Browsing by Author "Kubes, Paul"

Now showing 1 - 20 of 45
  • Thumbnail Image
    ItemOpen Access
  • Thumbnail Image
    ItemOpen Access
    Assessment of the safety and feasibility of administering anti-pyretic therapy in critically ill adults: study protocol of a randomized trial
    (BioMed Central, 2012-03-12) Niven, Daniel J.; Léger, Caroline; Kubes, Paul; Stelfox, H. Tom; Laupland, Kevin B.
  • Thumbnail Image
    ItemOpen Access
  • Thumbnail Image
    ItemOpen Access
    Closed Or Open after Source Control Laparotomy for Severe Complicated Intra-Abdominal Sepsis (the COOL trial): study protocol for a randomized controlled trial
    (2018-06-22) Kirkpatrick, Andrew W; Coccolini, Federico; Ansaloni, Luca; Roberts, Derek J; Tolonen, Matti; McKee, Jessica L; Leppaniemi, Ari; Faris, Peter; Doig, Christopher J; Catena, Fausto; Fabian, Timothy; Jenne, Craig N; Chiara, Osvaldo; Kubes, Paul; Manns, Braden; Kluger, Yoram; Fraga, Gustavo P; Pereira, Bruno M; Diaz, Jose J; Sugrue, Michael; Moore, Ernest E; Ren, Jianan; Ball, Chad G; Coimbra, Raul; Balogh, Zsolt J; Abu-Zidan, Fikri M; Dixon, Elijah; Biffl, Walter; MacLean, Anthony; Ball, Ian; Drover, John; McBeth, Paul B; Posadas-Calleja, Juan G; Parry, Neil G; Di Saverio, Salomone; Ordonez, Carlos A; Xiao, Jimmy; Sartelli, Massimo
    Abstract Background Severe complicated intra-abdominal sepsis (SCIAS) has an increasing incidence with mortality rates over 80% in some settings. Mortality typically results from disruption of the gastrointestinal tract, progressive and self-perpetuating bio-mediator generation, systemic inflammation, and multiple organ failure. Principles of treatment include early antibiotic administration and operative source control. A further therapeutic option may be open abdomen (OA) management with active negative peritoneal pressure therapy (ANPPT) to remove inflammatory ascites and ameliorate the systemic damage from SCIAS. Although there is now a biologic rationale for such an intervention as well as non-standardized and erratic clinical utilization, this remains a novel therapy with potential side effects and clinical equipoise. Methods The Closed Or Open after Laparotomy (COOL) study will constitute a prospective randomized controlled trial that will randomly allocate eligible surgical patients intra-operatively to either formal closure of the fascia or use of the OA with application of an ANPTT dressing. Patients will be eligible if they have free uncontained intra-peritoneal contamination and physiologic derangements exemplified by septic shock OR a Predisposition-Infection-Response-Organ Dysfunction Score ≥ 3 or a World-Society-of-Emergency-Surgery-Sepsis-Severity-Score ≥ 8. The primary outcome will be 90-day survival. Secondary outcomes will be logistical, physiologic, safety, bio-mediators, microbiological, quality of life, and health-care costs. Secondary outcomes will include days free of ICU, ventilation, renal replacement therapy, and hospital at 30 days from the index laparotomy. Physiologic secondary outcomes will include changes in intensive care unit illness severity scores after laparotomy. Bio-mediator outcomes for participating centers will involve measurement of interleukin (IL)-6 and IL-10, procalcitonin, activated protein C (APC), high-mobility group box protein-1, complement factors, and mitochondrial DNA. Economic outcomes will comprise standard costing for utilization of health-care resources. Discussion Although facial closure after SCIAS is considered the current standard of care, many reports are suggesting that OA management may improve outcomes in these patients. This trial will be powered to demonstrate a mortality difference in this highly lethal and morbid condition to ensure critically ill patients are receiving the best care possible and not being harmed by inappropriate therapies based on opinion only. Trial registration ClinicalTrials.gov , NCT03163095 .
