bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of agonistic α-4-1BB antibody on natural killer cell function
Authors: Lee Seung-Hwan , Hahm Dahn 
Published: January 2023

Abstract
4-1BB is a member of the Tumor Necrosis Factor Receptor (TNFR) family. The TNFR family regulates a variety of functions including immune response, inflammation, and cell life/death. 4-1BB is a co-stimulatory molecule known best for its ability to increase survival, proliferation, anti-viral/tumor effects on T cells, and thus is currently undergoing clinical trials. However, the effects of 4-1BB stimulation in other cell types, such as natural killer cells (NK), are not well studied. Using a murine cytomegalovirus (MCMV) infected mouse model, we investigated the effects of agonistic α-4-1BB antibody stimulation on NK cell function and its impact on viral resistance. We hypothesized that 4-1BB stimulation will induce robust activation and proliferation of NK cells, resulting in an increased resistance against MCMV. To the contrary, treatment of the α-4-1BB antibody increased viral burden on 4 days post infection (p.i.) with highly increased NK cell proportion in spleens and livers. Further studies showed higher viral burden on day 1.5 p.i. with a reduced NK cell frequency. This suggests that an uncontrolled viral replication due to low NK numbers on early days of MCMV infection allows rapid expansion of residual NK cells by day 4. In vitro, treatment with α-4-1BB along with α-FasL antibodies rescued NK cell reduction, indicating that the NK cell loss is induced by Fas-mediated death signaling. Taken together, our data demonstrates that 4-1BB stimulation induces cell death signaling in the NK cell population, and results in an impaired anti-viral response. Further studies will provide a more complete view of the effects of 4-1BB stimulation as a cancer therapeutic, and also into the mechanism of NK cell life/death through TNFR signaling.
An Nlrc4 mutation associated with systemic hyperinflammation drives spontaneous non-hematopoietic IL-18 hyperproduction
Authors: Tariq Zeshan , McGavern Dorian B , O’Shea John J , Canna Scott 
Published: January 2023

Abstract
Macrophage activation syndrome (MAS) is a life-threatening sepsis-like hyperinflammatory state arising in certain infectious and rheumatic diseases. Previous genetic associations have implicated genes critical for perforin-mediated cytotoxicity. However, we recently identified that activating mutations in inflammasome component NLRC4 lead to MAS and early-onset enterocolitis. Patients with NLRC4-MAS also have chronically and extraordinarily elevated serum IL-18. Notably, disease-causing mutations in other inflammasomes do not cause MAS or chronic IL-18 elevation.
In vitro, IL-1b production by THP1 cells expressing various NLRC4 patient mutations correlated with disease severity and identified pathogenic clusters in the molecular structure. To further study the function of NLRC4, we created a mouse bearing the T337S point mutation. Like NLRC4-MAS patients, NLRC4-T337S mice demonstrate elevated serum IL-18 in the absence of systemic inflammation. However, macrophages from NLRC4-T337S mice did not demonstrate enhanced IL-1β or IL-18 production. Correspondingly, bone marrow chimeras demonstrated that IL-18 hyperproduction was derived from non-hematopoietic cells. NLRC4-T337S mice did not demonstrate more severe disease in response to repeated systemic stimulation through TLR9 or TLR4, nor upon LCMV infection, but developed colitis with IL-10 receptor blockade. These results suggest intestinal epithelia, which express both NLRC4 and proIL-18, may be a source of pathogenic IL-18 in this model. Future work will clarify the source(s) of excessive IL-18 and identify how chronic IL-18 effects on gut homeostasis and T and NK cell responses may promote systemic hyperinflammation.
Autophagy and Inflammasome activation triggered by LPS-negative Ehrlichia is dependent on both mTOR activation and MyD88 signaling
Authors: Vorhauer Jennie , Alaoui-El-Azher Mounia , Wells Alan , Ismail Nahed 
Published: January 2023

