Interleukin-6 and indoleamine-2,3-dioxygenase as potential adjuvant targets for Papillomavirus-related tumors immunotherapy

High-risk Human papillomavirus (HPV) infections represent an important public health issue. Nearly all cervical malignancies are associated with HPV, and a range of other female and male cancers, such as anogenital and oropharyngeal. Aiming to treat HPV-related tumors, our group developed vaccines based on the genetic fusion of the HSV-1 glycoprotein D (gD) with the HPV-16 E7 oncoprotein (gDE7 vaccines). Despite the promising antitumor results reached by gDE7 vaccines in mice, combined therapies may increase the therapeutic effects by improving antitumor responses and halting immune suppressive mechanisms elicited by tumor cells. Considering cancer immunosuppressive mechanisms, indoleamine-2,3-dioxygenase (IDO) enzyme and interleukin-6 (IL-6) stand out in HPV-related tumors. Since IL-6 sustained the constitutive IDO expression, here we evaluated the therapeutic outcomes achieved by the combination of active immunotherapy based on a gDE7 protein-based vaccine with adjuvant treatments involving blocking IDO, either by use of IDO inhibitors or IL-6 knockout mice. C57BL/6 wild-type (WT) and transgenic IL-6-/- mice were engrafted with HPV16-E6/E7-expressing TC-1 cells and treated with 1-methyl-tryptophan isoforms (D-1MT and DL-1MT), capable to inhibit IDO. In vitro, the 1MT isoforms reduced IL-6 gene expression and IL-6 secretion in TC-1 cells. In vivo, the multi-targeted treatment improved the antitumor efficacy of the gDE7-based protein vaccine. Although the gDE7 immunization achieves partial tumor mass control in combination with D-1MT or DL-1MT in WT mice or when administered in IL-6-/- mice, the combination of gDE7 and 1MT in IL-6-/- mice further enhanced the antitumor effects, reaching total tumor rejection. The outcome of the combined therapy was associated with an increased frequency of activated dendritic cells and decreased frequencies of intratumoral polymorphonuclear myeloid-derived suppressor cells and T regulatory cells. In conclusion, the present study demonstrated that IL-6 and IDO negatively contribute to the activation of immune cells, particularly dendritic cells, reducing gDE7 vaccine-induced protective immune responses and, therefore, opening perspectives for the use of combined strategies based on inhibition of IL-6 and IDO as immunometabolic adjuvants for immunotherapies against HPV-related tumors.

Pathogenic and Prognostic Roles of Paraneoplastic Leukocytosis in Cervical Cancer: Can Genomic-Based Targeted Therapies Have a Role? A Literature Review and an Emblematic Case Report

Tumor-associated leukocytosis has been associated with poor prognosis in cervical cancer. Leukemoid reaction (i.e., white blood cell count > 40,000/μL) is defined paraneoplastic (PLR) when it occurs in the presence of a cytokine-secreting tumor (CST) without neoplastic bone marrow infiltration. Cervical cancers displaying PLR represent a peculiar entity characterized by a rapidly progressive behavior typically associated with chemo-radioresistance. The present paper aims to review the literature about the pathogenetic mechanisms of PLR and its prognostic role in cervical cancer. Moreover, it reports the emblematic case of a patient with an advanced cervical cancer associated with PLR that was chemotherapy resistant. The patient underwent a palliative cytoreductive surgery of high complexity, obtaining a temporary regression of PLR. The tumor sample stained positive for G-CSF and IL-6, thus indicating a CST. Notably, the tumor genomic analysis revealed a PI3CKA mutation. Therefore, at the instrumental evidence of a rapidly progressive disease relapse, which was accompanied by reappearance of PLR, we started a targeted treatment with a selective PIK3 inhibitor alpesilib combined with the JAK1-2 inhibitor ruxolitinib. We achieved a relief of symptoms and leukocytosis; however, severe side effects necessitated the treatment suspension. In conclusion, as therapeutic strategies for cancer with PLR are scarcely reported in literature, our study could contribute to expand our understanding of the topic and provide a basis for further research.