  • Thumbnail Image
    ItemOpen Access
    Discerning Alveolar Macrophage Ontogeny in Mice
    (2023-06) Zhang, Wen Xuan; Kubes, Paul; Jenne, Craig; Kelly, Margaret
    The adaptive and innate immunity are the two branches of the immune system our body uses to defend against invading microbes. After each encounter with a pathogen, the adaptive immune system develops a memory to prevent an infection with the same microbe. This ability to remember has recently also been shown in the innate immune system and was termed “trained immunity”, describing the ability to generate a stronger response towards a broad range of pathogens despite infection with just a single pathogen. The lung is an organ directly exposed to the microbes in the outside world, making it a likely site for immune cells to develop trained immunity. The predominant innate immune cells that reside in the lungs are the alveolar macrophages. These cells encounter countless pathogens every day and therefore are a likely cell in which to study trained immunity. Our lab recently figured out how to watch the macrophages crawl inside the lungs of living animals and this study examined how these macrophages behaved under different conditions (Neupane et al, 2020). However, these macrophages only live for a few months, so cells from the bone marrow constantly replace the macrophages, meaning that there are always two types of macrophages present in the lung. However, without an effective labelling tool, it was previously impossible to distinguish between the two macrophage populations, making their differences in behavior and function unknown. This study utilized a unique model to look at the two different macrophages and visualize these cells inside a living mouse to look for behavioural similarities and differences. Our findings determined the behavioral and functional similarities of these macrophages at homeostasis, their responses against the influenza virus, and provided support for both populations to be trained against influenza.
  • Thumbnail Image
    ItemOpen Access
    Efficacy and safety of active negative pressure peritoneal therapy for reducing the systemic inflammatory response after damage control laparotomy (the Intra- peritoneal Vacuum Trial): study protocol for a randomized controlled trial
    (BioMed Central, 2013-05-16) Roberts, Derek J; Jenne, Craig N; Ball, Chad G; Tiruta, Corina; Léger, Caroline; Xiao, Zhengwen; Faris, Peter D; McBeth, Paul B; Doig, Christopher J; Skinner, Christine R; Ruddell, Stacy G; Kubes, Paul; Kirkpatrick, Andrew W
  • Thumbnail Image
    ItemOpen Access
    Getting the invite list right: a discussion of sepsis severity scoring systems in severe complicated intra-abdominal sepsis and randomized trial inclusion criteria
    (2018-04-06) Tolonen, Matti; Coccolini, Federico; Ansaloni, Luca; Sartelli, Massimo; Roberts, Derek J; McKee, Jessica L; Leppaniemi, Ari; Doig, Christopher J; Catena, Fausto; Fabian, Timothy; Jenne, Craig N; Chiara, Osvaldo; Kubes, Paul; Kluger, Yoram; Fraga, Gustavo P; Pereira, Bruno M; Diaz, Jose J; Sugrue, Michael; Moore, Ernest E; Ren, Jianan; Ball, Chad G; Coimbra, Raul; Dixon, Elijah; Biffl, Walter; MacLean, Anthony; McBeth, Paul B; Posadas-Calleja, Juan G; Di Saverio, Salomone; Xiao, Jimmy; Kirkpatrick, Andrew W
    Abstract Background Severe complicated intra-abdominal sepsis (SCIAS) is a worldwide challenge with increasing incidence. Open abdomen management with enhanced clearance of fluid and biomediators from the peritoneum is a potential therapy requiring prospective evaluation. Given the complexity of powering multi-center trials, it is essential to recruit an inception cohort sick enough to benefit from the intervention; otherwise, no effect of a potentially beneficial therapy may be apparent. An evaluation of abilities of recognized predictive systems to recognize SCIAS patients was conducted using an existing intra-abdominal sepsis (IAS) database. Methods All consecutive adult patients with a diffuse secondary peritonitis between 2012 and 2013 were collected from a quaternary care hospital in Finland, excluding appendicitis/cholecystitis. From this retrospectively collected database, a target population (93) of those with either ICU admission or mortality were selected. The performance metrics of the Third Consensus Definitions for Sepsis and Septic Shock based on both SOFA and quick SOFA, the World Society of Emergency Surgery Sepsis Severity Score (WSESSSS), the APACHE II score, Manheim Peritonitis Index (MPI), and the Calgary Predisposition, Infection, Response, and Organ dysfunction (CPIRO) score were all tested for their discriminant ability to identify this subgroup with SCIAS and to predict mortality. Results Predictive systems with an area under-the-receiving-operating characteristic (AUC) curve > 0.8 included SOFA, Sepsis-3 definitions, APACHE II, WSESSSS, and CPIRO scores with the overall best for CPIRO. The highest identification rates were SOFA score ≥ 2 (78.4%), followed by the WSESSSS score ≥ 8 (73.1%), SOFA ≥ 3 (75.2%), and APACHE II ≥ 14 (68.8%) identification. Combining the Sepsis-3 septic-shock definition and WSESSS ≥ 8 increased detection to 80%. Including CPIRO score ≥ 3 increased this to 82.8% (Sensitivity-SN; 83% Specificity-SP; 74%. Comparatively, SOFA ≥ 4 and WSESSSS ≥ 8 with or without septic-shock had 83.9% detection (SN; 84%, SP; 75%, 25% mortality). Conclusions No one scoring system behaves perfectly, and all are largely dominated by organ dysfunction. Utilizing combinations of SOFA, CPIRO, and WSESSSS scores in addition to the Sepsis-3 septic shock definition appears to offer the widest “inclusion-criteria” to recognize patients with a high chance of mortality and ICU admission. Trial registration https://clinicaltrials.gov/ct2/show/NCT03163095 ; Registered on May 22, 2017.
