Medical Microbiology Commons^™

Differential Sensitivity Of Leukocyte Populations To Staphylococcus Aureus Biofilm, Nichole D. Brandquist, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a leading cause of prosthetic joint infection (PJI) typified by biofilm formation. Anti-inflammatory granulocytic myeloid-derived suppressor cells (G-MDSCs) represent the main leukocyte population in a mouse model of S. aureus PJI, followed by neutrophils (PMNs), and macrophages (Mφs), which is also seen during human PJI. Defining how each leukocyte population responds to S. aureus biofilm vs planktonic bacteria could have important implications for how S. aureus evades immune detection to facilitate biofilm persistence. This study compared the kinetics of leukocyte death and relationship to mitochondrial ROS (mtROS) production following exposure to planktonic S. aureus or biofilm. Mφs …

Mitochondrial Transfer To Granulocytic Myeloid-Derived Suppressor Cells Augments Immunosuppressive Activity, Prabhakar Arumugam, Cortney E. Heim, Rachel W. Fallet, Dhananjay Shinde, Vinai Chittezham Thomas, Rafael J. Argüello, Tammy Kielian

Journal Articles: Pathology and Microbiology

The anti-inflammatory properties of granulocytic myeloid-derived suppressor cells (G-MDSCs) promote Staphylococcus aureus (S. aureus) biofilm persistence. Evidence suggests that G-MDSC activity is shaped not only by S. aureus products but also by intrinsic metabolic programs. This study explores whether G-MDSC activity can be modulated by increasing mitochondrial abundance using a co-culture paradigm with macrophages as a mitochondrial donor. Macrophages transfer mitochondria directly to G-MDSCs via tunneling nanotubes, enhancing G-MDSC respiration, as reflected by increased basal, maximal, and spare respiratory capacity. Augmenting mitochondrial abundance in G-MDSCs enhances T cell-suppressive activity and reduces tumor necrosis factor (TNF) and interleukin 6 (IL-6) production. …

An Anti-Adhesive Compound Modulating The Production Of Staphylococcus Aureus Cell Wall-Anchored Proteins, Allison C. Leonard, Ruina Bao, Cindy Menjivar, Megan J. Myers, Telmo O. Paiva, Zhiyong Zheng, Kirsten A. Berry, Kenneth W. Bayles, Ronald S. Flannagan, Yves F. Dufrêne, Jeffrey L. Bose, David E. Heinrichs, Georgina Cox

Journal Articles: Pathology and Microbiology

As one of the leading global causes of death associated with antimicrobial resistance, Staphylococcus aureus frequently colonizes the human nasal cavity and adheres to keratinized skin, establishing reservoirs that drive subsequent infections and emphasize the need for new decolonization strategies. Using a high-throughput, whole-cell screening platform, here we identify geranylgeranoic acid (GGA), a naturally occurring polyunsaturated, branched-chain fatty acid, as having dual activity against methicillin-resistant S. aureus (MRSA). At elevated concentrations, GGA exhibits microbicidal effects, whereas at sub‑microbicidal doses, it effectively inhibits MRSA adhesion to keratin, fibronectin, fibrinogen, and immunoglobulins. GGA possesses anti-adhesive activity against a panel of multidrug-resistant S. …

A Lysosomal Surveillance Response To Stress Extends Healthspan, Terytty Yang Li, Arwen W Gao, Rendan Yang, Yu Sun, Yuxuan Lei, Xiaoxu Li, Lin Chen, Yasmine J Liu, Rachel N Arey, Kimberly Morales, Raya B Liu, Wenzheng Wang, Ang Zhou, Tong-Jin Zhao, Weisha Li, Amélia Lalou, Qi Wang, Tanes Lima, Riekelt H Houtkooper, Johan Auwerx

