Influence of thymosin and the supernatant of cultured mouse thymus reticuloepithelial cell on mouse immune responses.

Effects of the humoral factor extracted from the calf thymus (thymosin: Goldstein et al.) and the supernatant of cultured mouse thymus reticuloepithelial cell (TRC) on immunological functions of the mouse lymphocytes were studied, and the following conclusions were drawn: Thymosin treatment did not alter the capacity to form anti-SRBC antibody in adult mice which were lethally irradiated and reconsituted with bone marrow cells. When the spleen cells from JCL-ICR mice thymectomized within 24 hr after birth were cultured with thymosin or supernatant of cultured ICR-TRC, the Thy 1 positive cells were increased. A significant increase in the mitogenic (PHA, Con A) reactivity of BALB/C spleen cells was observed when these cells were preincubated in medium containing thymosin for 24 hr. The NZB spleen cells, however, exhibited spleen cells showed a slightly potentiated response only to Con A. Similarly, thymosin enhanced the MLC reaction of the spleen cells from BALB/C mice with preincubation for 2 hr, but not enhanced that from NZB mice.