Increase of human papillomavirus-16 E7-specific T helper type 1 response in peripheral blood of cervical cancer patients after radiotherapy

Immune correlates of therapy outcomes in women with cervical cancer treated with chemoradiotherapy: A systematic review

Background

Immune markers have been correlated with prognosis in a variety of solid tumors, including cervical cancer.

Objective

To review the literature on hematologic and immune markers and their association with recurrence and survival among patients with cervical cancer treated with chemoradiation.

Evidence review

This systematic review was conducted in accordance with PRISMA guidelines via searches of Ovid MEDLINE, Ovid Embase, and the Cochrane Library using keywords regarding cervical cancer, immune markers, and HIV. Studies involving patients treated with cisplatin‐based chemoradiotherapy were selected and reviewed by at least two independent reviewers, with disagreements resolved by a third reviewer.

Findings

A total of 737 studies were identified, of which 314 assessed immune biomarkers in immunocompetent patients (30 included in the final analysis) and 327 studies in immunosuppressed patients (5 included in the final analysis). The strongest prognostic indicators were lymphopenia and elevated neutrophil‐to‐lymphocyte ratio. Other potential markers included HPV‐specific lymphocyte response, cytokine profile, expression of immune‐blocking antigens on cell surfaces, and tumor‐associated lymphocyte, macrophage, and neutrophil infiltration. Studies of immunosuppressed patients described more severe cytopenic changes overall and concluded that viral suppression led to improved outcomes.

Conclusions

The immunologic interplay at work in cervical cancer development, progression, and treatment is complex. Strong evidence was found in favor of lymphopenia and elevated neutrophil‐to‐lymphocyte ratio being prognostic for worse outcomes with other markers showing potential associations as well. Although the interpretation of immune status with regard to treatment approach remains unclear, future studies should aim to tailor treatment that minimizes possible detrimental immune effects.

Immune markers have been correlated with prognosis in a variety of solid tumors, including cervical cancer. In this systematic review of immune markers for cervical cancer patients being treated with chemoradiation, we surveyed the literature for immunologic and hematologic prognostic markers and found the strongest negative prognostic indicators were lymphopenia and elevated neutrophil‐to‐lymphocyte ratio.

HPV post-infection microenvironment and cervical cancer

Human papillomavirus (HPV) is the most common sexually transmitted virus worldwide. More than 99% of cervical cancer cases are associated with certain types of HPVs, termed high-risk types. In addition to the well-known transformative properties, HPVs-infected cells actively instruct the local milieu and create a supportive post-infection microenvironment (PIM), which is becoming recognized as a key factor for the viral persistence, propagation, and malignant progression. The PIM is initiated and established via a complex interplay among virus-infected cells, immune cells, and host stroma, as well as their derived components including chemokines, cytokines, extracellular vesicles, and metabolites. In this review, we summarize the current understanding of these key components, characteristics, and effects of the PIM, and highlights the prospect of targeting the PIM as a potential strategy to improve therapeutic outcomes for cervical cancer.

A Phase 1 Trial Assessing the Safety and Tolerability of a Therapeutic DNA Vaccination Against HPV16 and HPV18 E6/E7 Oncogenes After Chemoradiation for Cervical Cancer

PURPOSE

This study assessed the safety and tolerability of therapeutic immunization against the human papillomavirus (HPV) viral oncoproteins E6 and E7 in patients with cervical cancer after chemoradiation.

METHODS AND MATERIALS

MEDI0457 (INO-3112) is a DNA-based vaccine targeting E6 and E7 of HPV-16/18 that is coinjected with an IL-12 plasmid followed by electroporation with the CELLECTRA 5P device. At 2 to 4 weeks after chemoradiation, patients with newly diagnosed stage IB1-IVA (cohort 1) or persistent/recurrent (cohort 2) cervical cancers were treated with 4 immunizations of MEDI0457 every 4 weeks. The primary endpoints were incidence of adverse events and injection site reactions. Immune responses against HPV antigens were measured by ELISpot for interferon-γ (IFNγ), enzyme-linked immunosorbent assay for antibody responses and multiplexed immunofluorescence for immune cells in cervical biopsy specimens.