Faculty, Staff and Students Publications

Lysosomes are cytoplasmic organelles central for the degradation of macromolecules to maintain cellular homoeostasis and health. However, how lysosomal activity can be boosted to counteract ageing and ageing-related diseases remains elusive. Here we reveal that silencing specific vacuolar H+-ATPase subunits (for example, vha-6), which are essential for intestinal lumen acidification in Caenorhabditis elegans, extends lifespan by ~60%. This longevity phenotype can be explained by an adaptive transcriptional response typified by induction of a set of transcripts involved in lysosomal function and proteolysis, which we termed the lysosomal surveillance response (LySR). LySR activation is characterized by boosted lysosomal activity …

Inactivation Of The Fusobacterium Nucleatum Rnf Complex Reduces Fada-Mediated Amyloid Formation And Tumor Development, Timmie A Britton, Ju Huck Lee, Chungyu Chang, Aadil H Bhat, Yi-Wei Chen, Rusul Mohammed Ali, Chenggang Wu, Asis Das, Hung Ton-That

Faculty, Staff and Student Publications

The Gram-negative anaerobe Fusobacterium nucleatum is an oral oncobacterium that promotes colorectal cancer (CRC) development with the amyloid-forming cell surface adhesin FadA integral to CRC tumorigenesis. We describe here molecular genetic studies uncovering a novel mode of metabolic regulation of FadA-mediated tumor formation by a highly conserved respiratory enzyme known as the Rnf complex. First, we show that genetic disruption of Rnf, via rnfC deletion, significantly reduces the level of fadA transcript, accompanied by a near-complete abolishment of the precursor form of FadA (pFadA), reduced assembly of FadA at the mature cell pole, and severe defects in the osmotic stress-induced …

Nkapl Facilitates Transcription Pause-Release And Bridges Elongation To Initiation During Meiosis Exit, Zhenlong Kang, Chen Xu, Shuai Lu, Jie Gong, Ruoyu Yan, Gan Luo, Yuanyuan Wang, Qing He, Yifei Wu, Yitong Yan, Baomei Qian, Shenglin Han, Zhiwen Bu, Jinwen Zhang, Xian Xia, Liang Chen, Zhibin Hu, Mingyan Lin, Zheng Sun, Yayun Gu, Lan Ye

Faculty, Staff and Students Publications

Transcription elongation, especially RNA polymerase II (Pol II) pause-release, is less studied than transcription initiation in regulating gene expression during meiosis. It is also unclear how transcription elongation interplays with transcription initiation. Here, we show that depletion of NKAPL, a testis-specific protein distantly related to RNA splicing factors, causes male infertility in mice by blocking the meiotic exit and downregulating haploid genes. NKAPL binds to promoter-associated nascent transcripts and co-localizes with DNA-RNA hybrid R-loop structures at GAA-rich loci to enhance R-loop formation and facilitate Pol II pause-release. NKAPL depletion prolongs Pol II pauses and stalls the SOX30/HDAC3 transcription initiation complex …

Interferon-Gamma Receptor Signaling Regulates Innate Immunity During Staphylococcus Aureus Craniotomy Infection, Zachary Van Roy, Gunjan Kak, Rachel W. Fallet, Tammy Kielian

Journal Articles: Pathology and Microbiology

A craniotomy is a neurosurgical procedure performed to access the intracranial space. In 3-5% of cases, infections can develop, most caused by Staphylococcus aureus biofilm formation on the skull surface. Medical management of this infection is difficult, as biofilm properties confer immune and antimicrobial recalcitrance to the infection and necessitate additional surgical procedures. Furthermore, treatment failure rates can be appreciably high. These factors, compounded with rapidly expanding rates of antimicrobial resistance, highlight the need to develop alternative treatment strategies to target and reverse the immune dysfunction that occurs during biofilm infection. Our recent work has identified CD4+ Th1 and Th17 …

Cd4+ T Cell-Innate Immune Crosstalk Is Critical During Staphylococcus Aureus Craniotomy Infection, Gunjan Kak, Zachary A. Van Roy, Rachel W. Fallet, Lee E. Korshoj, Tammy Kielian

