bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complement component C1q limits osteoarthritis pathology by regulating macrophage activation
Authors: Raghu Harini , Lingampalli Nithya , Wang Qian , Wong Heidi , Lepus Christin , Mao Rong , Robinson William H 
Published: January 2023

Abstract
Osteoarthritis (OA), the most common form of arthritis in the world, is characterized by articular cartilage breakdown in synovial joints. There is evidence of low-grade inflammatory responses in OA, but their contribution to OA pathogenesis is unclear. Studies have demonstrated that dysregulated complement activity is involved in OA pathogenesis. The complement component, C1q, is known to regulate inflammation via mechanisms involving apoptotic cell clearance and macrophage activation. Thus, we hypothesized that C1q is a key negative regulator of inflammatory mechanisms in OA. Using a combination of NanoString-based mRNA quantification and Luminex-based analyses for cytokine profiling, we found that differentiation of human monocyte-derived macrophages in C1q-depleted serum followed by stimulation with cartilage debris resulted in enhanced pro-inflammatory (e.g., IL1β) and reduced anti-inflammatory (e.g,. IL10) cytokine expression and secretion compared to cells grown in normal human serum. To definitively establish a regulatory role for C1q in OA, we used a well-established destabilization of the medial meniscus (DMM) model of knee OA in genetically-deficient mice. We found that knees of C1q-deficient mice subjected to DMM developed worse OA pathologies including exacerbated cartilage damage, osteophyte formation and synovitis relative to C1q-sufficient mice. Our data suggest that C1q deficiency exacerbates inflammation and cartilage damage through mechanisms involving dysregulated macrophage activation. Understanding the precise mechanisms underlying C1q-mediated regulation of inflammation may lead to the identification of novel targets for the treatment of inflammatory diseases including OA.
Integrin activation controls regulatory T cell identity and stability
Authors: Klann Jane Elizabeth , Kim Stephanie H , Remedios Kelly A , Metz Patrick J , Snider Adam K , Lopez Justine , Cantor Joseph M , Ablack Jai N , Mack Lauren A , Zheng Ye , Lu Li-Fan , Bui Jack D , Ginsberg Mark H , Petrich Brian G , Chang John T 
Published: January 2023

Abstract
Maintenance of the regulatory T (Treg) cell pool is essential for peripheral tolerance and prevention of autoimmunity. Integrins, heterodimeric transmembrane proteins consisting of α and β subunits that mediate cell-cell and cell-extracellular matrix interactions, have been shown to play an important role in facilitating cell contact-mediated suppression by Treg cells. Here we show that integrin activation plays an essential, previously unappreciated role in maintaining the stability of the Treg cell pool. Treg cell-specific loss of talin1, a β integrin-binding protein, or expression of talin1(L325R), a mutant that selectively abrogates integrin activation, resulted in dysregulation of Treg cell identity and lethal systemic autoimmunity. Moreover, the absence of sustained interactions between the integrin LFA-1 on Treg cells and its ligand ICAM-1 on dendritic cells reduced the expression of Foxp3 and caused Treg cells to adopt an effector CD4+ T cell-like phenotype. Taken together, these results reveal a critical role for tonic, integrin-mediated signals in controlling peripheral tolerance by virtue of maintaining Treg cell identity and stability.
Factor VIII-specific CAR regulatory T cells modulate murine anti-factor VIII immune responses
Authors: Fu Richard , Lyle Meghan J. , Wang Xuefeng , Miao Carol H. 
Published: January 2023

