| Shanmugam Nagarajan, PhD
|
Assistant Professor of Microbiology and Immunology |
Phone: (501) 364-2814
|
Research Overview
Dr. Nagarajan’s research centers on the global issue of how dietary factors modulate the immune system. Because of the central role of modulation of immune system in chronic diseases, his laboratory is interested in understanding the role of immune system in pathophysiology of atherosclerosis. Recent studies have suggested that the modification LDL-cholesterol by an oxidative process results in the formation of oxidized-LDL (oxLDL). OxLDL has also been shown to induce humoral immune response. Antibodies against oxLDL have been demonstrated on carotid artery plaques from atherosclerotic patients. This raises a possibility that in oxLDL-immune complexes binding to Fcgamma receptors may contribute to the progression of atherosclerosis. Dr. Nagarajan’s laboratory focuses on the role of Fcgamma receptors in the progression of atherosclerosis. Further, it is well known that cardiovascular incidence is lower in Asian population. It is plausible that the diets such as soy and rice may modulate the immune system, thus preventing atherosclerotic lesions. He is also studying the role of soy and rice protein isolates in modulating the immune response to prevent atherosclerosis.
More than 70% of infants are fed some type of infant formula during early growth and development. There has been a great deal of research attempting to mimic biologic actions of breast milk on immune development using infant formula. However, a detailed analysis of the immune status, particularly neonatal immune system development of breast-fed versus formula-fed infants, is lacking. The other aspect of Dr. Nagarajan’s research is to delineate the molecular mechanism(s) underlying the early dietary intervention on the development of neonatal immunity. Dr. Nagarajan also directs the Immunology Core at the Arkansas Children’s Nutrition Center
Key Publications
Nagarajan S, Venkiteswaran K, Anderson M, Sayed U, Zhu C and Selvaraj P. Cell specific, activation dependent regulation of neutrophil CD32A ligand binding function. Blood 95:1069-1077, 2000.
Nagarajan S, Fifadara NH, and Selvaraj P. Signal specific activation and regulation of human neutrophil Fcgamma receptors. Journal of Immunology 174:5423-5432, 2005.
Stewart BW and Nagarajan S. Recombinant Soluble CD36 Blocks OxLDL-Induced Monocyte Cell Adhesion. Molecular Immunology 43: 255-267, 2006.
Nagarajan S, Stewart BW and Badger TM. Soy isoflavones attenuates human monocyte adhesion to endothelial cell specific CD54 by inhibiting monocyte CD11a. Journal of Nutrition 136: 2384-2390, 2006.
Nagarajan S. Anti-oxLDL IgG blocks oxLDL interaction with CD36, but promotes Fcgamma receptor, CD32A-dependent inflammatory cell adhesion. Immunology Letters 108: 52-61, 2007.
Helm RM, Golden C, McMahon M, Thampi P, Badger TM and Nagarajan S. Diet regulates the development of gut-associated lymphoid tissue in neonatal piglets. Neonatology 91:248-255, 2007.
Thampi PT, Stewart BW, Joseph L, Stefan M, Hennings L, and Nagarajan S. Dietary homocysteine promotes atherosclerosis in apoE knockout mouse by up regulating scavenger receptors. Atherosclerosis 2007 (in press).
Research Support
USDA: The Effects of Dietary Factors during Development on Long-term Health Consequences: Effects of Dietary Factors on Cancer Prevention (Lead Scientist)
USDA: The Effects of Dietary Factors during Development on Long-term Health Consequences: Effects of Dietary Factors on Cancer Prevention (Co-Scientist)
Deans Research Development Grant: Role of CD32B, an inhibitory Fcgamma receptor, in the progression of atherosclerosis (PI)
Marion B. Lyon Fund: Fcgamma receptors in autoimmune atherosclerosis (PI)
American Heart Association: Role of scavenger receptor-like activity of Fcgamma receptors in atherosclerosis (PI)