Lactoferrin (Lf) is an iron binding protein produced in mammals. It
has antimicrobial and immunomodulatory properties. Some bacteria that
regularly colonize mammalian hosts have adapted to living in high Lf
environments. Helicobacter pylori, which inhabits the human gut, was
chosen as a model organism to investigate how bacteria may adapt to Lf.
H. pylori was able to use iron from fully saturated human Lf (hLf)
in various low iron media, achieving growth levels similar to the ironreplete
control. Partially saturated hLf decreased growth, yet both partially
saturated bovine Lf (bLf) and hLf were able to increase internalization of
bacteria into mammalian tissue culture cells. A substantially larger
increase in internalization was seen when bacteria were supplemented with
hLf in low iron conditions, possibly mediated by iron-regulated cellular
receptors or bacterial lactoferrin binding proteins.
In eukaryotes, Lf is known to bind and facilitate internalization of
DNA into cells and sometimes the nucleus, and upregulate gene
expression. Here, one hundred bacterial genomes were surveyed for known
Lf binding sites as an indication that Lf had similar functions using
bacterial DNA. While the frequency and location of Lf binding sites
suggest they occur at random, their presence in all genomes suggests that
Lf may be able to act as a vector for bacterial DNA, and facilitate the
movement of genes between species.
Lf is being widely considered for commercial and therapeutic uses,
with significant interest in producing it in genetically modified organisms
(GMO). Widespread production and use of Lf could increase the number
of bacteria that are adapted to it. How Lf interacts with bacteria adapted to
it, and the ability of it to act as a DNA vector, may have relevance for
GMO risk assessment.
| Identifer | oai:union.ndltd.org:canterbury.ac.nz/oai:ir.canterbury.ac.nz:10092/2850 |
| Date | January 2009 |
| Creators | Coray, Dorien Skye |
| Publisher | University of Canterbury. School of Biological Sciences |
| Source Sets | University of Canterbury |
| Language | English |
| Detected Language | English |
| Type | Electronic thesis or dissertation, Text |
| Rights | Copyright Dorien Skye Coray, http://library.canterbury.ac.nz/thesis/etheses_copyright.shtml |
| Relation | NZCU |
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