PCP4 and periodontitis: Pep 19 generates sequential spreading epitope to Pep19 subdominant autoantigens of human HSP60 (Hu19) in healthy subjects and mice, to P9 autoantigens of human HSP60 (Hu9) and to oxidized low-density lipoprotein (ox-LDL) (neoantigen) in the Periodontitis induced by P. gingivalis as well as in autoimmunity.