Faculty

Jimmy Ballard, Ph.D.Dr. Jimmy Ballard

 Professor and Chairman

Dr. Ballard studies toxins produced by Bacillus anthracis and Clostridium difficile, two prominent Gram-positive pathogens. He uses a combination of cellular and molecular biology, and bacteriology to study the effects these bacterial toxins on eukaryotic cells, and has pioneered the zebrafish embryo as a novel system to follow localization of toxins to major organs in real-time.

 
Darrin Akins, Ph.D.

Dr. Darrin Akins laboratory is focused on identifying molecules that could be used to develop a vaccine for Lyme disease.  Lyme disease is the most common infection transmitted by ticks to humans in the United States and a vaccine for this debilitating disease is a public priority.  Dr. Akins' laboratory has been identifying novel outer surface proteins from the organism that causes this disease so that they can be used in the future to prevent Lyme disease or improve diagnostic strategies for identifying patients afflicted with this disease.


Noah S. Butler, Ph.D.

Dr. Butler’s laboratory is focused on investigating protective immunity against the malaria parasite,Plasmodium. Two central questions are being pursued in parallel. First, what are the critical numerical and functional features of T cells and antibodies that coordinately act to limit or clear Plasmodium infections? Second, how does persistent malaria infection impact pre-existing anti-Plasmodial immunity or the ability of the host to mount de novo protective immune responses against the parasites?

 
Michelle C. Callegan, Ph.D.Dr. Michelle Callegan

Bacillus cereus is an insidious ocular pathogen, causing a rapid and fulminant endophthalmitis that invariably leads to blindness within one to two days. Despite aggressive antibiotic and surgical intervention, B. cereus endophthalmitis has a relatively poor prognosis. There is presently no universal therapeutic regimen for successful treatment of Bacillus and other forms of severe bacterial endophthalmitis. Clinicians and researchers have attributed the virulence of B. cereus and other virulent endophthalmitis pathogens to toxin production. For Bacillus however, toxins are not the complete story. Bacillus is also motile, and migrates throughout the eye in a short period of time, inciting an explosive intraocular inflammatory response in its wake. This inflammatory response is likely the result of breakdown of the protective blood ocular barrier in response to infection, the triggers of which are presently being investigated. In addition, during infection, retinal architecture collapses and retinal function drops precipitously. We hypothesize that either Bacillus or its toxins (or both) target specific cells in the retina that are involved in protection by the blood ocular barrier (retinal pigment epithelial [RPE] cells) or retinal function itself (Muller cells, photoreceptor cells), leading to the detrimental effects observed during infection. Since the ultimate goal of therapy is to kill offending organisms, arrest inflammation, and preserve organ function, an important goal is to develop more effective therapeutic regimens, with newer antibiotics, anti-inflammatory agents, and/or novel drugs that target bacteria- and host-derived virulence factors in order to prevent blindness.

Daniel J. Carr, Ph.D.

Dr. Daniel Carr

Dan Carr, Ph.D. investigates the host immune response to the highly prevalent human virus pathogens, herpes simplex virus (HSV) types 1 & 2.  In mouse ocular (HSV-1) and genital (HSV-2) models of infection, the role of chemokines and their receptors in the generation and recruitment of effector cells (T and NK cells) in response to infection is currently under evaluation.

 


Madeleine W. Cunningham, Ph.D.

Dr. Madeleine Cunningham has focused for 30 years on molecular mimicry, autoimmunity and infection in studies of inflammatory heart diseases related to streptococci and viruses. Her work involves studies of the pathogenensis of rheumatic carditis, myocarditis and cardiomyopathy as well as the fetal heart disease hypoplastic left ventricle syndrome(HLHS). A second area of her research focuses on the brain and the pathogenesis of movement and behavioral disorders associated with streptococci, including Sydenham chorea, the neurologic manifestation of rheumatic fever, and pediatric autoimmune neurologic disorder associated with streptococci (PANDAS). Currently her laboratory is involved in studies of human diseases, to improve their diagnosis and treatment and determine how infections play a role in autoimmune diseases of the heart and brain. Her laboratory studies both B and T cell immunology as well as neuronal and cardiomyocyte cell signaling. Dr. Cunningham is the director of the NIAID supported Immunology Training Program at the University of Oklahoma for the past 10 years. She has been the recipient of NHLBI Career Development and MERIT Awards and has been funded NIH for the past 25 years.

