Sarah E , Horn Kadi J , Schopper Melissa A 
Published: January 2023

Abstract
This study investigates how the lung microbiome influences the early immune response to infection. Prevotella are a major component of the endogenous airway flora, and Prevotella melaninogenica is one of the most commonly isolated species in the human lung. Increased abundance of P. melaninogenica correlates with reduced infection with the bacterial pathogen Streptococcus pneumoniae, indicating a potentially beneficial role. Using a mouse co-infection model, we found that P. melaninogenica enhanced protection against S. pneumoniae, resulting in rapid clearance from the lung and improved survival. This response required recognition of P. melaninogenica lipoproteins by toll-like receptor (TLR)2, the induction of TNFa, and neutrophils, as the loss of any of these factors abrogated Prevotella-induced protection. Improved clearance of S. pneumoniae was associated with increased serine protease-mediated killing by lung neutrophils. IL-10 was also important for restraining P. melaninogenica-induced inflammation in co-infected mice. Together, these findings highlight innate immune priming by the airway microbiome as an important protective feature in the respiratory tract.
Supported by the National Institute of Allergy and Infectious Diseases grant K22AI143922, an American Thoracic Society Research Program Grant, an American Lung Association Innovation Award, and a Boettcher Foundation Webb-Waring Biomedical Research Award.
Optimization of cell culture protocols and immunoassays in a non-model teleost.
Authors: Collias Alexandra , Steinel Natalie C 
Published: January 2023

Abstract
The threespine stickleback fish and its natural helminth parasite Schistocephalus solidus are an emerging model for studying host-parasite immune modulation. However, to serve as an effective immunological and host-pathogen interaction model in vitro protocols must be developed and optimized to assess immune function, including leukocyte viability, apoptosis, production of reactive oxygen species (ROS), phagocytosis, and proliferation. Unique features of stickleback leukocytes make them incompatible with many commercially available reagents and their small size make them undetectable by some instruments, presenting challenges in the development of these assays. Flow cytometry has proven to be a successful tool for performing streamlined cell counts and we have succeeded in identifying live, apoptotic, and dead leukocytes in this species. We have also optimized flow cytometry assays to detect the production of multiple ROS species using DHR-1,2,3 as well as a superoxide-specific detection assay. The small size of stickleback leukocytes makes them incompatible with large phagocytosis particles, such as zymosan. However, using a combination of lipophilic cell membrane dye and fluorescently tagged E. coli particles, in conjunction with confocal microscopy, we successfully quantified the phagocytic activity of stickleback splenocytes and confirmed internalization of the particles. Lastly, identifying proliferating stickleback leukocytes has been difficult; both EdU and Ki67 assays have been unsuccessful. Although challenging, identifying and documenting successful techniques to use with non-model organisms is essential for expanding our immunologic tool box and furthering our knowledge of these organisms.
Supported by grants from NIH (R01 AI146168)
Influenza-induced cytokine response predisposes hosts to secondary Aspergillus fumigatus infections
Authors: Grau Madeleine S , Wang Xi , Obar Joshua J 
Published: January 2023

Abstract
Influenza infected patients admitted to the ICU are at significant risk of developing secondary Aspergillus fumigatus (Af) infections, termed influenza-associated pulmonary aspergillosis (IAPA). IAPA affects both immunocompromised and immunocompetent patients, causing a higher morbidity and mortality −50–72% mortality rate–in comparison to other secondary infections. Influenza-induced secondary bacterial infections have been extensively studied, yet little is known about IAPA pathogenesis. We have developed a murine IAV-Af superinfection model in which immunocompetent C57BL/6J mice infected with influenza A virus (IAV) results in increased susceptibility to secondary Af challenge. IAV infection 6 days, but not 3 days, prior to Af challenge causes IAPA in these mice with significant fungal growth and germination leading to increased mortality. With this murine model of IAPA, we examined the potential role of cytokine dysregulation in driving IAV infection to secondary Af challenge. We observed a significant reduction in IAV-induced interferon gamma (IFNγ), which may be associated with impaired immune response during IAV-Af coinfection. However, IAPA infected C57BL/6J and Ifngr−/− mice developed similar disease. IAV-Af superinfected mice produce elevated TNFα during superinfection in comparison to IAV infection. Since myeloid immune cells stimulated with these cytokines have reduced bactericidal activities in COVID-19 patients this combination has the potential to similarly impair IAPA immune responses. Using our novel IAPA model we will assess the role of IFN dysfunction on innate immune cell populations, thereby increasing susceptibility to secondary Af infection by single cell RNA sequencing.
Supported by grant from NIH (1 R21 AI152019-1)
Sialophorin is an essential host element for immunity against fungal pneumonia
Authors: Mudalagiriyappa Srinivasu , Nanjappa Som Gowda 
Published: January 2023

