7th joint conference "Joint Microbiology & Infection Conference 2024" of the DGHM and VAAM

Prof. Dr.

Chair

Laudatio

Others

Abstract: Pathogenicity of most Gram-negative human and plant pathogenic bacteria depends on a type III secretion (T3S) system which injects effector proteins (T3Es) into the eukaryotic cell. We study the interaction between Xanthomonas euvesicatoria and its host plants pepper and tomato. The bacteria enter plant tissues via natural openings (stomata) or wounds and settle down in the intercellular spaces. This intimate contact induces expression of the bacterial T3S system, a nanomachine spanning both bacterial membranes, prolonged by a T3S pilus, a thin and hollow structure (in animal pathogens corresponding to the needle). The Xanthomonas T3S system injects more than 30 different T3Es into the plant cell, termed Avr (avirulence protein), if they were identified before the discovery of the T3S system, or Xop (Xanthomonas outer protein). The outcome of an infection depends on the genotype of both the plant and the bacterium. In susceptible plants, T3Es interfere with host cell processes to the benefit of the pathogen and allow its proliferation. In a resistant plant, a plant resistance gene mediates recognition of a “corresponding” T3E, often resulting in a hypersensitive response (HR), a rapid and localized programmed cell death restricting pathogen multiplication. T3Es from Xanthomonas exhibit different biochemical activities, e.g., as plant immunity suppressors, cell death inducers, ubiquitin ligase or transcription factor. Selected T3Es will be discussed.

How a plant pathogenic bacterium manipulates the plant

Plenary Speaker

Plenary Lecture

Abstract: The last few decades has seen a tremendous increase in our understanding of the mechanisms underlying the development of protective anti-microbial immunity. Key among these discoveries is the identification of pattern recognition receptors (or PRRs) expressed by immune cells, which recognise conserved microbial components. Recognition of these structures by PRRs, such as members of the C-type lectin receptor (CLR) family, triggers intracellular signalling cascades that initiate a variety of cellular and inflammatory responses, and induce the development of pathogen-specific adaptive immunity. We now understand that innate recognition by CLRs is essential for the development of protective antimicrobial immunity, but that they also play a key role in other aspects of immunity. In this presentation, I will present an up to date overview of the role of these receptors in immunity, with a particular focus on anti-fungal immunity, and highlight some aspects of ongoing work from my laboratory.

DGHM Lecture & Hans-Günter-Schlegel Lecture

Appointment

Chair

Programme