RESULTS

Ten patients (cohort 1, n = 7; cohort 2, n = 3) with HPV16 (n = 7) or HPV18 (n = 3) cervical cancers received MEDI0457 after chemoradiation. Treatment-related adverse events were all grade 1, primarily related to the injection site. Eight of 10 patients had detectable cellular or humoral immune responses against HPV antigens after chemoradiation and vaccination: 6 of 10 patients generated anti-HPV antibody responses and 6 of 10 patients generated IFNγ-producing T cell responses. At the completion of chemoradiation and vaccination, cervical biopsy specimens had detectable CD8⁺ T cells and decreased PD-1⁺CD8⁺, PD-L1⁺CD8⁺, and PD-L1⁺CD68⁺ subpopulations. All patients cleared detectable HPV DNA in cervical biopsies by completion of chemoradiation and vaccination.

CONCLUSIONS

Adjuvant MEDI0457 is safe and well tolerated after chemoradiation for locally advanced or recurrent cervical cancers, supporting further investigation into combining tumor-specific vaccines with radiation therapy.

Anti-human Interleukin(IL)-4 Clone 8D4-8 Cross-Reacts With Myosin-9 Associated With Apoptotic Cells and Should Not Be Used for Flow Cytometry Applications Querying IL-4 Expression

Interleukin(IL)-4 is produced by T cells and other leukocytes and is a critical mediator of monocyte and B cell responses. During routine flow cytometry panel validation for the investigation of intracellular cytokines, we observed unique IL-4 expression patterns associated with the widely available monoclonal antibody 8D4-8. Namely, IL-4 (8D4-8) expression was observed in the absence of cellular activation and enhanced following staurosporine exposure. Mass spectrometry analysis of immunoprecipitates from peripheral blood lymphocytes (PBL) revealed that 8D4-8 cross-reacts with the ubiquitous cytoskeletal protein myosin-9. We confirmed these results by western blotting immunoprecipitates, using immunofluorescence among staurosporine-treated Caco-2 cells, and by surface-labeling PBL for 8D4-8 and myosin-9 and analyzing by flow cytometry. Although previously reported from several independent groups, we found no evidence to support the hypothesis that IL-4 is produced by apoptotic cells. Rather, this appears to have been myosin-9. Our data indicate clone 8D4-8 should not be used in the flow cytometric study of IL-4. Furthermore, our work calls for a reevaluation of previous flow cytometric studies that have used this clone for IL-4 analysis and highlights the importance of validation in antibody-based assays.

Situation of HPV16 E2 gene status during radiotherapy treatment of cervical carcinoma

BACKGROUND

Human papillomavirus (HPV) integration within the E2 gene has been proposed as a critical event in cervical carcinogenesis. This study concerned whether HPV16 status and E2 gene intactness are predictive of radiation response in patients with cervical cancer.

MATERIALS AND METHODS

Biopsies of 44 patients with cervical cancer were collected before or after radiotherapy. The presence of HPV16 was assessed by polymerase chain reaction (PCR) using specific primers for the L1 region. E2 disruption was detected by amplifying the entire E2 gene.

RESULTS

HPV16 DNA was found in 54.5% of the clinical samples. Overall, 62.5% of the HPV16 positive tumors had integrated viral genome and 37.5% had episomal genome. There was a tendency of increase of HPV16 E2 negative tumors compared with HPV16 L1 ones in advanced stages (75% versus 20% in stage III respectively). Detection of E2 gene appeared influenced by the radiotherapy treatment, as the percentage of samples containing an intact HPV16 E2 was more frequent in pretreated patients compared to radiotherapy treated patients (66.6% versus 20%). The radiation therapy caused an eight-fold [OR= 8; CI=1.22-52.25; p=0.03] increase in the risk of HPV16 genome disruption. The integration status is influenced by the irradiation modalities, interestingly E2 disruption being found widely after radiotherapy treatment (75%) with a total fractioned dose of 50 Gy.

