Kosaku Yoshida

Evidence for the in vivo production of interleukin-3 in lethally irradiated mice transplanted with syngeneic murine splenocytes.

We wish to demonstrate new evidence for the in vivo production of interleukin-3 (IL-3). Syngeneic murine splenocytes were transplanted into lethally irradiated mice. The spleen cells in these transplant mice spontaneously produced IL-3 in cultures, and IL-3-like activity was detected in the serum. Chronological changes of the Thy-1 antigen expression on the bone marrow cells, and the number of myeloid progenitors in the bone marrow from post-transplant mice correlated with the amount of IL-3 produced in vivo. These results suggest that IL-3 may be produced by activated T cells during the syngeneic mixed lymphocyte reaction induced in vivo.