Mechanisms of induction of tolerance to syngeneic IgE

: We have previously shown that T cell tolerance to syngeneic IgE in mice is delayed after birth for 2-3 weeks and is induced concurrently with the appearance of IgE in serum. Although inoculation of IgE in saline on the day of birth caused T cell tolerance, an apparent inconsistency was our inability to tolerize mice after day 2, despite evidence indicating that endogenously-produced IgE is effective at the age of 2-3 weeks. Data presented here indicate that repeated i.p. inoculations, during this period, of smaller doses of IgE in saline induce tolerance in many individual mice, thus mimicking to a degree the naturally occurring events. Another earlier finding was that normal adult B cells, but not T cells, can tolerize T cells to IgE when administered on the day of birth. We have now observed that B cells bearing surface IgE are much more tolerogenic than the remaining B cells.