Background: Condyloma acuminatum (CA), caused by human papillomavirus (HPV), is characterized by a variable clinical course that can include significant morbidity, frequent disease recurrence and occasional oncogenicity. Effective CD8+ T-cell-mediated clearance of HPV-infected cells may be defective in patients with CA, leading to recurrent disease and failure to suppress latent HPV reactivation. The pathogenesis responsible for CA and the persistence of latent HPV infection remain unknown.
Objective: To determine whether expression of transporters associated with antigen processing 1 (TAP-1) and the major histocompatibility complex class I (MHC-I) is involved in HPV immune escape.
Methods: In this present study, we compared 31 CA lesions with 30 normal prepuces by immunohistochemistry and reverse transcription PCR for their expressions of TAP-1 and MHC-I.
Results: Expressions of TAP-1 and MHC-I were significantly reduced in CA tissue biopsies compared with normal prepuces. There was a statistically significant positive correlation between expressions of TAP-1 and MHC-I in CA lesions. Furthermore, we found that TAP-1 mRNA was significantly reduced in CA lesions compared with those in normal prepuces.
Conclusion: These results suggest that HPV may evade immune recognition by downregulating MHC-I cell surface expression via decreased TAP-1 levels.