We have addressed the notion that the initiation and progression of human papillomavirus associated cancer of the uterine cervix are associated with alterations of Langerhans cells (LC) within the mucosal squamous epithelium. Since the transformation zone (TZ) of the cervix is the site where the majority of squamous intraepithelial lesions (SIL) are initiated, in contrast to the exocervix, we decided to investigate the influence of the local microenvironment within the TZ on the function and density of LC. We show that the TZ is associated with a significant reduction in the density of immature LC (CD1a/LAG) compared to the exocervix. In contrast, the development of SILs is attributed with a relative increased density of immature LC, compared to the TZ. Furthermore, we show that this variability in LC density is correlated with a differential expression of TNF␣ and MIP3␣ within the micro-environment of the TZ and SILs. Both TZ and SIL epithelium-derived LC, in the presence of allogeneic PBMC, induced lower levels of proliferation and IL2 production and higher levels of the immunosuppressive cytokine IL10 in comparison to the exocervix. Nevertheless, the epithelium-derived LC in SILs exhibits a reduction in their functional activity, relative to the TZ. Together our studies suggest that the immunosurveillance within the epithelium of the TZ may be intrinsically perturbed due to the altered expression of chemokines/cytokines and the concomitant diminished density of LC. Furthermore, following HPV infection and the development of SILs, the function of LC may be further incapacitated by viral associated mechanisms. © 2002 Wiley-Liss, Inc. Key words: Langerhans cells (LC); transformation zone (TZ); squamous intraepithelial lesions (SILs); human papillomavirus (HPV); local immunityThe chronic infection of keratinocytes of the uterine cervix by the human papillomavirus (HPV) is associated with the development of cervical cancer. Despite the evidence that HPV is strongly implicated as the causative agent in the etiology of cervical cancer and its precursors (SIL, squamous intraepithelial lesion), HPV infection alone is not sufficient for cancer development. 1 The role of the intrinsic immunity in controlling HPV infection and the subsequent development of SILs is shown indirectly by the increased frequency of HPV-associated lesions in patients with depressed cell-mediated immunity. 2,3 For the most part, the development of SIL and/or cervical cancer is preferentially associated with a local type II (IL4/IL6) and/or immunosuppressive (IL 10) cytokine pattern, 4 -7 not a cell-mediated type I immune response, which is more appropriate for tumor immunity. Given that immune responses in mucosal sites are frequently dominated by a "default" type 2 response, 8,9 it is essential to consider mechanisms that contribute to this predisposition in order to design vaccine strategies to promote a localized cell-mediated immunity.The squamous epithelium of the cervix is composed mainly of keratinocytes, the primary target of HPV and a ...

This study addressed the notion that the progression of cervical cancer is associated with a T‐helper 2 (TH2) immunodeviation by analysing cytokine expression in 60 cervical biopsy specimens, spanning the spectrum from normal cervical tissue to high‐grade squamous intraepithelial lesions (SILs). The biopsies were analysed by immunohistochemistry for the expression of TH1 [interleukin‐2 (IL2), interferon gamma (IFNγ)] and of TH2‐type cytokines (IL4, IL6). Positive cells were usually observed in the subepithelial connective tissue, where most CD4+ cells were also detected. The density of IL2+ cells was significantly lower in high‐grade SILs than in normal tissues taken either from the ectocervix or from the transformation zone. In contrast, significantly higher densities of IL4+ cells and, to a lesser degree, IL6+ cells were found in SIL biopsies compared with histologically normal tissues taken from the adjacent ectocervical region. A significantly higher IL4+/CD4+ cell ratio was also found in high‐grade SILs (82 per cent) than in normal cervical biopsies taken from the transformation zone of healthy women showing squamous metaplasia (27 per cent). The elevated density of TH2+ cells in SIL biopsies was associated with both the expression of HLA‐DR by keratinocytes and a diminished number of intraepithelial Langerhans' cells (CD1a+). In conclusion, the increased TH2+/CD4+ cell ratio in SIL biopsies suggest the presence, during cervical carcinogenesis, of a TH2 immunodeviation that could participate in the immunoescape of preneoplastic cervical keratinocytes. © 1998 John Wiley & Sons, Ltd.

We have addressed the notion that the progression of cancer of the uterine cervix is associated with a preferential constraint on the development of a type 1 cellular mediated response, which is necessary to efficiently eliminate (pre)neoplastic cells. Based on the importance of cytokines in the regulation of an appropriate immune response, we have evaluated the expression of IL-12p40, IL-10 and transforming growth factor-beta 1 (TGF-beta1). Using reverse transcriptase-polymerase chain reaction (RT-PCR), the expression of these three cytokines was evaluated in both low-grade (LG) and high-grade (HG) cervical squamous intraepithelial lesions (SIL) and in normal exocervix and transformation zone biopsies. Our results show that the average level of IL-12 increases within both the LG and HG SIL, compared with both control groups. Interestingly, the percentage of HG SIL expressing IL-12p40 was lower compared with LG SIL. In contrast, the expression of IL-10 increased in parallel with the severity of the lesion to a maximal level in HG SIL. Using immunohistochemistry, we ascertained the presence of IL-12 protein in SIL and IL-10 protein in the transformation zone and SIL biopsies. Both IL-12- and IL-10-producing cells were localized in the stroma, not within the SIL. Furthermore, in this study we also observed that the region of the cervix the most sensitive to lesion development, the transformation zone, was associated with higher average levels of the immunosuppressive cytokines IL-10 and TGF-beta1.

The encouraging results obtained from this study performed on a limited number of subjects justify further analysis of the efficacy of the PD-E7/AS02B vaccine in CIN patients.

A formalin-fixation and paraffin-processing resistant epitope of Ki-67 cell proliferation-associated antigen was immunohistochemically detected by the MIB-1 monoclonal antibody (Immunotech, Marseille, France) in 25 routinely processed cervical biopsies showing normal squamous epithelium or squamous metaplasia and in 65 cervical intraepithelial lesions (SILs) (44 low grade and 21 high grade SILs) with human papillomavirus (HPV) infection. Expression of Ki-67 antigen was exclusively confined to the parabasal and basal layers of normal and metaplastic epithelium. There was no significant difference of Ki-67 antigen immunostaining between normal cervical biopsies and cases of squamous metaplasia. In SIL specimens, the staining was markedly increased in the parabasal and basal layers and Ki-67-positive cells were also distributed in the intermediate (low grade SIL) or all layers of epithelium (high grade SIL). Statistically significant differences for the density of Ki-67 antigen-labeled cells, which were assessed with an image analysis system, were found in comparisons between normal or metaplastic epithelium and SILs (P < .001) and between low grade SILs and high grade SILs (P < .001). In our series of SILs, HPV 16/18 and 31/33/35/novel types, which were found in both low grade and high grade SILs, were significantly associated with higher densities of Ki-67 antigen-positive cells than HPV 6/11 types that were found exclusively in low grade SILs. There was no significant difference found between the densities of Ki-67 antigen-labeled cells in HPV 16/18-positive and HPV 31/33/35/novel types-positive tissues in our series of SILs taken as a whole or when segregating SILs into low grade and high grade.