Organ distribution of immunocompetent cells in guinea pigs. II. Spleen, lymph node, bone marrow, or thymus cells in the restoration of the splenic plaque-forming cell response to sheep erythrocytes after irradiation.

The splenic plaque-forming cell response of inbred guinea pigs to sheep erythrocytes was abolished by whole-body X-irradiation with 600 rad. The minimum doses of various cell types from normal syngeneic donors to restore the response significantly were 100 X 10(6) spleen or lymph node cells or 500 X 10(6) bone marrow or thymus cells. The combination of 100 X 10(6) thymus and 100 X 10(6) bone marrow cells provided statistically significant restoration, but not much more than 100 X 10(6) bone marrow cells alone. The lack of thymus-marrow synergism suggests that in guinea pigs the antigen-reactive cells and antibody-forming cell precursors are not in the same way enriched in the thymus and bone marrow as in mice.