EFFECT OF CORYNEBACTERIUM-PARVUM ON HEMATOPOIETIC STEM-CELL KINETICS

The i.v. administration of 548 .mu.g of killed C. parvum [Propionibacterium acnes] into C57BL mice leads to a significant decrease in the number of bone marrow colony-forming-units in spleen (CFU) as early as 12 h after the injection of the bacterium. This decrease persisted in varying degrees for 3 wk. After an initial fall at 24 h, the splenic CFU exhibited a rapid expansion and reached values 10 times higher than the control range on the 9th day. A significant rise in the number of circulating CFU, reaching a 1st peak at 2 h and a 2nd on the 5th day, was observed. The proliferative status of femoral CFU was increased at 48 and 72 h, while that of splenic CFU presented a significant increase only 48 h after the injection of C. parvum. An accelerated migration of hemopoietic stem cells from bone marrow to spleen via the blood circulation probably has to take place.