Journal Articles: Pathology and Microbiology

Access to the brain for treating neurological sequalae requires a craniotomy, which can be complicated by infection. Staphylococcus aureus accounts for half of craniotomy infections, increasing morbidity in a medically fragile patient population. T cells preferentially traffic to the brain during craniotomy infection; however, their functional importance is unknown. Using a mouse model of S. aureus craniotomy infection, CD4+ T cells were critical for bacterial containment, as treatment of WT animals with anti-CD4 exacerbated infection that was similar to phenotypes in Rag1-/- mice. Single-cell RNA-Seq (scRNA-Seq) revealed transcriptional heterogeneity in brain CD3+ infiltrates, with CD4+ cells most prominent that displayed …

Pgc-1Α Activation To Enhance Macrophage Immune Function In Mycobacterial Infections, Joel R. Frandsen, Zhihong Yuan, Brahmchetna Bedi, Zohra Prasla, Seoung-Ryoung Choi, Prabagaran Narayanasamy, Ruxana Sadikot

Journal Articles: Pathology and Microbiology

Nontuberculous Mycobacteria (NTM) are a heterogeneous group of environmental microorganisms with distinct human pathogenesis. Their incidence and prevalence are rising worldwide, due in part to elevated antimicrobial resistance which complicates treatment and potential successful outcomes. Although information exists on the clinical significance of NTMs, little is known about host immune response to infection. NTM infections alter macrophage mitochondrial capacity and decrease ATP production, efficient immune response, and bacterial clearance. Transcription factor peroxisome proliferator activated receptor (PPAR) γ coactivator-1α (PGC-1α) is a master regulator of mitochondrial biogenesis, influencing metabolism, mitochondrial pathways, and antioxidant response. Mitochondrial transcription factor A (TFAM) is a …

Extracellular Adherence Proteins Reduce Matrix Porosity And Enhance Staphylococcus Aureus Biofilm Survival During Prosthetic Joint Infection, Mohini Bhattacharya, Tyler D. Scherr, Jessica Lister, Tammy Kielian, Alexander R. Horswill

Journal Articles: Pathology and Microbiology

Biofilms are a cause of chronic, non-healing infections. Staphylococcus aureus is a proficient biofilm-forming pathogen commonly isolated from prosthetic joint infections that develop following primary arthroplasty. Extracellular adherence protein (Eap), previously characterized in planktonic or non-biofilm populations as being an adhesin and immune evasion factor, was recently identified in the exoproteome of S. aureus biofilms. This work demonstrates that Eap and its two functionally orphaned homologs EapH1 and EapH2 contribute to biofilm structure and prevent macrophage invasion and phagocytosis in these communities. Biofilms unable to express Eap proteins demonstrated increased porosity and reduced biomass. We describe the role of Eap …

Identification Of Potential Prophylactic Medical Countermeasures Against Acute Radiation Syndrome (Ars), Kia T. Liermann-Wooldrik, Arpita Chatterjee, Elizabeth A. Kosmacek, Molly Myers, Oluwaseun Adebisi, Louise Monga-Wells, Liu Mei, Michelle P. Takacs, Patrick H. Dussault, Daniel R. Draney, Robert Powers, James W. Checco, Chittibabu Guda, Tomáš Helikar, David B. Berkowitz, Kenneth W. Bayles, Alan H. Epstein, Lynnette Cary, Daryl J. Murry, Rebecca E. Oberley-Deegan

