Marina Ulanova, MD, PhD
Dr. Marina Ulanova is a full time tenured faculty member in the Medical Sciences
Division, Northern Ontario School of Medicine (NOSM) at the Lakehead University
campus (Thunder Bay, Ontario). In addition to teaching Fundamentals of Medicine for
medical students, Dr. Ulanova is involved in the supervision of undergraduate and
graduate Lakehead University students enrolled in various programs (Biology,
Chemistry, Health Sciences, Applied Bio-Molecular Science, PhD Program in
Biotechnology). She also holds a faculty appointment at the Laurentian University
(Faculty of Medicine and the Biomolecular Sciences PhD program).
Dr. Ulanova obtained her MD from the Pirogov Memorial Moscow State Institute of
Medicine and her MSc and PhD in Immunology/Pediatrics from the Institute of
Pediatrics, Russian Academy of Medical Sciences (Moscow, Russia). She obtained a
second PhD in Clinical Immunology from the University of Gothenburg (Sweden). After
relocating to Canada in 2000, she completed postdoctoral training in Dr. Dean Befus’
group at the University of Alberta. She has been an Associate Professor at NOSM since
2005.
Since her early studies in pediatric immunology in Russia, Dr. Ulanova has always been
fascinated with the remarkable immunological mechanisms which protect the respiratory
system against any potential insults. She studied immunological mechanisms of
respiratory diseases for many years and at different levels, ranging from the role of
secretory immunoglobulins in mucosal immune defense against acute respiratory
infections in the 1980s, and specific immune response to pneumococcal serotypespecific antigens causing pneumonia in children in the 1990s, to signal transduction
mechanisms mediating asthma attacks during her postdoctoral training in the 2000s.
Her current research concerns the molecular mechanisms underlying the interactions
between pathogenic bacteria and lung epithelial cells with specific emphasis on innate
immune and inflammatory responses induced by the opportunistic pathogen
Pseudomonas aeruginosa. She is also interested in vaccine immunology, particularly in
the effect of pediatric vaccination against Haemophilus influenzae type b (Hib) and
Streptococcus pneumoniae on modern immunoepidemiology of invasive H. influenzae
and S. pneumoniae disease, i.e. changing host-pathogen interactions and microbial
ecology in the post-vaccine era. In collaboration with clinical faculty at NOSM, she
investigates immune response of immunodeficient patients to encapsulated bacterial
pathogens. In addition, she studies epidemiology of community acquired pneumonia with
particular emphasis on predisposing immunological factors in the Aboriginal population
of Northern Ontario.
The Ontario Thoracic Society had supported Dr. Ulanova’s research through the OTS
Grants-In-Add Program.
When she takes a break from her busy schedule, Dr. Ulanova greatly enjoys the unique
natural environment of Northern Canada. She spends her free time kayaking, hiking,
cross-country skiing, and doing nature photography.
The Role of Syk In Acute Pulmonary Infection Caused by Pseudomonas
Aeruginosa
Principal Investigator: Marina Ulanova, MD, PhD
Introduction
The opportunistic bacteria Pseudomonas aeruginosa cause severe lung damage in
patients with ventilator-associated pneumonia (VAP) in intensive care units.1 The overall
mortality rate for P. aeruginosa associated VAP is 69%, with septic shock being the most
common immediate cause of death.2 Although it is evident that an excessive
inflammation of infected cells in the lung is the reason for the detrimental tissue damage
caused by P. aeruginosa infection, the underlying molecular mechanisms are poorly
defined.
Since the non-receptor protein tyrosine kinase Syk was discovered in lung epithelial cells
several years ago,3 researchers have been puzzled by the role of this molecule in the
lung. It is well established that Syk is a critical component of immunoreceptor signaling
in hematopoietic cells and its activation in leukocytes is essential for phagocytosis and
the development of B- and T-lymphocytes. Syk also regulates innate immune responses
including pathogen recognition, inflammasome activation, and anti-fungal defense.4 Our
recent studies as well as the research conducted by other scholars demonstrated the
ability of Syk to regulate production of pro-inflammatory molecules by bronchial epithelial
cells stimulated with a cytokine TNF-α 5,6 or infected by human rhinovirus.7
We hypothesized that Syk is critically involved in the regulation of inflammatory
responses caused by P. aeruginosa infection and that its inhibition may alleviate the
process of lung tissue destruction during this infection. To test this hypothesis we used a
selective Syk inhibitor piceatannol, which is a naturally occurring non-toxic bioactive
compound present in various plants.