  • Thumbnail Image
    ItemOpen Access
  • Thumbnail Image
    ItemOpen Access
    Human Rhinovirus Infection of Airway Epithelial Cells Modulates Airway Smooth Muscle Migration
    (2015-12-22) Shariff, Sami; Leigh, Richard; Proud, David; Kubes, Paul; Giembycz, Mark
    The traditional paradigm of airway remodeling in asthma has held that remodeling occurs after many years of chronic inflammation. However, studies have confirmed that remodeling changes are observed in children even before the clinical diagnosis of asthma is established. There is now robust evidence to indicate that children with recurrent human rhinovirus (HRV)-induced wheezing episodes are at significantly increased risk of developing subsequent asthma. A feature of airway remodeling is increased airway smooth muscle (ASM) mass with a greater proximity of the ASM to the subepithelial region, and we interrogated the hypothesis that HRV-induced alterations of airway epithelial cell biology might regulate ASM migration. We demonstrated that ASM chemotaxis is GPCR dependent, can be regulated by cAMP and is dependent upon CCL5 release by the epithelium post-HRV infection. These observations substantiate the growing body of evidence that links HRV infections to the subsequent development of asthma.
  • Thumbnail Image
    ItemOpen Access
    Identification of dipeptidase-1 as an organ-selective adhesion receptor utilized by neutrophils and metastatic cancer cells in the liver and lungs
    (2018-04-30) Roy Choudhury, Saurav; Senger, Donna L.; Kubes, Paul; Liao, Shan; Morris, Don G.; Schriemer, David C.; Ferri, Lorenzo Edwin
    Lungs and liver are two major sites of neutrophil trafficking and inflammatory disease. Neutrophil recruitment in response to an inflammatory cue is a sequentially coordinated process where adhesion molecules expressed on the endothelium of a given organ mediate different steps in the classical leukocyte recruitment cascade [1]. However, molecules identified as being central in the canonical schema of neutrophil recruitment to different organs (mesentery, skin, and cremaster muscle) are not required in the inflamed pulmonary and hepatic vasculatures [2-8]. Using an unbiased functional screen in vivo, we isolated a peptide-displaying phage that homed to the liver and lungs of mice treated with a bacterial inflammatory stimulus (lipopolysaccharide). Employing intravital microscopy, we found that this phage, or its corresponding displayed-peptide, termed LSALT herein, inhibited the adhesion of neutrophils in the inflamed lungs and liver vasculatures in response to LPS. The corresponding synthetic peptide also reduced the metastatic colonization of melanoma cells to the lungs in human xenograft and immunocompetent mouse models. Using biochemical, genetic and confocal intravital imaging approaches we identified dipeptidase-1 (DPEP1) as the functional target of this peptide and established its role as a physical adhesion receptor for neutrophil and metastatic cancer cell adhesion independent of its enzymatic activity. Importantly, genetic ablation or functional peptide blocking of DPEP1 significantly reduced neutrophil recruitment and cancer metastasis to the lungs and liver, and in models of Acute Respiratory Distress Syndrome (ARDS), prevented septic lung injury and mortality. This study identified DPEP1 as an organ-selective vascular endothelial adhesion receptor for the recruitment of neutrophils and metastatic cancer cells to the lungs and liver and identifies DPEP1 as a novel therapeutic target for systemic inflammatory disorders as well as organ-selective metastatic diseases.
  • Thumbnail Image
    ItemOpen Access
    In Vivo Imaging of Neutrophil Responses to Localized S. aureus Infection
    (2013-12-13) Harding, Mark; Kubes, Paul; Zhang, Kunyan
    Methicillin-resistant Staphylococcus aureus (MRSA) is a highly virulent, multidrug –resistant pathogen responsible for the majority of soft tissue infections. The role of neutrophils in S. aureus soft tissue infections is currently unclear. The objective of this thesis was to characterize early neutrophil recruitment to a localized MRSA infection. Using spinning disk confocal microscopy, we developed a mouse model to visualize the behaviour of neutrophils in the skin following the introduction of an agarose bead embedded with GFP-expressing MRSA. We observed significant neutrophil recruitment not only in the venules but also in the capillaries, which we showed to be mediated by the β2 and α4 integrins. Blocking these integrins in mouse models increased capillary perfusion, reduced cell death at early time points, and altered lesion size during infection. Understanding the contribution of neutrophils in MRSA soft tissue infection will help to elucidate novel therapeutic targets in these infections.