Journal Articles: Pathology and Microbiology

Acute radiation syndrome (ARS) occurs when hematopoietic or gastrointestinal cells are damaged by radiation exposure causing DNA damage to the bone marrow and gastrointestinal epithelial stem cell populations. In these highly proliferative cell types, DNA damage inhibits stem cell repopulation. In humans and animals, this inability to regenerate stem cells is lethal. Within this manuscript, several compounds, Amifostine, Captopril, Ciprofloxacin, PrC-210, 5-AED (5-androstene-3β,17β-diol), and 5-AET (5-androstene-3β,7β,17B-triol), are assessed for their ability to protect against ARS in an in vitro and/or in vivo setting. ARS was accomplished by irradiating mouse bone marrow cells or rat intestinal epithelial (IEC-6) cells in vitro …

The Dna Demethylase Tet1 Modifies The Impact Of Maternal Folic Acid Status On Embryonic Brain Development, Lehua Chen, Bernard K Van Der Veer, Qiuying Chen, Spyridon Champeris Tsaniras, Wannes Brangers, Harm H M Kwak, Rita Khoueiry, Yunping Lei, Robert Cabrera, Steven S Gross, Richard H Finnell, Kian Peng Koh

Faculty, Staff and Students Publications

Folic acid (FA) is well known to prevent neural tube defects (NTDs), but we do not know why many human NTD cases still remain refractory to FA supplementation. Here, we investigate how the DNA demethylase TET1 interacts with maternal FA status to regulate mouse embryonic brain development. We determined that cranial NTDs display higher penetrance in non-inbred than in inbred Tet1−/− embryos and are resistant to FA supplementation across strains. Maternal diets that are either too rich or deficient in FA are linked to an increased incidence of cranial deformities in wild type and Tet1+/− offspring and to …

Uba1 Inhibition Sensitizes Cancer Cells To Parp Inhibitors, Sharad Awasthi, Lacey E Dobrolecki, Christina Sallas, Xudong Zhang, Yang Li, Sima Khazaei, Sumanta Ghosh, Collene R Jeter, Jinsong Liu, Gordon B Mills, Shannon N Westin, Michael T Lewis, Weiyi Peng, Anil K Sood, Timothy A Yap, S Stephen Yi, Daniel J Mcgrail, Nidhi Sahni

Faculty, Staff and Students Publications

Therapeutic strategies targeting the DNA damage response, such as poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi), have revolutionized cancer treatment in tumors deficient in homologous recombination (HR). However, overcoming innate and acquired resistance to PARPi remains a significant challenge. Here, we employ a genome-wide CRISPR knockout screen and discover that the depletion of ubiquitin-activating enzyme E1 (UBA1) enhances sensitivity to PARPi in HR-proficient ovarian cancer cells. We show that silencing or pharmacological inhibition of UBA1 sensitizes multiple cell lines and organoid models to PARPi. Mechanistic studies uncover that UBA1 inhibition not only impedes HR repair to sensitize cells to PARP inhibition …

Development Of A Ripk1 Degrader To Enhance Antitumor Immunity, Xin Yu, Dong Lu, Xiaoli Qi, Rishi Ram Paudel, Hanfeng Lin, Bryan L Holloman, Feng Jin, Longyong Xu, Lang Ding, Weiyi Peng, Meng C Wang, Xi Chen, Jin Wang

Faculty, Staff and Students Publications

The scaffolding function of receptor interacting protein kinase 1 (RIPK1) confers intrinsic and extrinsic resistance to immune checkpoint blockades (ICBs) and emerges as a promising target for improving cancer immunotherapies. To address the challenge posed by a poorly defined binding pocket within the intermediate domain of RIPK1, here we harness proteolysis targeting chimera (PROTAC) technology to develop a RIPK1 degrader, LD4172. LD4172 exhibits potent and selective RIPK1 degradation both in vitro and in vivo. Degradation of RIPK1 by LD4172 triggers immunogenic cell death, enhances tumor-infiltrating lymphocyte responses, and sensitizes tumors to anti-PD1 therapy in female C57BL/6J mice. This work reports …

The Rise, Fall, And Resurgence Of Phage Therapy For Urinary Tract Infection, Jacob J Zulk, Kathryn A Patras, Anthony W Maresso

