Lipids are known to play multiple roles in the immune system, ranging from functioning as immune precursors to acting as signaling molecules [1]. Recent studies have highlighted the importance of maintaining a balanced lipid composition in the body and speculated on the potential use of lipid supplements in improving the immune system [2]. Additionally, in the lab, a microarray analysis looking at the alteration of gene expression during infection showed an enrichment of lipid metabolic genes, with a particular down-regulation of genes involved in PUFA synthesis. This specific manipulation of lipid genes in response to infection points to potential roles for specific fatty acids in the innate immune response. We are interested in using the C.elegans model system to study the role of Poly Unsaturated Fatty Acids (PUFAs) in the immunity. We have shown that altering the composition of fatty acids, by interfering with PUFA synthesis, leads to an alteration of the immune response. Blocking the PUFA synthesis pathway at specific points leads to distinct alterations in fat composition [3], and each of these mutants show different resistance and susceptibility phenotypes against the pathogen Pseudomonas aeruginosa. Mutants such as
elo-1, which has increased levels of 18:0 and 18:3n6 fatty acids, show increased resistance to infection, while mutants such as
fat-3, which lacks many 18 and 20 carbon fatty acids, show increased susceptibility to infection. Gas chromatography analysis is being used to identify the individual fatty acids that could influence the immune response, and the results of this analysis will also be presented.1)Wallis JG, Watts JL, Browse J. Polyunsaturated Fatty Acid Synthesis: what will they think of next? Trends Biochem Sci, 2002. 27(9):467-473.2)Tricon S, Burdge GC, Kew S, Banerjee T, Russell JJ, Grimble RF, Williams CM, Calder PC, Yaqoob P. Effects of
cis-9,trans-11 and trans-10,
cis-12 conjugated linoleic acid on immune cell function in healthy humans. Am J Clin Nutr. 2004. 80 (6): 1626-1633.3)Watts JL, Browse J. Genetic dissection of polyunsaturated fatty acid synthesis in Caenorhabditis elegans. PNAS, 2002. 99: 5854-5859.