Steven A. Williams
Gates Professor of Biological Sciences, Smith College
Ph.D.: University of California at Davis
Postdoctoral Training: National Institutes of Health
Molecular biology research in my laboratory focuses on the nematode parasites that cause filarial disease in humans and animals. These parasites cause elephantiasis and African River Blindness in humans, and heartworm disease in dogs. Three major lines of research are currently being pursued in my laboratory: 1) As the director of the World Health Organization’s Filarial Genome Project, my laboratory is the center of this multinational project involving laboratories from Egypt, India, Uganda, Indonesia, the United States, and the United Kingdom. The main goals of this project are the identification, sequencing, and mapping of all the parasite’s genes in order to foster the development of new vaccine candidates and drug targets. 2) I also direct the Clark Foundation’s River Blindness Genome Project which has the same goals as the Filarial Genome Project. 3) Stage-specific, developmentally regulated gene expression.
Filarial parasites have an intriguing life cycle with five clear developmental stages. Some of these stages occur in the mammalian host and some occur in the insect vector that transmits the disease. We have developed cDNA libraries for all of these developmental stages and have identified numerous genes that are expressed in a stage-specific manner. Using immunohistochemistry and immunogold electron microscopy, we have also determined the precise localization of the proteins encoded by these genes. The genes and their encoded proteins that we are studying most intensely are a new class of antioxidants called thioredoxin peroxidases which appear to be the major proteins protecting the worm against host-induced free radical damage. Such knowledge will be extremely useful in the eventual identification of new vaccine candidates and drug targets to help eliminate these diseases.