1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
It is now well-accepted that maintaining good health requires eating a healthy diet. But what is a healthy diet? Healthy diets were once defined by their ability to prevent clinically-evident deficiency diseases. Now, with a more complete understanding of the physiological and molecular role of nutrients, definitions are changing. Vitamin A, for example, prevents blindness but has important functions beyond the eye which are not as obvious. Metabolites of vitamin A are now known to act as hormones and regulate gene expression in the immune system. The immune system also responds to oxidative stress that is produced during an infectious or inflammatory episode. Thus requirements for antioxidant micronutrients may increase and decrease depending on health status. Thus different dietary levels of micronutrients such as vitamin A, the antioxidant micronutrients (including carotenoids, vitamin E and vitamin C) have the potential to affect resistance to infectious disease, response to vaccines, and the development of immune-mediated diseases, such as autoimmune diseases and asthma. In addition, many newly described, food-derived antioxidants have shown anti-cancer, anti-inflammatory, and anti-atherosclerotic activities. Few detailed studies of their beneficial or detrimental effects on the immune response have been performed. This CRIS project is examining the effects of micronutrients (particularly vitamin A, but also antioxidants such as carotenoids and vitamin E) and other food-derived bioactive compounds (particularly plant-derived antioxidants) on immune function, particularly T lymphocyte-mediated immune responses. Some of these immune responses are beneficial (e.g., response to vaccination and infectious diseases) and others are not (e.g., autoimmune diseases and asthma). With regard to newly described, food-derived antioxidants, the specific goals of this project will be to understand how antioxidants found in foods may regulate lymphocyte activities and the immune response in general, and to define appropriate dietary intake levels of foods containing high concentrations of these antioxidants that would contribute to the production of a healthy immune system. The work of this CRIS project will allow us to make better, more specific, recommendations about healthy dietary levels of these compounds. Public health will benefit from increased knowledge of the effects of vitamin A and antioxidants on immune function. The research will improve public understanding of appropriate dietary intake of vitamin A and food-derived antioxidants as whole foods and/or supplements that leads to a healthy immune system. Due to the anti-inflammatory nature of many food-derived antioxidants, further investigations will evaluate whether an increase in dietary intake of these substances may be useful for managing chronic inflammatory diseases, such as autoimmune disorders. Vitamin A may also have similar benefits, as indicated by work in animal models of human autoimmune and inflammatory diseases.

This project is aligned with National Program 207, Human Nutrition.

2.List by year the currently approved milestones (indicators of research progress)
FY2006: 1. Complete microarray experiments. 2. Analyze microarray expression data (retinoid vs. control). 3. Identify candidate retinoid-responsive genes. 4. Conduct human studies on innate and adaptive immune response. 5. Initiate human studies on the immune response to dietary intake of foods with high levels of antioxidants. 5. Continue the assessment of the inhibitory activity of plant-derived antioxidants on leukemia in mice. 6. Continue studies of mechanistic action of antioxidants at a cellular level on leukemic and normal lymphocytes. 7. Continue investigations of anti-inflammatory effects of food-derived antioxidants on chronic inflammatory diseases.

FY2007: 1. Complete RT-PCR analyses of genes selected in year 1; 2. Determine if ligands for RXR partner receptors affect Th1/Th2 development. 3. Analyze immune function and clinical data. 4. Continue analysis on the immune response to dietary intake of foods with high levels of antioxidants using lymphocytes from healthy human volunteers. 5. Continue the mechanistic studies to determine activity of antioxidants at a cellular level in leukemic and normal lymphocytes. 6. Continue evaluation of anti-inflammatory effects of antioxidants from foods on chronic inflammatory diseases.

FY2008: 1. Determine if candidate genes affect Th1/Th2 development. 2. Determine if high-level dietary vitamin A, as well as vitamin A deficiency, affects development of T cell-mediated immunity and inflammation in vivo. 3. Conduct diet studies on Th1/Th2 development and asthma severity. 4. Continue analysis on the immune response to dietary intake of foods with high levels of antioxidants using lymphocytes from healthy human volunteers. 5. Continue the mechanistic studies to determine activity of antioxidants at a cellular level in leukemic and normal lymphocytes. 6. Continue evaluation of anti-inflammatory effects of antioxidants from foods on chronic inflammatory diseases.

