Abstract
Lysolipids can be divided into lysoglycerolipids and lysosphingolipids. These lipids are pleoitropic and perform many biological functions including cell arrest, cell growth, angiogenesis, tumour cell invasion and migration of lymphocytes, among many others. Receptors for these lipids belong to the heptahelical family of G protein-coupled receptors (GPCRs), making them prime targets for drug intervention. Receptors for lysophosphatidic acid (LPA) are known as LPA1, LPA2 and LPA3, and those for sphingosine 1-phosphate (S1P) are named S1P1, S1P 2, S1P3, S1P 4 and S1P5. Lysophosphatidylcholine (LPC or lysolecithin) binds at least three receptors known as G2A, GPR4 and PAFR, whereas sphingosylphosphorylcholine (SPC or lysosphingomyelin) binds OGR1, GPR4 and G2A. Psychsoine (Dgalactosyl- β1-1 sphingosine) which accumulates in the brain and other tissues of patients with globoid cell leukodystrophy (GLD), and D-glucosyl-β1-1 sphingosine, which accumulates in patients with Gaucher disease bind a receptor known as TDAG8. The accumulation of lysolipids results in various diseases, such as atherosclerosis, cancer, Krabbe and Gaucher diseases, to cite few examples. However, recent results showed that some of these lipids are important for maintaining the homeostasis of the immune system and for eradicating infections. The expression of receptors for these lipids has been reported in several cell types. However, such expression in lymphocytes has not been clearly established. This review will examine the up-to-date knowledge regarding the expression of receptors for lysolipids in natural killer (NK) and T lymphocytes. Because these cells are the major cell types in the innate and adaptive immunity respectively, it is hoped that the information provided might help in developing drugs to treat various diseases.
Keywords: lysolipids, nk, t cells, cancer, krabbe, gaucher, atherosclerosis
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