Relationship between CCR5 and acute graft-versus-host disease in murine bone marrow transplantation

This study was aimed to eveluate the role of CCR5 on donor cells in recipient models received intensive conditioning, so as provide the scientific evidence for clinical application of allo-HSCT. Lethally irradiated BALB/c mice received allogeneic bone marrow transplants from C57BL/6 mice. Mice divided into 4 groups according to receiving variant donor cells: B6 CCR5 KO group, receiving C57BL/6 CCR5(-/-) mice bone marrow cells and splenocytes; B6 WT BMC group, receiving C57BL/6 mice bone marrow cells and splenocytes; B6 CCR5 KO BMC group, receiving C57BL/6 CCR5(-/-) bone marrow cells alone; B6 WT BMC group, receiving C57BL/6 mice bone marrow cells alone. The result showed that compared to B6 WT BMC group, B6 CCR5 KO group succumbed to acute GVHD at an accelerated rate. Donor CD8(+) T cells expanded to a significantly greater extent in recipients of CCR5 KO, compared with B6 WT control cells. T cells recovered from recipients of CCR5 KO cells produced more IFN-gamma and TNF-alpha and proliferated to a T-cell at a significantly higher level than T cells from recipients of WT cells, indicating that CCR5 plays a role in downregualting donor alloreative CD8(+) T-cells expansion. Histological assessment of the mice indicated pathological lesions in the kidneys and a greater degree of liver pathological changes in mice that received CCR5 KO donor grafts. It is concluded that the knock-out of CCR5 on donor cells results in increase of GVHD and donor CD8(+) T cell expansion, as well as hepatic and renal lesions in allo-HSCT, which indicates that CCR5 is very important in allo-BMT.