• Effects of larval exposure to sublethal doses of Bacillus thuringiensis var. israelensis on body size, oviposition and survival of adult Anopheles coluzzii mosquitoes

      Gowelo, S.; Chirombo, J.; McCann, R. (Springer Nature, 2020)
      BACKGROUND: Application of the larvicide Bacillus thuringiensis var. israelensis (Bti) is a viable complementary strategy for malaria control. Efficacy of Bti is dose-dependent. There is a knowledge gap on the effects of larval exposure to sublethal Bti doses on emerging adult mosquitoes. The present study examined the effect of larval exposure to sublethal doses of Bti on the survival, body size and oviposition rate in adult Anopheles coluzzii. METHODS: Third-instar An. coluzzii larvae were exposed to control and sublethal Bti concentrations at LC20, LC50 and LC70 for 48 h. Surviving larvae were reared to adults under standard colony conditions. Thirty randomly selected females from each treatment were placed in separate cages and allowed to blood feed. Twenty-five gravid females from the blood-feeding cages were randomly selected and transferred into new cages where they were provided with oviposition cups. Numbers of eggs laid in each cage and mortality of all adult mosquitoes were recorded daily. Wing lengths were measured of 570 mosquitoes as a proxy for body size. RESULTS: Exposure to LC70Bti doses for 48 h as third-instar larvae reduced longevity of adult An. coluzzii mosquitoes. Time to death was 2.58 times shorter in females exposed to LC70Bti when compared to the control females. Estimated mortality hazard rates were also higher in females exposed to the LC50 and LC20 treatments, but these differences were not statistically significant. The females exposed to LC70 concentrations had 12% longer wings than the control group (P < 0.01). No differences in oviposition rate of the gravid females were observed between the treatments. CONCLUSIONS: Exposure of An. coluzzii larvae to sublethal Bti doses reduces longevity of resultant adults and is associated with larger adult size and unclear effect on oviposition. These findings suggest that anopheline larval exposure to sublethal Bti doses, though not recommended, could reduce vectorial capacity for malaria vector populations by increasing mortality of resultant adults.
    • Editorial: Cell-based Therapies for Stroke: Promising Solution or Dead End?

      Boltze, J.; Abe, K.; Janowski, M. (Frontiers Media S.A., 2020)
    • Age-related Smell and Taste Impairments and Vitamin D Associations in the U.S. Adults National Health and Nutrition Examination Survey

      Bigman, G. (Multidisciplinary Digital Publishing Institute (MDPI), 2020)
      Smell and taste decline with aging, and markedly deteriorate when nutritional deficiencies occur. This study aims to examine the associations between Vitamin D (VD) deficiency and smell and taste impairments among adults. This paper details a cross-sectional study utilizing data from the US National Health and Nutrition Examination Survey (NHANES, 2013-2014.). Smell impairment was assessed by the Pocket Smell Test and defined as failing to correctly identify six or more of the eight odors. Taste impairment was defined as failing to correctly identify quinine or sodium chloride. VD was measured as serum 25-hydroxyvitamin. Multivariable weighted logistic regressions were utilized. Adjusted odds ratio (OR) and 95% confidence interval (CI) were presented. Overall, 2216 (smell sample) and 2636 (taste sample) participants were included, aged between 40 and 80 years old. Of those, 18.3% had taste impairment, 12.2% had smell impairment, and 20% had VD deficiency (<20 ng/mL). Compared to participants with sufficient VD (>30 ng/mL), those with VD deficiency were more likely by 39% to report a higher prevalence of smell impairment (OR = 1.39, 95%CI: 1.02-1.89); and only participants aged 70-80 years with VD inadequacy (20-30 ng/mL) were more likely by 96% to report a higher prevalence of taste impairment (OR = 1.96, 95%CI: 1.35-1.85). VD may have a significant role in age-related smell impairment in adults aged 40 years or older, and in age-related taste impairment in the elderly aged 70-80 years.
    • Detecting geospatial patterns of Plasmodium falciparum parasite migration in Cambodia using optimized estimated effective migration surfaces

