Chick embryo cells (CEC) secrete a factor which inhibits HIV1 replicat
ion. Non-productive infection of CEC with vesicular stomatitis virus i
ncreases 5-10-fold the synthesis of this factor, After purification by
FPLC the biological activity is associated with a heat-resistant prot
ein of approximately 150 kDa, composed of two subunits of 70 and 58 kD
a and charged negatively. Monoclonal antibodies raised against this pr
otein block the inhibitory activity of the purified protein and react
with the 150-kDa and 58-kDa proteins in Western blots.