bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced cytotoxic CD8+ T cell (CTL) antigen recognition by LCK activation
Authors: Zheng Yating , Piper Taylor L , Courtney Adam H 
Published: January 2023

Abstract
The anti-tumor response of cytotoxic T cells requires detection of tumor-derived antigenic peptide-MHC complex (pMHC) by the T cell antigen receptor (TCR). Strategies that boost TCR signaling caused by weak pMHC could augment the recognition of poorly immunogenic tumors by T cells. Because LCK kinase phosphorylates the TCR complex and the recruited ZAP-70 kinase, increased LCK activity has been shown to increase TCR signaling in naïve T cells. Our previous study demonstrated that a small molecule inhibitor of CSK kinase, a negative regulator of LCK, increased LCK kinase activity and sensitized naïve T cells such that they became activated by weak antigens ex vivo. Our goal was to determine whether CD8+ cytotoxic T cells (CTL) could also be sensitized to detect weak antigens, and evaluate whether their capacity to recognize and kill cancer cells could be augmented. Because the Nur77-GFP reporter system responds to TCR-mediated signaling, we used it to determine that LCK activation sensitized OT-1 TCR transgenic CTLs to detect weak (low affinity) antigens displayed by splenocytes. We also observed increased phosphorylation of ZAP-70 and other signaling mediators upon TCR stimulation. We will next evaluate whether CTL-mediated effector functions can be enhanced by monitoring killing of MC38 cancer cells that display a weak antigen. Our findings will inform whether LCK kinase can be targeted to improve the recognition of cancer by T cells.
Tumor suppressor p53 controls thymic NKT17 cell development
Authors: Celli Sofia , Watanabe Masashi , Hodes Richard J 
Published: January 2023

Abstract
Natural killer T (NKT) cells are a lineage of innate-like lymphocytes that develop in the thymus, where they acquire effector phenotypes and differentiate into subsets, NKT1, NKT2, or NKT17. NKT2 cells express the highest PLZF levels; NKT1s depend on IL-15 signaling and express T-bet; and NKT17s depend on TGFβ and express RORγt. Although several factors distinguishing these subsets have been identified, more remains to be elucidated; in exploring such factors, we found that the tumor suppressor p53 plays a role in selectively regulating thymic NKT17s. In mice with T cell-specific p53-deficiency, thymic NKT17s are expanded up to tenfold. Among thymocyte populations analyzed, wildtype thymic NKT17s express the highest levels of p53, and upregulate the highest levels of p53 in response to irradiation. We examined γH2AX as a marker of DNA double-strand breaks, and found that the p53-deficient NKT17 subset had the highest γH2AX expression among all analyzed thymocyte populations. These results indicated that NKT17s have selectively greater genomic instability than other thymocyte populations and suggest a role for p53 in maintaining the expansion of the thymic NKT17s, potentially in response to genomic instability in this population. We are currently investigating the functional status of NKT17 cells in p53-deficient mice, as well as seeking to assess how this significantly increased “type 17” population impacts the thymic niche.
Apolipoprotein E enhance survival of effector memory regulatory T lymphocytes by regulating caspase-dependent apoptosis and lipid metabolism.
Authors: Atehortua Laura Melissa , Street Scott , Davidson W Sean , D’Alessandro Angelo , Chougnet Claire 
Published: January 2023

Abstract
Mechanisms underlying the pleiotropic anti-inflammatory effect of HDL remain incompletely understood. Regulatory T cells (Tregs) are essential for maintaining immune homeostasis in cardiovascular diseases (CVD) and metabolic disorders. We recently show Tregs, particularly effector memory Tregs (emTregs), bind/internalize HDL, which promotes their survival by limiting caspase-dependent apoptosis. As HDL contain a complex mix of proteins and lipids, we investigated which components of HDL mediate this process and found HDL proteins were the most critical. Using reconstituted HDL mimic vesicles containing recombinant HDL proteins and POPC, we found that APOE, but none of the APOA proteins, significantly decreased caspase expression in emTregs similarly to total HDL. Neither APOE nor HDL had any effect on naïve Tregs. APOE-depleted HDL did not rescue emTregs, confirming the critical role of APOE. Because Tregs have distinct metabolic requirements, we next investigated the effect of HDL, APOE3-POPC and APOE-depleted HDL on lipid metabolism in emTregs. APOE3-POPC and HDL significantly increased the concentration of long chain (14:0 20:0) and polyunsaturated fatty acids (FA, 18:3 22:6) in emTregs. Our data also suggested the involvement of de novo FA synthesis, as APOE3-POPC and HDL increased the concentration of palmitate (16:0), the earlier precursor of this pathway. Further, treatment of Tregs with the fatty acid synthase inhibitor C75 abolished HDL survival effect. Our results show that HDL, specifically APOE, promote emTregs survival by regulating de novo FA synthesis and caspase-dependent apoptosis. HDL-APOE levels seem to be dysregulated in CVD and obesity, suggesting this mechanism may contribute to HDL protective role
Th1 and Th17 cells are critical for limiting the severity of Staphylococcus aureus craniotomy infection
Authors: Kak Gunjan , Horn Christopher M , Heim Cortney E , Kielian Tammy 
Published: January 2023