Abstract
The immune response to factor VIII protein (FVIII; F8 in constructs) limits the effectiveness of treatments for hemophilia A (HemA) patients. Previously we demonstrated that regulatory T cells (Tregs) play a pivotal role in modulating anti-FVIII immune responses. For application of adoptive Treg therapy, we successfully expanded highly suppressive murine polyclonal Tregs antigen specifically in vitro. However, the FVIII-specific Tregs in the polyclonal population are still in very small numbers. Thus, we explored the strategy to generate FVIII-specific Tregs using the chimeric antigen receptor (CAR) approach. Lentiviral vector (LV) incorporating a high-binding anti-FVIII scFv linked to the CAR signaling domains and fused with a Foxp3 cDNA (F8CAR-Foxp3-LV) was prepared and used to transduce murine CD4+T cells. Flow cytometry analysis confirmed extracellular scFv and intracellular Foxp3 expression in transduced cells (F8CAR-Tregs). In vitro FVIII-specific suppressive assay showed that transduced cells had significantly higher suppressive activity than untransduced cells towards murine effector T cells. In addition, 1×106 transduced cells and untransduced cells were adoptively transferred into HemA mice and the treated mice were subsequently challenged with FVIII plasmid injected hydrodynamically. The anti-FVIII antibody titers are evaluated overtime. It is expected that F8CAR-Foxp3-LV transduced cells will prevent or decrease the production of anti-FVIII antibodies in HemA mice. We anticipate that compared with nonspecific or polyclonally expanded Tregs, FVIII-specific CAR Tregs will exert superior suppressive activity towards anti-FVIII immune responses without triggering systemic immune suppression.
Identify the differential response of Kupffer cell subsets during liver inflammation
Authors: Soysa Dilini Radika , Crispe Ian N 
Published: January 2023

Abstract
Kupffer cells (KC) are the resident macrophages that reside within the lumen of the liver sinusoid. Based on the origin there are two different sub sets of liver kupffer cells. The long-lived, radio-resistant subset also known as the sessile KC, derives from the progenitor cells generated during development in the yolk sac and maintains through self-renewal. The short-lived, radio-sensitive subset originates from hematopoietic stem cells. KCs play a major role in liver homeostasis, hepatic injury and induction of fibro-genesis as well as resolution of inflammation and fibrosis. Determination of the exact role of those ontogenetically different KC subpopulations in those critical liver functions is eluded by the inability to distinguish between the two subsets. Sessile KCs cannot be isolated and hence need an in situ method to study their gene expression. We propose to use the Ribo tag approach combined with Cre recombinase driven by a macrophage specific promoter (Emr1) to isolate actively translating polyribosomes using a ribo immunoprecipitation technique. The isolated KC subset-specific RNA will be used to analyze the transcriptome during both steady state conditions and liver inflammation.
Epithelial and bone marrow derived sources of Cd1d contribute to wound repair
Authors: Borkowski Andrew William , Havran Wendy L 
Published: January 2023

Abstract
Wound healing is a multifaceted process that depends on both epithelial and bone marrow derived cells to promote proper healing. Recent publications have shown that a subset of T cells in the skin are activated by certain lipids bound to CD1 molecules. Cd1d, the isoform of CD1 expressed in mice, is an MHC-like molecule that binds lipid antigens and is expressed by Langerhans cells (LCs), macrophages, B cells, and wounded keratinocytes. As our lab has previously shown that T cell activation in the skin promotes wound healing, we hypothesize that Cd1d is an important component of normal wound healing. To investigate this hypothesis, we administered full thickness wounds to the dorsal skin of WT and Cd1d−/− mice and analyzed wound closure. Cd1d−/− mice had a significant delay in wound healing between days 1 and 5 compared to WT controls. Analysis of ex vivo wound healing failed to show any difference in wound closure rates between WT and Cd1d−/− skin. This suggested that an infiltrating cell type is at least partially responsible for the observed difference in in vivo wound healing. Transfer of WT bone marrow cells into lethally irradiated Cd1d−/− mice did not rescue the wound healing defect observed in Cd1d−/− mice. Interestingly, transfer of Cd1d−/− bone marrow into WT mice caused a delay in wound healing. Analysis of wounded skin demonstrated that significantly fewer macrophages and LCs were present in Cd1d−/− epidermis. We conclude that the Cd1d-mediated wound healing defect is dependent on both resident LCs and infiltrating macrophages, and continue to investigate how Cd1d expressed by LCs promotes wound repair as studies have shown that LCs have an immunosuppressive effect in models of contact hypersensitivity and UVB-induced inflammation.
Ceramide mediates FasL-induced caspase 8 activation in colon carcinoma cells to enhance FasL-induced cytotoxicity by tumor-specific cytotoxic T lymphocytes
Authors: Coe Genevieve , Redd Priscilla , Paschall Amy V , Lu Chunwan , Albers Thomas , Lebedyeva Iryna , Liu Kebin 
Published: January 2023