Abstract
Lipopolysaccharide (LPS) positive pathogens trigger autophagy and inflammasome activation. Autophagy is an innate anti-microbial host defense that maintains tissue homeostasis and is regulated by the nutrient-sensing mTORC1 complex. However it is unknown how the LPS-negative, Gram negative Ehrlichia elicits the same response. Monocytic Ehrlichia triggers Type I IFN-dependent NLRP3 inflammasome activation, which detrimentally effects host response to Ehrlichia. In this study, we examined the regulatory mechanisms of autophagy and inflammasome activation. With toll like receptor (TLR)-adaptor molecule MYD88 deficient mice, we reveal a crucial role for MYD88 in mediation of Ehrlichia-dependent inflammasome activation and hepatic inflammation. This role is demonstrated by decreased Caspase 1 and IL-1β levels in infected liver tissues, and decreased inflammatory cytokines (TNF-α and IL-6) when compared to wild type. Ehrlichia-induced inflammasome activation in wild type mice correlated with inhibition of autophagy. Ehrlichia-induced inhibition of autophagy in infected macrophages was dependent on TLR9, TLR2, and their adaptor MYD88. Inhibition was enhanced by IFN-β stimulation. We also demonstrate that mTORC1 autophagy inhibition acts downstream of MYD88. These data suggest that LPS-negative Ehrlichia inhibit autophagy and activate the inflammasome through mTORC1 activation and MYD88 signaling, contributing to Ehrlichia-induced inflammatory disregulation and liver injury.
Guanylate-binding proteins and other interferon-inducible proteins are essential for the activation of the inflammasomes
Authors: Man Si Ming , Karki Rajendra , Kanneganti Thirumala-Devi 
Published: January 2023

Abstract
Recognition of pathogens by the cell is paramount for the initiation of an appropriate immune response. A subset of pattern-recognition receptor family, including NLRP3, NLRC4 and AIM2, are cytosolic sensors which induce formation of the inflammasome, a multi-protein complex which drives the release of the pro-inflammatory cytokines IL-1β and IL-18. Here, we found that guanylate-binding proteins and other novel interferon-inducible GTPases were required for activation of the DNA-sensing AIM2 inflammasome during infection with Francisella novicida. These proteins were recruited to the cell membrane of the bacteria to mediate bacteriolysis, and thereby, liberating DNA for sensing by AIM2. However, engagement of the AIM2 inflammasome by mouse cytomegalovirus or transfected double-stranded DNA did not require interferon-inducible GTPases. Our results reveal a specific mechanistic link between cell-autonomous immunity and innate immune sensing pathways in response to bacterial infection.
Differential epigenetic regulation of encephalitogenic T cells in relapse-remitting and chronic-progressive mouse models of multiple sclerosis
Authors: Gandy K. Alexa Orr , Nagarkatti Mitzi , Nagarkatti Prakash S 
Published: January 2023

Abstract
In this study, we used a mouse model of multiple sclerosis (MS), experimental autoimmune encephalitis (EAE), to evaluate the role of microRNA (miRNA) in modulating T helper cell function in chronic-progressive (CP) versus relapse-remitting (RR) forms of the disease. We hypothesized that encephalitogenic T cell function in RR-EAE and CP-EAE is differentially regulated my microRNA. Microarray analysis of brain-derived CD4+ T cells revealed significant up-regulation of 106 and down-regulation of 42 miRNAs in the chronic-progressive (relative to relapse-remitting) form of disease. In silico analysis of the top up-regulated miRNAs and their target genes revealed significant overlap with signaling pathways imperative for the generation and maintenance of immune tolerance. Specifically miRNA-34, -148, -326 and -6691 were found to be up-regulated in the chronic-progressive form of disease. These miRNAs were predicted to target genes required for TGF-β signaling (ITGB8, ITGAV, NOTCH1, NOTCH2, SMAD2 & SMAD3), and T regulatory (T reg) function (CREB1, RUNX1 & FOXP3). Given the role for T regs in suppression of inflammation and the inverse correlation between T regs and inflammatory resolution, like that which occurs in MS remission, it is fitting that miRNAs governing this process are up-regulated in a chronic versus relapse-remitting form of EAE, promoting perpetuation of T-cell-mediated neuroinflammation. The current study demonstrates a role for miRNA in differentially shaping the function of T cells in models of RRMS and CPMS. Information regarding tolerance–promoting or –inhibiting miRNAs can be harnessed for the potential development of miRNA-directed therapies for diseases possessing important inflammatory components.
Development of a Therapeutic to Preserve Vaccine Memory Following Ionizing Radiation Exposure
Authors: Aryankalayil Joseph B , McFarland Hugh I , Rosenberg Amy S 
Published: January 2023