Myeloid Immune Cells CARrying a New Weapon Against Cancer

Chimeric antigen receptor (CAR) engineering for T cells and natural killer cells (NK) are now under clinical evaluation for the treatment of hematologic cancers. Although encouraging clinical results have been reported for hematologic diseases, pre-clinical studies in solid tumors have failed to prove the same effectiveness. Thus, there is a growing interest of the scientific community to find other immune cell candidate to express CAR for the treatment of solid tumors and other diseases. Mononuclear phagocytes may be the most adapted group of cells with potential to overcome the dense barrier imposed by solid tumors. In addition, intrinsic features of these cells, such as migration, phagocytic capability, release of soluble factors and adaptive immunity activation, could be further explored along with gene therapy approaches. Here, we discuss the elements that constitute the tumor microenvironment, the features and advantages of these cell subtypes and the latest studies using CAR-myeloid immune cells in solid tumor models.

Local and Systemic STAT3 and p65 NF-KappaB Expression as Progression Markers and Functional Targets for Patients With Cervical Cancer

Cervical cancer, which main etiologic factor is Human Papillomavirus (HPV) infection, continues to be a burden for public health systems in developing countries. Our laboratory has been working with the hypothesis that signals generated in the tumor microenvironment can modulate local and systemic immune responses. In this context, it would be reasonable to think that tumors create pro-tumoral bias in immune cells, even before they are recruited to the tumor microenvironment. To understand if and how signaling started in the tumor microenvironment can influence cells within the tumor and systemically, we investigated the expression of key proteins in signaling pathways important for cell proliferation, viability, immune responses and tolerance. Besides, we used detection of specific phosphorylated residues, which are indicative of activation for Akt, CREB, p65 NFκB, and STAT3. Our findings included the observation of a significant STAT3 expression increase and p65 NFκB decrease in circulating leukocytes in correlation with lesion grade. In light of those observations, we started investigating the result of the inhibition of STAT3 in a tumor experimental model. STAT3 inhibition impaired tumor growth, increased anti-tumor T cell responses and decreased the accumulation of myeloid cells in the spleen. The concomitant inhibition of NFκB partially reversed these effects. This study indicates that STAT3 and NFκB are involved in immunomodulatory tumor effects and STAT3 inhibition could be considered as therapy for patients with cervical cancer.

CD163+ tumor-associated macrophage accumulation in breast cancer patients reflects both local differentiation signals and systemic skewing of monocytes

Objectives

The accumulation of tumor‐associated macrophages (TAMs) is correlated with poor clinical outcome, but the mechanisms governing their differentiation from circulating monocytes remain unclear in humans.

Methods

Using multicolor flow cytometry, we evaluated TAMs phenotype in 93 breast cancer (BC) patients. Furthermore, monocytes from healthy donors were cultured in the presence of supernatants from dilacerated primary tumors to investigate their differentiation into macrophages (MΦ) in vitro. Additionally, we used transcriptomic analysis to evaluate BC patients’ blood monocytes profiles.

Results

We observed that high intra‐tumor CD163‐expressing TAM density is predictive of reduced survival in BC patients. In vitro, M‐CSF, TGF‐β and VEGF from primary tumor supernatants skewed the differentiation of healthy donor blood monocytes towards CD163^highCD86^lowIL‐10^high M2‐like MΦ that strongly suppressed CD4⁺ T‐cell expansion via PD‐L1 and IL‐10. In addition, blood monocytes from about 40% of BC patients displayed an altered response to in vitro stimulation, being refractory to type‐1 MΦ (M1‐MΦ) differentiation and secreting higher amounts of immunosuppressive, metastatic‐related and angiogenic cytokines. Aside from showing that monocyte transcriptome is significantly altered by the presence of BC, we also demonstrated an overall metabolic de‐activation in refractory monocytes of BC patients. In contrast, monocytes from sensitive BC patients undergoing normal M1‐MΦ differentiation showed up‐regulation of IFN‐response genes and had no signs of metabolic alteration.

Conclusion

Altogether, our results suggest that systemic factors skew BC patient blood monocytes towards a pro‐metastatic profile, resulting in the accumulation of further polarised CD163^high TAMs resembling type‐2 MΦ (M2‐MΦ) in the local BC microenvironment. These data indicate that monitoring circulating monocytes in BC patients may provide an indication of early systemic alterations induced by cancer and, thus, be instrumental in the development of improved personalised immunotherapeutic interventions.

