Faculty Recruitment Public Seminars – GHI Position in Host-microbe Interactions

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Event details

Date 02.06.2022 03.06.202210:0015:30  
Speaker As per programme
Location
Category Conferences - Seminars
Event Language English
All seminars in SV 1717 except Amelia Barber Friday, June 3, 2022, 10.15 - 11.15 ---> AI 1153

Thursday, June 2, 2022, 10.00 - 11.00, SV 1717

Dr. Camille Goemans
EMBL, Heidelberg
The impact of antibiotics on the human gut microbiota

Antibiotics are used to fight pathogens but also target commensal bacteria, disturbing the composition of gut microbiota and causing dysbiosis and disease. Despite this well-known collateral damage, the activity spectrum of different antibiotic classes on gut bacteria remains poorly characterized. We tested the impact of 144 antibiotics on 38 representative human gut microbiome species and found out that antibiotics with broad inhibition spectrum but selective microbial killing may be the most dangerous for the gut microbiota. In addition, we screened and identified drugs that specifically antagonized the antibiotic activity against abundant Bacteroides species but not against relevant pathogens. These findings highlight the activity spectra of antibiotics in commensal bacteria and suggest strategies to circumvent their adverse effects on the gut microbiota.

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Thursday, June 2, 2022, 13.30 - 14.30, SV 1717
Dr.Ilana Gabanyi
Institut Pasteur, Paris
The cross-talk between gut-bacteria and neurons

The bacteria present in the intestine, both commensal and potentially pathogenic ones, are able to influence neuronal activity. This cross-talk controls immune responses and host metabolism. In my talk, I will first show how the activation of enteric-associated neurons induced by potentially pathogenic bacteria triggers a tissue-protective response in gut macrophages enabling them to protect the neurons in case of an enteric infection. Next, I will present how brain neurons sense microbiota-derived muropeptides, components of the peptidoglycan present in every bacterial cell wall. This new microbe-sensing mechanism regulates host metabolism and reveals that bacterial peptidoglycan plays a major role in mediating gut–brain communication via the neuronal Nod2 receptor. Activation of Nod2 in hypothalamic inhibitory neurons is essential for proper appetite and body temperature control, primarily in female mice. Understanding the action of neuroactive bacterial compounds helps further elucidate bacterial-host interactions and may open new avenues for the development of targeted treatments for enteric and metabolic diseases.

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Thursday, June 2, 2022, 15.30 - 16.30, SV 1717
Dr. Xin Li
Cornell University, New York
Host-mycobiota interactions: sensing intestinal fungi regulates both local and systemic immunity

The fungal microbiota (mycobiota) is an integral part of the complex, multi-kingdom microbial community which colonizes the mammalian gastrointestinal tract and plays an important role in immune regulation. Fungal dysbiosis has been linked to several immune-mediated diseases. In his seminar, he will share his recent work on the exploration of host-fungal immunological interactions in the gut using integrated approaches. His recent findings unveil the fungal strain-dependent nature of host-fungal interactions in the human gut. Dr. Li will also describe his work on how gut fungal dysbiosis activates the gut fungi-lung allergy immune axis. Dr. Li's future research focuses on how microbiota/mycobiota influence immunological interactions during homeostasis and inflammatory conditions, with the ultimate goal of identifying novel therapeutic targets of inflammatory origin.  

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Friday, June 3, 2022, 08.15 - 09.15, SV 1717
Dr. Ziad Al Nabhani
University of Bern
Early life imprinting of the immune system by gut microbiota

The way we grow up and learn to interact with others affects us lifelong. Similarly, upon birth, the immune system learns from, and interacts with, multiple microorganisms that colonize the intestine referred as "microbiota". Emerging evidence from human and mice studies suggest that perturbation of microbial-immune crosstalk early in infancy have a long-lasting consequence on the host immunity and on the susceptibility to develop chronic inflammatory diseases such as allergy, inflammatory bowel diseases, cancer, metabolic and neurodegenerative disorders. We recently revealed that a strong immune response is induced by the gut microbiota following milk secession and introduction of solid food at weaning. This response termed the "weaning reaction", is induced only at this weaning time window and is required to prevent the development and the exacerbation of chronic inflammatory diseases later in life. Antibiotic exposure and/or excessive fats intake during this critical window dysregulate the weaning reaction and increase the subsequent susceptibility to develop pathology, an immune memory phenomenon called the "pathological imprinting".

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Friday, June 3, 2022, 10.15 - 11.15, ---> AI 1153
Dr. Amelia Barber
Leibniz Institute for Natural Product Research and Infection
Biology-Hans Knöll Institute, Jena Institution
Drug resistance and the genomics of virulence in human fungal pathogens

Fungal infections represent a significant and increasing threat to human health and are responsible for more deaths each year than tuberculosis or malaria. Treatment of these infections remains a significant challenge due to their eukaryotic nature and high similarity to human cells, a problem that is further compounded by the widespread emergence of antifungal resistance. Despite this obvious importance, much about fungal pathogens remains unstudied. In one of the most problematic fungal pathogens, A. fumigatus, a comprehensive survey of genomic diversity and how it contributes to virulence and antifungal drug resistance has been lacking. Through the large-scale genomic analysis of environmental and clinical isolates, we identified a previously undescribed level of genetic variation in A. fumigatus. We also observed an enrichment for clinical isolates in a genetic cluster whose genomes were larger and carried a distinct genomic profile. Finally, we leveraged the power of genome-wide association to identify genomic variation associated with clinical isolates and triazole resistance, as well as characterize genetic variation in known virulence factors. Additional work has focused on identifying environmental drivers of antifungal resistance using a combination of field work, laboratory experiments, and bioinformatics. The work presented here provides a foundation to greatly expand our understanding of an important human fungal pathogen.

Practical information

  • Informed public
  • Free

Organizer

  • Prof. Bruno Lemaitre, Search Committee Chair

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