Inverse modulation of intraepithelial Langerhans' cells and stromal macrophage/dendrocyte populations in human papillomavirus-associated squamous intraepithelial lesions of the cervix

The cutaneous beta human papillomavirus type 8 E6 protein induces CCL2 through the CEBPα/miR-203/p63 pathway to support an inflammatory microenvironment in epidermodysplasia verruciformis skin lesions

Human papillomavirus type 8 (HPV8), a cutaneous genus beta HPV type, has co-carcinogenic potential at sun-exposed sites in patients suffering from the inherited skin disease epidermodysplasia verruciformis (EV). We had previously shown that Langerhans cells responsible for epithelial immunosurveillance were strongly reduced at infected sites and that the HPV8 E7 protein interferes with the CCAAT/enhancer-binding protein (C/EBP)β to suppress the Langerhans cell chemokine CCL20. At the same time, however, we observed that EV lesions are heavily infiltrated with inflammatory immune cells, which is similar to the situation in HPV8 E6 transgenic mice. To identify critical inflammatory factors, we used a broad multiplex approach and found that the monocyte attracting chemokine CCL2 was significantly and strongly induced by HPV8 E6 but not E7-expressing HaCaT cells, which were used as a model for UV-damaged skin keratinocytes. Conditioned media from HPV8 E6-expressing keratinocytes enhanced CCL2-receptor (CCR2)-dependent monocyte recruitment in vitro, and macrophages predominated in the stroma but were also detected in the epidermal compartment of EV lesions in vivo. CCL2 induction by HPV8 E6 was even stronger than stimulation with the proinflammatory cytokine TNF-α, and both HPV8 E6 and TNF-α resulted in substantial suppression of the transcription factor C/EBPα. Using RNAi-mediated knockdown and overexpression approaches, we demonstrated a mechanistic role of the recently identified C/EBPα/miR-203/p63 pathway for HPV8 E6-mediated CCL2 induction at protein and transcriptional levels. Epithelial co-expression of p63 and CCL2 was confirmed in HPV8 E6-expressing organotypic air-liquid interface cultures and in lesional EV epidermis in vivo. In summary, our data demonstrate that HPV8 oncoproteins actively deregulate epidermal immune homeostasis through modulation of C/EBP factor-dependent pathways. While HPV8 E7 suppresses immunosurveillance required for viral persistence, the present study provides evidence that E6 involves the stemness-promoting factor p63 to support an inflammatory microenvironment that may fuel carcinogenesis in EV lesions.

Chemoradiotherapy-induced increase in Th17 cell frequency in cervical cancer patients is associated with therapy resistance and early relapse

Cervical cancer therapy is still a major clinical challenge, as patients substantially differ in their response to standard treatments, including chemoradiotherapy (CRT). During cervical carcinogenesis, T-helper (Th)-17 cells accumulate in the peripheral blood and tumor tissues of cancer patients and are associated with poor prognosis. In this prospective study, we find increased Th17 frequencies in the blood of patients after chemoradiotherapy and a post-therapeutic ratio of Th17/CD4⁺ T cells > 8% was associated with early recurrence. Furthermore, Th17 cells promote resistance of cervical cancer cells toward CRT, which was dependent on the AKT signaling pathway. Consistently, patients with high Th17 frequencies in pretherapeutic biopsies exhibit lower response to primary CRT. This work reveals a key role of Th17 cells in CRT resistance and elevated Th17 frequencies in the blood after CRT correspond with early recurrence. Our results may help to explain individual treatment responses of cervical cancer patients and suggest evaluation of Th17 cells as a novel predictive biomarker for chemoradiotherapy responses and as a potential target for immunotherapy in cervical cancer.

Tumor-Associated CD163+ M2 Macrophage Infiltration is Highly Associated with PD-L1 Expression in Cervical Cancer

Background

Programmed death-ligand 1 (PD-L1) is a negative costimulatory molecule, and its main function is widely considered to be in the regulation of T cells. Tumor-associated macrophages (TAMs) are an important part of the tumor microenvironment, and they also play an important role in immunosuppression. However, the relationship between the expression of PD-L1 and TAMs in cervical carcinoma (CC) remains unclear. We detected the expression of PD-L1 and TAMs in tumor tissue to study the correlation between them.

Methods

Immunohistochemical staining of PD-L1, CD68 (pan-macrophage), and CD163 (M2-like macrophage) was performed in 120 cases of cervical squamous cell carcinoma. Logistic regression analysis was used to evaluate the predictors related to positive PD-L1 expression. We also apply the Kaplan-Meier method to study the recurrence-free and overall survival rate of CC patients.

Results

The increase in PD-L1 expression in tumor cells (TC) was significantly correlated with the increase in CD163 density (r=0.8550, p<0.0001), while PD-L1 in the stroma was also significantly associated with the intratumoral density of CD68- or CD163-positive cells (CD68 p<0.0001; CD163 p=0.0009). The mean infiltration rates of CD68- and CD163-positive cells in PD-L1-positive TC were significantly higher than in PD-L1-negative TC (CD68 p=0.0095; CD163 p<0.0001). In multivariate logistic regression analyses, only the density of CD163-positive cells was correlated with the expression of PD-L1 in TC cells (OR 1.52; p=0.032). In prognostic analysis, PD-L1 more than 10% was significantly correlated with short RFS (HR=2.66; p=0.028). For CD163⁺ macrophage evaluation, the density above the median was also significantly correlated with RFS (HR=2.48; p=0.021).

Conclusion

CD163⁺ M2-like macrophage infiltration is highly associated with PD-L1 expression in CC, suggesting that macrophage infiltration can serve as a potential therapeutic target.

Perspectives in HPV Secondary Screening and Personalized Therapy Basing on Our Understanding of HPV-Related Carcinogenesis Pathways

As cervical cancer is one of the most common malignancies in women worldwide even with present screening methods, the incidence in most developed countries is not decreasing for the last 15-20 years. A shift has been observed in the age of diagnosis in favour of younger women, and treatment of already developed cervical cancer is a challenge for surgeons. It is imperative to find new diagnostic methods for accurately pointing out patients at high risk of developing malignant disease and developing personalized treatment. Since cervical cancer is almost exclusively associated with HPV infection, understanding changes happening in an infected cell may prove invaluable for search of such methods, but it may also prove helpful in the diagnosis and treatment of other anogenital and nasopharyngeal region cancers. This review follows HPV-related changes in infected cell biology to point what potential markers and targets for therapy are in option when dealing with HPV-related diseases.

IL-6 expression promoted by Poly(I:C) in cervical cancer cells regulates cytokine expression and recruitment of macrophages

Poly(I:C) is a promising adjuvant for cancer treatment vaccines to enhance the host anti‐tumour immune response. However, the roles of poly(I:C) in the cervical cancer microenvironment and local immune reactions are not well understood. In this study, we investigated the roles of poly(I:C) in the cervical cancer. We analysed the cytokine transcription and secretion of cervical cancer cell lines and THP‐1–derived macrophages after poly(I:C) treatment, respectively. These results revealed that IL‐6 was significantly up‐regulated, and this up‐regulation was partly dose dependent. poly(I:C)‐stimulated supernatant of cervical cancer cells promoted M1‐type cytokine IL‐1β and IL‐6 expression of THP‐1–derived macrophages, but inhibited the expression of M2‐type cytokine, IL‐10 and CCL22. The recruitment of THP‐1–derived macrophages by poly(I:C)‐stimulated cervical cancer cell supernatant was also enhanced. Inhibition of IL‐6 expression in cervical cancer cells by siRNA transfection almost completely reversed the effects of poly(I:C) treatment. Finally, we found that phosphorylation of the NF‐κB signalling pathway in cervical cancer cells occurred quickly after poly(I:C) treatment. Moreover, the NF‐κB signalling pathway inhibitor PDTC significantly inhibited poly(I:C)‐induced IL‐6 expression. Taken together, these results suggest that poly(I:C) might regulate the effects of cervical cancer cells on tumour‐infiltrated macrophages, and subsequently promote a pro‐inflammatory tumour microenvironment.

