Joint cultivation of human erythroblastoid cells and mouse fibroblasts triggers release of a wide spectrum of cytotoxic factors.

It has been demonstrated that joint cultivation of human K-562 cells and mouse L-929 cells results in triggering apoptosis in L-929 cells and possibly also in K-562 cells. Analysis of proteins recovered from the culture medium has revealed the presence of three cytotoxic factors including TNF-alpha. This is the first observation of a release of cytotoxic factors by non-lymphoid cells in response to a direct contact with cells of different origin.