% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Zierow:63712,
author = {Zierow, Swen},
othercontributors = {Bernhagen, Jürgen and Wolf, Klaus},
title = {{S}tructure, function, and mechanism of human {MIF} and
parasitic orthologs},
address = {Aachen},
publisher = {Publikationsserver der RWTH Aachen University},
reportid = {RWTH-CONV-125136},
pages = {V, 112 S. : Ill., graph. Darst.},
year = {2008},
note = {Prüfungsjahr: 2008. - Publikationsjahr: 2010; Aachen,
Techn. Hochsch., Diss., 2008},
abstract = {The cytokine macrophage migration inhibitory factor (MIF)
is a key mediator of the innate and adaptive immune system
and plays a critical role in many inflammatory diseases. MIF
is required to combat serious infections; however,
high-level production of MIF has been linked to a severe
outcome of many diseases including adult respiratory
distress syndrome, septic shock, rheumatoid arthritis,
atherosclerosis and cancer. Over the last years, MIF has
also been ascribed important functions in the host defense
against several parasitic infections. Consequently, anti-MIF
therapies have been suggested as a potential therapeutic
approach for treating MIF-related diseases. Unique among
cytokines, MIF possesses an enzymatic activity that is
evolutionarily conserved. Herein, 4-iodo-6-phenylpyrimidine
(4-IPP), a MIF inhibitor which is ~ 5-10 times more potent
in blocking MIF-dependent catalysis than other prototypical
MIF inhibitors is described. Crystallographic studies reveal
4-IPP to serve as a suicide substrate for MIF, resulting in
the covalent modification of the catalytically active
N-terminal proline and loss of function of MIF-induced
monocyte migration. Additionally, two parasitic orthologs of
MIF, which are produced by the obligate intracellular
parasites, Leishmania major (LmMIF) and Plasmodium
falciparum (PfMIF) were studied. An interest in the
structure and function of MIF orthologs from parasites has
emerged recently as they might have relevant functions in
corrupting the host MIF’s induced immune defense
mechanisms. By co-evolving with the immune system, parasitic
organisms have evolved specialized strategies to circumvent
the host’s immune defense mechanisms to increase their own
chances of survival. To assess whether LmMIF and PfMIF have
the potential to disrupt immunological pathways of the
host’s immune system, the parasitic proteins were
recombinantly produced and purified. LmMIF and PfMIF show
significant binding interaction with the human MIF receptor,
CD74 (Kd ~ 28 nM), and like its mammalian counterpart, the
recombinant LmMIF protein is internalized by macrophages,
induces monocyte cell migration, ERK1/2 MAP kinase
activation, inhibits the activation-induced apoptosis of
macrophages and binds the Golgi-associated tethering protein
p115. The Leishmania MIF protein shows significant
structural homology with human MIF as revealed by a
high-resolution x-ray crystal structure (1.03 Å).
Significant differences between the two proteins in the
N-terminal tautomerization site are evident, and evidence
for the selective, species-specific inhibition of MIF by
small-molecule antagonists that target this site is
provided. Finally, this thesis was aimed to further
elucidate the molecular basis of MIF’s chemokine-like
functions which were recently shown to be mediated through
interaction to the chemokine receptors CXCR4 and CXCR2.
However, the molecular details of this interaction have not
yet been determined. Herein, a peptide derived from the
N-terminal extracellular region of the CXCR4 receptor as a
site of interaction with human MIF and Leishmania major MIF
is described. From a competitive binding assay and 1H15N
chemical shift perturbation studies, a direct binding
interaction between MIF and the N-terminal 27 residues of
CXCR4 is shown. Titration studies using steady-state
fluorescence spectroscopy resulted in a dissociation
constant of 3.1 µM. Notably, LmMIF/MIF-triggered monocyte
chemotaxis activity is ablated by this N-terminal CXCR4
peptide. The present study not only provides a
crystallographic characterization of the prototypic MIF
inhibitor 4-IPP for a potential treatment of MIF-related
autoimmune and inflammatory diseases, but also unfolds
possible new pathways of parasitic MIF-orthologs to
interfere with the host immune system. The study of the
molecular mode of interaction of MIF and its binding
partners will provide new opportunities to block these
interactions specifically, and thus may aid in the design of
new drugs targeting MIF-related diseases and immune evasive
strategies of parasites.},
keywords = {Cytokine (SWD) / Makrophagen-Inhibitionsfaktor (SWD) /
Leishmania major (SWD) / Plasmodium falciparum (SWD) /
Kristallstruktur (SWD) / Immunreaktion (SWD) / Inhibitor
(SWD)},
cin = {513000-4 / 161710 / 160000},
ddc = {570},
cid = {$I:(DE-82)513000-4_20140620$ / $I:(DE-82)161710_20140620$ /
$I:(DE-82)160000_20140620$},
typ = {PUB:(DE-HGF)11},
urn = {urn:nbn:de:hbz:82-opus-26550},
url = {https://publications.rwth-aachen.de/record/63712},
}
guest ::