Relationship between the enhanced expression of histocompatibility antigens on interferon-treated L 1210 cells and their position in the cell cycle.

We have determined the cell cycle position of individual mouse leukemia L 1210 cells by cytophotometric and autoradiographic techniques and simultaneously determined the amount of histocompatibility antigens expressed on the surface of individual cells by quantitative immunofluorescence. Interferon treatment of L 1210 cells was accompanied by an enhanced expression of histocompatibility surface antigens. The distribution of interferon-treated cells in the various phases of the cell cycle was similar to that for control cells and the enhanced expression of histocompatibility antigens was observed on interferon-treated cells in all phases of the cell cycle. We conclude, therefore, that this enhancement is not due to a preferential concentration of these cells in any one particular phase of the cell cycle.