      Shetty, A.C.; O'Connor, T.D.; Takala-Harrison, S. (BioMed Central Ltd., 2020)
      Background: Understanding the genetic structure of natural populations provides insight into the demographic and adaptive processes that have affected those populations. Such information, particularly when integrated with geospatial data, can have translational applications for a variety of fields, including public health. Estimated effective migration surfaces (EEMS) is an approach that allows visualization of the spatial patterns in genomic data to understand population structure and migration. In this study, we developed a workflow to optimize the resolution of spatial grids used to generate EEMS migration maps and applied this optimized workflow to estimate migration of Plasmodium falciparum in Cambodia and bordering regions of Thailand and Vietnam. Methods: The optimal density of EEMS grids was determined based on a new workflow created using density clustering to define genomic clusters and the spatial distance between genomic clusters. Topological skeletons were used to capture the spatial distribution for each genomic cluster and to determine the EEMS grid density; i.e., both genomic and spatial clustering were used to guide the optimization of EEMS grids. Model accuracy for migration estimates using the optimized workflow was tested and compared to grid resolutions selected without the optimized workflow. As a test case, the optimized workflow was applied to genomic data generated from P. falciparum sampled in Cambodia and bordering regions, and migration maps were compared to estimates of malaria endemicity, as well as geographic properties of the study area, as a means of validating observed migration patterns. Results: Optimized grids displayed both high model accuracy and reduced computing time compared to grid densities selected in an unguided manner. In addition, EEMS migration maps generated for P. falciparum using the optimized grid corresponded to estimates of malaria endemicity and geographic properties of the study region that might be expected to impact malaria parasite migration, supporting the validity of the observed migration patterns. Conclusions: Optimized grids reduce spatial uncertainty in the EEMS contours that can result from user-defined parameters, such as the resolution of the spatial grid used in the model. This workflow will be useful to a broad range of EEMS users as it can be applied to analyses involving other organisms of interest and geographic areas. Copyright 2020 The Author(s).
    • COVID-19 and the RAAS-a potential role for angiotensin II?

      Busse, L.W.; Chow, J.H.; McCurdy, M.T. (Springer Nature, 2020)
    • Histone demethylase JMJD1A promotes expression of DNA repair factors and radio-resistance of prostate cancer cells

      Fan, L.; Xu, S.; Zhang, F.; Cui, X.; Clark, D.J.; Yang, A.; Hussain, A.; Rassool, F.; Qi, J. (Springer Nature, 2020)
      The DNA damage response (DDR) pathway is a promising target for anticancer therapies. The androgen receptor and myeloblastosis transcription factors have been reported to regulate expression of an overlapping set of DDR genes in prostate cancer cells. Here, we found that histone demethylase JMJD1A regulates expression of a different set of DDR genes largely through c-Myc. Inhibition of JMJD1A delayed the resolution of γ-H2AX foci, reduced the formation of foci containing ubiquitin, 53BP1, BRCA1 or Rad51, and inhibited the reporter activity of double-strand break (DSB) repair. Mechanistically, JMJD1A regulated expression of DDR genes by increasing not only the level but also the chromatin recruitment of c-Myc through H3K9 demethylation. Further, we found that ubiquitin ligase HUWE1 induced the K27-/K29-linked noncanonical ubiquitination of JMJD1A at lysine-918. Ablation of the JMJD1A noncanonical ubiquitination lowered DDR gene expression, impaired DSB repair, and sensitized response of prostate cells to irradiation, topoisomerase inhibitors or PARP inhibitors. Thus, development of agents that target JMJD1A or its noncanonical ubiquitination may sensitize the response of prostate cancer to radiotherapy and possibly also genotoxic therapy. Copyright 2020, The Author(s).
    • Re-annotation of the Theileria parva genome refines 53% of the proteome and uncovers essential components of N-glycosylation, a conserved pathway in many organisms