Abstract
Invasive fungal infections (IFI) are emerging diseases accounting for 1.7 million deaths and 150 million life-threatening diseases worldwide annually. The increased population of immunocompromised individuals and lack of arsenal of antifungal drugs necessitate an understanding of mechanisms of host-pathogen interactions to define new preventive and therapeutic targets. Here, we show that sialophorin (CD43), a transmembrane glycoprotein, is necessary to mediate protective immunity against primary pulmonary fungal infection. Using a mouse model of lethal fungal infection with Blastomyces dermatitidis, we learned that ablation of sialophorin enhanced the severity of disease, pathology, and accelerated death. At the cellular level, alveolar macrophages, one of the first lines of innate cellular barriers, were blunted in the absence of sialophorin. Additionally, sialophorin deficiency truncated the numbers of inflammatory monocytes, CD103+ DC, and interstitial macrophages. Surprisingly, sialophorin was dispensable for neutrophils. Despite sialophorin implication, the defect seen under sialophorin deficiency was independent of the cell trafficking. Finally, we uncovered that sialophorin augmented IL-17A responses from innate lymphoid cells.
Collectively, we show that sialophorin is an essential host element for innate immunity against pulmonary fungal infection and can be an immune target for the control of fungal infections.
Funding support: Innovation Award by the American Lung Association to SGN.
Supported by Innovation Award by the American Lung Association to SGN.
The preterm infant microbiome impairs lung immune responses to respiratory syncytial virus infection
Authors: Brown Julia A , Carrow Hannah , Jin Jenny C , Ananthanarayanan Aparna , Sanidad Katherine Z , Johnson Elizabeth L , Perlman Jeffrey M , Worgall Stefan , Zeng Melody Y 
Published: January 2023

Abstract
The gut microbiome plays a critical role in neonatal immune development; early-life perturbations to the microbiome have been linked to later susceptibility to respiratory conditions, including asthma and chronic obstructive pulmonary disease. Preterm infants are at higher risk for adverse outcomes to respiratory infections such as respiratory syncytial virus (RSV). The microbiome in premature infants is significantly altered, but it remains unclear how this affects lung immune cell development and susceptibility to RSV infection independent of lung immaturity. In this study, we have generated a biorepository of stool specimens from preterm and term infants during the first weeks of life. Metagenomic sequencing studies indicate significant alterations in the gut microbiome between these two groups, including a lack of fiber-fermenting Bacteroides species in preterm infants. Using these stool specimens, we find that the altered gut microbiome in premature infants induces IL-17/neutrophil-biased immune responses but weaker anti-viral interferon responses in the lung, both at steady state and following RSV infection. Mice colonized with preterm infant stool bacteria produced lower levels of neutralizing antibodies against RSV than mice colonized with term infant stool bacteria. Taken together, our findings suggest that the altered gut microbiome in premature infants dysregulates immune cell development in the lung and impairs the infant’s ability to develop long-term immunity against respiratory infections. These findings might be potentially leveraged in the development of gut bacteria-based interventions to improve the development of protective immunity against respiratory viral pathogens in preterm infants.
Supported by grants from NIH/NCATS (TL1-TR-002386) and the Biocodex Microbiota Foundation
Understanding the role of maternal antibodies on protection from enteric pathogens
Authors: Wang Bingjie , Torres Stephanie , Koch Meghan 
Published: January 2023

