Lack of requirement for thymocytes for efficient antibody formation to trinitrophenylated mouse red cells in mice: role for thymocytes in suppression of the immune response.

The requirement of thymus-derived cells for the immune response to trinitrophenylated syngeneic mouse red cells (TNP-MRC) was investigated. In three sets of experiments the following results were obtained: a) irradiated mice which were reconstituted with bone marrow cells alone showed a better anti-TNP response after injection with TNP-MRC than those reconstituted with both bone marrow cells and thymocytes. b) Anti-thymocyte serum augmented the mouse anti-TNP response to TNP-MRC. c) Nude thymusless mice showed a better anti-TNP response to TNP-MRC than their normal littermate controls. These results indicate that the anti-TNP response of mice to TNP-MRC does not require thymus-derived helper cells. Moreover, thymus-derived cells have a suppressive effect on the anti-TNP response.