Novel Biomarkers of Early Atherosclerotic Changes for Personalised Prevention of Cardiovascular Disease in Cervical Cancer and Human Papillomavirus Infection

Cervical cancer is associated with a causative role of human papillomavirus (HPV), which is a highly prevalent infection. Recently, women with a genital HPV infection were found to have increased incidence of cardiovascular diseases (CVD), including severe cardiovascular events such as myocardial infarction and stroke. The pathomechanisms of this relation are not yet fully understood, and may significantly affect the health of a large part of the population. Accelerated atherosclerosis is assumed to play a key role in the pathophysiology of this relationship. To identify high-risk groups of the population, it is necessary to stratify the CVD risk. Current algorithms, as widely used for the estimation of CVD risk, seem to be limited by the individual misclassification of high-risk subjects. However, personalised prediction of cardiovascular events is missing. Regarding HPV-related CVD, identification of novel sensitive biomarkers reflecting early atherosclerotic changes could be of major importance for such personalised cardiovascular risk prediction. Therefore, this review focuses on the pathomechanisms leading to HPV-related cardiovascular diseases with respect to atherosclerosis, and the description of potential novel biomarkers to detect the earliest atherosclerotic changes important for the prevention of CVD in HPV infection and cervical cancer.

The Formation and Therapeutic Update of Tumor-Associated Macrophages in Cervical Cancer

Both clinicopathological and experimental studies have suggested that tumor-associated macrophages (TAMs) play a key role in cervical cancer progression and are associated with poor prognosis in the respects of tumor cell proliferation, invasion, angiogenesis, and immunosuppression. Therefore, having a clear understanding of TAMs is essential in treating this disease. In this review, we will discuss the origins and categories of macrophages, the molecules responsible for forming and reeducating TAMs in cervical cancer (CC), the biomarkers of macrophages and the therapy development targeting TAMs in CC research.

Immune deviation and cervical carcinogenesis

Evidence is emerging that a complex interplay between high-risk human papillomavirus infection, the local microenvironment and the immune system is critical for cervical carcinogenesis. To establish persistence, the virus has to evade or overcome immune control. At the transition from precancer to cancer, however, chronic stromal inflammation and immune deviation build up, which may eventually determine the course of disease. Understanding the molecular basis underlying these pivotal stage-specific changes may help to define new tools for better diagnosis and therapy that are required to efficiently combat human papillomavirus-associated disease.

Cervical Cancer-Instructed Stromal Fibroblasts Enhance IL23 Expression in Dendritic Cells to Support Expansion of Th17 Cells

Persistent infection with high-risk human papillomavirus (HPV) is a prerequisite for the development of cervical cancer. HPV-transformed cells actively instruct their microenvironment, promoting chronic inflammation and cancer progression. We previously demonstrated that cervical cancer cells contribute to Th17 cell recruitment, a cell type with protumorigenic properties. In this study, we analyzed the expression of the Th17-promoting cytokine IL23 in the cervical cancer micromilieu and found CD83⁺ mature dendritic cells (mDC) coexpressing IL23 in the stroma of cervical squamous cell carcinomas in situ. This expression of IL23 correlated with stromal Th17 cells, advanced tumor stage, lymph node metastasis, and cervical cancer recurrence. Cocultures of cervical cancer-instructed mDCs and cervical fibroblasts led to potent protumorigenic expansion of Th17 cells in vitro but failed to induce antitumor Th1 differentiation. Correspondingly, cervical cancer-instructed fibroblasts increased IL23 production in cocultured cervical cancer-instructed mDCs, which mediated subsequent Th17 cell expansion. In contrast, production of the Th1-polarizing cytokine IL12 in the cancer-instructed mDCs was strongly reduced. This differential IL23 and IL12 regulation was the consequence of an increased expression of the IL23 subunits IL23p19 and IL12p40 but decreased expression of the IL12 subunit IL12p35 in cervical cancer-instructed mDCs. Cervical cancer cell-derived IL6 directly suppressed IL12p35 in mDCs but indirectly induced IL23 expression in fibroblast-primed mDCs via CAAT/enhancer-binding protein β (C/EBPβ)-dependent induction of IL1β. In summary, our study defines a mechanism by which the cervical cancer micromilieu supports IL23-mediated Th17 expansion associated with cancer progression. SIGNIFICANCE: Cervical cancer cells differentially regulate IL23 and IL12 in DC fibroblast cocultures in an IL6/C/EBPβ/IL1β-dependent manner, thereby supporting the expansion of Th17 cells during cancer progression.

Immunopathogenesis of HPV-Associated Cancers and Prospects for Immunotherapy

Human papillomavirus (HPV) infection is a causative factor for various cancers of the anogenital region and oropharynx, and is supposed to play an important cofactor role for skin carcinogenesis. Evasion from immunosurveillance favors viral persistence. However, there is evidence that the mere presence of oncogenic HPV is not sufficient for malignant progression and that additional tumor-promoting steps are required. Recent studies have demonstrated that HPV-transformed cells actively promote chronic stromal inflammation and conspire with cells in the local microenvironment to promote carcinogenesis. This review highlights the complex interplay between HPV-infected cells and the local immune microenvironment during oncogenic HPV infection, persistence, and malignant progression, and discusses new prospects for diagnosis and immunotherapy of HPV-associated cancers.

Stromal Fibroblasts Induce CCL20 through IL6/C/EBPβ to Support the Recruitment of Th17 Cells during Cervical Cancer Progression

Cervical cancer is a consequence of persistent infection with human papillomaviruses (HPV). Progression to malignancy is linked to an inflammatory microenvironment comprising T-helper-17 (Th17) cells, a T-cell subset with protumorigenic properties. Neoplastic cells express only low endogenous levels of the Th17 chemoattractant CCL20, and therefore, it is unclear how Th17 cells are recruited to the cervical cancer tissue. In this study, we demonstrate that CCL20 was predominantly expressed in the stroma of cervical squamous cell carcinomas in situ. This correlated with stromal infiltration of CD4(+)/IL17(+) cells and with advancing International Federation of Gynecology and Obstetrics (FIGO) stage. Furthermore, we show that cervical cancer cells instructed primary cervical fibroblasts to produce high levels of CCL20 and to attract CD4/IL17/CCR6-positive cells, generated in vitro, in a CCL20/CCR6-dependent manner. Further mechanistic investigations identified cervical cancer cell-derived IL6 as an important mediator of paracrine CCL20 induction at the promoter, mRNA, and protein level in fibroblasts. CCL20 was upregulated through the recently described CCAAT/enhancer-binding protein β (C/EBPβ) pathway as shown with a dominant-negative version of C/EBPβ and through siRNA-mediated knockdown. In summary, our study defines a novel molecular mechanism by which cervical neoplastic cells shape their local microenvironment by instructing fibroblasts to support Th17 cell infiltration in a paracrine IL6/C/EBPβ-dependent manner. Th17 cells may in turn maintain chronic inflammation within high-grade cervical lesions to further promote cancer progression.

