Slumbering mucosal immune response in the cervix of human papillomavirus DNA-positive and -negative women

Abstract

Persistent human papillomavirus (HPV) infection is a prerequisite for cervical cancer and results from bypassing the local immune response. Twenty-four volunteers underwent an ectocervical biopsy, Pap smear, tests for sexually transmitted infections including HIV and HPV genotyping. All answered a questionnaire regarding medical history. Repeat Pap smear and HPV genotyping was performed 9-26 months later. Quantitative reverse transcriptase (qRT-)PCR was used to assess expression of CD3, CD4, CD8, CD19, CD27, IL-2, IL-12, IL-4, IL-10, IL-17, HLA-DRα, TGFβ, IFNγ, PD-1, PD-L1, CTLA-4, LAG3, IgA, IgG, CCR5, CCL5/RANTES and the IL-7 receptor in the biopsies. Eleven of 24 volunteers were HPV DNA-positive at baseline. Four of 10 were infected with a persistent HPV genotype at follow-up. All target molecules were successfully amplified and quantified except for IL-4. We found no difference in mRNA expression of these molecules when comparing HPV DNA-positive and -negative women, neither when comparing persistently infected individuals or those who cleared the infection. However, mRNA expression of the B cell phenotypic marker CD19 was higher in women using hormonal contraception than those not (p<0.05). HPV infection does not evoke a local inflammatory immune response in the ectocervix measurable with qRT-PCR. Hormonal contraception may influence B cell activity in the cervix.