Abstract
We have demonstrated that in a mouse model of Listeria monocytogenes (LM) infection, revaccination within 3 days after exposure to sub-lethal ionizing radiation prevents the death of memory effector T lymphocytes and preserves vaccine memory. Although revaccination immediately after radiation exposure circumvents an increased risk of infection, it is impractical to revaccinate victims of radiation exposure to the innumerable agents to which they have developed immunity. Thus, we are seeking to develop a single therapeutic or a combination that mimic the effects of T cell activation via revaccination. We have selected our array of potential therapeutics based on their differential targets within T cell survival pathways. Broad spectrum therapeutics, stimulating numerous cell types such as Nicotine, Cimetidine, and Valproic Acid activate AKT and inhibit GSK3-beta to prevent subsequent apoptotic signals. Common gamma chain cytokines such as IL-15 and IL-21 are also candidates because of their ability to potently and specifically promote lymphocyte activation and survival. In addition, we have included Lovastatin to increase levels of P21 by proteasome inhibition. P21 may improve survival through temporary cycle arrest and enhanced DNA repair in activated T cells. We also utilized supplements to our therapeutics such as the FOXP3 inhibiting peptide- P60 and the checkpoint inhibitors anti-CTLA4 and anti-CD25 since regulatory T cells are a radio-resistant population that hinder the immune response to infection. We show, through comparisons of Listeria burden in spleens, that these candidates, either alone or in combination, are able to preserve vaccine memory following radiation exposure.
Defining the contribution of T cell exhaustion to failed immunity during TB
Authors: Jacques Miye K , Jayaraman Pushpa , Kuchroo Vijay K , Behar Samuel M 
Published: January 2023

Abstract
Tuberculosis is a pulmonary disease, caused by Mycobacterium tuberculosis (Mtb) infection, which affects approximately one third of the global population and is a major public health concern. Although T cells are essential in mediating protection against Mtb infection, they are often unable to sterilize infected tissues. One possible reason for an ineffective immune response is the onset of T cell exhaustion or dysfunction. T cell exhaustion is characterized by the progressive loss of T cell effector function accompanied by an increase in expression of inhibitory receptors. Here we show that during Mtb infection, T cells express the inhibitory molecules Tim3 and PD1, and T cells that express both Tim3 and PD1 have decreased IFNγ and TNF production. In addition, antibody blockade of Tim3 improves T cell function and decreases bacterial burden. These results indicate that T cells are functionally exhausted during chronic Mtb infection and that blockade of inhibitory receptors can re-invigorate T cell function and improve the outcome of infection. Based on a possible role for CEACAM1 in the T cell inhibitory signal mediated by Tim3, we are currently performing experiments to determine how CEACAM1 affects host defense against Mtb. Understanding the roles of inhibitory receptors, such as Tim3 and PD1, during Mtb infection is providing insight into why T cell immunity is insufficient to eradicate Mtb infection.
Random mutagenesis reveals novel host-pathogen interactions in host defense against attaching and effacing pathogens
Authors: Wan Fengyi 
Published: January 2023

Abstract
Understanding the host-pathogen interactions in the gut is crucial for prevention and treatment of attaching and effacing (A/E) pathogen infections. Inoculation of mouse A/E pathogen, Citrobacter rodentium, in interleukin-22 (IL-22) null mice dramatically increases mortality and morbidity rate, highlighting the crucial role of IL-22 in orchestrating antibacterial immunity against A/E pathogens. However, the host-pathogen interactions under IL-22 compromised conditions remain poorly understood. By inoculating a C. rodentium mutant library (generated by transposon random mutagenesis) in Il22−/− mice, we identified an attenuated strain (designated as Mut1), which completely abolishes wild-type C. rodentium infection-induced severe morbidity and mortality in Il22−/− mice. Compared to wild-type C. rodentium, the Mut1 mutant has no effects on the growth rate, attachment to colonic epithelial cells, and colonization. However, the Mut1 mutation dramatically impedes the inflammatory cytokine/chemokine expression and immune cell infiltration in the infected colon in Il22−/− mice. These elucidated novel host-pathogen interactions in Il22−/− mice could provide novel strategies to control A/E pathogen infections under IL-22-compromised conditions associated with systemic lupus erythematosus, chronic HIV infection, organ transplantation, and other diseases.
Blood transcriptional profiling of childhood diarrheal diseases identifies gene signatures of Shigella and rotavirus infections
Authors: DeBerg Hannah A , Zaidi Mussaret B , Khaenam Prasong , Gersuk Vivian , Linsley Peter S , Estrada-Garcia Teresa 
Published: January 2023