Faculty, Staff and Students Publications

In the face of rising antimicrobial resistance, bacteriophage therapy, also known as phage therapy, is seeing a resurgence as a potential treatment for bacterial infections including urinary tract infection (UTI). Primarily caused by uropathogenic Escherichia coli, the 400 million UTI cases annually are major global healthcare burdens and a primary cause of antibiotic prescriptions in the outpatient setting. Phage therapy has several potential advantages over antibiotics including the ability to disrupt bacterial biofilms and synergize with antimicrobial treatments with minimal side effects or impacts on the microbiota. Phage therapy for UTI treatment has shown generally favorable results in recent …

Nomenclature For Human And Animal Fungal Pathogens And Diseases: A Proposal For Standardized Terminology, Sybren De Hoog, Thomas J Walsh, Sarah A Ahmed, Ana Alastruey-Izquierdo, Maiken Cavling Arendrup, Andrew Borman, Sharon Chen, Anuradha Chowdhary, Robert C Colgrove, Oliver A Cornely, David W Denning, Philippe J Dufresne, Laura Filkins, Jean-Pierre Gangneux, Josepa Gené, Andreas H Groll, Jaques Guillot, Gerhard Haase, Catriona Halliday, David L Hawksworth, Roderick Hay, Martin Hoenigl, Vit Hubka, Tomasz Jagielski, Hazal Kandemir, Sarah E Kidd, Julianne V Kus, June Kwon-Chung, Shawn R Lockhart, Jacques F Meis, Leonel Mendoza, Wieland Meyer, M Hong Nguyen, Yinggai Song, Tania C Sorrell, J Benjamin Stielow, Rachel Vilela, Roxana G Vitale, Nancy L Wengenack, P Lewis White, Luis Ostrosky-Zeichner, Sean X Zhang

Faculty, Staff and Student Publications

Medically important pathogenic fungi invade vertebrate tissue and are considered primary when part of their nature life cycle is associated with an animal host and are usually able to infect immunocompetent hosts. Opportunistic fungal pathogens complete their life cycle in environmental habitats or occur as commensals within or on the vertebrate body, but under certain conditions can thrive upon infecting humans. The extent of host damage in opportunistic infections largely depends on the portal and modality of entry as well as on the host's immune and metabolic status. Diseases caused by primary pathogens and common opportunists, causing the top approximately …

Amniotic Fluid-Derived Stem Cells: Potential Factories Of Natural And Mimetic Strategies For Congenital Malformations, Cristiane S R Fonteles, Julia Enterria-Rosales, Ying Lin, John W Steele, Ramiro A Villarreal-Leal, Jing Xiao, Daniel I Idowu, Beck Burgelin, Bogdan J Wlodarczyk, Richard H Finnell, Bruna Corradetti

Faculty, Staff and Students Publications

BACKGROUND: Mesenchymal stem cells (MSCs) derived from gestational tissues offer a promising avenue for prenatal intervention in congenital malformations although their application is hampered by concerns related to cellular plasticity and the need for invasive, high-risk surgical procedures. Here, we present naturally occurring exosomes (EXOs) isolated from amniotic fluid-derived MSCs (AF-MSCs) and their mimetic analogs (MIMs) as viable, reproducible, and stable alternatives. These nanovesicles present a minimally invasive therapeutic option, addressing the limitations of MSC-based treatments while retaining therapeutic efficacy.