CONCLUSIONS

This study reveals that the status of the viral DNA may be used as a marker to optimize the radiation treatment.

Chemoradiotherapy-induced upregulation of PD-1 antagonizes immunity to HPV-related oropharyngeal cancer

While viral antigens in human papillomavirus (HPV)-related oropharyngeal cancer (HPVOPC) are attractive targets for immunotherapy, the effects of existing standard-of-care therapies on immune responses to HPV are poorly understood. We serially sampled blood from patients with stage III-IV oropharyngeal cancer undergoing concomitant chemoradiotherapy with or without induction chemotherapy. Circulating immunocytes including CD4(+) and CD8(+) T cells, regulatory T cells (Treg), and myeloid-derived suppressor cells (MDSC) were profiled by flow cytometry. Antigen-specific T-cell responses were measured in response to HPV16 E6 and E7 peptide pools. The role of PD-1 signaling in treatment-related immunosuppression was functionally defined by performing HPV-specific T-cell assays in the presence of blocking antibody. While HPV-specific T-cell responses were present in 13 of 18 patients before treatment, 10 of 13 patients lost these responses within 3 months after chemoradiotherapy. Chemoradiotherapy decreased circulating T cells and markedly elevated MDSCs. PD-1 expression on CD4(+) T cells increased by nearly 2.5-fold after chemoradiotherapy, and ex vivo culture with PD-1-blocking antibody enhanced HPV-specific T-cell responses in 8 of 18 samples tested. Chemoradiotherapy suppresses circulating immune responses in patients with HPVOPC by unfavorably altering effector:suppressor immunocyte ratios and upregulating PD-1 expression on CD4(+) T cells. These data strongly support testing of PD-1-blocking agents in combination with standard-of-care chemoradiotherapy for HPVOPC.

Tc17 cells in patients with uterine cervical cancer

BACKGROUND

The existence of Tc17 cells was recently shown in several types of infectious and autoimmune diseases, but their distribution and functions in uterine cervical cancer (UCC) have not been fully elucidated.

METHODS

The frequency of Tc17 cells in peripheral blood samples obtained from UCC patients, cervical intraepithelial neoplasia (CIN) patients and healthy controls was determined by flow cytometry. Besides, the prevalence of Tc17 cells and their relationships to Th17 cells and Foxp3-expressing T cells as well as microvessels in tissue samples of the patients were assessed by immunohistochemistry staining.

RESULTS

Compared to controls, patients with UCC or CIN had a higher proportion of Tc17 cells in both peripheral blood and cervical tissues, but the level of Tc17 cells in UCC tissues was significantly higher than that in CIN tissues. Besides, the increased level of Tc17 in UCC patients was associated with the status of pelvic lymph node metastases and increased microvessel density. Finally, significant correlations of infiltration between Tc17 cells and Th17 cells or Foxp3-expressing T cells were observed in UCC and CIN tissues.

CONCLUSIONS

This study indicates that Tc17 cell infiltration in cervical cancers is associated with cancer progression accompanied by increased infiltrations of Th17 cells and regulatory T cells as well as promoted tumor vasculogenesis.

Variant splicing and influence of ionizing radiation on human endogenous retrovirus K (HERV-K) transcripts in cancer cell lines

