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Toll-like receptors (TLRs) are innate immune defenders thought to be critical for the clearance of human papillomavirus (HPV) infections hence preventing the development of HPV-associated high-grade cervical intra-epithelial neoplasia (CIN2 or 3), a potential cervical cancer precursor. However, the role of TLRs in the regression of established cervical lesions, such as CIN2, is hindered by a lack of prospective design studies. Using SYBR green real-time PCR assays, we have examined the gene expression of TLR2, TLR3, TLR7, TLR8 and TLR9, in cytobrush collected endocervical cells of 63 women diagnosed with CIN2 at study entry (baseline) and followed over a 3-year period. Wilcoxon rank-sum test was used to examine the association between TLR expression levels, measured at baseline, and CIN2 outcome (regression vs. persistence/progression) over time. HPV genotyping was performed using Roche Linear Array Assay detecting 37 HPV types. Women with CIN2 regression showed significantly higher baseline levels of TLR2 (p = 0.006) and TLR7 (p = 0.007), as well as a non-significant trend for a higher TLR8 expression (p = 0.053) compared to women with CIN2 persistence/progression. Six women with CIN2 regression, who presented with an HR-HPV DNA-negative CIN2 lesion at study entry, had significantly higher baseline levels of TLR2 (p = 0.005), TLR7 (p = 0.013) and TLR8 (p = 0.012), compared to women with CIN2 persistence/progression, suggesting their role in clearance of HPV prior to clearance of the lesion. Our results confirm a key role of TLRs in regression of CIN2 and support the potential use of TLR-agonists for treatment of these lesions.

Toll-like receptors (TLRs) are innate immune defenders thought to be critical for the clearance of human papillomavirus (HPV) infections hence preventing the development of HPV-associated high-grade cervical intra-epithelial neoplasia (CIN2 or 3), a potential cervical cancer precursor. However, the role of TLRs in the regression of established cervical lesions, such as CIN2, is hindered by a lack of prospective design studies. Using SYBR green real-time PCR assays, we have examined the gene expression of TLR2, TLR3, TLR7, TLR8 and TLR9, in cytobrush collected endocervical cells of 63 women diagnosed with CIN2 at study entry (baseline) and followed over a 3-year period. Wilcoxon rank-sum test was used to examine the association between TLR expression levels, measured at baseline, and CIN2 outcome (regression vs. persistence/progression) over time. HPV genotyping was performed using Roche Linear Array Assay detecting 37 HPV types. Women with CIN2 regression showed significantly higher baseline levels of TLR2 (p = 0.006) and TLR7 (p = 0.007), as well as a non-significant trend for a higher TLR8 expression (p = 0.053) compared to women with CIN2 persistence/progression. Six women with CIN2 regression, who presented with an HR-HPV DNA-negative CIN2 lesion at study entry, had significantly higher baseline levels of TLR2 (p = 0.005), TLR7 (p = 0.013) and TLR8 (p = 0.012), compared to women with CIN2 persistence/progression, suggesting their role in clearance of HPV prior to clearance of the lesion. Our results confirm a key role of TLRs in regression of CIN2 and support the potential use of TLR-agonists for treatment of these lesions.

Toll-like receptors (TLRs), important in rapid clearance of incident human papillomavirus (HPV) infections, may also be important in shaping the adaptive response to persistent infections. We examined here the association between TLR expression and clearance of HPV16 infections following periods of persistence, using longitudinal TLR measurements and a time-to-clearance analysis, as well as the interaction between TLRs and adaptive, cell-mediated responses involved in clearance. TLR2, TLR3, TLR7, TLR8, and TLR9 mRNA expression were measured in cervical cytobrush samples by quantitative PCR. Responses to the HPV16 E6 and E7 oncoproteins were measured by an interferon-γ immunospot assay. Bivariable and multivariable Cox proportional hazard models were used to estimate the effect of TLRs on HPV16 clearance. Higher expression of TLR3 or TLR7 at an HPV16-positive visit was a significant (p ≤ 0.05) predictor of clearance by the following visit, in both unadjusted and adjusted (for smoking and oral contraceptive use) models. In women with, but not those without, a positive response to E6, higher expression of TLR3 (hazard ratio: 1.2 [95% confidence interval: 1.04–1.39], p = 0.012), TLR7 (1.39 [1.14–1.7], p = 0.001), TLR8 (1.37 [1.11–1.69], p = 0.003), or TLR9 (1.53 [1.13–2.08], p = 0.006) was significantly associated with clearance, revealing an important link between innate and adaptive immunity in the control of HPV infections following periods of persistence.