METHODS: MIMs were generated from AF-MSCs by combining sequential filtration steps through filter membranes with different porosity and size exclusion …

Immune Responses Drive Chorioretinitis And Retinal Pathology After Neonatal Cmv Infection, Jessica L. Mccord, John Y.S. Han, Ross E. Staudt, Nancy J. Philp Phd, Christopher M. Snyder

Department of Microbiology and Immunology Faculty Papers

Human cytomegalovirus (CMV) causes a common congenital infection leading to long-term neurological impairments including brain, cochlear, and ocular pathology. Infection of newborn mice with murine (M)CMV is an established model of neuropathology caused by congenital CMV infection, with recent work suggesting that brain pathology may be driven by immune responses. In the eye, however, CMV retinitis is thought to result from virus-driven necrosis in the absence of T cell responses. We found that MCMV infection of newborn mice recapitulates human eye disease after congenital CMV infection, including focal chorioretinitis, inflamed vasculature, and disrupted blood-retinal barriers. Moreover, infection drove extensive T …

Camkk2: Bridging The Gap Between Ca2+ Signaling And Energy-Sensing, Luke M Mcaloon, Abbey G Muller, Kevin Nay, Eudora L Lu, Benoit Smeuninx, Anthony R Means, Mark A Febbraio, John W Scott

Faculty, Staff and Students Publications

Calcium (Ca2+) ions are ubiquitous and indispensable signaling messengers that regulate virtually every cell function. The unique ability of Ca2+ to regulate so many different processes yet cause stimulus specific changes in cell function requires sensing and decoding of Ca2+ signals. Ca2+-sensing proteins, such as calmodulin, decode Ca2+ signals by binding and modifying the function of a diverse range of effector proteins. These effectors include the Ca2+-calmodulin dependent protein kinase kinase-2 (CaMKK2) enzyme, which is the core component of a signaling cascade that plays a key role in important physiological and pathophysiological processes, including brain function and cancer. In addition …

Nerve Injury Inhibits Oprd1 And Cnr1 Transcription Through Rest In Primary Sensory Neurons, Ashok Subedi, Asieh Etemad, Aadhya Tiwari, Yuying Huang, Biji Chatterjee, Samantha M Mcleod, Yungang Lu, Diangelo Gonzalez, Krishna Ghosh, Mario Sirito, Sanjay K Singh, Elisa Ruiz, Sandra L Grimm, Cristian Coarfa, Hui-Lin Pan, Sadhan Majumder

Faculty, Staff and Students Publications

The transcription repressor REST in the dorsal root ganglion (DRG) is upregulated by peripheral nerve injury and promotes the development of chronic pain. However, the genes targeted by REST in neuropathic pain development remain unclear. The expression levels of four opioid receptor genes (Oprm1, Oprd1, Oprl1 and Oprk1) and the cannabinoid CB1 receptor (Cnr1) gene in the DRG regulate nociception. In this study, we determined the role of REST in controlling their expression in the DRG induced by spared nerve injury (SNI). SNI induced chronic pain hypersensitivity in wild-type mice and was accompanied by increased levels of Rest transcript and …

A Mouse Model For Conditional Expression Of Activated Β-Catenin In Epidermal Keratinocytes, Vineet K Maurya, Yan Ying, John P Lydon

Faculty, Staff and Students Publications

We report the generation and characterization of the K5: CAT bigenic mouse in which the constitutively activated form of β-catenin (ΔN89 β-catenin) is conditionally expressed in cytokeratin-5 (K5) positive epidermal keratinocytes. Following short-term doxycycline intake during the telogen resting phase, the adult K5: CAT bigenic develops enlarged pilosebaceous units that expand deep into the dermis, an expansion usually observed during the anagen growth phase. Prolonged doxycycline treatment results in significant thickening and folding of the K5: CAT epidermis. During this persistent induction period, there is clear evidence of increased keratinocyte proliferation, particularly in the epidermal basal cell layer and the …

Behavioral Screening Reveals A Conserved Residue In Y-Box Rna-Binding Protein Required For Associative Learning And Memory In C Elegans, Ashley N Hayden, Katie L Brandel, Edward W Pietryk, Paul R Merlau, Priyadharshini Vijayakumar, Emily J Leptich, Elizabeth S Gaytan, Meredith I Williams, Connie W Ni, Hsiao-Tuan Chao, Jill A Rosenfeld, Rachel N Arey