      Tretina, K.; Pelle, R.; Silva, J.C. (Springer Nature, 2020)
      BACKGROUND: The apicomplexan parasite Theileria parva causes a livestock disease called East coast fever (ECF), with millions of animals at risk in sub-Saharan East and Southern Africa, the geographic distribution of T. parva. Over a million bovines die each year of ECF, with a tremendous economic burden to pastoralists in endemic countries. Comprehensive, accurate parasite genome annotation can facilitate the discovery of novel chemotherapeutic targets for disease treatment, as well as elucidate the biology of the parasite. However, genome annotation remains a significant challenge because of limitations in the quality and quantity of the data being used to inform the location and function of protein-coding genes and, when RNA data are used, the underlying biological complexity of the processes involved in gene expression. Here, we apply our recently published RNAseq dataset derived from the schizont life-cycle stage of T. parva to update structural and functional gene annotations across the entire nuclear genome. RESULTS: The re-annotation effort lead to evidence-supported updates in over half of all protein-coding sequence (CDS) predictions, including exon changes, gene merges and gene splitting, an increase in average CDS length of approximately 50 base pairs, and the identification of 128 new genes. Among the new genes identified were those involved in N-glycosylation, a process previously thought not to exist in this organism and a potentially new chemotherapeutic target pathway for treating ECF. Alternatively-spliced genes were identified, and antisense and multi-gene family transcription were extensively characterized. CONCLUSIONS: The process of re-annotation led to novel insights into the organization and expression profiles of protein-coding sequences in this parasite, and uncovered a minimal N-glycosylation pathway that changes our current understanding of the evolution of this post-translational modification in apicomplexan parasites.
    • Attitudes and Perceptions Toward Authorized Deception: A Pilot Comparison of Healthy Controls and Fibromyalgia Patients

      Goo, S.J.; Frangos, E.; Colloca, L. (Oxford University Press, 2020)
      Objective: Little is known about the perceptions and attitudes of participants who volunteer in studies involving authorized deception. Thus, this cross-sectional pilot study measured, for the first time, the perceptions about participation in an authorized-deception placebo analgesia study in chronic pain patients with fibromyalgia and assessed whether their perceptions differed from healthy controls. Methods: An anonymous survey with questions about trust in research and willingness to participate in future research involving deception was mailed to participants in both groups after completion of the parent study. Statistical analyses were performed using the Mann-Whitney U and chi-square tests (31 controls and 16 fibromyalgia patients were included in the analyses). Results: The majority of participants expressed little or no concern about the deception, still trusted the scientific process, and found the debriefing procedure helpful and worthwhile. Group differences were found in willingness to 1) participate in the parent study had the deceptive element been disclosed in advance (controls = definitely, fibromyalgia patients = probably, U = 341.5, P = 0.01) and 2) participate in future studies (controls = definitely, fibromyalgia patients = probably, U = 373, P < 0.001). Conclusions: Despite slightly less favorable responses of fibromyalgia patients and the relatively small size of the study, these findings suggest that attitudes and perceptions about participating in an authorized placebo study remain positive in both healthy and chronic pain populations.
    • Review of Emerging Pharmacotherapy for the Treatment of Coronavirus Disease 2019

      Barlow, A.; Landolf, K.M.; Yeung, S.Y.A.; Heavner, J.J.; Claassen, C.W.; Heavner, M.S. (Wiley-Blackwell, 2020)
      The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has evolved into an emergent global pandemic. Coronavirus disease 2019 (COVID‐19) can manifest on a spectrum of illness from mild disease to severe respiratory failure requiring intensive care unit (ICU) admission. As the incidence continues to rise at a rapid pace, critical care teams are faced with challenging treatment decisions. There is currently no widely accepted standard of care in the pharmacological management of patients with COVID‐19. Urgent identification of potential treatment strategies is a priority. Therapies include novel agents available in clinical trials or through compassionate use, and other drugs, repurposed antiviral and immune modulating therapies. Many have demonstrated in vitro or in vivo potential against other viruses that are similar to SARS‐CoV‐2. Critically ill patients with COVID‐19 have additional considerations related to adjustments for organ impairment and renal replacement therapies, complex lists of concurrent medications, limitations with drug administration and compatibility, and unique toxicities that should be evaluated when utilizing these therapies. The purpose of this review is to summarize practical considerations for pharmacotherapy in patients with COVID‐19, with the intent of serving as a resource for health care providers at the forefront of clinical care during this pandemic.
    • National Institutes of Health (NIH) grant awards: does past performance predict future success?

