Human lymphocyte colony formation in agar culture: cell phenotype studies on individual colonies indicate a polyclonal origin of such colonies.

Monoclonal origin of human lymphocyte colonies grown in agar culture under mitogenic stimulation is still disputed. To solve this question we used different markers: we failed with the G6PD technic and with the successive staining for X and Y chromosomes on individual colonies. Therefore, individual colonies were investigated for the presence of different cell types using membrane receptor identification and cytochemistry. At different stages of the colony formation, presence of a macrophage surrounded by lymphocytes, of a mixture of T cells and B cells, plasma cells and c.Ig negative cells, in the same colony was demonstrated. The mixture of cells from different lineages in individual colonies indicated a polyclonal origin of such colonies, the capacity for the cells to migrate in a short distance, and the involvement of cell-cell contact throughout the colony formation. Human lymphocyte colony formation appears as a new technic for the study of cellular cooperation.