Antiviral effect of proline-rich polypeptide in murine resident peritoneal cells.

It is known that resident peritoneal (RP) cells from BALB/c female mice express a constitutive non-specific antiviral immunity which is progressively reduced during several days of cultivation in vitro. In this report, we have studied the effect of a proline-rich polypeptide (PRP) isolated from ovine colostrum on the kinetics of vesicular stomatitis virus (VSV) replication in freshly isolated and one-day cultured RP cells. The polypeptide was added to the cells immediately after virus adsorption or one day before or after viral infection. Independently on time of PRP addition, an inhibition of VSV replication (virus titres reduced by up to 4 log units) was observed. Occasionally, however, a weak stimulation of VSV replication by PRP (virus titres increased by 1-2 log units) was noticed in RP cells constitutively resistant to the infection.