Human endogenous retrovirus K (HERV-K) is the most intact retrovirus in the human genome. There are multiple full-length or near full-length HERV-K proviruses in it. To analyze which HERV-K proviruses give rise to viral transcripts in cancer cell lines and to test whether ionizing radiation can alter the levels of HERV-K transcripts, RT-PCR studies were undertaken using multiple human cancer cell lines. Primers from several positions in the viral genome were used and included pairs designed to cross splice junctions in viral RNAs. In the absence of ionizing radiation, transcripts were detected from multiple HERV-K proviruses in cell lines from human prostate, cervical, head and neck, or breast cancers, and the proviruses from which the transcripts originated varied among the different lines. Only one of 13 cell lines tested (cervical cancer line C33A) failed to show HERV-K transcripts. Spliced RNAs detected included viral RNAs spliced as expected at the conventional viral splice sites, plus several alternatively spliced RNAs. Alternatively spliced transcripts arose from specific proviruses, and were detected in most of the cell lines used. Quantitative RT-PCR was performed to assess the effects of ionizing radiation. These analyses showed that HERV-K transcripts were elevated in four of twelve lines tested, specifically all three prostate cancer lines used and one breast cancer line. The increases were transient, peaking at 24 hours following a single dose of gamma-irradiation that ranged from 2.5 to 20 Gy, and returning to baseline levels by 72 hours. In summary, these studies showed that ionizing radiation can affect the levels of HERV-K transcripts in cells, and these effects vary among different cells. The changes in HERV-K transcript levels might affect multiple biological processes in cells, and future studies of the effects of ionizing radiation on HERV-K are worth pursuing.

Substantial increase in the frequency of circulating CD4+NKG2D+ T cells in patients with cervical intraepithelial neoplasia grade 1

Background

The NKG2D receptor confers important activating signals to NK cells via ligands expressed during cellular stress and viral infection. This receptor has generated great interest because not only is it expressed on NK cells, but it is also seen in virtually all CD8⁺ cytotoxic T cells and is classically considered absent in CD4⁺ T cells. However, recent studies have identified a distinctive population of CD4⁺ T cells that do express NKG2D, which could represent a particular cytotoxic effector population involved in viral infections and chronic diseases. On the other hand, increased incidence of human papillomavirus-associated lesions in CD4⁺ T cell-immunocompromised individuals suggests that CD4⁺ T cells play a key role in controlling the viral infection. Therefore, this study was focused on identifying the frequency of NKG2D-expressing CD4⁺ T cells in patients with cervical intraepithelial neoplasia (CIN) 1. Additionally, factors influencing CD4⁺NKG2D⁺ T cell expansion were also measured.

Results

Close to 50% of patients with CIN 1 contained at least one of the 37 HPV types detected by our genotyping system. A tendency for increased CD4⁺ T cells and CD8⁺ T cells and decreased NK cells was found in CIN 1 patients. The percentage of circulating CD4⁺ T cells co-expressing the NKG2D receptor significantly increased in women with CIN 1 versus control group. Interestingly, the increase of CD4⁺NKG2D⁺ T cells was seen in patients with CIN 1, despite the overall levels of CD4⁺ T cells did not significantly increase. We also found a significant increase of soluble MICB in CIN 1 patients; however, no correlation with the presence of CD4⁺NKG2D⁺ T cells was seen. While TGF-beta was significantly decreased in the group of CIN 1 patients, both TNF-alpha and IL-15 showed a tendency to increase in this group.

Conclusions

Taken together, our results suggest that the significant increase within the CD4⁺NKG2D⁺ T cell population in CIN 1 patients might be the result of a chronic exposure to viral and/or pro-inflammatory factors, and concomitantly might also influence the clearance of CIN 1-type lesion.

Human papillomavirus type 16 E6/E7-specific cytotoxic T lymphocytes for adoptive immunotherapy of HPV-associated malignancies

Vaccines prevent human papillomavirus (HPV)-associated cancer but, although these tumors express foreign, viral antigens (E6 and E7 proteins), they have little benefit in established malignancies, likely due to negative environmental cues that block tumor recognition and induce T-cell anergy in vivo. We postulated that we could identify mechanisms by which ex vivo stimulation of T cells could reactivate and expand tumor-directed T-cell lines from HPV cancer patients for subsequent adoptive immunotherapy. A total of 68 patients with HPV-associated cancers were studied. Peripheral blood T cells were stimulated with monocyte-derived dendritic cells loaded with pepmixes [peptide libraries of 15-mers overlapping by 11 amino acids (aa)] spanning E6/E7, in the presence or absence of specific accessory cytokines. The resulting T-cell lines were further expanded with pepmix-loaded activated B-cell blasts. Interferon-γ release and cytotoxic responses to E6/E7 were assessed. We successfully reactivated and expanded (>1200-fold) E6-specific/E7-specific T cells from 8/16 cervical and 33/52 oropharyngeal cancer patients. The presence of the cytokines interleukin (IL)-6, IL-7, IL-12, and IL-15 is critical for this process. These T-cell lines possess the desirable characteristics of polyclonality, multiple T-cell subset representation (including the memory compartment) and a TH1 bias, and may eliminate E6/E7 targets. In conclusion, we have shown it is possible to robustly generate HPV16 E6/E7-directed T-cell lines from patients with HPV16-associated cancers. Because our technique is scalable and good-manufacturing procedures-compliant, these lines could be used for adoptive cellular immunotherapy of patients with HPV16 cancers.