Faculty, Staff and Students Publications

RNA-binding proteins (RBPs) regulate translation and plasticity which are required for memory. RBP dysfunction has been linked to a range of neurological disorders where cognitive impairments are a key symptom. However, of the 2,000 RBPs in the human genome, many are uncharacterized with regards to neurological phenotypes. To address this, we used the model organism C. elegans to assess the role of 20 conserved RBPs in memory. We identified eight previously uncharacterized memory regulators, three of which are in the C. elegans Y-Box (CEY) RBP family. Of these, we determined that cey-1 is the closest ortholog to the mammalian Y-Box …

Creb-Binding Protein/P300 Bromodomain Inhibition Reduces Neutrophil Accumulation And Activates Antitumor Immunity In Triple-Negative Breast Cancer, Xueying Yuan, Xiaoxin Hao, Hilda L Chan, Na Zhao, Diego A Pedroza, Fengshuo Liu, Kang Le, Alex J Smith, Sebastian J Calderon, Nadia Lieu, Michael J Soth, Philip Jones, Xiang Hf Zhang, Jeffrey M Rosen

Faculty, Staff and Students Publications

Tumor-associated neutrophils (TANs) have been shown to promote immunosuppression and tumor progression, and a high TAN frequency predicts poor prognosis in triple-negative breast cancer (TNBC). Dysregulation of CREB-binding protein (CBP)/P300 function has been observed with multiple cancer types. The bromodomain (BRD) of CBP/P300 has been shown to regulate its activity. In this study, we found that IACS-70654, a selective CBP/P300 BRD inhibitor, reduced TANs and inhibited the growth of neutrophil-enriched TNBC models. In the bone marrow, CBP/P300 BRD inhibition reduced the tumor-driven abnormal differentiation and proliferation of neutrophil progenitors. Inhibition of CBP/P300 BRD also stimulated the immune response by inducing …

Targeting Nuclear Receptor Coactivator Src-1 Prevents Colorectal Cancer Immune Escape By Reducing Transcription And Protein Stability Of Pd-L1, Yilin Hong, Qiang Chen, Zinan Wang, Yong Zhang, Bei Li, Hanshi Guo, Chuanzhong Huang, Xu Kong, Pingli Mo, Nengming Xiao, Jianming Xu, Yunbin Ye, Chundong Yu

Faculty, Staff and Students Publications

Programmed death-ligand 1 (PD-L1) is overexpressed in multiple cancers and critical for their immune escape. It has previously shown that the nuclear coactivator SRC-1 promoted colorectal cancer (CRC) progression by enhancing CRC cell viability, yet its role in CRC immune escape is unclear. Here, we demonstrate that SRC-1 is positively correlated with PD-L1 in human CRC specimens. SRC-1 deficiency significantly inhibits PD-L1 expression in CRC cells and retards murine CRC growth in subcutaneous grafts by enhancing CRC immune escape via increasing tumor infiltration of CD8

Identification And Characterization Of A Skin Microbiome On Caenorhabditis Elegans Suggests Environmental Microbes Confer Cuticle Protection, Nadia B Haghani, Robert H Lampe, Buck S Samuel, Sreekanth H Chalasani, Molly A Matty

Faculty, Staff and Students Publications

In the wild, C. elegans are emersed in environments teeming with a veritable menagerie of microorganisms. The C. elegans cuticular surface serves as a barrier and first point of contact with their microbial environments. In this study, we identify microbes from C. elegans natural habitats that associate with its cuticle, constituting a simple “skin microbiome.” We rear our animals on a modified CeMbio, mCeMbio, a consortium of ecologically relevant microbes. We first combine standard microbiological methods with an adapted micro skin-swabbing tool to describe the skin-resident bacteria on the C. elegans surface. Furthermore, we conduct 16S rRNA gene sequencing studies …

Women In Stem Becoming Independent: Our Shared Motivation And Enthusiasm Are Our Driving Force, Liudmila Andreeva, Lidia Bosurgi, Shu Zhen Chong, Coco Chu, Yejing Ge, Esther Hoste, Kellie A Jurado, Jette Lengefeld, Archita Mishra, Stefanie Wculek, Arabella Young

Faculty, Staff and Student Publications

This year at JEM, we are highlighting women in science by sharing their stories and amplifying their voices. In this Viewpoint, we hear from a cross section of women, across multiple research fields, discussing their science and the process of setting up a lab as an independent researcher.