Swainsonine, an alpha-mannosidase inhibitor, may worsen cervical cancer progression through the increase in myeloid derived suppressor cells population

Cervical cancer, caused by high oncogenic risk Human Papillomavirus (HPV) infection, continues to be a public health problem, mainly in developing countries. Using peptide phage display as a tool to identify potential molecular targets in HPV associated tumors, we identified α-mannosidase, among other enriched sequences. This enzyme is expressed in both tumor and inflammatory compartment of the tumor microenvironment. Several studies in experimental models have shown that its inhibition by swainsonine (SW) led to inhibition of tumor growth and metastasis directly and indirectly, through activation of macrophages and NK cells, promoting anti-tumor activity. Therefore, the aim of this work was to test if swainsonine treatment could modulate anti-tumor immune responses and therefore interfere in HPV associated tumor growth. Validation of our biopanning results showed that cervical tumors, both tumor cells and leukocytes, expressed α-mannosidase. Ex vivo experiments with tumor associated macrophages showed that SW could partially modulate macrophage phenotype, decreasing CCL2 secretion and impairing IL-10 and IL-6 upregulation, which prompted us to proceed to in vivo tests. However, in vivo, SW treatment increased tumor growth. Investigation of the mechanisms leading to this result showed that SW treatment significantly induced the accumulation of myeloid derived suppressor cells in the spleen of tumor bearing mice, which inhibited T cell activation. Our results suggested that SW contributes to cervical cancer progression by favoring proliferation and accumulation of myeloid cells in the spleen, thus exacerbating these tumors systemic effects on the immune system, therefore facilitating tumor growth.

Lactate secreted by cervical cancer cells modulates macrophage phenotype

Cervical cancer continues to be a public health problem in developing countries. Previous studies have shown that cervical cancer cells display markers of aerobic glycolysis, indicating that these tumors are likely to secrete lactate. Mostly, lactate is recognized as a molecule capable of suppressing immune responses, through inhibition of T cells, Mϕs, and dendritic cells. We and others have previously shown that Mϕs are frequent cells infiltrating cervical cancers with the ability to inhibit antitumor immune responses and promote tumor growth through angiogenesis. Here, we have tested the hypothesis that lactate, secreted by cervical cancer cells, can modulate Mϕ phenotype. First, we showed higher lactate plasma concentrations in patients with increasing cervical lesion grades, with maximum concentration in the plasma of cancer patients, which supported our hypothesis. We then inhibited lactate production in tumor cell spheroids established from cervical cancer derived cell lines, using the lactate dehydrogenase inhibitor, oxamate, prior to co-culture with monocytes. Lactate mediated part of the crosstalk between tumor cells and Mϕs, promoting secretion of IL-1β, IL-10, IL-6, and up-regulation of hypoxia induced factor-1α expression, and down-regulation of p65-NFκB phosphorylation in Mϕs. We also showed that Mϕs from co-cultures treated with oxamate were better inducers of T cell activation. Of note, experiments performed with inhibition of the monocarboxylate transporters rendered similar results. Our data confirms the hypothesis that lactate, secreted by cervical tumor cells, influences the phenotype of tumor Mϕs, promoting a suppressive phenotype.

B lymphocytes can be activated to act as antigen presenting cells to promote anti-tumor responses

Immune evasion by tumors includes several different mechanisms, including the inefficiency of antigen presenting cells (APCs) to trigger anti-tumor T cell responses. B lymphocytes may display a pro-tumoral role but can also be modulated to function as antigen presenting cells to T lymphocytes, capable of triggering anti-cancer immune responses. While dendritic cells, DCs, are the best APC population to activate naive T cells, DCs or their precursors, monocytes, are frequently modulated by tumors, displaying a tolerogenic phenotype in cancer patients. In patients with cervical cancer, we observed that monocyte derived DCs are tolerogenic, inhibiting allogeneic T cell activation compared to the same population obtained from patients with precursor lesions or cervicitis. In this work, we show that B lymphocytes from cervical cancer patients respond to treatment with sCD40L and IL-4 by increasing the CD80+CD86+ population, therefore potentially increasing their ability to activate T cells. To test if B lymphocytes could actually trigger anti-tumor T cell responses, we designed an experimental model where we harvested T and B lymphocytes, or dendritic cells, from tumor bearing donors, and after APC stimulation, transplanted them, together with T cells into RAG1-/- recipients, previously injected with tumor cells. We were able to show that anti-CD40 activated B lymphocytes could trigger secondary T cell responses, dependent on MHC-II expression. Moreover, we showed that dendritic cells were resistant to the anti-CD40 treatment and unable to stimulate anti-tumor responses. In summary, our results suggest that B lymphocytes may be used as a tool for immunotherapy against cancer.

