Pamela J. Fraker Research Interests continued
Nutritional - Immunology - continued
This leads to enhanced rates of infection and mortality. Zinc deficiency is a component of the aforemention diseases and a frequent dietary deficiency noted in the human population. For this reason our studies have primarily utilized the zinc deficient mouse as a model for study. We have recently shown that the lymphopenia that accompanies many forms of malnutrition is caused by disruption of lymphopoiesis.
The latter is caused by heightened levels of apoptosis among precursor T and B-cells that is mediated by the chronic production of glucocorticoids induced during zinc deficiency, protein-calorie malnutrition, wasting, etc. Studies are in progress to determine the effect of suboptimal nutriture in the rate of lymphopoiesis, status of pro and precursor lymphocytes, rates of apoptosis, cell cycle status, cytokine production, etc., using flow cytometry as the primary assessment tool.
Of additional interest is the recent discovery of an important adaptive response to malnutrition. It now appears that the first line of immune defense - the phagocytic cells may be protected during stress-malnutrition. Both the peripheral blood and the marrow of zinc deficient mice contained enhanced numbers of these cells. Interesting human neutrophils exposed to levels of glucocorticoids analogous to those found in malnourished subjects have longer half-lives and greater resistance to apoptosis! Studies are in progress to further define this important observation to include biochemical evaluation of the changes in neutrophils, etc., that make them more resistant to apoptosis during nutritional deficiencies. Protocols for measuring cell cycle status, apoptosis, ploidy, receptor expression, oncogene expression, Ca++ flux, mitochondrial status, phenotypic distribution of leukocytes, etc., are routinely performed. Opportunities exist for students to learn flow cytometry which is an important and highly marketable skill.
Full text of research interests