The immune reactivity of lymph node-derived spleen colonies and intercolonial cells.

Using a method for cloning lymph node (LN) derived cells in the spleens of lethally irradiated mice, it was determined that the macroscopic colonies observed were haemopoietic whereas the intercolonial cells were primarily lymphoid. The immune response detected in isolated colonies was shown to be attributable to contamination of the clones by immunologically reactive interclonal cells. It was also demonstrated that pre-treatment of LN donor mice with PHA enhanced cloning efficiency but was not a necessary procedure for obtaining LN-derived colonies in the spleens of irradiated recipient mice.