Local and systemic immunomodulatory mechanisms triggered by Human Papillomavirus transformed cells: a potential role for G-CSF and neutrophils

Cervical cancer is the last stage of a series of molecular and cellular alterations initiated with Human Papillomavirus (HPV) infection. The process involves immune responses and evasion mechanisms, which culminates with tolerance toward tumor antigens. Our objective was to understand local and systemic changes in the interactions between HPV associated cervical lesions and the immune system as lesions progress to cancer. Locally, we observed higher cervical leukocyte infiltrate, reflected by the increase in the frequency of T lymphocytes, neutrophils and M2 macrophages, in cancer patients. We observed a strong negative correlation between the frequency of neutrophils and T cells in precursor and cancer samples, but not cervicitis. In 3D tumor cell cultures, neutrophils inhibited T cell activity, displayed longer viability and longer CD16 expression half-life than neat neutrophil cultures. Systemically, we observed higher plasma G-CSF concentration, higher frequency of immature low density neutrophils, and tolerogenic monocyte derived dendritic cells, MoDCs, also in cancer patients. Interestingly, there was a negative correlation between T cell activation by MoDCs and G-CSF concentration in the plasma. Our results indicate that neutrophils and G-CSF may be part of the immune escape mechanisms triggered by cervical cancer cells, locally and systemically, respectively.

Vaccination during myeloid cell depletion by cancer chemotherapy fosters robust T cell responses

Therapeutic vaccination with human papillomavirus type 16 synthetic long peptides (HPV16-SLPs) results in T cell-mediated regression of HPV16-induced premalignant lesions but fails to install clinically effective immunity in patients with HPV16-positive cervical cancer. We explored whether HPV16-SLP vaccination can be combined with standard carboplatin and paclitaxel chemotherapy to improve immunity and which time point would be optimal for vaccination. This was studied in the HPV16 E6/E7-positive TC-1 mouse tumor model and in patients with advanced cervical cancer. In mice and patients, the presence of a progressing tumor was associated with abnormal frequencies of circulating myeloid cells. Treatment of TC-1-bearing mice with chemotherapy and therapeutic vaccination resulted in superior survival and was directly related to a chemotherapy-mediated altered composition of the myeloid cell population in the blood and tumor. Chemotherapy had no effect on tumor-specific T cell responses. In advanced cervical cancer patients, carboplatin-paclitaxel also normalized the abnormal numbers of circulating myeloid cells, and this was associated with increased T cell reactivity to recall antigens. The effect was most pronounced starting 2 weeks after the second cycle of chemotherapy, providing an optimal immunological window for vaccination. This was validated with a single dose of HPV16-SLP vaccine given in this time window. The resulting proliferative HPV16-specific T cell responses were unusually strong and were retained after all cycles of chemotherapy. In conclusion, carboplatin-paclitaxel therapy fosters vigorous vaccine-induced T cell responses when vaccination is given after chemotherapy and has reset the tumor-induced abnormal myeloid cell composition to normal values.

Comparative assessment of lipid based nano-carrier systems for dendritic cell based targeting of tumor re-initiating cells in gynecological cancers

We aimed to identify an optimum nano-carrier system to deliver tumor antigen to dendritic cells (DCs) for efficient targeting of tumor reinitiating cells (TRICs) in gynecological malignancies. Different lipid based nano-carrier systems i.e. liposomes, ethosomes and solid lipid nanoparticles (SLNPs) were examined for their ability to activate DCs in allogeneic settings. Out of these three, the most optimized formulation was subjected for cationic and mannosylated surface modification and pulsed with DCs for specific targeting of tumor cells. In both allogeneic and autologous trials, SLNPs showed a strong ability to activate DCs and orchestrate specific immune responses for targeting TRICs in gynecological malignancies. Our findings suggest that the mannosylated form of SLNPs is a suitable molecular vector for DC based therapeutics. DCs pulsed with mannosylated SLNPs may be utilized as adjuvant therapy for specific removal of TRICs to benefit patients from tumor recurrence.

