Colonization of Germ-free Transgenic Mice with Genotyped Helicobacter pylori Strains from a Case-Control Study of Gastric Cancer Reveals a Correlation between Host Responses and HsdS Components of Type I Restriction-Modification Systems

Posted by: | August 17, 2020 | Comments

Real  time  quantitative  RT-PCR  assays  of  host  re-sponses  to  colonization  with  clinical  isolates: fold  changes Hsp70, pIgR, and IL-1β mRNA levels in the stomachs of tox176 mice sacrificed 4 weeks after inoculation of the indicated isolate (reference control = age-matched germ-free mice). Mean values ± 1 S.E. for each group of four colonized mice are plotted. Binding, based on the in situ assay results shown in Table I.

Abstract

Helicobacter pylori infects the stomachs of half of all humans. It has a relatively benign relationship with most hosts but produces severe pathology, including gastric cancer, in others. Identifying the relative contributions of host, microbial, and environmental factors to the outcome of infection has been challenging. Here we describe one approach for identifying microbial genes that affect the magnitude of host responses to infection. Single colony purified H. pylori isolates were obtained from 25 cases and 71 controls in a Swedish case-control study of gastric cancer. Strains were first phenotyped based on their ability to produce adhesins that recognize two classes of human gastric epithelial receptors. Thirteen binding strains and two non-binding controls were then subjected to whole genome genotyping using H. pylori DNA microarrays. A cohort of “variable” genes was identified based on a microarray-determined call of “absent” in at least one member of the strain panel. Each strain was subsequently introduced into two types of germ-free transgenic mice, each programmed to express a different host factor postulated to pose increased risk for development of severe pathology.

Read more at: The Journal of Biological Chemistry

Britta M. Björkholm, Janaki L. Guruge, Jung D. Oh, Andrew J. Syder, Nina Salama, Karen Guillemin, Stanley Falkow, Christina Nilsson, Per G. Falk, Lars Engstrand, and Jeffrey I. Gordon. The Journal of Biological Chemistry. DOI: 10.1074/jbc.M203613200. 8 July 2002.





Stay up-to-date!
Email Address *
First Name
Last Name

* indicates required
Privacy Policy




Terms & Conditions | Privacy Policy | © 2020 The Translational Microbiome Research Forum