ANTIVIRAL EFFECT OF PROLINE-RICH POLYPEPTIDE IN MURINE RESIDENT PERITONEAL-CELLS

It is known that resident peritoneal (RP) cells from BALB/c female mic e express a constitutive non-specific antiviral immunity which is prog ressively 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 stomatiti s 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 o n 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.