Spontaneous production of tumor necrosis factor alpha by Kupffer cells of MRL/lpr mice.

We report that freshly isolated, unstimulated Kupffer cells (KC) from MRL/lpr female mice in short-term culture spontaneously produce high levels of TNF-alpha. TNF production was first detected in KC cultures at age 6 wk and increased with the age of the mice. Moreover, the levels of spontaneous TNF production by KC directly correlated with the age of the MRL/lpr mice. Although TNF production by KC could be induced with C. parvum in vivo or LPS in vitro in all nonautoimmune C3H/HeN, BALB/c, DBA/2, C57B16 mice, the only other strain in which spontaneous TNF production by KC was observed was MRL/++ mice greater than 10 mo old.