Sphingolipids as Mediators in the Crosstalk between Microbiota and Intestinal Cells: Implications for Inflammatory Bowel Disease

Figure 3

Bacterial α-galactosylceramide as iNTK regulator in colon cancer. Treatment with azoxymethane followed by DSS reduces the number of iNTK cells and augments CD25⁺ CD4⁺ T cells, NKT1.1⁺ T cells, and IL-13⁺ CD3⁺ cells, as well as IL-13 release. All this contributes to form a greater number of tumors of a larger size. Probiotic bacteria can produce compounds similar to α-galactosylceramide, which prevents inflammation and reduces the number and size of tumors. B. fragilis produces α-galactosylceramide which stimulates iNKT cells binding to CD1d, increasing production of IFN-γ and proliferation of CD3⁺ Vα24⁺ cells. DSS: dextran sulphate sodium, iNKT: invariant natural killer, NKT: natural killer T cell, and PT: serine palmitoyltransferase.