Human lupus-type inclusions in umbilical cord blood mononuclear cells.

Mononuclear cells purified from umbilical cord blood activated oligoadenylate synthetase and formed human lupus-type inclusions (LI) when cultured with the purified recombinant human leukocyte interferon, IFLrA. LI frequencies increased from 0% to a low of 0.75% and a high of 6.25% in 4-day cultures with IFLrA (100 units/ml). These interferon-induced responses in the mononuclear cells of neonates indicate that LI are solely an intrinsic product of normal cells, and not an exogenous virus or some other environmental agent.