Abstract
A major function of the microbiota is to shield the host from infection with pathogens via a process called colonization resistance. High affinity, T cell-dependent antibodies, produced through interaction between CD4 T follicular helper (Tfh) cells and germinal center (GC) B cells, can modulate gut microbiota diversity and function. We discovered that mice lacking maternal antibodies display increased levels of Tfh and GC B cells in gut draining lymphoid tissues such at the mesenteric lymph nodes and Peyer’s patches. This response is seen in the context of colonization by microbes as germ-free mice lacking maternal antibodies do not show increased Tfh and GC B cell responses.
Given the importance of Tfh cells and TD antibody responses in regulating host-microbe interactions, we tested whether the elevation in Tfh and GC B cells seen in maternal antibody deficient pups alter susceptibility to colonization by the pathogen Salmonella typhimurium. We infected maternal antibody sufficient and deficient pups with the model pathogen Salmonella typhimurium via oral gavage. To block the Tfh and GC B cell response, we treated half of the pups from each group with anti-inducible T cell co-stimulator ligand (aICOSL) while the other half received an isotype control antibody. We found no difference in Salmonella typhimurium burden in the spleen, liver or cecum between maternal antibody sufficient or deficient pups treated aICOSL or isotype control antibody. Taken together, our data suggest that maternal antibodies and the subsequent rise in Tfh and GC B cells do not alter susceptibility to Salmonella typhimurium colonization later in life.
Supported by AAI Careers in Immunology Fellowship
Gamma delta T cells and keratinocytes modulate wound repair via Perforin-2
Authors: Strbo Natasa , Rivas Katelyn , Padula Laura , Fisher Eva , Marjanovic Jelena , Burgess Jamie Lee , Wikramanayake Tongyu , Pastar Irena , Tomic-Canic Marjana 
Published: January 2023

Abstract
Effective and precisely timed immune response is vital for efficient wound closure. Cutaneous gamma delta T (GDT) cells are poised to perform skin-specific roles in inflammation and repair while factors that shape gamma delta T cell activity are still not known. GDT cell deficient mice exhibit significantly delayed wound closure compared to WT mice. We found that GDT cells constitutively express novel antimicrobial protein Perforin-2 (P-2), and we postulated that P-2 contributes to GDT cell activation and recruitment in response to wounding.
We induced full thickness wounds on the dorsal skin of 2- or 10-month-old C57/BL6 WT and P-2 deficient (−/−) mice and assessed healing at day 3 and 6 post wounding. We analyzed re-epithelialization and keratinocyte activation using histomorphometry and Keratin-6 staining.
We found that in 10-month old mice, wound re-epithelialization was significantly delayed at day 6 in P-2 −/− mice compared to WT. This delay was accompanied by significantly decreased Keratin-6 expression at the wound edge. Immunofluorescence staining and flow cytometric analysis revealed significantly fewer GD T cells in the wound bed in aged P-2 −/− mice. The P2 −/− GD T cells also displayed lower expression of activation markers, including significantly lower Skint1 expression in the P-2−/− skin on day 6 post-wounding.
Our data demonstrate impaired keratinocyte activation and GD T cell infiltration in the absence of P-2 that is more pronounced in aged mice, indicating a potential role for this protein in modulating the inflammatory response upon wounding.
CD40 is Required For Protective T Cell Responses Against Cryptosporidium
Authors: O’Dea Keenan , Hunter Christopher A 
Published: January 2023

Abstract
The apicomplexan intestinal parasite Cryptosporidium infects intestinal epithelial cells (IECs) and is a leading cause of life-threatening disease in infants, toddlers, and immunocompromised patients. No vaccine against Cryptosporidium exists, and current treatments are ineffective in immunocompromised individuals. A prominent immunodeficiency associated with susceptibility to Cryptosporidium is hyper-IgM syndrome, which is caused by defects in CD40 signaling. In a murine model of Cryptosporidiosis, mice deficient in CD154 (CD40L) are defective in parasite control and clearance, and complementation of CD40L restores protection. Therefore, characterizing CD40-mediated immune responses against Cryptosporidium may enhance progress toward effective therapy in at-risk individuals. CD40 engagement on dendritic cells (DCs) promotes IL-12 production that induces differentiation and proliferation of T helper type 1 (Th1) cells and their production of interferon-γ (IFN-γ), which is known to be essential for control and clearance of Cryptosporidium infection. Our findings suggest a defect in T cell responses in CD40−/− mice infected with Cryptosporidium. CD40 deletion on Xcr1+ DCs also resulted in increased susceptibility to Cryptosporidium along with a defect in CD8+ T cell expansion. Therefore, we conclude that CD8+ T cell responses against Cryptosporidium require CD40 on cDC1s.
Supported by NIH grant U01AI163671
EAE suppression caused by Δ-8-THC treatment is due to downregulation of CNS infiltrating CD4+ T-cells, proinflammatory cytokines and apoptotic genes expression
Authors: Kakar Khadija , Nagarkatti Prakash , Nagarkatti Mitzi 
Published: January 2023

