Research

The mammalian immune system possesses a remarkable ability to discern self from non-self, a critical function in safeguarding against infections. At the molecular level, this discrimination is facilitated by pattern recognition receptors present on eukaryotic cells, which can identify conserved non-self molecules characteristic of microorganisms. Among these molecules, lipopolysaccharide (LPS) stands out as a complex glycolipid abundantly present in Gram-negative bacterial cell wall, playing a central role in host-pathogen interaction. LPS is universally recognised by specific innate immune proteins that elicit a beneficial pro-inflammatory defense response to infection while maintaining immune homeostasis. However, bacterial pathogens possess various mechanisms to adapt their cell membranes in response to transmission between the environment, vectors, and human hosts, often altering LPS composition to modulate the host immune response. In particular, modifications to the phosphate groups of lipid A, the major immunostimulatory component of LPS, can shield bacteria from recognition by host cationic antimicrobial peptides. Yet, the impact of such modifications on LPS-specific pattern recognition receptors of the host innate immune system remains largely unexplored, particularly with regard to the recently identified cytosolic LPS-sensing proteins crucial for anti-tumor immunity. Due to the high heterogeneity of bacterial glycans and the inherent instability of modified phosphate groups, the isolation of structurally defined intact LPS fragments from bacterial sources is not feasible. Chemical synthesis, however, is a reliable method for providing molecularly defined immunomodulatory LPS motifs to study the effects of unique phosphate group modifications on the interaction with host immune receptors involved in antitumour defence. Carbohydrate chemistry, or glycochemistry, offers versatile tools for the synthesis of complex glycans, providing structurally defined, homogeneous molecules of high purity suitable for biological studies. Leveraging the glycochemistry toolbox, our project aims to develop innovative synthetic strategies for the assembly of complex phosphorylated glycans, culminating in a library of bacterial LPS motifs with phosphate group modifications reflecting those found in different bacterial species. In collaboration with international research groups in immunology and structural biology, we will investigate the immunobiological activity and interaction of our synthetic phosphorylated glycolipid-glycan library with corresponding proteins. By developing a collection of synthetic bacterial lipid A variants and LPS epitopes with uniquely modified phosphate groups, our research aims to elucidate the structural and molecular basis of their interaction with host innate immune receptors, thereby advancing our understanding of LPS-induced antibacterial defense and antitumor immunity mechanisms.

Considering the pressing global challenges posed by climate change and the plastic waste crisis, there is an urgent need for researchers to address environmental issues. This requires exploring alternative resources and adopting novel approaches to minimize waste generation and replace oil-based, non-degradable plastics with renewable and sustainable bio-based alternatives. A highly promising source for the latter purpose is agri-food by-products. Despite their abundance —the annual production of wheat straw and corn stover equals almost 3000 Mt—their efficient valorization and processing into shapeable and strong materials remains a major challenge. The research hypothesis of the here-submitted research project SusFoMa is that accruing lignocellulosic feedstocks can be directly processed into precursors of cellulose nanofiber-reinforced thermoplastics by a sustainable chemical approach. The proposed chemical modification is based on esterification approaches, which can be controlled to selectively modify the biopolymer matrix of locally available food waste, such as corn stover and sugarcane bagasse, transforming these secondary biomass streams into moldable biopolymers. Our proposed chemical modification is based on esterification techniques, which allow us to selectively modify the biopolymer matrix of locally available food waste, such as corn stover and sugarcane bagasse. By doing so, we aim to convert these secondary biomass streams into moldable biopolymers. What sets our method apart from previous approaches is our emphasis on preserving the structural integrity of cellulose nanofibers. These nanofibers, known for their exceptional mechanical strength, are the smallest building blocks within the cellulose fiber of plant cells. SusFoMa aims to utilize these nanofibers to create high-performance bioplastics that are competitive in the market.

The HistoGenes project unites historians, archaeologists, geneticist, anthropologists, and specialists in bio-informatics, isotope analysis and other scientific methods in order to investigate human migration in the Carpathian Basin after the break down of the Roman Empire 400-900 CE. www.histogenes.org The Institute of Analytical Chemistry (IAC) at the University of Natural Resources and Life Sciences, Vienna will perform the analysis of strontium isotopic n(87Sr)/n(86Sr) ratios and multi-elemental patterns of teeth from individuals excavated at two Awar cemeteries in Austria. Furthermore, the IAC will cooperate with the other beneficiaries for interpretation of the results, which can only be done in an interdisciplinary team due to the complexity of the burial site. The gained information will allow to understand if individuals were local or migrated. This will advance our knowledge about population dynamics in a key period in European history.