Modelling SARS-CoV-2 infection in a human alveolus microphysiological system.

The coronavirus 2019 pandemic has highlighted the importance of physiologically relevant models to assist preclinical research. Here, we describe the adaptation of a human alveolus microphysiological system (MPS) model consisting of primary human alveolar epithelial and lung microvascular endothelial cells to study infection with SARS-CoV-2 at Biosafety Level 3 facility. This infection model recapitulates breathing-like stretch and culture of epithelial cells at the air-liquid interface and resulted in clinically relevant cytopathic effects including cell rounding of alveolar type 2 cells and disruption of the tight junction protein occludin.

enhances HS production in .

Sulfate- and sulfite-reducing bacteria (SRB) are a group of strict anaerobes found within the human gut. , a sulfite-reducing bacterium which produces hydrogen sulfide (HS) from taurine and isethionate respiration, is a common member of the healthy commensal human gut microbiota but has been implicated in several disease states including inflammatory bowel disease and colorectal cancer. , one of the most prominent gut bacteria, has sulfatases which release sulfate, serving as a potential substrate for sulfate-reducing bacteria.

The human gut Bacteroides eggerthii expresses a new galactofuranose-containing lipooligosaccharide with weak immunostimulatory properties.

Lipopolysaccharides (LPS) decorating the cell surface of Gram-negative bacteria exhibit nuanced functionalities linked to their precise structural composition. However, despite their critical role in health and disease, information on the structure and function of LPS from members of the human gut microbiota is still limited. Here, we deciphered the complete structure of the LPS isolated from the human gut bacterium Bacteroides eggerthii 1_2_48FAA.

Multifrequency-STD NMR unveils the first Michaelis complex of an intramolecular trans-sialidase from Ruminococcus gnavus.

RgNanH is an intramolecular trans-sialidase expressed by the human gut symbiont Ruminococcus gnavus, to utilise intestinal sialylated mucin glycan epitopes. Its catalytic domain, belonging to glycoside hydrolase GH33 family, cleaves off terminal sialic acid residues from mucins, releasing 2,7-anhydro-Neu5Ac which is then used as metabolic substrate by R. gnavus to proliferate in the mucosal environment.

The human gut symbiont Ruminococcus gnavus displays strain-specific exopolysaccharides modulating the host immune response.

Ruminococcus gnavus is a prevalent member of the human gut microbiota and over-represented in inflammatory bowel diseases. R. gnavus ATCC 29149 was previously shown to produce a pro-inflammatory exopolysaccharide (EPS) referred to here as glucorhamnan-I or EPS.