4a.List the single most significant research accomplishment during FY 2006.
Disruption of the retinoid x receptor alpha gene (Rxra) in T lymphocytes decreases proliferation and increases cell death. Vitamin A acts to regulate cellular processes by binding to the retinoic acid and retinoid X receptors. To determine which cells in the immune system require vitamin A for activity in vivo requires a cell-targeted approach. The Rxra gene was disrupted in murine T lymphocytes using Cre-lox methods. This disruption resulted in altered numbers of T lymphocytes, decreased proliferation, increased T lymphocyte death. This study was done in collaboration with Dr. Kent Lloyd of UC Davis, demonstrating that vitamin A acts directly on T lymphocytes to maintain normal cell proliferation and survival during an immune response. This addresses the Health Promoting Properties of Plant and Animal Foods Component of the National Program 107, Human Nutrition.

Plant-derived antioxidant studies. The anti-leukemia activity of resveratrol, a polyphenol from grapes, is enhanced by combinatorial treatment with anti-cancer drugs. Using leukemia cell lines, we showed that pre-treatment with CsA or PK11195, modulators of the mitochondrial membrane transition pore, significantly enhanced resveratrol-mediated apoptosis and mitochondrial membrane depolarization in these leukemic cells. These data suggest that targeting the MPTP sensitizes B- and T-cell ALL to the anti-cancer activity of resveratrol, and may be particularly useful for the treatment of high-risk leukemias. These analyses were conducted in the laboratory of Dr. Zunino. These results provide information on the usefulness of resveratrol in the clinic for treating infants with high-risk leukemia. This addresses the Health Promoting Properties of Plant and Animal Foods Component of the National Program 107, Human Nutrition.

4b.List other significant research accomplishment(s), if any.
High prevalence of vitamin D deficiency in African American adolescents and young adults. African Americans are at increased risk of vitamin D deficiency because skin pigmentation blocks dermal vitamin D synthesis. In a cross-sectional study of adolescents and young adults with or without HIV infection we found that nearly 80% of subjects (75% of whom were African American and 20% Hispanic) Although their dietary intake was the same as previously seen in the NHANES III national survey (for age, gender and race/ethnicity) the prevalence of deficiency was much higher, suggesting that low sun exposure due to lower outdoor activity may account for the difference. Obesity was much more prevalent in these subjects than in the NHANES III study, a second factor that increases risk of vitamin D deficiency. This study was done among members of the Reaching for Excellence in Adolescent Health (REACH) cohort study with collaborators from the University of Alabama at Birmingham (Dr. Craig Wilson) and the Iowa State University (Dr. Grace Marquis and Lori Kruzich). This study demonstrates that increased food fortification or use of supplements is needed to address this issue in African American adolescents and young adults. This research addresses Component 5 of NP107, Health Promoting Properties of Plant and Animal Foods.

4c.List significant activities that support special target populations.
Dr. Stephensen's analysis of data from the REACH population is providing information on the role of immune-modulating nutrients on progression of HIV disease in a cohort of subjects that are primarily young, African American women. A significant percentage of subjects is also Hispanic. In addition, Dr. Stephensen continues to be an active member of the UC Davis Center of Excellence for Nutritional Genomics funded by the National Center for Minority Health Disparities at NIH. Activities this year included beginning pilot studies with Dr. Kelley of the WHNRC and co-investigators from the Ethnic Health Institute at Alta-Bates-Summit Medical Center in Oakland and Berkeley. The research is examining the impact of genetic variation in the arachidonate 5-lipoxygenase gene (ALOX5) on response to dietary supplementation with omega-3 fatty acids from cold-water fish. These fatty acids decrease the risk of cardiovascular disease and the ALOX5 variant of interest may confer both increased risk of cardiovascular disease and increased benefit from fish oil supplements since these oils are metabolized by arachidonate 5-lipoxygenase. The ALOX5 variant genotypes of interest are more prevalent in African Americans than in Caucasians, Hispanics or Asians.

4d.Progress report.
None.

5.Describe the major accomplishments to date and their predicted or actual impact.
This project is in its third year and the principal accomplishments have been outlined above.

6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Results of our research have been transmitted to the scientific community via publication in peer-reviewed journals.

7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
No publications have appeared in the popular press.

Review Publications
Zunino, S.J., Storms, D.H. Resveratrol-induced apoptosis is enhanced in acute lymphoblastic leukemia cells by modulation of the mitochondrial permeability transition pore. Cancer Letters. 2006; Vol 240:123-134.