Articles by Neveda Naz in JoVE
Enteric Bacterial Invasion Of Intestinal Epithelial Cells In Vitro Is Dramatically Enhanced Using a Vertical Diffusion Chamber Model Neveda Naz1, Dominic C. Mills1, Brendan W. Wren1, Nick Dorrell1 1Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine Performing cell culture assays for investigating bacterial adhesion and invasion under aerobic conditions is usually unrepresentative of the in vivo environment. A Vertical Diffusion Chamber model allows study of interactions of the human pathogen Campylobacter jejuni with intestinal epithelial cells under more in vivo-like conditions, resulting in enhanced bacterial invasion.
Other articles by Neveda Naz on PubMed
Campylobacter Jejuni Lipooligosaccharide Sialylation, Phosphorylation, and Amide/ester Linkage Modifications Fine-tune Human Toll-like Receptor 4 Activation The Journal of Biological Chemistry. Jul, 2013 | Pubmed ID: 23629657 Campylobacter jejuni is a leading cause of acute gastroenteritis. C. jejuni lipooligosaccharide (LOS) is a potent activator of Toll-like receptor (TLR) 4-mediated innate immunity. Structural variations of the LOS have been previously reported in the oligosaccharide (OS) moiety, the disaccharide lipid A (LA) backbone, and the phosphorylation of the LA. Here, we studied LOS structural variation between C. jejuni strains associated with different ecological sources and analyzed their ability to activate TLR4 function. MALDI-TOF MS was performed to characterize structural variation in both the OS and LA among 15 different C. jejuni isolates. Cytokine induction in THP-1 cells and primary monocytes was correlated with LOS structural variation in each strain. Additionally, structural variation was correlated with the source of each strain. OS sialylation, increasing abundance of LA d-glucosamine versus 2,3-diamino-2,3-dideoxy-d-glucose, and phosphorylation status all correlated with TLR4 activation as measured in THP-1 cells and monocytes. Importantly, LOS-induced inflammatory responses were similar to those elicited by live bacteria, highlighting the prominent contribution of the LOS component in driving host immunity. OS sialylation status but not LA structure showed significant association with strains clustering with livestock sources. Our study highlights how variations in three structural components of C. jejuni LOS alter TLR4 activation and consequent monocyte activation.