Objective: To study the relationship between LAK/activated NK cells and hematopoiesis as well as the effects of LAK/activated NK cells on hematopoietic reconstitution after syngeneic bone marrow transplantation(BMT) in mice.
Methods: 1. LAK/activated NK cells were cocultured with bone marrow cells(BMC) in semi-solid agar medium to determine their effects on CFU-GM formation. 2. Syngeneic LAK/activated NK cells were transferred with BALB/c BMCs into lethally irradiated syngeneic recipients to determine their effects on hematopoietic reconstitution.
Results: When BMC were cultured under optimal growth conditions in the presence of exogenous hematopoietic growth factors, the effects of LAK/activated NK cells were mainly inhibitory. However, when BMCs were cultured under growth-limiting conditions without exogenous hematopoietic growth factors, the LAK/activated NK cells could support CFU-GM formation. Syngeneic LAK/activated NK cells significantly increased CFU-S and CFU-GM numbers after syngeneic BMT, and also significantly improved platelet and white blood cell count.
Conclusions: LAK/activated NK cells could be bidirectionally regulate CFU-GM formation in vitro and promote hematopoietic reconstitution after syngeneic BMT in mice.