Abstract
Globally, diarrheal diseases are a leading cause of death in children under five and disproportionately affect children in developing countries. To identify changes in gene expression associated with diarrheal disease, we performed RNA sequencing on whole blood of 192 children less than 10 years of age with acute diarrhea at the Hospital General O’Horan, and 47 age-matched healthy controls from Yucatan, Mexico. We found strong transcriptional signatures associated with rotavirus and Shigella infections relative to other diarrheal infections. The other organisms in our study (Salmonella, E. coli, norovirus, and adenovirus) did not produce transcriptional changes that could be detected in whole blood. Weighted gene correlation network analysis was used to generate modules of genes with similar expression patterns that could be linked to biological functions. In the case of Shigella and rotavirus infections, differentially expressed genes with increased expression were grouped in modules associated with immune system functions. In Shigella infections, modules enriched for genes in adaptive immunity, especially in lymphocyte activation, showed decreased expression while modules enriched for innate immunity, including genes involved in complement activation, an inflammatory response and a response to bacteria, had increased expression. In rotavirus, but not other viral infections, the expression of a module containing genes involved in a type 1 interferon response was increased. Our data suggest that immune gene expression in peripheral blood may distinguish diarrheal diseases caused by Shigella and rotavirus infections from diseases caused by other organisms.
Exploring the antigen-specific memory CD4 T cell response to Chlamydia female reproductive tract reinfection
Authors: Li Lin-Xi 
Published: January 2023

Abstract
Chlamydia is now the most commonly reported infectious disease in the United States and more than 3 million new cases occur annually. Despite numerous attempts made by researchers to develop a vaccine strategy over the past two decades, to date, no Chlamydia vaccine is available. Among all immunization strategies tested in mouse models of Chlamydia infection, none generates protective immunity any better than a naturally resolved prior Chlamydia female reproductive tract (FRT) infection. Research in our laboratory aims to understand how immunological memory shaped by a natural episode of Chlamydia primary infection confer such potent protective immunity. Using Chlamydia-specific MHC Class II tetramers, our preliminary studies show that Chlamydia secondary infection induced massive clonal expansion of antigen-specific CD4 T cells in the FRT seven days post reinfection. In contrast, a robust recall response is not observed in local draining lymph nodes or spleen at any time point post challenge. Surprisingly, Chlamydia-specific memory CD4 T cells in the FRT do not express a common marker for tissue-resident T cells, CD69. We are now focusing our efforts on understanding the activation, effector function, and maintenance of Chlamydia-specific memory CD4 T cells in the FRT during Chlamydia reinfection.
Optimal replication and suppression of inflammation by virulent Francisella tularensis is achieved through reprogramming of host glycolysis.
Authors: Wyatt Elliott V , Diaz Karina , Griffin Amanda , Rasmussen Jed , Crane Deborah , Jones Bradley , Bosio Catharine M 
Published: January 2023

Abstract
Francisella tularensis (Ft) is a gram negative, facultative intracellular bacterium that is the causative agent of pneumonic tularemia. Inhalation of as a few as 15 organisms can result in lethal infection. The virulence of Ft is attributed to the bacterium’s ability to both evade and suppress the activation of macrophages. However, the mechanisms and bacterial components required for evasion and suppression by Ft are unclear. Activation of macrophages and induction of antimicrobial responses requires a metabolic shift from oxidative phosphorylation to aerobic glycolysis. Thus, we postulated that Ft manipulates host metabolism as a mechanism of virulence. We established that virulent Ft suppresses induction of aerobic glycolysis among infected macrophages. Moreover, utilizing purified capsule and defined capsule mutants, we elucidated a novel role for Ft capsule as a component contributing to this suppression. The requirement for inhibition of host cell glycolysis in Ft pathogenesis was confirmed via direct inhibition of glycolysis using 2-deoxyglucose. Addition of 2-DG to macrophages infected with capsule mutants partially restored the early intracellular survival and replication of these bacteria, and impaired the secretion of pro-inflammatory cytokines that is typical of infection with these mutants. Together, our data demonstrate that manipulation of host metabolism is an important component of Ft pathogenesis and uncovers a previously unappreciated function of bacterial capsule in the virulence of Ft.
Gpr43, dietary fiber and composition of gut microbiota in colonic inflammation and carcinogenesis
Authors: Singh Nagendra , Sivaprakasam Sathish 
Published: January 2023

