Association between toll-like receptor expression and human papillomavirus type 16 persistence

Area of Science:

• Immunology
• Virology
• Gynecology

Background:

• Mucosal immune control of cervical human papillomavirus (HPV) infections is not well understood.
• Toll-like receptors (TLRs) are crucial for innate immune responses.

Purpose of the Study:

• To investigate the association between TLR expression and the persistence or clearance of oncogenic HPV types 16 or 51 in young women.
• To explore the role of TLRs in the innate immune response to HPV infection.

Main Methods:

• Quantitative reverse transcription-PCR was used to measure mRNA expression of TLR1, TLR2, TLR3, TLR4, TLR6, TLR7, TLR8, and TLR9 in endocervical specimens.
• Specimens were collected from a cohort of women before and after HPV acquisition.
• Statistical analysis (Wilcoxon rank sum test) compared TLR expression changes between women who cleared and those who did not clear HPV infections.

Main Results:

• Clearance of HPV 16 infections was significantly associated with increased expression of viral nucleic acid-sensing TLRs (TLR3, TLR7, TLR8, TLR9) and TLR2.
• Similar associations were not observed for HPV 51 infections.
• In women who cleared HPV 16, changes in TLR1, TLR3, TLR7, and TLR8 expression correlated with changes in interferon-α2 levels.

Conclusions:

• Dampened TLR expression in cervical mucosa may be a type-specific mechanism used by HPV 16 to evade innate immune responses and establish persistence.
• Upregulation of TLRs and subsequent cytokine induction are important for clearing HPV 16 infections.