Polyclonal antibody synthesis by bone marrow cells of New Zealand black mice. I. Assessment of activity in an adoptively transferred histocompatible host.

The activity of polyclonal antibody synthesis (PAS) of bone marrow cells (BMC) was assessed by enumerating anti-trinitrophenyl (TNP) plaque-forming cells (PFC) or immunoglobulin-secreting cells (IgSC) generated in the spleen of BMC-reconstituted syngeneic or H-2-compatible hosts. BMC of NZB mice generated large numbers of anti-TNP PFC or IgSC as compared with those of C57BL/6 mice or H-2-compatible, nonautoimmune strains of mice (BALB/c, DBA/2 and B10 . D2 mice). Causes for the enhanced PAS activity were explored. Susceptibility to known B cell mitogens was examined and it was shown that spleen cells of the recipients of NZB BMC were refractory to the mitogens while PAS was apparent and acquired responsiveness after 15 days as those from nonautoimmune strains of mice. Furthermore, environmental factor(s) did not seem to be responsible for the enhanced PAS, since BMC from nonautoimmune BALB/c mice showed little PAS activity when transferred into heavily irradiated NZB mice and those of NZB mice showed enhanced PAS activity when transferred into B10 . D2 or BALB/c mice. It seems most likely that enhanced PAS activity of BMC of NZB mice is a genetically inherent phenomenon. PAS activity of BMC and spleen cells of NZB mice increased significantly with increasing age of mice.