David L. Haviland, Ph.D.
Assistant Professor,
Center for Immunology & Autoimmune Diseases
phone 713.500.2413; fax: 713.500.2424
David.L.Haviland@uth.tmc.edu
Dr. Haviland obtained his B.A. from the University of California at San Diego in 1980, an M.A. from the University of California at Riverside in 1982, and also his Ph.D. in 1987.
Dr. Haviland then went to Washington University in St. Louis for a Post-Doctoral Fellowship in the lab of Dr. Rick Wetsel. He was subsequently promoted to Instructor in 1992 and then to Research Assistant Professor in 1994. He came to the University of Texas-Houston Health Science Center in the Institute of Molecular Medicine for the Prevention of Human Diseases in 1996.
Work in Dr. Haviland's laboratory centers on the expression and regulation of the human and murine N-formyl peptide receptors (fMLF-R), a receptor for bacterial and mitochondrial breakdown products (N-formyl peptides). These peptides induce the migration of neutrophils to sites of inflammation. Although it was thought that the human receptor was expressed only on white blood cells, it is now clear that the fMLF-R (as well as the C5a receptor) is expressed on cells in other organs.
The pathological function of fMLF-R in these non-migrating cells is unknown, however, the observation that it mediates the production of acute phase proteins by liver cells suggest that is plays a role in inflammation. These results further suggest that the biological functions mediated by chemoattractant receptors such as the fMLF-R are likely to be more pleotropic than directing the migration of neutrophils. Efforts to identify other members of the murine N-formyl peptide receptor family has led to the finding of an fMLF-R related receptor. Initially our work has centered on the biology of the pro-inflammatory N-formyl peptide receptor (fMLF-R). During the study in searching for related receptors to the murine fMLF-R we have identified what appears to be a second receptor that can bind the "anti-inflammatory" ligand Lipoxin A4. Despite sharing a surprising 70% sequence identity, these two receptors mediate opposite biological effects.
The N-formyl peptide receptor mediates pro-inflammatory effects, while a closely related receptor, called the Lipoxin A4 receptor mediates anti-inflammatory effects. We have identified a murine receptor that is very closely related to the murine Lipoxin A4 receptor. Studies are currently underway to determine the ligand(s) and function of this new receptor.
In addition to our studies with pro-inflammatory receptors our laboratory has begun to focus in the area of infectious disease models and how these processes work with the complement system, a component of our innate immune system. A Staphococcus aureus dermal infection model was established in which bacteria are introduced intradermally. In examining the skin of mice deficient in complement component C3 we made the observation that the subcutaneous fat layer is remodeled or replaced with collagen while the skin of wild type mice shows no such remodeling of the subcutaneous fat layer. The physiological bases behind this observation as well as examining other bacteria using this model are currently under investigation.