Systems-level effects of ectopic galectin-7 reconstitution in cervical cancer and its microenvironment

Background

Galectin-7 (Gal-7) is negatively regulated in cervical cancer, and appears to be a link between the apoptotic response triggered by cancer and the anti-tumoral activity of the immune system. Our understanding of how cervical cancer cells and their molecular networks adapt in response to the expression of Gal-7 remains limited.

Methods

Meta-analysis of Gal-7 expression was conducted in three cervical cancer cohort studies and TCGA. In silico prediction and bisulfite sequencing were performed to inquire epigenetic alterations. To study the effect of Gal-7 on cervical cancer, we ectopically re-expressed it in the HeLa and SiHa cervical cancer cell lines, and analyzed their transcriptome and SILAC-based proteome. We also examined the tumor and microenvironment host cell transcriptomes after xenotransplantation into immunocompromised mice. Differences between samples were assessed with the Kruskall-Wallis, Dunn’s Multiple Comparison and T tests. Kaplan–Meier and log-rank tests were used to determine overall survival.

Results

Gal-7 was constantly downregulated in our meta-analysis (p < 0.0001). Tumors with combined high Gal-7 and low galectin-1 expression (p = 0.0001) presented significantly better prognoses (p = 0.005). In silico and bisulfite sequencing assays showed de novo methylation in the Gal-7 promoter and first intron. Cells re-expressing Gal-7 showed a high apoptosis ratio (p < 0.05) and their xenografts displayed strong growth retardation (p < 0.001). Multiple gene modules and transcriptional regulators were modulated in response to Gal-7 reconstitution, both in cervical cancer cells and their microenvironments (FDR < 0.05 %). Most of these genes and modules were associated with tissue morphogenesis, metabolism, transport, chemokine activity, and immune response. These functional modules could exert the same effects in vitro and in vivo, even despite different compositions between HeLa and SiHa samples.

Conclusions

Gal-7 re-expression affects the regulation of molecular networks in cervical cancer that are involved in diverse cancer hallmarks, such as metabolism, growth control, invasion and evasion of apoptosis. The effect of Gal-7 extends to the microenvironment, where networks involved in its configuration and in immune surveillance are particularly affected.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2700-8) contains supplementary material, which is available to authorized users.

Association Study of Single-Nucleotide Polymorphisms of STAT2/STAT3/IFN-γ Genes in Cervical Cancer in Southern Chinese Han Women

OBJECTIVE

Interferon-γ (IFN-γ) and signal transducers and activators of transcription (STATs) each play an important role in carcinogenesis associated with viral infection. Cervical cancer is almost invariably associated with infection by human papillomavirus (HPV), and previous studies suggested that dysregulation of the signal pathway involved in IFN-γ and STATs is associated. Our objective was to evaluate the association of SNPs in STAT2, STAT3, and IFN-γ with cervical cancer susceptibility in Chinese Han women in Hunan province.

MATERIALS AND METHODS

Genomic DNA was extracted from peripheral blood samples of 234 cervical cancer patients and 216 healthy female controls. STAT2 and STAT3 genotyping was performed using polymerase chain reaction-restriction enzyme (PCR-RE) analysis. IFN-γ genotyping was detected by PCR-amplification of specific allele (PASA).

RESULTS

For STAT2 rs2066807 polymorphisms, there was no significant difference of genotype distribution (P=0.827) and allele frequencies (P=0.830, OR=1.09, 95% CI: 0.51-2.31) between cases and controls. For STAT3 rs957970 polymorphisms, there was no significant difference of genotype distribution (P=0.455) and allele frequencies (P=0.560, OR=0.92, 95% CI: 0.71-1.20) between cases and controls. For IFN-γ +874A/T polymorphisms, there was no significant difference of genotype distribution (P=0.652) and allele frequencies (P=0.527, OR=1.12, 95% CI: 0.79-1.59) between cases and controls.

CONCLUSION

These results suggest that polymorphisms in STAT2, STAT3 and IFN-γ genes are not likely to be strong predictors of cervical cancer in Han women in southern China.