Human papillomavirus E7 oncoprotein increases production of the anti-inflammatory interleukin-18 binding protein in keratinocytes

Human papillomavirus (HPV) can successfully evade the host immune response to establish a persistent infection. We show here that expression of the E7 oncoprotein in primary human keratinocytes results in increased production of interleukin-18 (IL-18) binding protein (IL-18BP). This anti-inflammatory cytokine binding protein is a natural antagonist of IL-18 and is necessary for skin homeostasis. We map increased IL-18BP production to the CR3 region of E7 and demonstrate that this ability is shared among E7 proteins from different HPV types. Furthermore, mutagenesis shows that increased IL-18BP production is mediated by a gamma-activated sequence (GAS) in the IL-18BP promoter. Importantly, the increased IL-18BP levels seen in E7-expressing keratinocytes are capable of diminishing IL-18-mediated CD4 lymphocyte activation. This study provides the first evidence for a virus protein that targets IL-18BP and further validates E7 as a key component of the HPV immune evasion armor.

IMPORTANCE

Infection with human papillomavirus is a leading cause of morbidity and mortality worldwide. This study demonstrates that the E7 protein increases production of the anti-inflammatory IL-18BP, a major regulator of epithelial homeostasis. A number of E7 proteins can increase IL-18BP production, and a region within the CR3 of E7 is necessary for mediating the increase. A consequence of increased IL-18BP production is a reduction in CD4-positive lymphocyte activation in response to IL-18 costimulation. These findings may shed light on the immune evasion abilities of HPV.

Human dendritic cells transfected with a human papilloma virus-18 construct display decreased mobility and upregulated cytokine production

The marked depletion of dendritic cells (DCs) in skin cancers, as well as preneoplastic and neoplastic cervical epithelium, suggests a central role for DCs in productive human papillomavirus (HPV) infection and cancer promotion. It has been suggested that HPV may facilitate tumor development by reducing DC density, contributing to a decrease in local immune surveillance. In this study, we have examined the response of human DCs transfected with a construct containing the HPV18 genome and their subsequent expression of papilloma virus proteins. Transfected cells expressed the L1 major capsid protein and upregulated E6 and E7 oncoprotein transcripts as detected by RT-PCR. Transfection of DCs also resulted in a significant increase in cytokine production. Finally, we observed that HPV18 transfection decreased the migratory activity of DCs. Our data indicate that HPV transfection of DCs leads to changes in migratory activity and cytokine production, which potentially can suppress or delay immune responses to viral antigens. Additionally, changes in cytokine production by HPV-transformed human fibroblasts and human cervical epithelial cells revealed that the migratory and antigen-presenting functions of DCs may be impaired by the suppressive effects of cytokines produced by HPV-infected epithelial and stromal cells.

Tumor-infiltrating CD14-positive myeloid cells and CD8-positive T-cells prolong survival in patients with cervical carcinoma

One of the hallmarks of cancer is the influx of myeloid cells. In our study, we investigated the constitution of tumor-infiltrating myeloid cells and their relationship to other tumor-infiltrating immune cells, tumor characteristics and the disease-specific survival of patients with cervical cancer (CxCa). Triple-color immunofluorescence confocal microscopy was used to locate, identify and quantify macrophages (CD14), their maturation status (CD33) and their polarization (CD163) in a cohort of 86 patients with cervical carcinoma. Quantification of the numbers of myeloid cells revealed that a strong intraepithelial infiltration of CD14+ cells, and more specifically the population of CD14+CD33-CD163- matured M1 macrophages, is associated with a large influx of intraepithelial T lymphocytes (p = 0.008), improved disease-specific survival (p = 0.007) and forms an independent prognostic factor for survival (p = 0.033). The intraepithelial CD8+ T-cell and regulatory T-cell (Treg) ratio also forms an independent prognostic factor (p = 0.010) and combination of these two factors reveals a further increased benefit in survival for patients whose tumor displays a dense infiltration with intraepithelial matured M1 macrophages and a high CD8 T-cell/Treg ratio, indicating that both populations of immune cells simultaneously improve survival. Subsequently, we made a heatmap including all known immune parameters for these patients, whereby we were able to identify different immune signatures in CxCa. These results indicate that reinforcement and activation of the intratumoral M1 macrophages may form an attractive immunotherapeutic option in CxCa.

Molecular pathobiology of human cervical high-grade lesions: paracrine STAT3 activation in tumor-instructed myeloid cells drives local MMP-9 expression

In many tumors, the switch from precancerous lesions to malignancy critically relies on expression of the matrix-metalloprotease MMP-9, which is predominantly provided by infiltrating inflammatory cells. Our study defines a novel molecular cascade, how human neoplastic cells instruct tumor-associated myeloid cells to produce MMP-9. In biopsies of human papillomavirus-associated precancerous cervical intraepithelial neoplasia (CIN III lesions), we show broad activation of the transcription factor STAT3 and coexpression of MMP-9 in perivascular inflammatory cells. For the first time, we establish a causative link between tumor-mediated paracrine STAT3 activation and MMP-9 production by human tumor-instructed monocytes, whereas NF-κB activation is dispensable for this response. Our data provide evidence that STAT3 does not directly induce MMP-9 but first leads to a strong production of the monocyte chemoattractant protein-1 (CCL2) in the nanogram range. In a second phase, autocrine stimulation of the CCR2 receptor in the tumor-instructed monocytes amplifies MMP-9 expression via intracellular Ca(2+) signaling. These findings elucidate a critical mechanism in the molecular pathobiology of cervical carcinogenesis at the switch to malignancy. Particularly in tumors, which are associated with infectious agents, STAT3-driven inflammation may be pivotal to promote carcinogenesis, while at the same time limit NF-κB-dependent immune responses and thus rejection of the infected preneoplastic cells. The molecular cascade defined in this study provides the basis for a rational design of future adjuvant therapies of cervical precancerous lesions.

Local applications of GM-CSF induce the recruitment of immune cells in cervical low-grade squamous intraepithelial lesions

PROBLEM

Quantitative alterations of antigen-presenting cells (APC) in (pre)neoplastic lesions of the uterine cervix associated with human papillomavirus (HPV) infection suggest a diminished capacity to capture viral antigens and to induce a protective immune response.

METHOD OF STUDY

To test whether a cervical application of GM-CSF could restore an immune response against HPV in women with cervical low-grade squamous intraepithelial lesions (LSIL), we performed two clinical trials with 11 healthy women and 15 patients with LSIL.

RESULTS

GM-CSF applications were well tolerated in all enrolled women, and no difference in toxicity between the treated and placebo groups was observed during the follow-up (until 30 months). Interestingly, in the GM-CSF treated group, a significant increase of APC and cytotoxic T-lymphocyte infiltration was observed in the cervical biopsies with no change in regulatory T cell numbers. All the HPV16(+) patients exhibited an immune response against HPV16 after GM-CSF applications, as shown by NK and/or T cells producing IFN-gamma whereas no cellular immune response was observed before the treatment. Moreover, the anti-virus-like particles antibody titers also increased after the treatment.

CONCLUSION

These encouraging results obtained from a limited number of subjects justify further study on the therapeutic effect of APC in cervical (pre)neoplastic lesions.