Abstract
A craniotomy is performed to access the brain for tumor resection, localization and resection of epileptogenic foci, and aneurysm clipping. Despite prophylaxis, infectious complications after craniotomy range from 1–3%, with approximately half caused by Staphylococcus aureus (S. aureus), which forms a biofilm on the bone flap that is recalcitrant to antibiotics. Using our novel mouse model of S. aureus craniotomy infection, Th1 and Th17 infiltrates were found to preferentially home to the brain but not the subcutaneous galea; however, their functional importance is unknown. RAG1 knockout (KO) mice displayed significant increases in bacterial burden in the brain, galea, and bone flap at days 3, 7, and 14 post-infection, which was negated following the adoptive transfer of either in vitro skewed Th1 or Th17 cells. Interestingly, in vitro skewed Th17 cells acquired Th1 characteristics upon migrating into the brain in vivo as revealed by the production of Th1-associated cytokines such as IFN-γ and TNF-α with minimal IL-17A. We established that the window of T cell protection was during acute infection, since delaying Th1 or Th17 adoptive transfer until day 7 post-infection was no longer able to attenuate S. aureus burden in RAG1 KO mice compared to T cell transfers at day −1 or 3 after infection that were effective. In vitro studies established that both Th1 and Th17 cells augmented microglial, macrophage, and neutrophil S. aureus bactericidal activity and IL-12p70 and CXCL10 production. Collectively, these findings highlight the importance of an early adaptive immune response for bacterial containment during S. aureus craniotomy infection by promoting the antimicrobial activity of infiltrating leukocytes and resident microglia.
5-Hydroxyndole-3-acetic acid suppresses activation of glutamate oxaloacetate transaminase 1 linked to Th1/17 cell differentiation and ameliorates rheumatoid arthritis
Authors: Lee Jong Yeong , Lim Hyo Jung , Choi Jin kyeong 
Published: January 2023

Abstract
It has been established that cell proliferation and survival activities can be controlled according to metabolic resources in inflammation. However, it is not clear how T cell-mediated inflammatory immune responses in rheumatoid arthritis (RA) affect the activity and regulation of inflammatory cells by meeting biosynthesis and bioenergy requirements. This study evaluated the effect of serotonin-derived metabolite 5-Hydroxyndole-3-acetic acid (5-HIAA) on the increase in glutamate oxaloacetate transaminase 1 (GOT1) by the differentiation of Th1, Th17, or Th1/17 cells. The differentiation of Th1, Th17, or Th1/17 cells increased GOT1 and showed that GOT1 promotes the differentiation of Th1, Th17, or Th1/17 cells. Conversely, selective inhibition of GOT1 using 5-HIAA blocked the differentiation of Th1, Th17, or Th1/17 cells. Furthermore, inhibition of GOT1 using 5-HIAA ameliorated RA through up-regulation of regulatory T cells (Foxp3+ CD4+), suppression of pro-inflammatory cytokines, and inhibition of Th1/17 responses in mouse joints. Therefore, targeting glutamate-dependent metabolic pathways would be an effective therapeutic strategy for rheumatoid arthritis and a wide spectrum of autoimmune diseases.
Supported by 21st Century Medical Science Creative Human Resource Development Center
CXCR6 is required for tissue resident memory T cell formation across diverse peripheral non-lymphoid tissues
Authors: Heim Taylor , Steele Maria M , Mudianto Tenny , Lund Amanda W 
Published: January 2023

