Table 1.: Key Characteristics of the Immune Cells in Persistent Papillomavirus Infection and Regressing Disease

Regression

Persistence

increased TLR expression TNFα production by infiltrating mononuclear cells infiltration of antigen presenting cells Th1 response CD4 infiltrate CD8 infiltrate high CD4:CD8 ratio cell-mediated immunity to early antigens

reduced TLR expression chronic inflammation including macrophage infiltration, increased neutrophils and lymphocytes in the epidermis impaired NK cell function impaired IFN pathways reduced numbers of antigen presenting cells and impaired antigen presentation Th2 response Treg infiltrate few or no CD4 T cells at site CD8 infiltrate low CD4:CD8 ratio limited cell-mediated immune response increased likelihood of antibodies to capsid