Inflammation causes white blood cells to drastically change shape. This cell is viewed at 8000x! #MacArtofResearch pic.twitter.com/lbWllnnDK6
— MacArtofResearch (@McArtofResearch) April 2, 2016
Dessi Loukov is the lab’s most recent PhD candidate having passed her comprehensive exam with distinction. Congratulations Dessi!
The Bowdish lab is thrilled to participate in NSERC’s “Science, Action!” video contest. An undergraduate team of videographers (Yung Lee, Karanbir Brar, and Tony Chen) filmed our lab discussing our NSERC funded work on discovering the evolutionary origins of phagocytosis. Please “like” and share our video to help us move on to the next level of the competition.
Our NSERC funding has been integral to the lab. This was one of the first grants that got the lab up and running and to date we have had 5 NSERC funded graduate students and 10 undergraduate students including 3 NSERC Undergraduate Summer Research Assistants in the lab. This funding has also been instrumental in developing new techniques, technologies and collaborations that have extended our research capacity.
What are we studying with our NSERC funded research?
Our NSERC Discovery Grant entitled “Uncovering mechanisms of phagocytosis by class A scavenger receptors” allows us to use bioinformatics and molecular biology to understand the very origins of immunity.
Our lab studies macrophages, which are sentinel cells of the innate immune response. They patrol the body and engulf damaged tissues or pathogens and destroy them. This Pac-man like ability to eat microbes is called “phagocytosis”. We study a particular class of receptors that macrophages use to phagocytose called the scavenger receptors.
Phagocytosis is an ancient process that is central to defence and nutrient acquisition in single-celled organisms and embryonic development, clearance of modified host proteins and innate immunity in multi-cellular organisms. During phagocytosis a phenomenal amount of information is transmitted to the cell including the size and shape of the particle, its composition, and potential toxicity. How this information is transmitted is not really understood but is the focus of our work.
All the major discoveries in immunology (e.g. toll like receptors, intracellular sensors, signalling pathways) began with studies in comparative or evolutionary biology and my program of research continues this tradition. Indeed, the process of phagocytosis is believed to be the prototype function of the immune system as acquisition of nutrients developed into a mechanism of self- versus non-self recognition. The process of uptake is so ancient that it must have occurred prior to or in conjunction with the expression of protein receptors on the surface of the cell. The scavenger receptors, being primitive but effective uptake receptors may rely on membrane dynamics and lipid interactions more than their more evolutionarily recent counterparts (e.g. Fc receptors). We use bioinformatics to study the genomes of ancient and modern animals to study how the scavenger receptors change over time. Parts of the scavenger receptor gene or protein that haven’t changed over time, are likely very important for function. We use molecular biology to uncover how these particular regions of the protein work. Studying these processes will uncover novel mechanisms of signalling and contribute to our understanding of the cell biology of endocytosis and phagocytosis, which are processes integral to embryonic development, immunity, homeostasis, implant recognition and adhesion and consequently essential to many fields of biology.
Check out the other videos of the “Science, Action!” video contest here.
http://www.nserc-crsng.gc.ca/ScienceAction/index_eng.asp
To read more about our NSERC funded work click here.
To read the whole article (in German), click here.
Antibiotic treatment alone may not be sufficient to treat pneumonia in older adults. In fact, it appears as though the inflammation that comes naturally with age increases the risk of developing pneumonia. “It sounds counterintuitive to limit inflammatory responses during a bacterial infection, but clinical observations and our research indicates anti-bacterial strategies need to be tailored to the age of the patient,” said MIRC’s Associate Professor Dawn Bowdish.
Aging is accompanied by a chronic state of low-level inflammation — sometimes called ‘inflamm-aging’ — which is associated with diseases such as cardiovascular disease, dementia and infections, particularly pneumonia. Upon recognition of an infectious agent, an acute inflammatory response is required to fight infection and resolves shortly after. However, in older adults, where systemic inflammation is already elevated, increases in inflammation during infection do not resolve as quickly. Exposure to these high levels of inflammation appears to impair the ability of monocytes and macrophages to fight infection.
Published today in the journal PLoS Pathogens, MIRC graduate Dr. Alicja Puchta & PhD student Avee Naidoo demonstrated that the higher levels of inflammation in the blood of old mice caused the premature egress of inflammatory monocytes into the blood stream, and contributed to greater systemic inflammation. Although small amounts of inflammation are required to fight infection, enhanced production of inflammation in old mice lead to reduced monocyte and macrophage function. Reducing levels of inflammation in the young mice had no effect but reducing levels in the old mice resulted in improved bacterial clearance and survival against S.pneumoniae.
The research follows a 2015 McMaster study that showed that older adults with pneumonia do better when given drugs, such as corticosteroids, to reduce inflammation in addition to antibiotics. “Our study in mice is consistent with clinical studies that recommend using anti-inflammatories as part of treatment to improve older adults’ defence against pneumonia, and that points to the development of better care,” said Bowdish.
To read the PLoS Pathogens article, please click here.
We are in the enviable position of being a popular lab and have received a large number of applications for a very small number of positions. We thank you for your interest but I’m afraid that we are no longer accepting applications but wish all the undergraduates searching for summer/thesis positions the very best of luck in their search.
I’ve included this diversity statement on our “Lab Philosophy” page. It’s the first version and may be updated but do let us know what you think about it.
Diversity: Our lab values diversity because we believe that diverse viewpoints and opinions bring with them new perspectives and ultimately better, more creative, more innovative, science. We have members of diverse career stages (high school students to emeritus professors), diverse cultures (we’ve had all 6 continents represented in the lab and our potluck events are delicious!), and diverse upbringings, families, religions, opinions and viewpoints. We acknowledge that each of us brings with us perspectives shaped by our experiences as well as challenges and obstacles. By valuing and celebrating our differences and supporting each other to overcome our personal obstacles, we believe that our science will be the best it can be and, perhaps as importantly, that our trainees will get the support, validation and encouragement they need to be successful and increase the diversity of the scientific community as a whole.
The Bowdish lab will support one application for a PDF fellowship through this funding opportunity. To be competitive, applicants must have an excellent track record of publishing/presenting their PhD work and must write an application that clearly states how working at McMaster and in the Bowdish lab will further their career.
Potential projects include:
1) Discovery of novel immunotherapeutic drugs
2) Uncovering how the microbiota contributes to the aging process
3) Studying mouse models of polymicrobial pneumonia
4) Studying how monocyte function changes with age and contributes to infection
5) Others – please see the projects page for some of our current work.
Interested applicants should contact Dr. Bowidish with a c.v. and brief description of their research interests. Only applicants who have a strong publication record will be competitive for this application.
CFL legend Michael “Pinball” Clemons has partnered with the Ontario Lung Association on an exciting campaign to raise awareness of pneumococcal pneumonia. Launched in recognition of World Pneumonia Day, #Grounded includes a media tour and video. For each view of the #Grounded video or share of the hashtag on social media – Facebook or Twitter – $5.00 will be donated to the OLA! Here is the link. Please watch and share!