Abstract
CD8 T cell control of viral infections in peripheral tissues is largely dependent upon their spatial positioning. Clearance of pathogens requires direct contact between CD8 T cells and infected cells. Chemokine receptors play an essential role in this process by facilitating T cell entry into tissues, directing T cell positioning within tissues and by influencing egress out of tissues. Tissue resident memory T cells (TRM), which fail to egress after pathogen clearance and scan cells for signs of infection, are potent sources of immunity to secondary encounters with pathogens. Here we show that expression of the chemokine receptor CXCR6 is a conserved feature of TRM after viral infection in many non-lymphoid tissues. Using CXCR6KO TCR-tg T cells, we found that CXCR6 is necessary for proper formation of TRM in all non-lymphoid tissues examined. CXCR6 was necessary for early accumulation of effector T cells in several tissues such as the kidney and salivary gland but CXCR6 was dispensable for early accumulation in the skin. After vaccinia infection in the skin, CXCR6 expression is reinforced upon antigen re-encounter and promotes CD8 T cell accumulation in a migration-independent manner. Using single cell transcriptional analysis, we show that CXCR6KO TRM appear to exhibit a survival disadvantage and are outcompeted by wildtype T cells. This work reveals a critical requirement for generating TRM in diverse anatomical locations and may benefit strategies for vaccine design, anti-tumor immunity and reducing T-cell mediated autoimmunity.
Supported by R01CA238163 T32Al100853-10
The E3 Ubiquitin ligase Cul4b is required for CD8+ T cell-mediated antiviral immunity
Authors: Dar Asif Amin , Gordon Scott , Klinzing Kathleen , Dale Kim , Porter Nadia , Guha Ipsita , Behrens Edward M , Oliver Paula M 
Published: January 2023

Abstract
CD8+ T cells play crucial roles in cellular immune mechanisms that clear invading viruses and prevent reinfection. Virus specific CD8+ T cells expand approximately 10,000 fold, undergoing up to 20 cell divisions in the first week of infection. While this rapid expansion is needed to reduce viral loads, replication can lead to DNA damage and telomere shortening, resulting in growth arrest. T cells must be equipped with mechanisms that promptly promote DNA repair to protect cells from premature senescence and death. We recently determined that the E3 Ubiquitin ligase Cullin-4b (Cul4b) regulates genome integrity in CD4+ T cells by helping to resolve DNA damage. In keeping with this, aberrant expression of Cul4b and its ortholog Cul4a has been reported in many cancers. However, whether Cul4b is important in controlling CD8+ T cell numbers or viral clearance is not known. To address this, we infected control and Cul4bcKO mice with LCMV. Following infection, virus-specific CD8+ T cells lacking Cul4b failed to expand or acquire effector functions. As a consequence, Cul4bcKO mice were unable to clear LCMV. Furthermore, Cul4b-deficient CD8+ T cells were unable to differentiate into memory T cells. Using IP and tandem mass spectrometry, we found Cul4b associated with the chromatin remodeling BAF complex (SWI/SNF). Specifically, our data supports that Brg1, a component of SWI/SNF complex, is a client of the Cul4b ubiquitin ligase. Loss of Cul4b increased Brg1 binding to chromatin following CD8+ T cell activation, impacting gene expression and/or cell cycle arrest. Together, these data support that Cul4b limits the amount of Brg1 associated with chromatin, and allows the expansion and differentiation of CD8+ T cells thus promoting antiviral immunity.
Hepcidin deficiency increases susceptibility to disseminating candidiasis and renal failure
Authors: Scindia Yogesh , Kasem Sadat , Mansouri Samira , Desai Dhruv , Agarwal Annanya , Khodayari Nazli , Lionakis Michail , Mehrad Borna 
Published: January 2023

Abstract

Background
Candida albicans is the single most common human fungal pathogen, and invasive candida infections carry a mortality rate of about 25%. C. albicans possesses a range of iron acquisition mechanisms that contribute to its persistence, and virulence. Patients with fungal infection have substantially increased transferrin saturation and serum iron concentrations independent of underlying hematological disorder, suggesting that host iron handling is critical to the outcome of the infection. Using a murine model of systemic iron overload, we investigated whether C.albicans-induced pathology is influenced by iron availability.

Experiment
Iron overloaded hepcidin knockout (Hamp−/−) and wild type (WT) litter mates were infected with C. albicans SC5314 and outcomes of infection were evaluated after 3 days.

Results
Compared to WT mice, Hamp−/− mice displayed increased renal fungal burden, had more renal injury, inflammation and mortality. C. albicans was in yeast form in the kidneys of WT mice but had transformed into hyphae in the iron rich renal tubular segments of Hamp−/− mice. Despite the greater pathogen burden, kidneys of Hamp−/− mice had reduced numbers of neutrophils with increased expression of p21.