Abstract
Cytotoxic T Lymphocytes (CTLs) are the major effectors of the host cancer immune surveillance. FasL-induced cytotoxicity is one of the two effector mechanisms that CTLs use to kill tumor cells. Fas is the physiological ligand of FasL and its expression and function is often deregulated in cancer cells. Ceramide is a sphingolipid metabolite that mediates Fas function. We aimed at testing the hypothesis that ceramide analogs are effective in modulating Fas function to sensitize colon carcinoma cells to FasL-induced apoptosis by tumor-specific CTLs. We show that Fas is expressed in human colon carcinoma cells. However, human colon carcinoma cells are not sensitive to FasL-induced apoptosis. Based on structures of existing ceramide analogs and ceramidase inhibitors, we used rationale design and synthesized twenty ceramide analogs as Fas function modulators. Six of these twenty ceramide analogs, IG4, IG7, IG8, IG14, IG17 and IG19, exhibit potent activity in sensitization of human colon carcinoma cells to FasL-induced apoptosis. At the molecular level, we observed that these six ceramide analogs dramatically increased FasL-induced activation of caspase 8, an essential initiator caspase of the Fas receptor-death-inducing signaling complex. Finally, a sublethal dose of ceramide analog significantly increased CTL-mediated and FasL-induced apoptosis of colon carcinoma cells. We have therefore developed six novel ceramide analogs that act at sublethal doses to enhance the efficacy of tumor-specific CTLs and hold great promise for further development as adjunct agents in CTL-based colon cancer immunotherapy.
A dynamic (epi)genomic landscape of CD8+ T cell differentiation drives cell-fate decisions
Authors: Amezquita Robert A , Gray Simon M , Guan Tianxia , Kaech Susan M , Kleinstein Steven 
Published: January 2023

Abstract
Long-lived memory CD8+ cytotoxic T lymphocytes (CTLs) are a critical component of long-term protective immunity against intracellular pathogens following infection or vaccination. During many acute viral infections, memory CD8 T cells arise from a heterogeneous pool of CTLs that contains terminal effector (TE) cells, which are highly-functional terminally differentiated CTLs that subsequently undergo programmed contraction, and memory precursor (MP) cells, which are less differentiated effector cells that have the greatest potential to persist and seed the memory T cell pool. How these effector CTLs adopt these distinct cell fates is an important question. Several key transcription factors (TFs) have been discovered that regulate the development of these two effector CTL subsets and promote the acquisition of their unique gene signatures, but it is unclear how the epigenome contributes to the development of terminally differentiated TE and mulitpotent MP cells. To understand this question, we are profiling RNA expression, histone modifications, and DNA accessibility to dissect the (epi)genomic network throughout the early CTL response to characterize the genetic networks controlling TE and MP cell differentiation during LCMV infection. Specifically, we are focusing on how changes in enhancer utilization and chromatin remodeling are regulated by key TFs, such as T-bet and ZEB2, in controlling the expression of target genes that regulate effector cell fates. This work will provide greater insight into how T cell memory forms after infection and vaccination, which could inform future T cell based vaccine strategies to improve immunity against foreign pathogens.
High School students conduct research on the neonatal immune response as part of the Students and Teachers As Research Scientists (STARS) program
Authors: Shornick Laurie P , Mares Kenneth R 
Published: January 2023