Epigenetic repression of E-cadherin by human papillomavirus 16 E7 protein

A common feature shared between several human cancer-associated viruses, such as Epstein-Barr virus, Hepatitis B virus and Hepatitis C virus, and Human papillomavirus (HPV) is the ability to reduce the expression of cellular E-cadherin. Since E-cadherin is used by Langerhans cells to move through the stratified epithelium, its reduction may affect the efficiency by which the immune system responds to HPV infection and the length of persistent HPV infections. We observed that the E7 protein of this virus (HPV16) is most efficient at reducing E-cadherin levels. This E7 activity is independent of retinoblastoma protein or AP-2α degradation. Instead it is associated with augmentation of cellular DNA methyltransferase I (Dnmt1) activity. Significantly, inhibition of Dnmt activity re-established E-cadherin levels of the cells, presenting the possibility that similar epigenetic intervention clinically may be a way to re-establish the influx of Langerhans cells into infected epithelium to counteract HPV persistence.

Increased migration of Langerhans cells in response to HPV16 E6 and E7 oncogene silencing: role of CCL20

Human papillomavirus (HPV) infection, particularly type 16, is causally associated with cancer of the uterine cervix. The persistence or progression of cervical lesions suggests that viral antigens are not adequately presented to the immune system. This hypothesis is reinforced by the observation that most squamous intraepithelial lesions (SILs) show quantitative and functional alterations of Langerhans cells (LC). The infiltration of immature LC in the squamous epithelium is mainly controlled by Macrophage Inflammatory Protein 3alpha/CCL20. After having shown that CCL20 production is altered in HPV-transformed keratinocytes (KC), the possible role of HPV16 E6 and E7 viral oncoproteins in the reduced CCL20 levels observed in SILs was investigated by silencing HPV16 E6 and E7 oncogenes by RNA interference (siRNA). This treatment not only increased CCL20 secretion but also resulted in the modulation of NF-kappaB p50, p52 and p65 precursor localization. Moreover, silencing of E6 and E7 oncogenes in HPV16-transformed KC induced a significantly higher migratory capacity of LC in a Boyden chamber assay and in an in vitro formed (pre)neoplastic epithelium reminiscent of high-grade SILs. Anti-CCL20 neutralizing antibody experiments showed that the increased migration of LC is due to the re-expression of CCL20 in E6 and E7 siRNA transfected KC. These data suggest that HPV16 E6/E7-induced down-regulation of CCL20 observed during the cervical carcinogenesis may contribute to a diminished capacity of the immune system to control HPV infection.

Evolving immunosuppressive microenvironment during human cervical carcinogenesis

Chronic infection with human papillomavirus (HPV) can result in cervical cancer. To understand how HPV escapes immune eradication, we examined biophenotypes of immune cells in human normal cervix, cervical intraepithelial neoplasia (CIN), and cancer. Expression and cellular localization of Forkhead box protein-3 (FOXP3), indolamine 2,3-dioxygenase (IDO), interleukin (IL)-10, and interferon (IFN)-gamma were examined by immunofluorescence and immunohistochemistry. Mean cell densities of stromal FOXP3+ cells, IDO+ cells, IL-10+ cells, CD1a+ cells, and macrophages significantly increased from normal cervix to cancer, whereas densities of IFN-gamma+ and MMP-9+ cells increased from normal cervix to CIN but decreased in cancer. Flow cytometry confirmed significant elevation of cervical T cells expressing IFN-gamma and transforming growth factor-beta in CIN compared with normal cervix. Upon activation, a significantly increased proportion of cervical T cells expressed IFN-gamma in CIN than normal. A unique subset of morphologically immature stromal dendritic cells expressing IL-10 and IDO was more numerous in cancer than in normal cervix and CIN. The potentially suppressive immune milieu in the cervix may be permissive of HPV-associated cervical carcinogenesis.

Silencing of E7 oncogene restores functional E-cadherin expression in human papillomavirus 16-transformed keratinocytes

Human papillomavirus (HPV) infection, particularly type 16, is causally associated with cancer of the uterine cervix. The persistence or progression of cervical lesions suggests that viral antigens are not adequately presented to the immune system. This hypothesis is reinforced by the observation that most squamous intra-epithelial lesions show quantitative and functional alterations of Langerhans cells (LCs). Moreover, E-cadherin-dependent adhesion of LC to keratinocytes (KCs) is defective in cervical HPV16-associated (pre)neoplastic lesions. The possible role of viral oncoprotein E7 in the reduced levels of cell surface E-cadherin was investigated by silencing HPV16 E7 by RNA interference (siRNA). This treatment induced an increased cell surface E-cadherin expression in HPV16-positive KC and a significant adhesion of LC to these squamous cells. The E-cadherin re-expression following HPV16 E7 silencing was associated with increased detection levels of retinoblastoma protein and the activating protein (AP)-2alpha transcription factor. These data suggest that HPV16 E7-induced alterations of LC/KC adhesion may play a role in the defective immune response during cervical carcinogenesis.

Prognostic significance of HIF-2alpha expression on tumor infiltrating macrophages in patients with uterine cervical cancer undergoing radiotherapy

Hypoxia-inducible factor (HIF)-2alpha, a basic helix-loop-helix (bHLH)-PAS protein, is the principal regulator of the hypoxic transcriptional response. An immunohistochemical study reported strong HIF-2alpha expression in the cytoplasm of tumor infiltrative macrophages (TIMs). Thus we assessed the expression of HIF-2alpha in human cervical cancer tissue before radiation therapy and its relationship to the clinical outcome. Seventy three patients with histologically proven primary advanced squamous cell carcinoma of the uterine cervix underwent radiotherapy in Tokushima University Hospital after biopsy specimens were taken. Among 73 specimens stained for HIF-2alpha, 53 (72.6%) exhibited HIF-2alpha immunoreactivity in the TIMs. In only 5 of 73 cases, HIF-2alpha immunoreactivity was observed in the nuclei of tumor cells. The HIF-2alpha positive cell count ratio in TIMs was associated with disease-free survival (DFS) with the worst DFS (p=0.024) being in cases in the group with a high positive cell count ratio. A high HIF-2alpha positive cell count ratio in TIMs increased the risk of local recurrence (p=0.0142). These findings might suggest that the ratio of the HIF-2alpha positive cell in TIMs may be a new predictive indicator for prognosis before radiation therapy for uterine cervical cancer.

Interaction between inflammation and angiogenesis during different stages of cervical carcinogenesis

OBJECTIVE

The primary aim of this study was to investigate the role of angiogenesis and inflammatory cell response in cervical carcinogenesis.

METHODS

Formalin-fixed tissue specimens from 58 uterine cervical specimens (8 CIN1, 14 CIN2, 28 CIN3, and 8 SCC), representing the different stages of cervical carcinogenesis, were immunohistochemically analyzed. Normal cervical tissue specimens were also included as controls. The present study assessed the expression of CD31 and CD105 to evaluate microvessel density (MVD), the macrophage marker CD68 and the panleukocyte marker CD45. In addition, expression of iNOS (inducible Nitric Oxide Synthase) was also evaluated.