      Prasad, J.M.; Shipley, M.T.; Rogers, T.B.; Puche, A.C. (Palgrave Macmillan Ltd., 2020)
      The NIH is the major federal biomedical research funding agency within the United States, and NIH funding has become a priority in institutional decisions on faculty recruitment, salary, promotion, and tenure. The implicit assumption is that well-funded investigators will maintain their funding success; however, our analysis of NIH awardees from 2000 to 2015 suggests that regardless of how well funded an investigator is, their research portfolio exhibits "regression to the mean," matching the typical NIH funding profile within just 10-15 years. Thus, outperformance in past funding is not a strong predictor of future outperformance in funding success. This study indicates that faculty performance should not be solely judged upon grant success but should include other institutional mission priorities such as provision of clinical care, education, and service to community/profession. Copyright 2020, The Author(s).
    • Cost Analysis of Treating Pediatric Supracondylar Humerus Fractures in Community Hospitals Compared With a Tertiary Care Hospital

      Shasti, M.; Li, T.P.; Case, A.L.; Hariharan, A.R.; Jauregui, J.J.; Abzug, J.M. (Wolters Kluwer Health, 2020)
      OBJECTIVE: In the current healthcare environment, providing cost-efficient care is of paramount importance. One emerging strategy is to use community hospitals (CHs) rather than tertiary care hospitals (TCHs) for some procedures. This study assesses the costs of performing closed reduction percutaneous pinning (CRPP) of pediatric supracondylar humerus fractures (SCHFs) at a CH compared with a TCH. METHODS: A retrospective review of 133 consecutive SCHFs treated with CRPP at a CH versus a TCH over a 6-year period was performed. Total encounter and subcategorized costs were compared between the procedures done at a CH versus those done at a TCH. RESULTS: Performing CRPP for a SCHF at a CH compared with a TCH saved 44% in costs (P < 0.001). Cost reduction of 51% was attributable to operating room costs, 19% to anesthesia-related costs, 16% to imaging-related costs, and 7% to supplies. DISCUSSION: Performing CRPP for a SCHF at a CH compared with a TCH results in a 44% decrease in direct cost, driven largely by surgical, anesthesia, and radiology-related savings.
    • A non-coding RNA landscape of bronchial epitheliums of lung cancer patients

      Lin, Y.; Holden, V.; Dhilipkannah, P.; Deepak, J.; Todd, N.W.; Jiang, F. (MDPI AG, 2020)
      We propose to systematically identify a non-coding RNA (ncRNA) profile of exfoliated bronchial epitheliums of sputum from lung cancer patients. Bronchial epithelial cells enriched from sputum of 32 lung cancer patients and 33 cancer-free smokers were analyzed by next-generation sequencing to comprehensively characterize the ncRNA profiles. In addition, 108 miRNAs, 88 small nucleolar RNAs, 13 piwi-interacting RNAs, 6 transfer RNAs, 4 ribosomal RNAs, 19 small nuclear RNAs, and 25 long-noncoding (lnc) RNAs displayed a significantly different level in bronchial epitheliums of sputum of lung cancer patients versus cancer-free smokers (all < 0.001). PCR analysis confirmed their different expression levels in the sputum specimens. A high expression of SNHG9, an lncRNA, was validated in 78 lung tumor tissues, and the expression was inversely associated with overall survival of lung cancer patients (p = 0.002). Knockdown of SNHG9 in cancer cells reduced the cell growth, proliferation, and invasion in vitro and tumorigenesis in vivo. The multiple differentially expressed ncRNAs in bronchial epitheliums may contribute to the development and progression of lung cancer and provide potential biomarkers and therapeutic targets for the disease. Copyright 2020 by the authors.
    • A combination of radiotherapy, hyperthermia, and immunotherapy inhibits pancreatic tumor growth and prolongs the survival of mice

