Shevtsova, A. | bioRxiv Science

bioRxiv2023

Helicobacter pylori attachment-blocking antibodies protect against duodenal ulcer disease

The majority of the world population carry the gastric pathogen Helicobacter pylori. Fortunately, most individuals experience only low-grade or no symptoms, but in many cases the chronic inflammatory infection develops into severe gastric disease, including duodenal ulcer disease and gastric cancer. Here we report on a protective mechanism where H. pylori attachment and accompanying chronic mucosal inflammation can be reduced by antibodies that are present in a vast majority of H. pylori carriers. These antibodies block binding of the H. pylori attachment protein BabA by mimicking BabAs binding to the ABO blood group glycans in the gastric mucosa. However, many individuals demonstrate low titers of BabA blocking antibodies, which is associated with an increased risk for duodenal ulceration, suggesting a role for these antibodies in preventing gastric disease.

immunology↗

bioRxiv2018

Targeted genomic integration of EGFP under tubulin beta 3 class III promoter and mEos2 under tryptophan hydroxylase 2 promoter does not produce sufficient levels of reporter gene expression

Neuronal tracing is a modern technology that is based on the expression of fluorescent proteins under the control of cell type-specific promoters. However, random genomic integration of the reporter construct often leads to incorrect spatial and temporal expression of the marker protein. Targeted integration (or knock-in) of the reporter coding sequence is supposed to provide better expression control by exploiting endogenous regulatory elements. Here we describe the generation of two fluorescent reporter systems: EGFP under pan-neural marker class III {beta}-tubulin (Tubb3) promoter and mEos2 under serotonergic neuron specific tryptophan hydroxylase 2 (Tph2) promoter. Differentiation of Tubb3-EGFP ES cells into neurons revealed that though Tubb3-positive cells express EGFP, its expression level is not sufficient for the neuronal tracing by routine fluorescent microscopy. Similarly, the expression levels of mEos2-TPH2 in differentiated ES cells was very low and could be detected only on mRNA level using PCR-based methods. Our data shows that the use of endogenous regulatory elements to control transgene expression is not always beneficial compared to random genomic integration.

developmental biology↗