Abstract
Δ-8-THC a naturally occurring cannabinoid found in trace amounts in Cannabis plants. It possesses potent anti-inflammatory properties along with several other medical benefits. Δ-8-THC has been shown to induce immune system homeostasis particularly in individuals with autoimmune disorders by reducing the activity of T cells and B cells. In current study, we used the experimental model of MS to better understand how Δ-8-THC suppresses neuroinflammation in immune cell-mediated disease called experimental autoimmune encephalomyelitis (EAE). Δ-8-THC administration reduced significantly the clinical severity score with an increase in body weight by suppression of Th17 cells. In the CNS, there was decreased expression of pro-inflammatory cytokine IL-17, an increase in brain infiltrating CD4+ T cells and B cells, while anti-inflammatory phenotype such as FoxP3 was perturbed. Based on preliminary miRNA sequencing data and in silico examination of differential expression of miRNAs, we found that the decrease in neuroinflammation following treatment may be due to up-regulation of miRs, mmu-miR-129–3p, mmu-miR-129-5p, mmu-miR-125-5p and mmu-miR-193-3p as well as down-regulation of mmu-miR-21-3p, mmu-miR-142-5p and mmu-miR147-3p in immune cells in the CNS. Target genes were predicted by TagetScan, miRbase, miRDB. The target genes associated with upregulated miRs included Hrk, CHMP2b, Arid3a and Dcaf7 which are mostly involved in apoptosis, autophagy and migration, while genes associated with down-regulated miRNAs were Abi2, ZFPM2, NDUFA4 that are mostly involved in cell growth, proliferation and differentiation. In summary, Δ-8-THC treatment may offer novel strategies for treatment of neuroinflammation by targeting miRs.
Supported by NIH P01AT003961, P20GM103641, R01AI129788, R01 ES030144, R01 AI160896 and R01AI123947
Non-classical anti-inflammatory drugs (NCAIDs) ameliorates brain inflammation and improves memory in Alzheimer’s diseases mice model
Authors: Islam Md Jahirul , Koh Young-Jae , Chung Chu Young , Seong Seung-Yong 
Published: January 2023

Abstract
Alzheimer’s disease (AD) is the most common cause of dementia due to inflammatory neurodegeneration in the brain. Neuroinflammation caused by damage associated molecular pattern (DAMP: Aβ, ATP) leads to neuronal apoptosis. From our study HY209, a NCAIDs and a TGR5 agonist, inhibits neuroinflammation and neurodegeneration. In vitro, HY209 suppressed NLRP3-ASC oligomerization and production of mature IL-1β/IL-18 in microglia cells by Aβ ± ATP. HY209 inhibited Ca++ influx incurred by ATP or BzATP (P2X7 agonists). Ca++ influx of microglia from TGR5 KO was like that of P2X7 KO compared to wild type mice in response to BzATP. Suggesting that TGR5 is essential in P2X7-mediated Ca++ signaling and HY209 might play a role as an inverse agonist for TGR5 colocalized with P2X7. HY209 activates adenylate cyclase and cAMP. cAMP inhibits priming phase of inflammasomal activation, suppresses pro-inflammatory cytokine (TNF-α) production and oligomerization of NLRP3-ASC complex. Indicating that HY209 suppresses both priming and activation phase of NLRP3 inflammasome. In the 5x Familial Alzheimer’s disease (5xFAD) mice model, HY209 (1 mpk, i.p. or 30 mpk, p.o.) improves memory function, decreases Aβ plaque and neuronal apoptosis in the brain. Structure activity relationships were studied to screen out more potent HY209 derivatives (next generation NCAIDs) with increased bioavailability and higher BBB permeability. Considering efficacies of NSAIDs, PPARγ agonists, specific inhibitors (for TNF-α, ROS, RAGE, HMG-CoA, p38 MAPK, P2X7 and NLRP3) targeting limited number of proinflammatory pathways, NCAIDs could ameliorate broad spectrum of neuroinflammation that is crucial in preventing neurodegeneration and improving cognition and memory in AD.
Novel gene immunotherapy prevents Aquaporin-4 (AQP4) mediated neuroinflammation and demyelination in a mouse model of multiple sclerosis
Authors: Senior Kevin G , Cote Isabelle , Sagadevan Addelynn Sonia , Gaddie Cristina D , Keeler Geoffrey D , Min Daniel , Main Madisyn T , Rechdan Michaela N , Assakawa Stefanie , Hoffman Brad E 
Published: January 2023