Zachary Dalebroux, Ph.D.
Dr. Zachary Dalebroux

Non-typhoidal Salmonella species, such as Salmonella enterica serovar Typhimurium, cause an estimated one million cases of foodborne gastroenteritis annually in the United States alone. Within immunocompromised humans, S. Typhimurium can inflict a more severe, systemic, febrile, bacteriaemia resulting in sepsis and sometimes death. Dr. Dalebroux’s research focuses on S. Typhimurium resistance and evasion of innate immunity. Specifically, his laboratory investigates how Gram-negative bacterial pathogens, like S. Typhimurium, regulate the lipid content of their outer-membrane (OM) bilayer to survive within immune phagocytes known as macrophages. Regulated remodeling of cell-surface lipids increases bacterial resistance to macrophage killing mechanisms and promotes bacterial evasion of macrophage detection strategies. The goals of his research are define protein-lipid interactions that will aid in the development of future antimicrobials that target OM-barrier function of Gram-negative pathogens, and to discover new strategies of Gram-negative bacterial immune evasion and host detection involving bacterial OM-lipid molecules. 


David Dyer, Ph.D.

Dr. David Dyer's work centers on microbial pathogenesis and microbial genomics. His laboratory has been responsible for sequencing the genomes of the human pathogens Neisseria gonorrhoeae andAggregatabacter actinomycetemcomitans and in the sequencing of a strain of nontypeableHaemophilus influenzae.Additional studies are exploring the regulation of the iron regulon inNeisseria gonorrhoeae, and initial studies in gene regulation in Bacillus anthracis.


Joseph J. Ferretti, Ph.D.

Dr. Ferretti's laboratory was the first to complete the genome analysis ofStreptococcus mutans. Recent work has centered on the genetics of sugar transport and metabolism and the regulatory mechanisms involved in metabolism and virulence.

 

Allison Gillaspy, Ph.D. 

Dr. Gillaspy is the Director of the Laboratory for  Genomics and Bioinformatics at the OUHSC which is a state of the art facility that specializes in genomic technology and custom DNA sequencing. A major focus for our lab in recent years has been to aid in the integration of next generation sequencing technology, specifically the SOLiD platform from Applied Biosystems, into existing biomedical research.


William H. Hildebrand, Ph.D.

The Hildebrand Laboratory is focused on the major histocompatibility complex (MHC) class I and class II molecules. These molecules mediate the rejection of organ and bone marrow transplants, the targeting of cancerous and virus-infected cells for immune destruction  and autoimmune responses such as diabetes and arthritis. To delineate the role that MHC molecules play in these various immune scenarios, the Hildebrand Laboratory studies MHC genes and the proteins they encode.


Molly Hill, Ph.D.

Dr. Molly Hill

Dr. Hill is the graduate student liaison and education coordinator for the Department.  Her duties include directing the academic program of graduate students in the department and coordinating the teaching activities for graduate, medical and dental students.  


Mark Lang, Ph.D.

Dr. Mark Lang

Dr. Lang and his team are researching the development and maintenance of antibody-mediated immunity also known as humoral immunity. The major focus is on mechanisms by which a specialized subset of T cells known as natural Killer-like T cells (NKT) are activated and in turn boost long-term humoral immunity. The laboratory has two specific goals: (i) understand the mechanisms by which NKT cells regulate long-term humoral immunity, (ii) apply the knowledge to develop novel vaccine strategies against pathogenic bacteria and viruses.

 
Fengxia(Felicia) Qi, Ph.D. 

The research interests of Dr. Qi's lab have focused on the molecular mechanism of interspecies interactions in the human infection associated biofilms, using the human oral microbiome as a model. The focus of her laboratory centers on two questions: 1)how do different species interact to maintain an ecological balance? And 2)how do the bacterial species keep the yeast in check?

 

Rodney K. Tweten, Ph.D.

The focus of Dr. Tweten's research is on the molecular mechanism and cell biology of the cholesterol-dependent cytolysins (CDCs) and, more recently, the membrane attack complex/perforin (MACPF)-like proteins. The CDCs comprise a large family of toxins that contribute to the pathogenesis of a wide variety of Gram-positive bacterial pathogens. The MACPF proteins, which appear to be ancient relatives of CDCs, contribute to immune defense, pathogenesis of various eukaryotic pathogens and may be associated with developmental patterning processes. The study of the CDCs has revealed new paradigms in protein structure and function as well providing insights into their contribution to pathogenesis and the development of vaccine strategies.                                


Lauren Zenewicz, Ph.D.Dr. Lauren Zenewicz

Cytokines, as small secreted signaling molecules, are essential for both regulation of the immune system and for signaling between the host and the immune system.  Dr. Zenewicz’s research focuses on the cytokines that have critical roles in the initiation, progression and resolution of inflammation.  Her laboratory is particularly interested in elucidating signaling pathways between the immune system and inflamed tissues and is focused on interleukin-22 (IL-22), an important cytokine in hepatitis and colitis.