RESULTS

MVD, measured by either CD31 or CD105, increased along the continuum from normal epithelium to squamous cell carcinoma, and a significant correlation between the CD105-MVD and the CD31-MVD was observed (r=0.8735; p<0.0001). Furthermore, the number of infiltrating macrophages was significantly associated with progression to malignancy. Interestingly, there was a close positive correlation between macrophage counts and CD105-MVD (r=0.7525; p<0.0001). In striking contrast to the other angiogenic and inflammatory markers tested, iNOS expression was significantly reduced as cervical lesion grade progressed from low to high.

CONCLUSIONS

Our findings demonstrated a positive correlation between neovascularity and macrophage counts, whereas iNOS expression displayed an inverse relationship with macrophage density and tumor progression. Low iNOS expression may modify the function of tumor-infiltrating macrophages toward a malignant phenotype that promotes tumor progression rather than an anti-tumor response.

MIP3 alpha stimulates the migration of Langerhans cells in models of human papillomavirus (HPV)-associated (pre)neoplastic epithelium

Although human papillomavirus (HPV) DNA is detected in the majority of cervical cancers and their precursors (squamous intraepithelial lesions; SIL), the persistence or progression of cervical lesions could be associated with quantitative and functional alterations of dendritic/Langerhans cells (DC/LC). As LC abnormalities have been associated with a decreased expression of macrophage inflammatory protein 3alpha (MIP3alpha) in cervical SIL, we tested the effect of exogenous MIP3alpha on the migration of LC in a (pre)neoplastic epithelium formed in vitro. By using a Boyden chamber assay, we first showed that the migratory capacity of LC generated in vitro is significantly increased in the presence of MIP3alpha compared to control medium. We next demonstrated that MIP3alpha is able to increase the 3D infiltration of LC in organotypic cultures of HPV-transformed keratinocytes. This property to stimulate LC migration was not altered after inclusion of MIP3alpha in a bioadhesive polycarbophil gel. Moreover, the function of DC to exert cytostatic effects and to present alloantigens was not altered in the presence of MIP3alpha.

Role of hormone cofactors in the human papillomavirus-induced carcinogenesis of the uterine cervix

If human papillomavirus (HPV) is necessary for the development of (pre)neoplastic lesions of the uterine cervix, it is not sufficient. Among the cofactors involved in the malignant transformation of cells infected by HPV, sex hormones may facilitate the cervical carcinogenesis by different mechanisms, including the induction of squamous metaplasia in the transformation zone of the cervix, interactions between steroid hormones and HPV gene expression and alterations of the local immune microenvironment.

Langerhans Cells in Cervical Intraepithelial Neoplasia Related to Smoking Habits

OBJECTIVE

Compare the numerical densities of intraepithelial Langerhans cells of uterine cervix of women affected by cervical intraepithelial neoplasia grade 3 (CIN 3) with their smoking habits.

MATERIALS AND METHODS

A total of 71 conization specimens of women affected by CIN 3 were separated in 3 groups according to their smoking habits (smokers, nonsmokers, and former smokers). The identification of the Langerhans cells was performed by immunohistochemical analysis using antibodies to S100 protein. The number of intraepithelial Langerhans cells was counted at x400 magnification under a light microscope, and a 10-field count was performed in areas of CIN 3 of each section. Results were expressed as number of cells per square millimeter of epithelium.

RESULTS

There was no significant difference in the number of Langerhans cells per square millimeter of epithelium in areas affected by CIN 3 among the 3 groups (p = .5). There was also no significant difference in the number of cigarettes smoked per day (p = .09), duration of consumption (p = .34), total amount of cigarettes smoked during the whole life (p = .18), and duration of abstention (p = .2).

CONCLUSIONS

It was not shown that smoking reduces the number of intraepithelial Langerhans cells in the cervix of women affected by CIN 3.

In situ detection of SOCS and cytokine expression in the uterine cervix from HIV/HPV coinfected women

The purpose of this study was to look for associations between a newly described class of suppressors of cytokine signaling (SSI/SOCS) and cytokine expression in the uterine cervix from HIV/HPV coinfected women. We examined the pro-inflammatory cytokines TNF-alpha and IL-6 since their expressions are linked and responsible for many aspects of both localized and systemic inflammatory responses. Further, expression of SSI/SOCS has been implicated in the negative feedback regulation of cytokine receptor signaling. PCR-amplified HIV-1 cDNA was noted mainly in the stroma, showing a perivascular distribution, and most of the infected cells colabeled with the macrophage marker CD68. The distribution of IL-6 and TNF-alpha was in the same area to HIV-1 and much greater than normal cervices from women with no evidence of viral infection. SOCS/SSI-1 and -3 mRNA positive cells in the uterine cervix were commonly detected in these noninfected cervical tissues; however, very few cells that contained SOCS were evident in areas where HIV-1, TNF-alpha, and IL-6 expressing cells were found. This suggests that viral-related suppression of SOCS/SSI-1-3 expression may be a factor in the marked local enhancement of TNF-alpha and IL-6 production which, in turn, may help facilitate viral spread; however, further studies should be done in order to elucidate the exact mechanisms of SOCS in the cervix.

Modulation of apoptosis by human papillomavirus (HPV) oncoproteins

The regulation of host-mediated apoptosis by the E6 and E7 oncoproteins has garnered attention because it is believed to be an important strategy employed by high-risk (HR)-human papillomaviruses (HPVs) to evade immune surveillance. Additionally, the revelation that E5 can protect cells from tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis suggests that it may also play a role in undermining host defense mechanisms. Cellular transformation is an unintended consequence of persistent infection by HR-HPVs, and it is therefore likely that the primary function of E5, E6 and E7 is to regulate cell survival throughout the normal viral life cycle in order to ensure viral replication and promote the spread of progeny. The purpose of this article is to review the literature on the regulation of host-mediated apoptosis by E5, E6 and E7 that describes the mechanisms employed by HR-HPVs to persist in the host and create the conditions necessary for cellular transformation.

Langerhans' cells and smoking in intraepithelial neoplasia of the cervix

OBJECTIVE

To compare the intraepithelial population of Langerhans' cells (LC) in normal cervix epithelium adjacent to cervical intraepithelial neoplasia grade 3 (CIN 3) and correlate to smoking habit.

METHODS

Cases in this study included conization specimens from 48 women affected by CIN 3. The LC count was performed in areas without histopathologic alteration adjacent to CIN 3. The control group is compound by normal cervix from 46 hysterectomy specimens. The identification of LC was done by immunohistochemical study demonstrating immunoreactivity to S-100 protein. The number of intraepithelial LC was determined using 400x magnification light microscope in 10 high-power fields, and results were expressed in number of cells per square millimeter (LC/mm(2)).

RESULTS

In the control group, there was lower number of Langerhans' cells in smokers than in non-smokers (P = 0.045). There was lower number of Langerhans' cells in normal areas adjacent to CIN 3 than in normal cervix control group (P = 0.004). There was no significant difference in the number of Langerhans' cells in normal areas of the cervix with CIN 3 between smokers and non-smokers (P = 0.991). The number of cigarettes consumed daily, time of consume, total number of cigarettes consumed showed a reduced LC count, yet was not statistically significant.

CONCLUSIONS

It was revealed that smoking reduces the number of intraepithelial Langerhans' cells in the uterine cervix. In women with CIN 3, the LC count was lower, despite the habit of smoking.