Mechanisms for the control and resolution of human papillomavirus (HPV) infection of the cervix include the local production of cytokines, which control recruitment and function of cells integral to pathogen control. We established a cohort of women for long-term follow-up to examine the mucosal expression of antiviral (IFN-α2), Type-1 (IFN-γ, IL-12), regulatory (IL-10), and proinflammatory (IL-1α, IL-1β, IL-6, IL-8, MIP-1α, and TNF) cytokines in association with the clearance of incident cervical HPV infection. Interviews and specimens for HPV DNA analysis and cytokine protein measurement were obtained at baseline and at 4-month intervals. A Cox proportional hazards model was used to study the relationship between clearance of 107 high-risk and 111 low-risk incident HPV infections and cytokine levels among 154 women. Positive changes from baseline levels of IL-10, IL-12, MIP-1α, and TNF were associated with significantly longer times to type-specific HPV clearance. Inverse trends in the hazard ratios associated with clearance of high-risk HPV infections were monotonic and significant for IL-12 (ptrend = 0.02) and TNF (ptrend = 0.02); the likelihood of high-risk HPV clearance was reduced by 65% and 67%, respectively, among women in the highest as compared with the lowest quartile of change from baseline. Our results suggest that in women with a nontransient cervical HPV infection, proinflammatory, Type-1, and regulatory cytokines are elevated, underscoring the long-term commitment of local immune mediators to viral eradication.

New strategies for cervical cancer screening include human papillomavirus (HPV) DNA testing. Using self-testing methods would increase access to testing in both developed and developing countries. The purpose of this study was to compare time-to-clearance of specific HPV types between clinician-collected-lavage (CC-L) and self-collected (SC) sampling in a single cohort. CC-L and SC samples were obtained every 4 months at alternate 2-month windows from 537 women. Eighteen high-risk (HR) HPV and 4 low-risk (LR) HPV were examined. Proportional hazards model was used to compare time-to-clearance between methods for combined HR and for 13 specific HPV types. Prentice-Wilcoxon test was used for within-subject paired comparison. In the independent analysis for combined HR and LR types, no differences were found. For specific types, time-to-clearance for all HPV types examined between CC-L and SC samples was similar except for HPV 66 which showed a trend to clear slower by SC (p = 0.09). When comparing methods in the same woman, time-to-clearance was similar for all types except for HPV 16 which showed a trend to clear slower by CC-L means (p = 0.08). When we examined pattern of clearance among the CC-L samples, the fastest types to clear were HPV 6, 18, 66, 84 and 39 and the slowest were HPV 62, 68, 59 and 16. These patterns of fast and slow were similar for SC samples. Our findings suggest using SC vaginal swabs would observe similar natural histories of HPV compared to studies using CC-L specimens making self-testing feasible for repeated HPV DNA detection.

The mechanisms involved in mucosal immune control of cervical human papillomavirus (HPV) infection remain ill-defined. Because Toll-like receptors (TLRs) are key players in innate immune responses, we investigated the association between TLR expression and viral persistence or clearance in young women with incident infections with oncogenic HPV types 16 or 51. Messenger RNA expression of TLR1, TLR2, TLR3, TLR4, TLR6, TLR7, TLR8, and TLR9 was measured by quantitative reverse transcription-PCR using human endocervical specimens, collected before and following viral acquisition, in a cohort well characterized for HPV infections. Wilcoxon rank sum test was used to compare the change seen from pre-infection to incident infection between women who subsequently cleared infection with those who did not. HPV 16 infections that cleared were significantly (P < 0.05) associated with an increase in expression of the four viral nucleic acid-sensing TLRs (TLR3, TLR7, TLR8 and TLR9) as well as TLR2 upon viral acquisition. Similar associations were not observed for HPV 51. In women who subsequently cleared their HPV 16 infection, changes in TLR1, TLR3, TLR7, and TLR8 expression levels between pre-incident and incident visits were significantly correlated with parallel changes in the levels of interferon-α2, measured by immunoassay in cervical lavage specimens. This study suggests that dampened TLR expression in the cervical mucosa is a type-specific mechanism by which HPV 16 interferes with innate immune responses, contributing to viral persistence, and that TLR upregulation and resultant cytokine induction is important in subsequent viral clearance.

Cervical mucosal expression of cytokines involved in mediating cellular immunity is believed to influence the persistence of human papillomavirus (HPV) infection, a necessary prerequisite for the development of cervical intraepithelial neoplasia (CIN). Additionally, regulatory T (Treg) cells are increasingly understood to be important modulators of cellular immunity. Using quantitative RT-PCR, we measured, in cross-sectional design, the cervical mRNA expression of IFN-gamma, IL-10, and IL-12, as well as the Treg transcription factor Forkhead box P3 (Foxp3), in a cohort of young women representing CIN 1, 2, and 3, as well as benign histology. Higher levels of IFN-gamma and IL-10 were significantly (p