Conclusion
Our data identify systemic iron overload as a susceptibility factor to C. albicans induced renal failure. Hepcidin deficiency was associated with increased renal iron burden and transformation of yeast into hyphae, suggesting increased virulence. Increased p21 expression in neutrophils suggests impaired NETosis and may possibly explain increased fungal burden. Our data highlight importance of dysregulated iron metabolism in disseminating candidiasis.
Effective clearance of Chlamydia from the murine female reproductive requires IL-12p40, but not T-bet driven Th1 responses
Authors: Rixon Jordan , McSorley Stephen J 
Published: January 2023

Abstract
Protective immune responses to Chlamydia infection within the female reproductive tract (FRT) are incompletely understood. MHC class II-restricted IFN-γ+ Th1 responses are thought to be vital for bacterial clearance, but the Th1 master transcription factor T-bet had not yet been fully interrogated in primary infection. Here, we investigated T-bet and IFN-γ involvement in clearance of primary infection from the FRT. Surprisingly, IFN-γ producing CD4+ T cells from the FRT expressed low levels of T-bet, indicating that Chlamydia-specific CD4 T cells are not classical T-bet+ Th1 cells. Additionally, mice deficient in T-bet competently cleared infection with wild-type kinetics and showed significant skewing towards Th17 responses, indicating compensation pathways through alternate Th fates. On the other hand, IFN-γ-, and IFN-γR-deficient mice resolved much of FRT infection, but displayed systemic dissemination and 100% mortality. Thus, IFN-γ protects mice from fatal systemic disease, but classical T-bet+ Th1 cells are not required for primary clearance. In investigating alternative Th fates, RORγt mutant mice deficient for Th17 responses exhibited a short delay in clearance of FRT infection, demonstrating an unanticipated role for Th17 cells in Chlamydia clearance. However, mice deficient in the cytokine subunit IL-12p40 that promotes both Th1 and Th17 cells displayed a prolonged delay in FRT clearance despite CD4 T cells retaining the capacity for IFN-γ production. In summary, the type 1 cytokine IFN-γ plays an essential role in systemic control of Chlamydia, while clearance of primary infection within the FRT is largely dependent on an IL-12p40 driven mechanism that does not require T-bet or classical IFN-γ producing Th1 cells.
Supported by grants from NIH (RO1 A1103422, T32 AI060555)
Using Dictyostelium discoideum as a model for phagocytosis resistance in Escherichia coli
Authors: Riddick Terra L B , Perez-Vazquez Marta , Snyder Michelle 
Published: January 2023

Abstract
Escherichia coli related illnesses continue to be a problem around the world, especially in developing countries that lack clean water and proper sanitation. Dictyostelium discoideum is a soil dwelling amoeba that phagocytizes bacteria for nutrients. D. discoideum is a great model to study host pathogen interactions, and it has been used to identify virulence factors in bacteria. Our objective is to use Dictyostelium discoideum as a model to identify bacterial genes involved in resistance to phagocytosis. We hypothesize that D. discoideum can be used as a model organism to identify virulence genes associated with E. coli. The aims of this study are to identify E. coli genes predicted to grant resistance to D. discoideum grazing and phagocytosis and further characterize genes identified as potential virulence factors and observe the genes’ effects on D. discoideum grazing and phagocytic killing. Intestinal pathogenic, extraintestinal pathogenic, and laboratory E. coli strains were classified according to grazing phenotype. Previous comparative genomic analysis by large-scale BLAST score ratio (LS-BSR) identified genes prevalent amongst strains resistant to D. discoideum grazing. The gene gipA (growth in Peyer’s patches) was one gene found in various E. coli strains resistant to D. discoideum grazing. We are currently working to characterize the role of E. coli genes associated with resistance to D. discoideum grazing by manipulating E. coli strains for expression of these genes. We will observe the interactions between these strains and D. discoideum grazing and phagocytosis. This experiment will give insight into bacterial genes and virulence factors responsible for evading phagocytosis and the immune system.
This project was funded in part by federal funds from the National Institute of Allergy and Infectious Diseases, National Institute of Health, and Department of Health and Human Services under grant number U19 AI110820. Dr. M. Snyder was funded by an NIH NIGMS grant F33 GM116618, a Franklin Research Grant from the American Philosophical Society and a grant from the TU FDRC committee. This research was also supported by an NIH NIGMS R25 GM19970.
TNF-α signaling is required for fungal clearance during brain infection with Cryptococcus neoformans via promoting the recruitment of CD4+ T cells and inflammatory monocytes
Authors: Chen Yanli , Strickland Ashley , Shi Meiqing 
Published: January 2023