Methods
We infected Syk-positive H292 or Syk-negative A549 lung epithelial cell lines with P.
aeruginosa and assessed the resulting cellular responses, i.e. production of proinflammatory cytokines, adhesion molecule expression, generation of reactive oxygen
species (ROS), and apoptosis of infected cells, using multiplex bead-based
immunoassay and flow cytometry. We also studied internalization of P. aeruginosa using
the gentamicin exclusion assay. To assess the involvement of Syk, we pretreated cell
cultures with a low dose of piceatannol considered to be Syk-selective.
Results & Discussion
P. aeruginosa infection caused potent activation of inflammatory responses of infected
cells, i.e. release of pro-inflammatory cytokines IL-2, IL-6, IL-8, IFN-γ, GM-CSF, TNF-α,
along with the up-regulation of the expression of ICAM-1, an adhesion molecule involved
in the recruitment of activated leukocytes into inflamed lung tissue. Moreover, the
infected cells produced large amounts of intracellular ROS and underwent apoptosis,
reproducing an in vivo infectious process when P. aeruginosa induce the oxidative stress
of infected cells enhancing inflammation and tissue damage. As ROS can initiate
apoptosis of epithelial cells infected with P. aeruginosa,8 such mechanism may further
contribute to lung injury.
We found that piceatannol treatment significantly suppressed inflammation, oxidative
stress, and apoptosis in H292, but not in A549 cells, implicating Syk participation in the
regulation of the pathological processes induced by P. aeruginosa infection.
Considering that normal lung epithelium, i.e. bronchial epithelial cells, as well as type I
and II pneumocytes express large amounts of Syk¸3 its activation during P. aeruginosa
infection may be significantly involved in the pathogenesis of acute lung injury caused by
this pathogen. Intriguingly, piceatannol was able to down-regulate the internalization of
P. aeruginosa by both Syk-positive, and Syk-negative cell lines implying that the
mechanisms of action of this compound, even when used at a low concentration, may
extend beyond Syk inhibition.
Clinical Relevance
Our findings provide a rationale for the use of specific inhibitors of Syk tyrosine kinase to
alleviate two central components in the pathogenesis of acute P. aeruginosa pulmonary
infection, i.e. inflammation and tissue damage. The effect of piceatannol on P.
aeruginosa infection is apparently more complex than expected, and may involve
targeting multiple signaling pathways, apart from Syk-dependent ones. As piceatannol
can interfere with several mechanisms of bacterial pathogenesis, including Sykindependent internalization, this natural compound deserves further study as a potential
therapeutic option in P. aeruginosa infection.
References
1. Garau J and Gomez L: Pseudomonas aeruginosa pneumonia. Curr Opin Infect Dis
(2003) 16:135-43.
2. Crouch Brewer S, Wunderink RG, Jones CB, et al: Ventilator-associated pneumonia
due to Pseudomonas aeruginosa. Chest 1996, 109:1019-29.
3. Ulanova M, Duta F, Puttagunta L, et al: Spleen tyrosine kinase (Syk) as a novel target
for allergic asthma and rhinitis. Expert Opin Ther Targets 2005, 9:901-21.
4. Mócsai A, Ruland J, Tybulewicz VLJ: The SYK tyrosine kinase: a crucial player in
diverse biological functions. Nature Rev Immunol 2010, 10:387-402.
5. Ulanova M, Puttagunta L, Marcet-Palacios, et al: Syk tyrosine kinase participates in
β1-integrin signaling and inflammatory responses in airway epithelial cells. Am J Physiol
Lung Cell Mol Physiol 2005, 288:L497-507.
6. Ulanova M, Marcet-Palacios M, Munoz S, et al: Involvement of Syk kinase in TNFinduced nitric oxide production by airway epithelial cells. Biochem Biophys Res Commun
2006, 351: 431-7.
7. Wang X, Lau C, Wiehler S, et al: Syk is downstream of intercellular adhesion
molecule-1 and mediates human rhinovirus activation of p38 MAPK in airway epithelial
cells. J Immunol 2006, 177:6859-70.
8. Jendrossek V, Grassme H, Mueller I, Lang F, Gulbins E: Pseudomonas aeruginosainduced apoptosis involves mitochondria and stress-activated protein kinases. Infect
Immun 2001, 69: 2675-83.
Research Review 2011; Volume 8