1972 Volume 25 Issue 1 Pages 25-31
Properties of rosette-forming cells (RFC) and plaque-forming cells (PFC) were investigated in a culture of mouse spleen cells with sheep red blood cells (SRBC) . 1) In our culture with good primary response of direct PFC, some differences were noticed regarding the mode of RFC response compared with the in vivo response; the RFC number at the maximum in vitro response was about 1/10 of in vivo one. In addition, the in vitro RFC rarely included RFC with large agglutinates of SRBC which are considered as hemagglutininproducing cells and are rich in the in vivo RFC. These findings indicate that the in vitro RFC contained only a part of the in vivo RFC population. 2) Moderate in vitro RFC response occurred even in the absence of SRBC, while the PFC response was extremely low under the same culture conditions. This suggests that the RFC response was not so specific as the PFC response. 3) The RFC appearing in the culture did not form plaques within 30 min of incubation with complement and SRBC; this showed that the in vitro RFC hardly included PFC. 4) The characteristics of the RFC in the culutre were discussed.