Description
The role of sphingolipids (SLs) in the immune system has come under increasing scrutiny recently due to the emerging contributions that these important membrane components play in regulating a variety of immunological processes. The acyl chain length of SLs appears particularly critical in determining SL function. Here we show a role for very-long acyl chain SLs (VLC-SLs) in invariant natural killer T (iNKT) cell maturation in the thymus and homeostasis in the liver. Ceramide synthase 2 (CerS2) null mice, which lack VLC-SLs, were susceptible to a hepatotropic strain of lymphocytic choriomeningitis virus, which is due to a reduction in the number of iNKT cells. Bone marrow chimera experiments indicated that hematopoietic-derived VLC-SLs are essential for maturation of iNKT cells in the thymus, whereas parenchymal-derived VLC-SLs are crucial for iNKT cell survival and maintenance in the liver. Our findings suggest a critical role for VLC-SL in iNKT cell physiology. Overall design: Liver mRNA profiles of 3-4 month old wild type (WT), WT iNKT cell transfered and CerS2-/-mice, infected or not with LCMV were generated by deep sequencing. Several replicateswere included and pocessed using the MARS-seq protocol (Jaitin et al. 2014 Science.343:776-9) and sequencing in the Illumina NextSeq 500 instrument