Decreased migration of Langerhans precursor-like cells in response to human keratinocytes expressing human papillomavirus type 16 E6/E7 is related to reduced macrophage inflammatory protein-3alpha production

Infection with high-risk human papillomavirus (HPV) types, particularly types 16 and 18, contributes to 90% of cervical cancer cases. HPV infects cutaneous or mucosal epithelium, tissue that is monitored for microbial infection or damage by Langerhans cells. In lesions produced by HPV type 16, there is a reduction in numbers of immune cells, especially Langerhans cells. Langerhans precursor cells selectively express CCR6, the receptor for macrophage inflammatory protein 3alpha (MIP-3alpha), and function as potent immune responders to inflamed epithelium and initiators of the innate immune response. It has been reported that E6 and E7 of high-risk HPVs interfere with immune mediators in order to suppress the recruitment of immune cells and antiviral activities of infected cells. Here we show that, following proinflammatory stimulus, HPV-16 E6 and E7 inhibit MIP-3alpha transcription, resulting in suppression of the migration of immature Langerhans precursor-like cells. Interestingly, the E6 and E7 proteins from the low-risk HPV types also inhibited MIP-3alpha transcription. These results suggest that one mechanism by which HPV-infected cells suppress the immune response may be through the inhibition of a vital alert signal, thus contributing to the persistence of HPV infection.

Relationship between HIV viral load and Langerhans cells of the cervical epithelium

AIM

To determine the relationship between the density of cervical mucosa Langerhans cells, cervical histology, and HIV viral load.

METHODS

Eighty-four HIV-infected and 17 women at high risk for HIV had cervical biopsies assessed for squamous intraepithelial lesions and Langerhans cell density. Langerhans cells were identified using the S-100 immunohistochemical stain and were counted manually. Polymerase chain reaction assays were used to detect cervical human papillomavirus (HPV)-DNA. T-cell subsets were determined using immunofluorescent flow cytometry. Plasma HIV RNA levels were measured using a nucleic acid sequence-based amplification technique. The associations between cervical Langerhans cell density, cervical histology, CD4 counts, HIV viral loads, HPV-DNA detection, and smoking status were assessed using multivariate statistical models.

RESULTS

In multivariate analysis among women infected with HIV, the mean Langerhans cell density per high-powered field was 4.00 among women with no detectable plasma HIV-RNA, and 1.92 among those with detectable HIV-RNA (P = 0.01). The mean cervical Langerhans cell density was increased in women with high-grade squamous intraepithelial lesions compared with those with low-grade squamous intraepithelial lesions and normal/metaplastic histology (3.87 vs 2.11; P = 0.05). Neither HPV-DNA detection, smoking status, nor CD4 count was significantly associated with Langerhans cell density.

CONCLUSIONS

The decrease in cervical Langerhans cell density in women with detectable HIV-RNA suggests an impaired mucosal immune response to local infections, such as HPV. Conversely, HPV infection resulting in high-grade dysplasia might be associated with an enhanced local immune response.

E-cadherin-dependent adhesion of dendritic and Langerhans cells to keratinocytes is defective in cervical human papillomavirus-associated (pre)neoplastic lesions

Although human papillomavirus (HPV) DNA is detected in the majority of squamous intraepithelial lesions (SILs) and squamous cell carcinomas (SCCs) of the uterine cervix, the persistence and progression of cervical lesions suggest that viral antigens are not adequately presented to the immune system. This hypothesis is reinforced by the observation that most SILs show quantitative and functional alterations of Langerhans cells (LCs). The aim of this study was to determine whether modulation of E-cadherin-mediated homophilic and heterotypic interactions between keratinocytes and LCs is involved in these abnormalities of LCs in (pre)neoplastic cervical epithelium. Cell membrane expression of E-cadherin and the density of CD1a+ LCs were low in the epithelium of SILs and SCC biopsy specimens, compared with normal exocervical epithelium. Dendritic cells (DCs) and LCs generated in vitro were randomly distributed throughout the full thickness of organotypic cultures of E-cadherin- HPV-transformed cells. In contrast, these cells rapidly adhered to the keratinocyte cell layers when HPV-transformed cells transfected with E-cadherin were used. These data suggest that the E-cadherin-mediated contact between keratinocytes and LCs is potentially important for initiating or maintaining the immune response during chronic HPV infection.

Langerhans' cell count and HLA class II profile in cervical intraepithelial neoplasia in the presence or absence of HIV infection

OBJECTIVES

The progression of immunosuppression in human immunodeficiency virus (HIV)+ women has been correlated with elevated incidence of squamous intraepithelial lesions (SIL), probably indicating the role of local immune milieu. In this study, we analysed S100, and HLA class II molecule expression in cervical biopsies according to HIV status, to the severity of SIL and to human papillomavirus (HPV) type.

METHODS

Biopsies from 34 HIV+ and 44 HIV- patients with normal cervix or low- or high-grade SIL were studied. Langerhans' cells (LC) (S100), HLA class II and HLA-DQ molecules were evaluated by immunohistochemistry. HPV detection was performed using polymerase chain reaction (PCR). For statistical analysis Mann-Whitney (P< or =0.05) and Spearman test were used.

RESULTS

Epithelial S100 and HLA class II density were significantly increased with the severity of lesion (P=0.032; P=0.005). Epithelial S100+ increased in HPV+ (P=0.038), and HLA class II density decreased in HPV 16+ (P=0.035) or 18+ (P<0.0001) samples. HIV infection was associated with increased stromal S100+ (P=0.0005) and decreased HLA class II densities (P=0.0001). Decreased stromal S100+ was observed in women with CD4<500 cells/microl (P=0.050). Among HIV+ patients with SIL, the lowest S100 and epithelial HLA class II densities were detected in women with CD4<200 cells/microl (P=0.045).

CONCLUSIONS

After the establishment of AIDS, increased numbers of immature LCs and a reduction in HLA class II occurred, possibly turning the cervical milieu more favourable to HPV persistence. HPV 16 and 18 infections may interfere with the antigen presenting activity, possibly as an evasion mechanism.

High intraepithelial expression of estrogen and progesterone receptors in the transformation zone of the uterine cervix

OBJECTIVE

Because sex hormones may be involved in tumor initiation and progression, we analyzed the presence of hormone receptors in the transformation zone of the uterine cervix where the majority of human papillomavirus infections and associated (pre)neoplastic lesions develop.

STUDY DESIGN

By using 23 total hysterectomy samples from young women who underwent surgery for noncervical benign uterine disease, we analyzed, by immunohistologic techniques, the in situ expression of estrogen (E(2)-R) and progesterone (P(4)-R) receptors in the transformation zone and ectocervix of the same women.

RESULTS

The expression of estrogen receptors and progesterone receptors is significantly higher in the transformation zone compared with the ectocervix. Immunohistochemical localization indicated that hormone receptor-positive cells are mainly observed in (para)basal and intermediate cell layers in both the transformation zone and ectocervical epithelium. When transformation zone samples were segregated into epithelial tissues with a predominantly mature (7/23 samples) or immature (16/23 samples) squamous metaplasia, only biopsy specimens with immature squamous metaplasia showed a significantly higher density of hormone receptor-positive cells compared with ectocervical epithelium (P<.01).

CONCLUSION

Our results suggest that the cervical transformation zone may be at increased risk of the development of cancer because of a high sensitivity to sex hormone regulation.