  • Thumbnail Image
    ItemOpen Access
    Incidence, prevalence, and occurrence rate of infection among adults hospitalized after traumatic brain injury: study protocol for a systematic review and meta-analysis
    (BioMed Central, 2013-08-24) Scott, Brittney NV; Roberts, Derek J; Robertson, Helen Lee; Kramer, Andreas H; Laupland, Kevin B; Ousman, Shalina S; Kubes, Paul; Zygun, David A
  • Thumbnail Image
    ItemOpen Access
    Integration of metabolic and inflammatory mediator profiles as a potential prognostic approach for septic shock in the intensive care unit
    (Critical Care, BioMed Central, 2015-01-15) Mickiewicz, Beata; Tam, Patrick; Jenne, Craig N; Leger, Caroline; Wong, Josee; Winston, Brent W; Doig, Christopher; Kubes, Paul; Vogel, Hans J
    Introduction Septic shock is a major life-threatening condition in critically ill patients and it is well known that early recognition of septic shock and expedient initiation of appropriate treatment improves patient outcome. Unfortunately, to date no single compound has shown sufficient sensitivity and specificity to be used as a routine biomarker for early diagnosis and prognosis of septic shock in the intensive care unit (ICU). Therefore, the identification of new diagnostic tools remains a priority for increasing the survival rate of ICU patients. In this study, we have evaluated whether a combined nuclear magnetic resonance spectroscopy-based metabolomics and a multiplex cytokine/chemokine profiling approach could be used for diagnosis and prognostic evaluation of septic shock patients in the ICU. Methods Serum and plasma samples were collected from septic shock patients and ICU controls (ICU patients with the systemic inflammatory response syndrome but not suspected of having an infection). 1H Nuclear magnetic resonance spectra were analyzed and quantified using the targeted profiling methodology. The analysis of the inflammatory mediators was performed using human cytokine and chemokine assay kits. Results By using multivariate statistical analysis we were able to distinguish patient groups and detect specific metabolic and cytokine/chemokine patterns associated with septic shock and its mortality. These metabolites and cytokines/chemokines represent candidate biomarkers of the human response to septic shock and have the potential to improve early diagnosis and prognosis of septic shock. Conclusions Our findings show that integration of quantitative metabolic and inflammatory mediator data can be utilized for the diagnosis and prognosis of septic shock in the ICU.
  • Thumbnail Image
    ItemOpen Access
    Intravenous immunoglobulin in leukocyte recruitment
    (2005) Gill, Varinder; Doig, Christopher J.; Kubes, Paul
  • Thumbnail Image
    ItemEmbargo
    Investigating the Role of Maternal Microbiota and Antibodies in Development of the Neonatal Immune System
    (2023-05-02) Czyz, Sonia; McCoy, Kathy D.; Kubes, Paul; Ousman, Shalina
    Microbial colonization in early life plays a critical role in the development and education of the host’s immune system. However, the precise mechanisms underlying microbial-immune interactions during the early life period are still under investigated. Postnatal colonization of the body with microbes was assumed to be the main stimulus for neonatal immune development. However, our group previously demonstrated that the maternal microbiota during gestation shapes the immune system of the offspring, both in utero and postnatally. This thesis aims to examine the underlying mechanisms by which the maternal microbiota drives neonatal immune development and the functional consequence of the maternal microbiota on offspring resistance to systemic infection. To disassociate the effects of the maternal microbiota from microbial signals coming from colonization after birth, a model of ‘gestational-only colonization’ was utilized. Firstly, the neonatal Fc receptor (FcRn) was found to be required for gestational-only colonization to induce ILC3 populations in the neonatal gut. Mechanistically, this suggests that the FcRn is necessary for transportation of maternal IgG-bound microbial products and metabolites to the offspring. Secondly, transfer of maternal anti-E. coli IgG induced ILC3 populations in the neonate, even when it was associated with products and metabolites generated by another bacterial species. This suggests that bacterial molecules may bind IgG in a non-specific manner and that this is sufficient to transfer the associated molecules to induce offspring immune cell changes. Lastly, we found gestational-only colonization led to reduced bacterial load in multiple offspring systemic organs after intravenous challenge with the pathogen S. aureus. Despite this, gestational-only colonization was not sufficient to protect the neonate from bacterial sepsis. Overall, this thesis revealed how maternal microbial products and metabolites are handled at the maternal-offspring interface in early life to educate the neonatal immune system and impact health outcomes in systemic infection.