Characterization Of Turbo, A Tlr Ligand-Based Adjuvant For Glycoconjugate Vaccines, Kishore R. Alugupalli

Department of Microbiology and Immunology Faculty Papers

Many bacterial polysaccharide vaccines, including the typhoid Vi polysaccharide (ViPS) and tetravalent meningococcal polysaccharide conjugate (MCV4) vaccines, do not incorporate adjuvants and are not highly immunogenic, particularly in infants. I found that endotoxin, a TLR4 ligand in ViPS, contributes to the immunogenicity of typhoid vaccines. Because endotoxin is pyrogenic, and its levels are highly variable in vaccines, I developed monophosphoryl lipid A, a nontoxic TLR4 ligand-based adjuvant named Turbo. Admixing Turbo with ViPS and MCV4 vaccines improved their immunogenicity across all ages and eliminated booster requirement. To understand the characteristics of this adjuvanticity, I compared Turbo with alum. Unlike alum, …

Vertebrate And Invertebrate Animal Infection Models Of Candida Auris Pathogenicity, Melissa Martinez, Danielle A Garsin, Michael C Lorenz

Faculty, Staff and Student Publications

Candida auris is an emerging fungal pathogen with several concerning qualities. First recognized in 2009, it has arisen in multiple geographically distinct genomic clades nearly simultaneously. C. auris strains are typically multidrug resistant and colonize the skin much better than most other pathogenic fungi; it also persists on abiotic surfaces, enabling outbreaks due to transmission in health care facilities. All these suggest a biology substantially different from the 'model' fungal pathogen, Candida albicans and support intensive investigation of C. auris biology directly. To uncover novel virulence mechanisms in this species requires the development of appropriate animal infection models. Various studies …

Fine-Tuning Ampk In Physiology And Disease Using Point-Mutant Mouse Models, Naghmana Ashraf, Jeanine L Van Nostrand

Faculty, Staff and Students Publications

AMP-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that monitors the cellular energy status to adapt it to the fluctuating nutritional and environmental conditions in an organism. AMPK plays an integral part in a wide array of physiological processes, such as cell growth, autophagy and mitochondrial function, and is implicated in diverse diseases, including cancer, metabolic disorders, cardiovascular diseases and neurodegenerative diseases. AMPK orchestrates many different physiological outcomes by phosphorylating a broad range of downstream substrates. However, the importance of AMPK-mediated regulation of these substrates in vivo remains an ongoing area of investigation to better understand its precise …

The Significant Role Of Amino Acid Metabolic Reprogramming In Cancer, Xiaohong Liu, Bo Ren, Jie Ren, Minzhi Gu, Lei You, Yupei Zhao

Faculty, Staff and Student Publications

Amino acid metabolism plays a pivotal role in tumor microenvironment, influencing various aspects of cancer progression. The metabolic reprogramming of amino acids in tumor cells is intricately linked to protein synthesis, nucleotide synthesis, modulation of signaling pathways, regulation of tumor cell metabolism, maintenance of oxidative stress homeostasis, and epigenetic modifications. Furthermore, the dysregulation of amino acid metabolism also impacts tumor microenvironment and tumor immunity. Amino acids can act as signaling molecules that modulate immune cell function and immune tolerance within the tumor microenvironment, reshaping the anti-tumor immune response and promoting immune evasion by cancer cells. Moreover, amino acid metabolism can …