Abstract: | Short-term (15 min) sodium periodate (NaIO4) treatment of mouse spleen cells previously primed in vivo or in vitro against alloantigens induced the formation of secondary (2 degree) cytolytic T lymphocytes (CTL) specific for the priming antigens. CTL formation was readily demonstrable within 24 hr after treatment.This early CTL response occurred equally well in the presence or absence of cytosine arabinoside (Ara C), indicating that NaIO4 could induce CTL independently of DNA synthesis. Forty-eight hours after periodate treatment, the lytic activity was similar to that observed in parallel cultures stimulated with irradiated allogeneic spleen cells, although the peak activity was reached earlier (day 4) and was somewhat lower than that induced by alloantigen. The addition of irradiated NaIO4-treated unprimed syngeneic spleen cells to cultures of untreated alloimmune spleen cells also led to CTL formation, which suggests an indirect mechanism of activation. In contrast to alloimmune spleen cells, normal spleen cells treated with NaIO4 developed only very low levels of cytotoxicity after 4 days of incubation. However, in the presence of PHA, such cells were capable of lysing syngeneic and allogeneic target cells. |