Imiquimod-responsive basal cell carcinomas and factor XIIIa-enriched dendrocytes

Dermal dendrocytes (DDs) are dendritic cells that exhibit immunoreactivity for factor XIIIa, and are frequently found in conjunction with basal cell carcinomas (BCCs). Imiquimod was applied to 12 superficial BCCs every 3 days for 8 weeks. One week after completion of treatment, seven lesions appeared to have resolved, while five displayed evidence of residual BCC. Prior to initiation of treatment, the seven imiquimod-responsive BCCs were surrounded by numerous DDs, whereas the five imiquimod-resistant BCCs had fewer DDs next to them at the time of entry into the study. It appears that the pretreatment density in DDs may affect the efficacy of imiquimod in eradicating skin tumours.

Distinct T cell subsets and cytokine production in cultures derived from transformation zone and squamous intraepithelial lesion biopsies of the uterine cervix

PROBLEM

The characterization of lymphocytes issued from squamous intraepithelial lesions (SIL) and from the transformation zone (TZ), where the majority of SIL occur, is important to understand the role of immunity in SIL development.

METHOD OF STUDY

We compared lymphocyte populations of the TZ and SIL with those of normal exocervix, using a technique allowing for the isolation of lymphocytes, either from the epithelium or from the underlying stroma of small biopsies.

RESULTS

The majority of cells derived from the epithelium of all biopsies were CD8+ T cells. Some SIL-derived cultures were characterized by an increased proportion of activated TCRgammadelta+. The production of the immunosuppressive cytokine IL10 was significantly higher in lymphocyte cultures from the normal TZ in comparison with the exocervix. A decreased percentage of effector T cells was observed in cultures derived from the stroma of normal TZ (TCRgammadelta+) or SIL (CD8+) in comparison with the exocervix.

CONCLUSIONS

Our results suggest that a low proportion of effector T cells and IL10 production could contribute to the predisposition of the TZ to the development of SIL and to the progression of SIL to cervical cancer.

Presence and quantification of macrophages in squamous cell carcinoma of the cervix

Cervical cancer is a major cause of morbidity and mortality in women. The presence of macrophages as well as other inflammatory cells has been noted in many of these tumors. Intratumoral macrophages/monocytes induce anergy to cytokine therapy and cause apoptosis in natural killer(NK) and T cells. The aim of this study was to better evaluate and quantify the presence of macrophages in these tumors. Twenty-four cases of squamous cell carcinoma of the cervix seen at our institution were evaluated. Sections were stained with CD68, a marker for macrophages. Staining was graded microscopically by two reviewers together on a scale of 0-4+, with 4+ representing the greatest number of positive cells. Image analysis was conducted to quantify the percent area stained in a given lesion. For each lesion, 10 fields were evaluated, and a mean percentage area stained was calculated. 4+ staining was observed in five cases, 3+ in zero cases, 2+ in three cases, 1+ in six cases, 1-2+ in one case, and nine cases were negative. Image analysis results correlated well with the light microscopic scoring. Presence of a prominent infiltrate of macrophages did not correlate with tumor grade or with histologic lymph node status, but showed a strong negative correlation with tumor stage. Some squamous cell carcinomas of the cervix show a prominent macrophage component in the tumor-associated inflammatory infiltrate. The presence of this prominent infiltration of macrophages did not correlate with tumor grade or lymph node status, but showed a strong negative correlation with tumor stage. The results suggest that immunotherapy may have a potential role in the treatment of cervical carcinoma. Computerized image analysis appears to be a valid measure to assess macrophage counts in such lesions.

Influence of the mucosal epithelium microenvironment on Langerhans cells: implications for the development of squamous intraepithelial lesions of the cervix

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 TNFalpha and MIP3alpha 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.

Anti-CD3/anti-epidermal growth factor receptor-bispecific antibody retargeting of lymphocytes against human neoplastic keratinocytes in an autologous organotypic culture model

Local cellular immune defects have been described in several tumors including human papillomavirus (HPV)-associated cervical cancer. This observation suggests the potential therapeutic benefit of immune manipulations that restore cellular immunity. Here, we evaluated the ability of bispecific monoclonal antibodies (bimAbs) to redirect T cells against keratinocytes transformed in vitro by HPV in an autologous three-dimensional culture model (organotypic cultures). The epidermal growth factor receptor (EGFR) was chosen as target for an anti-CD3/anti-EGFR bimAb because it is overexpressed in many malignant epithelial lesions and only weakly expressed in the basal layers of normal squamous epithelium. Interestingly, in organotypic cultures, the pattern of expression of EGFR was similar to that observed in vivo. The ability of T cells retargeted by CD3/EGFR bimAb to lyse HPV-transformed cell lines was confirmed in monolayer cultures. In autologous organotypic cultures, an increase in apoptotic HPV(+) keratinocytes and a significant decrease in the thickness of HPV(+) organotypic cultures were observed when activated lymphocytes and bimAbs were added to the cultures, whereas organotypic cultures of normal keratinocytes were not significantly affected. These data were similar to those obtained in the allogeneic model. These results suggest the potential usefulness of CD3-EGFR bimAb-retargeted lymphocytes in immunotherapeutic protocols for malignant epithelial lesions.

Dendritic cells induce the death of human papillomavirus-transformed keratinocytes

Although human papillomavirus (HPV) antigens are expressed in a majority of (pre)neoplastic lesions (squamous intraepithelial lesions; SILs) of the uterine cervix, progression to invasive cancer may occur, which suggests that the presentation of viral antigens to the immune system is deficient in some SILs. To determine whether professional antigen-presenting cells die in SILs, we assayed for the apoptosis of immature dendritic cells (DC) in organotypic cultures of HPV-transformed keratinocytes, which reproduce many features of in vivo observed SILs. Unexpectedly, the infiltration of organotypic cultures by DC specifically induced the apoptosis of HPV+ tumor cells, whereas DC were not affected. In the same conditions and in coculture experiments, apoptosis was not observed in normal keratinocytes. The induction of apoptosis required membrane contacts between DC and HPV-transformed keratinocytes. Although the HPV+cell lines were sensitive to the effects of TRAIL, soluble TRAILR2-Fc did not block the DC-induced apoptosis. Furthermore, although FasL and Fas were detected on DC and HPV+ cell lines, respectively, functional analysis revealed that this pathway is not responsible for the apoptosis induced by the DC. All together these results suggest that DC may be at the interface between innate and adaptive immunity by inducing the apoptosis of (pre)neoplastic cells.

Quantitative analysis of IL-10 and IFN-gamma mRNA levels in normal cervix and human papillomavirus type 16 associated cervical precancer

Human papillomavirus type 16 is a major factor in cervical carcinogenesis. Inappropriate cytokine synthesis may direct the local immune response away from a type-1 (cellular) pattern and may subsequently contribute to the development and progression of precancer. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) using a competitive mimic was carried out to determine type-1 (interferon gamma (IFN-gamma)) and type-2 (interleukin-10 (IL-10)) cytokine mRNA levels in whole cervical specimens (without microdissection) from seven normal and nine HPV-16 positive CIN formalin-fixed paraffin-embedded tissues. Microdissection was used to measure separately the epithelial and sub-epithelial levels of IFN-gamma and IL-10 mRNAs in 11 specimens of normal cervix and 25 HPV-16 positive CIN (nine CIN 1, seven CIN 2 and nine CIN 3). IFN-gamma mRNA was lower in CIN than normal (p=0.04). IL-10 mRNA level in CIN was significantly higher (p=0.005) than in normal cervix (before microdissection). Epithelial IFN-gamma mRNA showed a significant decrease in all grades of CIN (median=3.58) compared with normal (7.74) (p<0.05), but there was no significant difference between the grades. A significant decrease in sub-epithelial IFN-gamma mRNA was found in CIN 1(9.81), CIN 2 (3.82) and CIN 3 (4.62) compared with normal cervix (27.35) (p<0.05). Also, sub-epithelial IFN-gamma mRNA was significantly lower in CIN 2 and CIN 3 than in CIN 1 (p=0.005 and 0.0005, respectively). IL-10 was detected in the epithelium of only one of 11 normal and one of 25 CIN, but sub-epithelial IL-10 was significantly higher in CIN 2 (0.08) and CIN 3 (0.26) than in normal (0.00) (p=0.036 and 0.0032, respectively). There was no significant difference in the sub-epithelial level of IL-10 between normal and CIN 1 (0.00) (p=0.96). Our results suggest that reduced epithelial and sub-epithelial IFN-gamma, as well as increased sub-epithelial IL-10 synthesis may play a role in the development and progression of HPV-16 associated cervical precancer.

