▁function ▁experiments ▁have ▁confirmed ▁that ▁P . ▁ging ival is ▁mut ants ▁def ic ient ▁for ▁F im ▁C , ▁D , ▁or ▁E ▁have ▁dr ast ically ▁at ten u ated ▁vir ul ence . ▁ ▁E vas ion ▁of ▁host ▁def enses ▁and ▁imm une ▁responses ▁ ▁P . ▁ging ival is ▁has ▁many ▁ways ▁of ▁ev ading ▁host ▁imm une ▁responses ▁which ▁affect s ▁its ▁vir ul ence . ▁It ▁does ▁this ▁by ▁using ▁a ▁combination ▁of ▁ging ip ain ▁prote ases , ▁a ▁caps ular ▁pol ys ac char ide , ▁induction ▁of ▁host ▁cell ▁pro l ifer ation , ▁and ▁the ▁cle av age ▁of ▁chem ok ines ▁responsible ▁for ▁neut roph il ▁rec ruit ment . ▁ ▁Vir ul ent ▁P . ▁ging ival is ▁further ▁mod ul ates ▁le uk ocy te ▁rec ruit ment ▁by ▁prote ol ysis ▁of ▁cy tok ines ▁and ▁chem ok ines ▁that ▁are ▁secret ed ▁by ▁the ▁host ▁cells . ▁The ▁arg - ging ip ain ▁and ▁l ys - ging ip ains ▁are ▁responsible ▁for ▁this ▁prote ol ysis . ▁In ▁a ▁study ▁using ▁a ▁mouse ▁model , ▁P . ▁ging ival is ▁was ▁specifically ▁found ▁to ▁down - reg ulate ▁IL - 8 ▁induction , ▁causing ▁delayed ▁neut roph il ▁rec ruit ment . ▁Pre vention ▁of ▁neut roph il ▁rec ruit ment ▁may ▁in hib it ▁the ▁clear ance ▁of ▁the ▁b acter ium ▁from ▁the ▁site ▁of ▁in fection ▁allowing ▁for ▁colon ization . ▁P .