Michael R. Miller, Ph.D.
	Professor of Biochemistry Graduate Training: Hershey Medical School, Penn State University Fellowship: Harvard Medical School and Dana-Farber Cancer Institute Department of Pharmacology
	Office: 2286 HSC Lab: 2077 HSC PO Box 9142 Morgantown, WV 26506	Email: mmiller@hsc.wvu.edu Phone: (304) 293-7762 Fax: (304) 293-6846

Research Interests:

We are investigating various aspects of Lyme disease, which is caused by the spirochete Borrelia burgdorferi (Bb).Bb are transmitted to humans via tick bites; once in the skin Bb move through the dermis, often causing a characteristic “bulls eye” inflammation. Bb enter the vascular system where they are disseminated to other tissues, inducing inflammation. In collaboration with Dr. Ping He (WVU Dept. Physiology and Pharmacology) we are studying the interaction of Bb with the vascular system. We have shown that “spent” medium from cultures of virulent Bb rapidly causes an inflammatory reaction in rat microvessels that is characterized by a transient increase in vessel permeability (Figure 1 and publication no. 6 below) and intracellular calcium. This inflammatory reaction is not caused by avirulent Bb, which has lost 8 of the 20 circular and linear plasmids associated with virulent Bb. We are characterizing this inflammatory reaction and the compound(s) responsible for this inflammation. In addition, we are studying, in real time and in vivo, the interaction of Bb with endothelial and blood cells in microvessels. When Bb are introduced into microvessels, they rapidly bundle to leukocytes, with many spirochetes bound to a single leukocyte (Figures 2 and 3 below). In Figure 2 endothelial nuclei are red, spindle shaped; leukocyte nuclei are red, round or polymorphonuclear shape; Bb are green.

Figure 3 is a cross section of a single leukocyte (not stained or colored), showing multiple Bb (green) bundled to it. Figure 4 shows that when Bb attach to endothelial cells (cell can’t be seen in this picture), one end or “head” attaches and the other end or “tail” remains free to move. From these studies we are observing, for the first time, in a living animal, how Bb interacts with cells in the vascular system and how the spirochete penetrates blood vessels.

In collaboration with Dr. Nyles Charon (WVU Dept. Microbiology and Immunology) and Dr. Motaleb (East Carolina University Dept. Microbiology) we are studying the molecular mechanisms regulating Bb chemotaxis and motility. Bb is unusual in that it contains periplasmic flagella which originate at each end of the organism and extend toward the other end, overlapping in the center of the spirochete (see Figure 5).

Rotation of the flagella causes the spirochete to move. Bb can move toward attractants and away from repellents via complex chemotaxis mechanisms. The swimming pattern of Bb is also rather unusual, as demonstrated in Movie 1 – the spirochetes can ‘run’ or translate, ‘flex’ or stop running and ‘reverse’ or change directions. Mutation of some chemotaxis genes causes altered swimming behavior, illustrated in Movie 2 (constant running) and Movie 3 (constant flexing). We have identified several chemo-attractants (ref no. 2 & 3 below), and are characterizing the chemotaxis phospho-transfer system (publication no. 1 & 4 below).

Movie 1	Movie 2	Movie 3

 

Selected Publications:

1. Md.A. Motaleb, M.R. Miller, C. Li, R.G. Bakker, S.F. Goldstein, R.E. Silversmith, R.B. Bourret, and N.W. Charon “CheX is a CheY-P phosphatase essential for Borrelia burgdorferi chemotaxis” J. Bacteriology 187, 7963 – 7969 (2005). PMID: 16291669 PubMed Article
    
    
2. R. G. Bakker, C. LI, M. R. Miller,C. Cunningham, and N. W. Charon "Identification of specific chemoattractants and complementation of cheA2 of Borrelia burgdorferi: A flow cytometry-based capillary tube chemotaxis assay". Applied Env. Microbiol. 73, 1180-1188 (2007). PMID: 17172459 PubMed Article
    
3. Md. A. Motaleb, M. R. Miller, R. G. Bakker, C. Li and N. Charon "Isolation and Characterization of Chemotaxis Mutants of the Lyme Disease Spirochete Borrelia burgdorferi Using Allelic Exchange Mutagenesis, Flow Cytometry and Cell Tracking" Methods in Enzymology, 422, 421-437 (2007). PMID: 17628152 PubMed Article
    
4. Md. A. Motaleb, M. R. Miller, C. Li and N. W. Charon "Phosphorylation assays of chemotaxis two-component system proteins in Borrelia burgdorferi", Methods in Enzymology, 422, 438 – 447 (2007). PMID: 17628153 PubMed Article
    
5. A.M. Magro, A.D. Magro, C. Cunningham and M.R. Miller "Down-regulation of vinculin upon MK886-induced apoptosis in LN18 glioblastoma cells", Neoplasma, 54, 517 - 526 (2007). PMID: 17949236 PubMed Article
    
6. X. Zhou, M. R. Miller, Md. Motaleb, N. W. Charon, P. He “Spent culture medium from virulent Borrelia burgdorferi increases permeability of individually perfused microvessels of rat mesentery” PLoS ONE 3: e4101 (2008). PMID: 19116656 PubMed Article