      Mahmood, J.; Alexander, A.A.; Samanta, S.; Kamlapurkar, S.; Singh, P.; Saeed, A.; Carrier, F.; Cao, X.; Vujaskovic, Z. (MDPI AG, 2020)
      Background: Pancreatic cancer (PC) is the fourth-most-deadly cancer in the United States with a 5-year survival rate of only 8%. Unfortunately, only 10-20% of PC patients are candidates for surgery, with the vast majority of patients with locally-advanced disease undergoing chemotherapy and/or radiation therapy (RT). Current treatments are clearly inadequate and novel strategies are crucially required. We investigated a novel tripartite treatment (combination of tumor targeted hyperthermia (HT), radiation therapy (RT), and immunotherapy (IT)) to alter immunosuppressive PC-tumor microenvironment (TME). (2). Methods: In a syngeneic PC murine tumor model, HT was delivered before tumor-targeted RT, by a small animal radiation research platform (SARRP) followed by intraperitoneal injections of cytotoxic T-cell agonist antibody against OX40 (also known as CD134 or Tumor necrosis factor receptor superfamily member 4; TNFRSF4) that can promote T-effector cell activation and inhibit T-regulatory (T-reg) function. (3). Results: Tripartite treatment demonstrated significant inhibition of tumor growth (p < 0.01) up to 45 days post-treatment with an increased survival rate compared to any monotherapy. Flow cytometric analysis showed a significant increase (p < 0.01) in cytotoxic CD8 and CD4+ T-cells in the TME of the tripartite treatment groups. There was no tripartite-treatment-related toxicity observed in mice. (4). Conclusions: Tripartite treatment could be a novel therapeutic option for PC patients. Copyright 2020 by the authors.
    • Smcr8 deficiency disrupts axonal transport-dependent lysosomal function and promotes axonal swellings and gain of toxicity in C9ALS/FTD mouse models

      Liang, C.; Shao, Q.; Chen, R. (Oxford University Press, 2020)
      G4C2 repeat expansions in an intron of C9ORF72 cause the most common familial amyotrophic lateral sclerosis and frontotemporal dementia (collectively, C9ALS/FTD). Mechanisms and mediators of C9ALS/FTD pathogenesis remain poorly understood. C9orf72 and Smcr8 form a protein complex. Here, we show that expression of Smcr8, like C9orf72, is reduced in C9ALS/FTD mouse models and patient tissues. Since Smcr8 is highly conserved between human and mouse, we evaluated the effects of Smcr8 downregulation in mice. Smcr8 knockout (KO) mice exhibited motor behavior deficits, which resemble those of C9ALS/FTD mouse models, and displayed axonal swellings in their spinal cords and neuromuscular junctions. These deficits are caused by impaired autophagy-lysosomal functions due to disrupted axonal transport in mutant motor neurons. Consistent with its interaction with C9orf72 and their downregulation in patient tissues, Smcr8 deficiency exacerbated autophagy-lysosomal impairment in C9orf72 KO mice. The disease relevance of Smcr8 downregulation was ref lected by exacerbated axonal swellings and gain of toxicity pathology arising from Smcr8 haploinsufficiency in a mouse model of C9ALS/FTD. Thus, our in vivo studies suggested that Smcr8 deficiency impairs axonal transport dependent autophagy-lysosomal function and exacerbates axonal degeneration and gain of toxicity in C9ALS/FTD mouse models.
    • Losing sleep! Are we missing the future of sleep medicine?

