Dear colleagues,

don't forget today's seminar at 12.15 via zoom (link below).

The speaker is Dr. Lotta-Riina Sundberg from University of Jyväskylä, on

"Is the test tube telling the whole story? Impact of the mucosal environment on phage-bacterium interplay"

Mucosal surfaces are the first barriers against invading pathogens. However, in addition to immune functions, the outmost layers of mucosal surfaces maintain tissue-specific microbiomes. Viruses, such as bacteriophages are major partners in the microbiomes of the mucosal milieu, contributing to the dynamics of their bacterial hosts. Indeed, many phages have Ig-like binding domains in their structural proteins the capacity to bind to mucins, the large glycoproteins giving the viscous properties for the mucosal surface. This has led to the Bacteriophage Adherence to Mucus -(BAM) hypothesis: eukaryotes accommodate phages on their mucosal surfaces to provide external immunity against bacterial disease. This may have resulted into a symbiotic relationship between metazoans and phages, in which the metazoan host provides phages an environment to encounter bacterial hosts, and phages protect from bacterial infections in this process. We have studied phage binding on mucus and the effect of mucosal environment on phage-bacterium interactions. Our results show that phage adhesion to mucus results in preventive protection against bacterial infections. Interestingly, exposure to mucus upregulates bacterial virulence, which is exploited by phages for infection by increasing infection rate. In response, mucosal environment change the ecology of bacterial resistance against phages by increasing the activity of the CRISPR-Cas adaptation. These results suggest that the traditional co-culture studies may give a biased view on host-associated phage-bacterium interactions, which is strongly influenced by the chemical cues of the metazoan host. This phenomenon might be widespread in the biosphere and thus crucial for understanding mucosal diseases, their outcome and treatment.

Lotta-Riina is an associate professor at the Department of Biological and environmental science, and the Nanoscience Center in Jyväskylä, find out more on her research here: https://lrsundberg.weebly.com/

The rest of the seminar program for the spring is under construction, but we have a few speakers confirmed already: https://thursdayseminarbiology.wordpress.com/

See you soon, Heikki

Heikki Helanterä is inviting you to a scheduled Zoom meeting.

Topic: Biology Thursday seminar Time: This is a recurring meeting Meet anytime

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=============================================== Heikki Helanterä Associate Professor (tenure track) Ekologian ja genetiikan tutkimusyksikkö / Ecology and Genetics Research Unit Oulun Yliopisto / University of Oulu / Finland heikki.helantera@oulu.fimailto:heikki.helantera@oulu.fi +358-40-7507 334