Antibody production by 'cloned' cell populations.

A method for the instrasplenic cloning of lymph node cells, based on the injection into X-irradiated recipients of cells from phytohaemagglutinin treated donors was developed. Clones were tested for their capacity to form anti-Shigella antibodies, and to produce a graft versus host immune response. It was found that each of the randomly chosen clones produced antibodies to Shigella. When immunized `cloned' cell populations were injected into secondary recipients, and the latter were again immunized with Shigella, an increased response was obtained. Clones produced by bone marrow cells in spleens of X-irradiated animals, similarly tested for the immunological competence did not produce antibodies to Shigella. Cells of lymphoid clones of parental strain origin produced a graft versus host response in newborn F hybrids. Bone marrow derived clones did not. Thus, each cloned cell population appears to be pluripotential with respect to antibody formation. The immunological findings, analysed in relation to the population sizes of the tested clones, seem to indicate that each immune competent cell may, in fact, be pluripotential.