Abstract
Being a primary driver of gut microbiota metabolism, diet has overwhelming affect on promoting or suppressing growth of specific members of gut microbiota. Abundance of certain gut mcirobiota is also shaped by host genetics. Numerous human and animals studies show that dietary fiber consistently increase only one group of gut bacteria, which are Bifidobacterium species (spp), the primary fermenters of dietary fiber. It is unknown whether genetic make up of host influences dietary fiber mediated promotion of Bifidobacterium spp in vivo and its impact on colonic inflammation and carcinogenesis. Gpr43 is a receptor for short chain fatty acids, acetate, propionate and butyrate. Our results demonstrate that dietary fiber mediated promotion of Bifidobacterium spp and suppression of Prevotellaceae is dependent on Gpr43. Similarly, dietary fiber mediated suppression of colonic inflammation and carcinogenesis is Gpr43-dependent. Dietary fiber mediated increase in Bifidobacterium spp is relevant to suppression of colonic inflammation and carcinogenesis because administration of Bifidobacterium spp decreased susceptibility of Gpr43−/− animal to colonic inflammation and carcinogenesis. Consistent with these findings, we found that Gpr43 is down regulated and number of Bififdobacterium is decreased whereas that of Prevotellaceae is increased in human colon cancers. These findings suggest that interplay between dietary fiber and Gpr43 play a key role in promoting healthy composition of gut microbiota leading to suppression of colonic inflammation and carcinogenesis.
Notch Signaling Negatively Regulates Pathogenic IL-17 Production from Th17 cells during γ-Herpesvirus Induced Pneumonitis and Pulmonary Fibrosis Following Bone Marrow Transplantation
Authors: Gurczynski Stephen J , Zhou Xiaofeng , Maillard Ivan , Moore Bethany B 
Published: January 2023

Abstract
The Notch signaling pathway is an important mediator of T-cell cytokine responses in a variety of immunological maladies such as GVHD, rheumatoid arthritis, and systemic lupus erythematosus. Using a genetically altered mouse model wherein CD4+ and CD8+ T-cells were ablated for all Notch signaling through expression of a dominant negative version of the Notch transcriptional regulator Mastermind Like Ligand (DNMAML) we have identified Notch as a regulator of cytokines during Murine Gamma Herpesvirus 68 (MHV-68) infection following bone marrow transplantation (BMT). Wild type syngeneic BMT mice infected with MHV-68 develop severe pneumonitis and pulmonary fibrosis by 21 dpi driven in part by a switch from TH1 to TH17 mediated immunity. Expression of the Notch ligands DLL1, DLL4, Jagged1, and Jagged2 were decreased in the lungs following BMT and CD4+ T-cells isolated from the lungs and spleens of infected WT BMT mice displayed defects in Notch signaling resulting in decreased expression of Notch target genes. T-cell Notch deficient DNMAML BMT mice developed increased fibrosis 21 dpi in comparison to wild type BMT mice, and displayed elevated levels of IL-17 and IL-6 in the lungs as well as an expansion of TH17 cells and a decrease in TH1 cells. Further, both in vitro culture of BMT lung leukocytes with recombinant DLL4 and adoptive transfer of WT CD11C+ APCs after BMT restored T-cell Notch signaling, decreasing production of IL-17 and rescuing fibrotic pathology. Thus, alterations in T-cell Notch signaling during γ-herpesvirus challenge following BMT correlated with increased expression of IL-17 from TH17 cells shifting the immunologic balance from a protective TH1 response towards a pathogenic TH17 response.