  • Thumbnail Image
    ItemOpen Access
  • Thumbnail Image
    ItemOpen Access
    Leukocyte recruitment in contact sensitivity
    (2004) Hwang, John Muen; Kubes, Paul
    Contact sensitivity is an inflammatory disorder characterized by leukocyte recruitment. We used intravital microscopy to directly visualize leukocyte rolling and adhesion. By blocking specific adhesion molecules, we elucidated the molecular mechanisms mediating early leukocyte recruitment to be E- and P-selectin and then demonstrated that leukocyte recruitment in the late phase had a different adhesive profile (mainly a4- integrin). Complete blockade of E- and P-selectin within the first 2 hours of leukocyte­endothelial cell interactions eliminated selectin-independent leukocyte recruitment at 24 hours. Specific elimination of CD4, lymphocytes in the early phase eliminated the late response. Addition of these same CD4+ lymphocytes two hours after antigen challenge was too late for these cells to home to the skin. We further established that mast cells act to modulate the T-lymphocyte response in CS. In the absence of mast cells, T1-1l cells preferentially adhere to vascular endothelium, whereas T112 cells preferentially adhere in wild-type mice.
  • Thumbnail Image
    ItemOpen Access
    Leukocyte recruitment mechanisms in acute and chronic inflammation
    (1999) Johnston, William Brent; Kubes, Paul
  • Thumbnail Image
    ItemOpen Access
    Lymph Node Stromal Network-Guided Lymph Drainage Regulates Neutrophil Response to S. aureus Infection
    (2024-09-12) Xue, Jingna; Liao, Shan; Kubes, Paul; Peters, Nathan; Lahl Christoforo, Katharina; Gommerman, Jennifer
    The lymph transports various molecules (i.e., tissue waste, antigens, immunoregulators, cells) to the lymph nodes (LNs). A unique LN conduit network made by fibroblastic reticular cells (FRC-conduit network) guides the drainage of lymph-derived molecules inside the LNs from entry to exit, as well as to high endothelial venules (HEVs) efficiently. Thereby, lymph drainage ensures timely immune protection. Within 4 hour-post-Staphylococcus aureus skin infection (4hpi), neutrophils infiltrate the LN through HEVs and prevent systemic S. aureus dissemination. The mechanism of this efficient recruitment and the connection between skin and LN was not fully understood. Here, I found that the timely neutrophil migration from HEV relies on lymph drainage using a lymphatic occlusion model. Further studies showed that the essential regulatory factors drained with lymph that regulate neutrophil recruitment in the LN are infection-induced chemokines (i.e., CXCL1 and CXCL2) rather than bacteria. Infection often occurs with complicated pre-existing conditions, potentially due to the pre-altered host immune environment. Using Oxazolone (OX)-induced skin inflammation, I observed an interrupted FRC-conduit network and reduced lymph reaching HEV in the LN. When infection occurs during OX-induced inflammation, I found altered neutrophil distribution, which diminished interaction with bacteria and a decreased CXCL1/2 level in the LN. A prolonged bacterial clearance was also observed in OX-inflamed LN, and a trend of systemic bacterial spreading was found in OX-induced inflammation. Next, I investigated the mechanism by which the FRC-conduit network is altered and explored whether targeting the FRC-conduit network can improve neutrophil response. Using single-cell RNA sequencing (scRNAseq) and immunofluorescence staining, I characterized the alteration of FRC subsets and plotted the changes to the LN niches. Notably, I identified a new FRC subset, Cxcl13inter RCs, generated in the OX-inflamed LNs, which only produce low levels of conduit components and thus cause a conduit loss. The induction of this new subset is from proliferative adjacent FRCs depending on B cell-derived lymphotoxins. Depletion of B cells eliminates the induction of Cxcl13inter RCs and preserves the conduit network and lymph drainage to HEVs. Upon subsequent S. aureus infection, the neutrophil response was also rescued, which is associated with better restrained systemic bacteria dissemination. Overall, this thesis demonstrates that lymph drainage guided by the FRC-conduit network in the LNs is critical to ensure optimal neutrophil migration and timely innate immune protection in S. aureus infection.
  • Thumbnail Image
    ItemOpen Access
    Mechanisms involved in thrombin-induced leukocyte recruitment
    (2002) Kaur, Jaswinder; Kubes, Paul