Paul Kelly is currently a Professor of Cell Biology at the Necker Faculty of
Medicine, where he directs a laboratory of 25 scientists, graduate students,
post-doctoral fellows and technicians. Dr. Kelly's world-renowned research over
the past 30 years research has been focussed in the area of signal transduction,
in particular the action of prolactin and growth hormone.
Whilst a post-doctoral fellow with Henry Friesen, he was one of the first to identify and characterize the receptors for prolactin and growth hormone, suggesting that receptor expression could regulate hormonal responses. He and his group were also the first to purify the prolactin receptor and raise polyclonal and monoclonal antibodies to the receptor protein. In 1988, Dr. Kelly's group cloned the prolactin receptor cDNA and identified the family of growth hormone-prolactin receptors, which has now expanded to include upwards of 30 members of the class I cytokine receptor superfamily. Following the identification of the receptors, Dr. Kelly and his group moved on to establish the downstream events leading to the identification of the tyrosine kinase, Jak2, and the Stat proteins as mediators of both prolactin and growth hormone action. Dr. Kelly's group reported the null mutation of the prolactin receptor and the major phenotypes observed; female infertility and effects on mammary gland development. Since this initial landmark paper, numerous other publication have appeared demonstrating a role for prolactin and its receptor in bone development, maternal behavior, islet cell function, lacrimal gland function, hair development, and immune function.
Parallel studies on growth hormone signaling and actions has demonstrated that similar but not identical pathways are involved in the intracellular signal transduction cascade activiated by the binding of growth hormone to its receptor. More recent studies have characterized and compared the bone phenotypes in mice in with the genes for the growth hormone receptor or Stat5 transcription factor have been knocked out.
The major thrust and direction of Dr. Kelly's laboratory is to continue studies on growth hormone and prolactin signal transduction and their assocaited biological activities. Also, since prolactin is such an important hormone in the differentiation of mammary epithelial cells and has been shown to play a role in the progression of murine breast and prostate cancers, Dr. Kelly and his collaborators are developing specific receptor antagonists to block the function of prolactin produced in the pituirary or acting locally via a paracrine-autocrine mechanism.
In addition to organizing and participating in courses given to medical and graduate students in the areas of Cell Biology and Endocrinology, Dr. Kelly is the Director of the Research Institute of the Necker-Enfants Malades Medical School, formed by 800 scientists, physician-scientists, technicians, graduate students and post-doctoral fellows working in the fields of immunology, genetics, microbiology and cell biology. He has served, and continues to serve, on the board of numerous scientific journals and has organized and participated in several international meetings.