Team:Ciencias-UNAM/Project

Home > Project > Overview

ABSTRACT

The human peptide LL-37 is a cationic peptide with antimicrobial activity against both Gram-positive and Gram-negative microorganisms. It has been shown to protect against gastritis caused by Helicobacter pylori infection. Most of the current synthetic expression systems for LL-37 depend on the construction of soluble fusion partners to avoid cytotoxic effects of the antimicrobial peptide in the E. coli host strain. However, the fusion systems require additional cleavage steps using enzymatic or chemical methods, which makes them impossible to express an active LL-37 peptide in vivo. In order to create a resistant host that can export LL-37 to the media, we intend to overexpress the E. coli marRAB operon, which activates the AcrAB-TolC efflux pump, a mechanism that has been related with resistance to this and similar antimicrobial peptides by expulsion. Our aim is to create a system in which E. coli expels LL-37 only when H. pylori and other pathogenic bacteria are present. In order to do this, we are using the LsrA promoter, which allows transcription in presence of AI-2, a molecule produced by bacteria to communicate via quorum-sensing.

Helicobacter pylori colonizes the stomach of 50% of the world's human population throughout their lifetimes. Colonization with this organism is the main risk factor for peptic ulceration as well as for gastric adenocarcinoma and gastric MALT (mucosa-associated lymphoid tissue) lymphoma. Treatment for H. pylori has revolutionized the management of peptic ulcer disease, providing a permanent cure in most cases. Such treatment also represents first-line therapy for patients with low-grade gastric MALT lymphoma. Treatment of H. pylori is of no benefit in the treatment of gastric adenocarcinoma, but prevention of H. pylori colonization could potentially prevent gastric malignancy and peptic ulceration [1,2].

Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Maecenas ut semper libero. Sed vel risus sit amet nisl tempor fringilla eget vitae mauris. Maecenas eget mauris lobortis, tincidunt ligula a, malesuada mauris. Donec quam nisi, gravida sit amet suscipit eget, ornare ut risus. Cras dui ante, semper at nisi in, volutpat rutrum lectus. Pellentesque orci sem, faucibus venenatis lacus eu, tempus vehicula justo. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis molestie elementum magna. Donec faucibus placerat sem, nec lobortis quam pharetra posuere. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam convallis aliquam pretium. Nunc eu lectus vitae odio venenatis rutrum ac non est. Morbi congue eros id lobortis fermentum. Aliquam erat metus, interdum mollis laoreet eget, aliquet at mi.

Aliquam vitae dolor non elit auctor laoreet nec a purus. Fusce lacinia facilisis est nec facilisis. Aliquam ac felis quis mauris ornare semper. Vivamus posuere dui non erat ullamcorper, in semper justo posuere. Donec vitae elit dui. Nulla eget lorem sem. Sed venenatis, magna nec hendrerit commodo, elit tortor fermentum dui, tincidunt tristique dolor nisi non tellus. Donec aliquam.

PROJECT MENU

Overview

General Design

Wet Lab

BioBricks

Results

Characterization

Protocols

Dry Lab

Modelling

Conclusions

Future Work

References