Abstract
Cryptococcus neoformans is a pathogenic fungus accounting for 180,000 deaths worldwide per year. The infection starts in the lung; however, the fungus can migrate to the brain, causing fatal meningoencephalitis primarily in immunocompromised individuals. TNF-α has been shown to mediate protective immunity in the lung during pulmonary infection with C. neoformans. However, the functions of TNF-α signaling during brain infection with C. neoformans remain poorly understood. Recent studies have shown that CD4+ T cells and inflammatory monocytes (IMs) mediate cryptococcal clearance in the brain at the cost of inducing immunopathology. Here, we study the role of TNF-α in the context of CD4+ T cells and IMs during brain infection with C. neoformans. We found that TNF-α levels in the brain were significantly increased during infection. The increase of TNF-α was associated with enhanced mRNA expression of various chemokines and accumulation of CD4+ T cells and IMs. Genetic ablation of TNF-α receptor (TNF-αR) in mice led to significantly higher brain fungal burdens and early mortality during C. neoformans infection. Infected TNF-αR−/− mice displayed significantly reduced recruitment of CD4+ T cells and IMs in the brain compared to infected wild-type mice. This was accompanied with reduced mRNA levels of KC, MIP-2, CCL2 and CCL7. Interestingly, deficiency of TNF-αR also resulted in a significant drop in the mRNA levels of ICAM-1 and VCAM-1 as well as the expression of CD11a and VLA4 in CD4+ T cells and IMs. Collectively, these results suggest TNF-α signaling is essential for the recruitment of CD4+ T cells and IMs, mediating fungal clearance during brain infection with C. neoformans.
Supported by AI131219 and AI131905
Dynamics of the Immune Response to MRSA Subcutaneous Skin Infection
Authors: Bose Jeffrey L , Gilchrist Aubrey K , Ridder Miranda J , Dai Hongyan , Pritchard Michele T , Markiewicz Mary A 
Published: January 2023

Abstract
Staphylococcus aureus is a leading cause of skin and soft tissue infections (SSTIs). While studies have examined how the immune system responds to S. aureus SSTIs, most are limited in scope to a single time point or outcome. To set a foundation for future studies, we conducted a S. aureus skin infection experiment using female C57BL/6J mice and USA300 S. aureus to examine the host-pathogen interface up to 15 days post-infection (d.p.i.). We measured lesion size, bacterial titers, local cytokine and chemokine levels, phenotyped responding leukocytes, and collected skin for histopathologic analysis and Gram staining. Lesions were largest at 1 d.p.i. with peak necrotic tissue area at 3 d.p.i. and were largely resolved by 15 d.p.i. IL-6, IL-4, CCL2, and IL-1β were highest during early infection, while IL-17A/F peaked 7 days post-infection. Neutrophils were abundant in the skin throughout the infection and were the primary immune cell present until 9 d.p.i. Histopathologic analysis demonstrated swift and extensive keratinocyte death and robust and persistent neutrophil infiltration. Gram staining revealed subdermal S. aureus colonization and, later, limited migration into upper skin layers. Most leukocyte subsets decreased within 8h after infection and returned during wound resolution coincident with declining bacterial titers. These (re)emerging leukocytes included CD4+ T cells, innate lymphoid cells, inflammatory monocytes, macrophages, and dendritic cells. Collectively, these data illustrate a dynamic immune response to S. aureus skin infections and provide a foundation for further studies characterizing the host-pathogen interface.
This research was supported by funding from the National Institute of Allergy and Infectious Diseases (NIAID) award R01AI121073 as well as pilot project grants from K-INBRE (P20GM130418) and University of Kansas Chemical Biology of Infectious Disease COBRE grant P20GM113117 to JLB. We acknowledge the Kansas Intellectual and Developmental Disabilities Research Center Histology Core which is sponsored in part by the NIH/NICHD (U54 HD090216) and the Flow Cytometry Core Laboratory, which is sponsored, in part, by the NIH/NIGMS COBRE grant P30 GM103326 and the NIH/NCI Cancer Center grant P30 CA168524.