Acquisition of human papillomavirus (HPV) results in an infection of variable duration which may or may not be associated with clinically apparent lesions. Lesions caused by skintropic HPV types generally manifest as cutaneous warts and most often resolve over a period of months to years. On the other hand, anogenital infections are more likely to remain clinically inapparent. The development of DNA amplificationbased tests has demonstrated that anogenital infections are quite common and generally self-limited. For example, we and others have shown by PCR testing of multiple samples collected at different points in time-that 70 to 90% of sexually active adolescents and young women who develop an incident cervical HPV infection will show clearance of infection within 12 to 30 months (47,61,94). The factors influencing the natural history of these infections are not well understood. Given that persistent anogenital infection with oncogenic HPV types is associated with increased risk of neoplasia and invasive cancers (22,59,70,71,94,124) and that cervical carcinoma remains a leading cause of death among women in developing countries (129), understanding these factors is of considerable importance.Substantial effort has been directed recently at understanding the role of the host's immune response in the natural history of HPV, and in particular, anti-viral, cell-mediated immunity. Empirical evidence for the importance of cell-mediated immunity in control of HPV infection comes from an extensive body of literature documenting the increased prevalence of HPV infection and associated disease among immunosuppressed populations, including those with iatrogenic immunosuppression such as renal transplant recipients and individuals with human immunodeficiency virus (HIV) infection. Sillman and coauthors (128) reported in 1984 on 20 immunosuppressed women with various causes of immunosuppression who had lower genital neoplasia, describing evidence of associated HPV infection in all 20. Penn, in 1986, reported a 100-fold increase in cancer of the vulva and anus in renal transplant recipients (111). In the 1990s, as molecular testing for HPV infection came into its own, several reports confirmed increased incidence of HPV infection (50) and associated morbidities, including warts (77) and cervical squamous intraepithelial lesions (SIL) (104), among immunosuppressed renal transplant recipients.The most persuasive evidence for the association between cellular immune defects and HPV infection and related morbidities comes from persons with HIV infection. Such individuals show increased prevalence of anogenital HPV infection (31, 32, 60, 105-107) as well as longer periods of HPV persistence (31,40,46,90,136). In addition, infection with multiple HPV types and with oncogenic types are more common (9,31,46,78,90,107,136). Associations between markers of HIV disease status (e.g., viral load and CD4 lymphocyte count) and HPV infection have been inconsistent. Most studies have suggested that advanced disease and greater immunological ...

Cytotoxic T lymphocyte (CTL) responses to the human papillomavirus (HPV) type 16 E6 and E7 proteins were measured in 20 women with known HPV and cervical disease status. CTL assays were performed after stimulation with E6 or E7 fusion proteins using autologous B lymphoblastoid cells infected with vaccinia viruses expressing E6 or E7. CTL responses to E6 and E7 were detected in 6 (75%) of 8 and 5 (56%) of 9 HPV-16-positive women without cervical intraepithelial neoplasia (CIN), respectively. Responses to E6 or E7 were each detected in only 2 (29%) of 7 HPV-16-positive women with CIN. Responses to both antigens were found in 63% of women without CIN and 14% of those with CIN. CTL responses to E6 or E7 are more commonly detectable in HPV-16-positive women without CIN than in HPV-16-positive women with CIN, suggesting that CTL response may play a role in disease protection.

Our cross-sectional study suggested that cytotoxic T lymphocyte (CTL) responses have a protective effect in squamous intraepithelial lesion (SIL) development. More CTL responses in women with human papillomavirus type 16 (HPV 16) infection without SILs than with SILs were detected. In the current longitudinal study, the role of CTL in clearing HPV 16 infection in women without SILs was investigated. Women with HPV 16 infection (n=51) were enrolled, along with HPV 16-negative control women (n=3). Twenty-two (55%) of 40 women who cleared HPV 16 infection had an E6 CTL response at least once, compared with none of 9 women who had HPV 16 persistence (P=.003). Such a difference was not demonstrated for E7; 25 (63%) of 40 women who cleared HPV 16 infection responded, versus 5 (56%) of 9 women with persistence (P=.720). It appears that lack of response to E6 is important in the persistence of HPV 16 infection.

: Non-surgical treatments for cervical intraepithelial neoplasia 2/3 (CIN2/3) are needed as surgical treatments have been shown to double preterm delivery rate. The goal of this study was to demonstrate safety of a human papillomavirus (HPV) therapeutic vaccine called PepCan, which consists of four current good-manufacturing production-grade peptides covering the HPV type 16 E6 protein and skin test reagent as a novel adjuvant.: The study was a single-arm, single-institution, dose-escalation phase I clinical trial, and the patients (n = 24) were women with biopsy-proven CIN2/3. Four injections were administered intradermally every 3 weeks in limbs. Loop electrical excision procedure (LEEP) was performed 12 weeks after the last injection for treatment and histological analysis. Six subjects each were enrolled (50, 100, 250, and 500 μg per peptide). : The most common adverse events (AEs) were injection site reactions, and none of the patients experienced dose-limiting toxicities. The best histological response was seen at the 50 μg dose level with a regression rate of 83% (n = 6), and the overall rate was 52% (n = 23). Vaccine-induced immune responses to E6 were detected in 65% of recipients (significantly in 43%). Systemic T-helper type 1 (Th1) cells were significantly increased after four vaccinations ( = 0.02). : This study demonstrated that PepCan is safe. A significantly increased systemic level of Th1 cells suggests that which induces interleukin-12 (IL-12) , may have a Th1 promoting effect. A phase II clinical trial to assess the full effect of this vaccine is warranted.