The formation of human lymphocyte colonies in semisolid cultures in response to allogeneic mixed-lymphocyte stimulation.

A technique is described for the growth of human lymphocyte colonies in semisolid culture systems in response to allogeneic lymphocyte stimulation. Colonies did not form to any major extent using autologous lymphocyte stimulation. Both one-way and two-way mixed-lymphocyte reactions were investigated. Ultrastructurally, such colonies are composed of cells with lymphoblastic and lymphocytic morphology. The majority of the lymphoid elements composing the colonies were T-cells based on their ability to rosette with sheep red blood cells. Our studies suggest that the colonies are clonogenic in origin and therefore the technique offers the potential for isolation of specific clones, or subpopulations of lymphocytes involved in allogeneic reactions and characterization of their function. Studies directly comparing the stimulation indices achieved with standard mixed lymphocyte cultures utilizing 3HTdr-incorporation to the colony-forming assay indicate that the cloning technique produces higher stimulation indices for allogeneic/autologous reactions and produces less autologous (background) response than the 3HTdr incorporation technique. In addition to lymphocyte colonies, we also observed colonies of surface-adherent populations of macrophages, including multinucleated giant cells. Thus, the technique appears to provide a new and potentially more sensitive method for the study of transplantation immunology and cell-mediated immunity in humans.