Description of organ-specific phenotype, and functional characteristics of tissue resident lymphocytes from liver transplantation donor and research on immune tolerance mechanism of liver

AIM: Prior to transplantation, Donation after Cardiac Death (DCD) liver transplantation livers are perfused with preservation solution. Therefore, this provides an abundant source of human liver lymphocytes, as well as mesenteric lymph node and spleen for the study of lymphocyte subset diversity in the peripheral blood, lymph node, spleen and liver. METHODS: Lymphocyte subsets were isolated and purified from peripheral blood, lymph node, spleen and liver perfusion, the phenotypic and functional analysis of the tissue resident lymphocyte were performed by flow cytometry. RESULTS: In a direct comparison between blood, liver, lymph node and spleen cells from liver transplantation donors, the abundance of natural killer (NK) cells, CD3(+)CD56(+)NKT (NT) cells and CD8(+) T cells in intrahapatic lymphocytes (IHL) did not match what was present in peripheral blood and other peripheral lymphoid organs. The activation state of peripheral blood-derived lymphocytes was significantly different from lymph node-, spleen- and liver-derived cells. Intriguingly, NK cells, CD4(+) T cells, and CD8(+) T cells from liver perfusion display more suppressive characteristics, that is, express and produce more anti-inflammatory cytokine interleukin (IL)-10, less inflammatory cytokine interferon (INF)-γ. CONCLUSION: Our findings imply that different tissues entail resident lymphocyte subsets with a distinct phenotype and function considering the organ is well vascularized, particularly in liver. It is better to understand the mechanism of liver immune tolerance.