      Collen, J.F.; Wickwire, E.M.; Capaldi, V. (The American Academy of Sleep Medicine, 2020)
      Innovation stems from necessity. A nationwide shortage of medical specialists coupled with a tech-savvy patient population is an opportunity for advances in health care access. Because sleep medicine is a not a procedure-based specialty, our field holds special promise for telehealth-based approaches. Across the United States, there is a marked shortage of sleep medicine physicians, with an estimated patient to physician ratio of 43,000:1. Validated questionnaires for estimating pretest probability for sleep-disordered breathing, computer-based cognitive behavioral therapy for insomnia (CBT-I), home sleep testing, actigraphy, commercial wearables, and modem-enabled continuous positive airway pressure devices provide a robust platform for effective sleep telehealth. Sleep telehealth has already been evaluated in a number of settings and has promise for remote care in particular.
    • Circulating cell free DNA during definitive chemo-radiotherapy in non-small cell lung cancer patients-Initial observations

      Ahlborn, L.B.; Bentzen, S.M.; Nygård, L. (Public Library of Science, 2020)
      Background The overall aim was to investigate the change over time in circulating cell free DNA (cfDNA) in patients with locally advanced non-small cell lung cancer (NSCLC) undergoing concurrent chemo-radiotherapy. Furthermore, to assess the possibility of detecting circulating cell free tumor DNA (ctDNA) using shallow whole genome sequencing (sWGS) and size selection. Methods Ten patients were included in a two-phase study. The first four patients had blood samples taken prior to a radiation therapy (RT) dose fraction and at 30 minutes, 1 hour and 2 hours after RT to estimate the short-term dynamics of cfDNA concentration after irradiation. The remaining six patients had one blood sample taken on six treatment days 30 minutes post treatment to measure cfDNA levels. Presence of ctDNA as indicated by chromosomal aberrations was investigated using sWGS. The sensitivity of this method was further enhanced using in silico size selection. Results cfDNA concentration from baseline to 120 min after therapy was stable within 95% tolerance limits of +/- 2 ng/ml cfDNA. Changes in cfDNA were observed during therapy with an apparent qualitative difference between adenocarcinoma (average increase of 0.69 ng/ml) and squamous cell carcinoma (average increase of 4.0 ng/ml). Tumor shrinkage on daily cone beam computer tomography scans during radiotherapy did not correlate with changes in concentration of cfDNA. Conclusion Concentrations of cfDNA remain stable during the first 2 hours after an RT fraction. However, based on the sWGS profiles, ctDNA represented only a minor fraction of cfDNA in this group of patients. The detection sensitivity of genomic alterations in ctDNA strongly increases by applying size selection. Copyright 2020 The Authors.
    • Emergency medical care of incarcerated patients: Opportunities for improvement and cost savings

      Martin, R.A.; Couture, R.; Carter, C. (Public Library of Science, 2020)
      In the United States (US), the lifetime incidence of incarceration is 6.6%, exceeding that of any other nation. Compared to the general US population, incarcerated individuals are disproportionally affected by chronic health conditions, mental illness, and substance use disorders. Barriers to accessing medical care are common in correctional facilities. We sought to characterize the local incarcerated patient population and explore barriers to medical care in these patients. We conducted a retrospective, observational cohort study by reviewing the medical records of incarcerated patients presenting to the adult emergency department (ED) of a single academic, tertiary care facility with medical or psychiatric (med/psych) and trauma-related emergencies between January 2012 and December 2014. Data on demographics, medical complexity, trauma intentionality, and barriers to medical care were analyzed using descriptive statistics, unpaired student's t-test or one-way analysis of variance for continuous variables, and chi-square analysis or Fisher's exact test as appropriate. Trauma patients were younger with fewer medical comorbidities and were less likely to be admitted to the hospital than med/psych patients. 47.8% of injuries resulted from violence or were self-inflicted. Most trauma-related complaints were managed by the emergency medicine physician in the ED. While barriers to medical care were not correlated with hospital admission, 5.4% of med/psych and 2.9% of trauma patients reported barriers as a contributing factor to the ED encounter. Med/psych patients commonly reported a lack of access to medications, while trauma patients reported a delay in medical care. Trauma-related presentations were less medically complex than med/psych-related complaints. Medical management of most injuries required no hospital resources outside of the ED, indicating a potential role for outpatient management of trauma-related complaints. Additional opportunities for health care improvement and cost savings include the implementation of programs that target violence, prevent injuries, and promote the continuity of medical care while incarcerated. Copyright: 2020 Martin et al.
    • Cauliflower Mosaic Virus TAV, a Plant Virus Protein That Functions like Ribonuclease H1 and is Cytotoxic to Glioma Cells

