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.