Abstract
Neuromyelitis optica (NMO) is an auto-inflammatory demyelinating disease that typically affects optic nerves and spinal cord that is characterized by the presence of serum aquaporin-4 immunoglobulin G antibodies (AQP4-IgG). NMO accounts for &gt;45% of the demyelinating disease in Asians and warrants the development of a suitable therapy other than generalized immunosuppressants. It is thought that autoimmune activated AQP4-specific T cells disrupt the BBB and allow increased entry of AQP4-IgG and other immune effectors into tissues containing astrocytes expressing AQP4 in their membranes. Recently we have established an adeno-associated viral (AAV) gene immunotherapy that effectively prevents and reverses experimental autoimmune encephalomyelitis (EAE) via generation of suppressive antigen-specific regulatory T cells (Tregs). In this report, using a similar antigen-specific approach, we have demonstrated that AAV.AQP4 gene immunotherapy prevented the development of AQP4-mediated neuroinflammation and clinical neurological disability in almost 100% of C57BL/6J mice when AAV.AQP4 vector was administered to mice 2 weeks prior to immunization with an immunogenic epitope of AQP4. Moreover, in contrast to AAV.AQP4 treated mice which remained unremarkable, histological analysis of the spinal cord sections from untreated vehicle only mice showed multiple areas of significant focal inflammation within the spinal cord. Based on our clinical and pathological data, we’ve successfully demonstrated that our novel AAV.AQP4 gene immunotherapy can indeed suppress the induction of AQP4 mediated autoimmune disease. Further evaluation will determine if it can also treat preexisting disease.
MOG variant 45D does not properly activate high-affinity, MOG reactive effector T cells but allows for high-affinity FoxP3+ Treg function
Authors: Faust Michael A , Kolawole Elizabeth M , Evavold Brian D 
Published: January 2023

Abstract
Although it’s well appreciated that autoreactive T cells can drive autoimmune disease, how T cells precisely distinguish and respond to epitopes is unclear. For example, T cells can proliferate in response to multiple epitopes of myelin oligodendrocyte glycoprotein (MOG), but not all epitopes are encephalitogenic. Here, we investigate why T cells specific for MOG 35–55 are encephalitogenic. We compare the wildtype MOG epitope (wtMOG) to a single amino acid substitute, 45D, which was engineered to expresses the same T cell receptor (TCR) contact residues as wtMOG but is mutated such that its affinity for MHC II is decreased. We employed the micropipette adhesion frequency assay to demonstrate that a monoclonal, MOG-specific, high-affinity TCR binds to 45D with the same affinity as wtMOG. Despite conserved TCR contact residues, the MOG 45D variant is not encephalitogenic and fails to prime high-affinity tetramer-positive TCR clones. We also extended our polyclonal analysis to FoxP3+ regulatory T cells (Tregs) and found that, compared to wtMOG, 45D priming increases the frequency of MOG-specific Tregs. We further show that these Tregs are functional and suppress the proliferation of MOG-specific T cells. Our work begins to dissect the differential T cell receptor kinetic properties that allow for a response, or lack thereof, in Tregs and Teffs to myelin peptides.
Supported by NIH R01 NS071518-09
Targeting proteolytic cleavage of Toll-Like receptors by alpha-1 antitrypsin inhibited dendritic cells activation and function
Authors: Elshikha Ahmed Samir , Abboud Georges , Morel Laurence , Song Sihong 
Published: January 2023

Abstract
Toll-like receptors (TLRs) on dendritic cells (DC) interact with self-antigens and play a critical role in systemic lupus erythematosus (SLE) pathogenesis. TLR3, TLR7/8, or TLR9 are endosomal receptors that require proteolytic processing in the endolysosome to initiate signaling in response to DNA, single-stranded RNA, and double-stranded RNA. Targeting this proteolytic processing may represent a novel strategy for inhibiting TLR mediated pathogenesis. Human alpha 1 antitrypsin (hAAT) is a protease inhibitor with anti-inflammatory and immunoregulatory properties. However, the effect of hAAT on TLRs is not clear. In this study we first tested the effect of hAAT on DCs. We showed that hAAT treatment inhibited TLR7/8 and TLR9 agonists induced DC expressions of CD80, CD86 and MHC-II and significantly reduced the productions of IL-12, IFN-α and CXCL-10. Mechanistically, hAAT lowered the expression of interferon signature genes (MX-I, Isg-15, IRF-7, Il-12p40 and TNF-α). Importantly, western blot analysis showed that hAAT treatment reduced the active form (cleaved) of TLR9 in DCs indicating a novel mechanism of hAAT function in the immune system. Our in vivo studies in mouse models also showed that hAAT attenuated TLR agonist-induced pathogenesis. These data demonstrated that hAAT inhibited TLR7/8 and TLR9 signaling pathways in DCs, which are critical for lupus development. These findings not only advanced the current knowledge of hAAT biology, but also implied an insight for clinical application of hAAT.