Abstract
The Students and Teachers As Research Scientists (STARS) program offers academically-talented high school students in the Saint Louis metropolitan area an opportunity to do research in a variety of scientific fields. Fourteen students have been mentored in my immunology laboratory during the last 9 summers as a part of the STARS program. Students take on small-scale, hypothesis-driven independent projects related to the neonatal immune response of respiratory viral infection using a mouse model. The high school students take basic safety training, blood borne pathogen training and biohazard animal training within the first few days of the program. Each student learns the basic mouse model and then specific techniques (immunostaining, western blot analysis, qPCR and flow cytometry) needed to test to their hypothesis. Students learn how to keep laboratory notebooks, how to find and read primary journal articles, and basic laboratory skills. While the main goal of the program is to teach the scientific process, other structured activities include lectures by nationally-known scientists, information concerning the higher education admissions process, and social activities. The program culminates with a written research paper and a short powerpoint presentation. The papers are written in the style of a peer-reviewed journal article in the field of immunology; each student receives assistance in writing from the primary mentor and from a STARS advisor. Since its inception in 1987, the STARS program has sent on more than 2,000 students with research experience to top universities.
An Immunology Course-Based Research Experience for Undergraduate Students that Introduces Computational and Modeling Skills
Authors: Kurt Robert A , Liew Chun Wai 
Published: January 2023

Abstract
Previously, we developed a computational modeling lab for undergraduate immunology students that introduced them to the SIR model and the Vensim modeling program. In short, students modeled an epidemic of strep throat and were required to model the Susceptible (S), Infected (I) and Recovered (R) in order to find the best approach to decreasing the length of the epidemic and the number of people infected. While this lab experience was valuable in teaching some basic immunology and modeling skills, the short time frame for the lab provided limited exposure to the importance and potential of modeling skills in immunology. Here we developed a semester-long course-based research experience (CRE) where students develop their own hypothesis, design the experiments, conduct the studies, and analyze their findings. Moreover, in addition to the wet lab component that exposes students to immunology techniques such as flow cytometry, qRT-PCR, cell separation and tissue culture, the students model a signaling pathway providing them with experience in computational modeling. We developed a software package that generates a computational model in Netlogo from the specifications provided by the students. The computational approach allows students to model any type of cell signaling cascade providing a large number of possible hypotheses that can be tested. We piloted this approach with four first-year students with no immunology or modeling/programming experience and the students successfully generated and tested their own hypotheses, and using Netlogo they modeled several different G Protein Coupled Receptor signaling cascades in CD4 and CD8+ T cells. We are in the process of running this CRE with students enrolled in a 200 level immunology class.
Kinesthetic Learning Modalities’ Approach in Understanding Concepts of Hypersensitivities Immunological Reactions.
Authors: Lana Valentina , Royan Ayla , Fazal Nadeem 
Published: January 2023

Abstract
It is now generally accepted that there are four learning modalities. Auditory learners learn best by listening so lecturing would be the way they would prefer to learn. Visual learners are those who prefer the printed word. They would learn best by reading or responding to the use of an overhead projector type of teaching. Tactile learners learn best by manipulating objects so they would prefer laboratory exercises. Kinesthetic (also known as whole body learners) prefer to learn through physical activities. This is the group of learners who would benefit most by this type of role-playing workshop. There are three basic modalities to process information to memory: visual (learning by seeing), auditory (learning by hearing), and kinesthetic (learning by doing). We tested role-playing modality at College of Pharmacy Chicago State University. This was done during spring semester where pharmacy year 1 students were taking Immunology as a didactic course. The students were divided into different small learning groups of 7–10 students in a class of 90 students and were made to role-play different types of hypersensitivity reactions. The role-playing acts were acted up in front of the whole class and also recorded. Asking Likert-type ordinary scale data analysis questions assessed the effectiveness of this modality and student learning. A statistically significant number of students found this immunology role-playing exercise as a fun and very beneficial activity. Students strongly agreed that this group-base role-playing approach was very powerful in conceptual understanding of hypersensitivity reactions, which is a clinically important and significant immunology topic.
Mechanisms of Non-canonical Inflammasome Activation by Rickettsia
Authors: Smalley Claire A , Bechelli Jeremy , Walker David , Fang Rong 
Published: January 2023