Altered HLA class I and HLA-G expression is associated with IL-10 expression in patients with cervical cancer

Although high-risk human papillomaviruses (HPVs) are an important risk factor in the etiopathogenesis of cervical cancer, increasing evidence suggests that the ability to avoid immune surveillance seems to be linked to the transforming potential of HPV and a rapid progression to cancer. In other cancer models, IL-10 contributes to impair anti-tumor immune response either by downregulating human leukocyte antigen Class I (HLA-I) expression or by increasing HLA-G expression. To comprehend how these alterations could contribute to evasion of immune surveillance in cervical cancer, we analyzed HLA-I, HLA-G and IL-10 expressions by immunohistochemistry in 63 biopsies from patients with cervical intraepithelial neoplasia III (CIN-III) and cervical cancer. Immunohistochemistry showed absent or weak HLA-I expression in 50/59 cases. In these cases, a high percentage had loss of heterozygosis. IL-10 and HLA-G expression were observed in 46.6 and 27.6% of cases, respectively. Concurrent upregulation of IL-10 was found in 87.5% of HLA-G positive cases (p = 0.000). Similarly, a significant association between IL-10 expression and HLA-I downregulation was found (p = 0.028). Finally, we observed higher HLA-G expression in patients with HLA-I downregulation than in those with normal HLA-I expression (p = 0.004). Our results suggest that, in cervical cancer, the IL-10 expression may induce an immunosuppressive environment by upregulating HLA-G expression and downregulating HLA class I expression.

The detection of circulating human papillomavirus-specific T cells is associated with improved survival of patients with deeply infiltrating tumors

A detailed analyses of HPV-specific immunity was performed in a large group of patients with HPV-induced cervical cancer (CxCa) in relation to HLA-types and prognostic factors. Patients were HLA-typed and HPV16/18-specific T-cell immunity was assessed by proliferation assay and cytometric bead array using freshly isolated PBMC and by phenotypic analysis of HPV-specific T cells. The results were analyzed in relation to known disease-related HLA-types (DR7, DR13, DR15/DQ06), invasion-depth and size of tumor, lymph node (LN) status and disease free survival. In total 119 HLA-typed patients with CxCa were analyzed. Patients expressing the HLA-DR13 haplotype were underrepresented as compared to the Dutch population (p = 0.014), whereas HLA-DR7 was overrepresented in patients with HPV16+ CxCa (p = 0.006). In 29 of 94 patients (31%) from whom blood could be tested, a proliferative response to HPV16/18 was detected, which was associated with increased numbers of HPV-specific CD4+CD25+ (activated) T cells (p = 0.03) and HPV-specific CD4+CD25+FoxP3-positive T cells (p = 0.04). The presence of both FoxP3-positive and negative HPV-specific CD4+CD25+ T cells was significantly correlated (p = 0.01). Interestingly, the detection of HPV-specific proliferation was associated with invasion depth (p = 0.020) but not with HLA type, tumor size nor LN status. Moreover, the detection of HPV-specific immunity was associated with an improved disease free survival (p = 0.04) in patients with deeply infiltrating tumors. In conclusion, HPV-specific proliferative T-cell response, comprising higher percentages of HPV-specific CD25+ and CD25+FoxP3-positive CD4+T cells, are more frequently detected in patients with deep infiltrating CxCa tumors and associated with an improved survival.