Cultured murine parenchymal liver cells induce differentiation of bone marrow cells to macrophage like cells which present antigen to TH1 clones but inhibit their proliferation by nitric oxide and prostaglandinsa

Suppressor cells were developed from nylon-wool non-adherent CD4(-)8(-)TCR beta, bone marrow cells (TN-NWP-BMC) co-cultured with parenchymal liver cel ls (PLC) for 2.5 days. The major suppressor cell population consists of nyl on-wool/plastic dish adherent, phagocytic Mac-1(+) CD3(-)4(-)8(-)cells (Ad cells), with 34% of the Ad cells being F4/80(+) and 24% Ia(+). These cells supressed the antigen specific proliferation of Th1 clones in an MHC-non-re stricted manner. They showed a dose-dependent increase in suppressive activ ity, with both the nitric oxide (NO) and prostaglandin E-2 (PGE(2)) levels in the culture supernatant rising with Ad cell concentration. If Ad cells d id actually exist in the liver sinusoid, they would thus be bound to play a major role in inducing peripheral tolerance by the liver.