      Turri, V.; Latinovic, O.S.; Toyang, N. (Hindawi Limited, 2020)
      Recent comparisons between plant and animal viruses reveal many common principles that underlie how all viruses express their genetic material, amplify their genomes, and link virion assembly with replication. Cauliflower mosaic virus (CaMV) is not infectious for human beings. Here, we show that CaMV transactivator/viroplasmin protein (TAV) shares sequence similarity with and behaves like the human ribonuclease H1 (RNase H1) in reducing DNA/RNA hybrids detected with S9.6 antibody in HEK293T cells. We showed that TAV is clearly expressed in the cytosol and in the nuclei of transiently transfected human cells, similar to its distribution in plants. TAV also showed remarkable cytotoxic effects in U251 human glioma cells in vitro. These characteristics pave the way for future analysis on the use of the plant virus protein TAV, as an alternative to human RNAse H1 during gene therapy in human cells. Copyright 2020 Valentina Turri et al.
    • The lymph node stromal laminin α5 shapes alloimmunity

      Li, L.; Shirkey, M.W.; Zhang, T.; Xiong, Y.; Piao, W.; Saxena, V.; Paluskievicz, C.; Lee, Y.; Toney, N.; Cerel, B.M.; et al. (American Society for Clinical Investigation, 2020)
      Lymph node stromal cells (LNSCs) regulate immunity through constructing lymphocyte niches. LNSC-produced laminin α5 (Lama5) regulates CD4+ T cells but the underlying mechanisms of its functions are poorly understood. Here we show that depleting Lama5 in LNSCs resulted in decreased Lama5 protein in the LN cortical ridge (CR) and around high endothelial venules (HEVs). Lama5 depletion affected LN structure with increased HEVs, upregulated chemokines, and cell adhesion molecules, and led to greater numbers of Tregs in the T cell zone. Mouse and human T cell transendothelial migration and T cell entry into LNs were suppressed by Lama5 through the receptors α6 integrin and α-dystroglycan. During immune responses and allograft transplantation, depleting Lama5 promoted antigen-specific CD4+ T cell entry into the CR through HEVs, suppressed T cell activation, and altered T cell differentiation to suppressive regulatory phenotypes. Enhanced allograft acceptance resulted from depleting Lama5 or blockade of T cell Lama5 receptors. Lama5 and Lama4/Lama5 ratios in allografts were associated with the rejection severity. Overall, our results demonstrated that stromal Lama5 regulated immune responses through altering LN structures and T cell behaviors. This study delineated a stromal Lama5–T cell receptor axis that can be targeted for immune tolerance modulation.
    • Sphingosine Kinase Blockade Leads to Increased Natural Killer T Cell Responses to Mantle Cell Lymphoma

      Lee, M.S.; Sun, W.; Webb, T.J. (MDPI AG, 2020)
      Mantle cell lymphoma (MCL) is an aggressive subtype of non-Hodgkin's lymphoma. Despite being responsive to combination chemotherapy, median survival remains around 5 years due to high rates of relapse. Sphingolipid metabolism regulates MCL survival and proliferation and we found that sphingosine-1-phosphate (S1P) is upregulated in MCL cells. Therapeutic targeting of the S1P1 receptor or knockdown of sphingosine kinase 1 (SK1), the enzyme responsible for generating S1P, in human MCL cells results in a significant increase in Natural Killer T (NKT) cell activation. NKT cells recognize glycolipid antigens presented on CD1d and can reduce MCL tumor burden in vivo. Lipidomic studies identified cardiolipin, which has been reported to bind to CD1d molecules, as being upregulated in SK1 knockdown cells. We found that the pretreatment of antigen presenting cells with cardiolipin leads to increased cytokine production by NKT cell hybridomas. Furthermore, the ability of cardiolipin to activate NKT cells was dependent on the structure of its acyl chains. Collectively, these studies delineate novel pathways important for immune recognition of malignant cells and could lead to the development of new treatments for lymphoma.