THE EFFECT OF LITHIUM ON THE GROWTH OF MURINE BONE-MARROW-DERIVED STROMAL LINES INFECTED WITH A LP-BM5 MULV MURINE LEUKEMIA-VIRUS

We have previously demonstrated that lithium when administered in vivo to immunodeficient mice infected with LP-BMS MuLV reduced significant ly the development of lymphadenopathy, splenomegaly, and the lymphoma associated with late-stage immunodeficiency disease in this model, and increased the survival of these immunodeficient animals compared to v iral-controls not receiving lithium. In this model, retrovirus infecti on is associated with altered cytokine gene expression in the bone mar row stroma such that the stroma becomes dysfunctional and fails to sup port immunohematopoiesis in vitro. We report here the results of studi es designed to examine the ability of lithium to influence the growth kinetics of marrow stromal cell lines developed from LP-BM5 MuLV infec ted animals, and test whether the ability of lithium to influence the immune deficient state following administration in vivo may in part be mediated by the ability of lithium to influence the growth kinetics o f these cell lines. When lithium chloride was added in a dose-response manner to cell cultures of SC-1 and KLTM1 stromal cells, cell growth peaked earlier in a time course fashion compared to cell cultures not exposed to lithium and also declined earlier when compared to control non-lithium treated cultures. These results suggest lithium influences the cell growth rate of viral-infected marrow stromal cell lines in v itro; however, whether such exposure influences changes in the functio nal activity of these cells in vivo remains to be investigated.