Abstract
Rickettsiae are Gram-negative, obligately intracellular bacteria that infect macrophages, however, the molecular mechanisms involved in the interactions of rickettsiae with macrophages remain poorly understood. We have found that R. australis activates the inflammasome in mouse primary macrophages as evidenced by caspase-1/11-dependent secretion of IL-1β as well as the cleavage of caspase-1 in both cell lysates and supernatant. In the present study, we show the cleavage of caspase-11 and the induction of pyroptosis in mouse macrophages upon infection with R. australis. Furthermore, inhibitors of caspase-4 significantly reduced the levels of IL-1β secreted by infected human macrophages. Our results suggest that rickettsiae also activate caspase-11/4-dependent noncanonical inflammasome in macrophages. We are currently investigating the role of cytosolic rickettsial lipopolysaccharide (LPS) in activating noncanonical inflammasome in mouse and human macrophages and the molecular mechanisms involved. Considering the distinct features of rickettsial LPS from other obligately intracellular Gram-negative bacteria, our studies will not only provide novel activating mechanisms of noncanonical inflammasome by employing rickettsiae as an infection model, but also help us to better understand the immune pathogenesis of fatal rickettsioses.
Microbiota regulated IL-25 protects from Clostridium difficile infection via eosinophils
Authors: Buonomo Erica L , Cowardin Carrie , Wilson Madeline , Saleh Mahmoud , Petri William 
Published: January 2023

Abstract
Clostridium difficile infection (CDI) occurs when the microbiota has been disrupted, stressing the beneficial role of commensal bacteria. The ability of the microbiota to contribute to protection has historically been linked to the induction of host factors such as bile acids and out competing the pathogen for nutrients and space. The influence of the microbiota to modulate the host immune response to dictate CDI outcome remains unexplored. Here, we show that IL-25, a cytokine regulated by the microbiota, is suppressed in the intestine during CDI in humans and mice. Administration of IL-25 protected mice from CDI-associated mortality and enhanced the integrity of the epithelial tissue in spite of equivalent quantities of C. difficile bacteria and toxin in the gut. Surprisingly, we identified eosinophils, a cell previously unexamined during CDI, as the cellular mechanism by which IL-25 protects. Using two distinct models, IL-25 was unable to reduce mortality or prevent gut barrier disruption in the absence of eosinophils. Thus, our study identifies IL-25 as the first immune mediator that is both regulated by the microbiota and enhances survival during CDI. This work provides a novel mechanism by which induction of innate immune responses, specifically eosinophils, can reduce the severity of CDI by protecting host tissue.
Proteasome degradative activity regulates CD8+ T lymphocyte metabolism and fate specification
Authors: Widjaja Christella E , Metz Patrick J , de Bruin Gerjan , Leestemaker Yves , Savas Jeffrey N , Phan Anthony T , Goldrath Ananda W , Yates John R , Florea Bogdan I , Overkleeft Hermen S , Ovaa Huib , Chang John T 
Published: January 2023

Abstract
During an immune response to microbial infection, CD8+ T lymphocytes can undergo asymmetric division, giving rise to daughter cells that exhibit distinct tendencies to adopt the terminal effector and memory fates. Here we show that ‘pre-effector’ and ‘pre-memory’ cells arising from the first CD8+ T cell division in vivo exhibit low and high rates of proteasome degradative activity, respectively. Pharmacologic inhibition of proteasome activity in activated CD8+ T cells resulted in increased inflammatory cytokine production and effector cell-associated molecule expression in vitro, as well as a loss of survival capacity and an impaired recall response to secondary infection in vivo. By contrast, increasing proteasome activity using a novel small molecule proteasome activator resulted in augmented memory cell-associated characteristics in vitro and an increased proportion of central memory cells with enhanced recall capabilities in vivo. Transcriptomic and proteomic analyses revealed that modulating proteasome activity in activated CD8+ T cells affected processes associated with cellular metabolism. These proteasome-induced metabolic consequences were mediated, in part, through asymmetric segregation of Myc, a transcription factor that has been shown to control glycolysis and proliferation, during cell division. Taken together, these results suggest proteasome degradative activity as a key regulator of CD8+ T lymphocyte fate specification by virtue of effects on cellular metabolism.