The organotypic culture of HPV-transformed keratinocytes: an effective in vitro model for the development of new immunotherapeutic approaches for mucosal (pre)neoplastic lesions

The purpose of this study is to develop a reliable in vitro human model to test new immunotherapeutic approaches for squamous cell carcinoma that develop on mucosal surfaces. The organotypic (raft) culture permits cells to proliferate and differentiate at an air-liquid interface on a dermal equivalent support. Normal keratinocytes stratify and fully differentiate in a manner similar to the normal squamous epithelial tissues, while human papillomavirus-immortalized and established squamous carcinoma cell lines exhibit dysplastic morphologies similar to (pre)neoplastic lesions seen in vivo. We have demonstrated the ability of these organotypic cultures to be manipulated by altering the epithelial stratification with cytokines (interferon-gamma and tumor necrosis factor-alpha) and by integrating activated lymphocytes or dendritic cells into the in vitro formed epithelial sheet. This model may provide a useful tool to investigate the factors contributing to the presence and function of immunocompetent cells within a neoplastic epithelium that develops on a mucosal surface.

Dermal dendritic cells in anogenital warty lesions unresponsive to an immune-response modifier

BACKGROUND

Human papilloma viruses (HPV) are responsible for a variety of proliferative epithelial lesions including anogenital condylomas. These lesions may regress during treatment with an immune-response modifier such as imiquimod. The release of specific cytokines from the monocyte-macrophage lineage induces a cascade of events abating the HPV replication.

METHOD

A total of 14 persistent warty anogenital lesions were excised 4 to 7 weeks after completing a 4-month imiquimod treatment. Another series of 25 untreated condylomas and 8 bowenoid papulosis served as controls. All examined lesions had been excised in otherwise healthy individuals with a normal immune status. Lesions were examined for the presence of Langerhans cells and subpopulations of the monocyte/macrophage/dendrocyte lineage using immunohistochemical detection of L1-protein, CD68, lysozyme and Factor-XIIIa. CD45R0-positive T lymphocytes were also identified. HPV capsid antigens and genotypes were searched for using immunohistochemistry and in situ hybridization, respectively.

RESULTS

The persistent although treated anogenital lesions were identified as 10 viral condylomas, 3 bowenoid papulosis and 1 basal cell carcinoma. The inflammatory cell densities and distributions were similar in the untreated and imiquimod-resistant condylomas with the exception of Factor XIIIa-positive dendrocytes. These dermal dendritic cells were slim and rare in all imiquimod-resistant lesions. In contrast, about two-thirds of the untreated condylomas were enriched in these cells.

CONCLUSION

As dermal dendritic cells play a role in the immune surveillance, their low densities in some lesions might be a key feature responsible for low cytokine local production and failure of imiquimod treatment. The combined apparent lack of Langerhans cell activation might suggest that both intraepidermal and intradermal compartments of antigen-presenting cells are affected in imiquimod-resistant lesions.

Evaluation of Langerhans' cells in the cervical epithelium of women with cervical intraepithelial neoplasia

OBJECTIVE

Cervical infection with human papillomavirus (HPV) results in a more permissive environment for malignant transformation. In squamous epithelia the Langerhans' cell (LC) is responsible for antigen presentation. Studies that use S-100 immunostaining demonstrate low LCs in cervical intraepithelial neoplasia (CIN) while those that use other methods have shown normal numbers of LCs. This observation led us to postulate that a defect in S-100 proteins, not a simple decrease in LC number, may be the cause of immune suppression. To evaluate this we identified LCs in the cervix of women with HPV/CIN in a prospective fashion using two antibodies, S-100 and CD1, each targeting a different element of the LC.

METHODS

Paired biopsies of the cervix were taken, one paraffin embedded for S-100 and the other snap frozen for CD1 staining. LCs were counted and expressed as the number of cells per millimeter of epithelium. Analysis of variance was used to assess differences between counts in normal, low-grade, and high-grade lesions. HPV was tested by hybrid capture.

RESULTS

S-100 LCs were significantly reduced in dysplasia, LG 8.6 and HG 6.0, compared to normal at 16.7 cells/mm (P = 0.04). S-100 LCs were reduced in HPV-infected cases at 5.9 vs 12.8 cells/mm in HPV negatives (P = 0.02). Acute inflammatory infiltrates were associated with increased S-100 LCs independent of pathology. CD1 LCs were not significantly altered by any parameters tested.

CONCLUSIONS

HPV/CIN may exert an immunosuppressive effect by decreasing the S-100 LCs. The association of S-100-positive LCs coupled with cervical inflammatory changes suggests an important function of the S-100 proteins in the development of an anti-HPV response.

Colonization of in vitro-formed cervical human papillomavirus- associated (pre)neoplastic lesions with dendritic cells: role of granulocyte/macrophage colony-stimulating factor

The purpose of this study was to investigate the ability of CD1a+ Langerhans/dendritic cells (LCs/DCs) to infiltrate human papillomavirus (HPV)-associated (pre)neoplastic lesions of the uterine cervix. Migration of LCs/DCs in the presence of keratinocytes derived from normal cervix and HPV-transformed cell lines was evaluated in Boyden chambers and in organotypic cultures and correlated with granulocyte/macrophage colony-stimulating factor (GM-CSF) production by the cells, as determined by ELISA. Conditioned media of HPV-transformed keratinocytes contained lower amounts of GM-CSF and induced a decreased motile response of LCs/DCs in the Boyden chamber assay compared with those of normal cervical keratinocytes. The migration of LCs/DCs in the presence of conditioned media from normal keratinocytes could be blocked by an anti-GM-CSF antibody, and the migration of LCs/DCs in the presence of conditioned media from HPV-transformed keratinocytes could be increased by supplementing the media with recombinant GM-CSF. GM-CSF was also a potent factor in enhancing the colonization of LCs/DCs into organotypic cultures of HPV-transformed keratinocytes, as the infiltration of LCs/DCs in the in vitro-formed (pre)neoplastic epithelium was minimal under basal conditions and dramatically increased after the addition of GM-CSF to the cultures. These results suggest that GM-CSF could play an important role in the recruitment of LCs/DCs into the HPV-transformed (pre)neoplastic cervical epithelium and be useful as a new immunotherapeutic approach for cervical (pre)cancers.

Correlation of T-helper secretory differentiation and types of antigen-presenting cells in squamous intraepithelial lesions of the uterine cervix

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 (IFN gamma)] 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.