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Supplemental figure 3) Synergistic effects between cisplatin and peptide vaccination preserved with other treatment protocol

Induction of tumor-specific T-cell responses are dependent on cisplatin treated tumor cells.

Supplemental Video 2. TC-1 cells were in vitro cultured and treated with cisplatin (2 μg/ml). Cell death was followed for 22 hours using Annexin-V staining and automated imaging on a BD pathway 855 imager. Every hour a picture was taken.

Supplemental figure 2) Activation markers on T cells are not affected by cisplatin treatment.

Supplemental figure 1) Peptide vaccination synergizes with cisplatin, which allows lowering of the cisplatin dose.

Supplemental Video 4. TC-1 cells were in vitro cultured and treated with cisplatin (2 μg/ml) and TNFα (250iU). Cell death was followed for 22 hours using Annexin-V staining and automated imaging on a BD pathway 855 imager. Every hour a picture was taken.

Modulation of costimulatory molecule expression by HMGB1.

Purpose: Cancer immunotherapy, such as vaccination, is an increasingly successful treatment modality, but its interaction with chemotherapy remains largely undefined. Therefore, we explored the mechanism of synergy between vaccination with synthetic long peptides (SLP) of human papillomavirus type 16 (HPV16) and cisplatin in a preclinical tumor model for HPV16.Experimental Design: SLP vaccination in this preclinical tumor model allowed the elucidation of novel mechanisms of synergy between chemo- and immunotherapy. By analyzing the tumor immune infiltrate, we focused on the local intratumoral effects of chemotherapy, vaccination, or the combination.Results: Of several chemotherapeutic agents, cisplatin synergized best with SLP vaccination in tumor eradication, without requirement for the maximum-tolerated dose (MTD). Upon SLP vaccination, tumors were highly infiltrated with HPV-specific, tumor necrosis factor-α (TNFα)- and interferon-γ (IFNγ)–producing T cells. Upon combined treatment, tumor cell proliferation was significantly decreased compared with single treated and untreated tumors. Furthermore, we showed that TNFα strongly enhanced cisplatin-induced apoptotic tumor cell death in a JNK-dependent manner. This is consistent with upregulation of proapoptotic molecules and with enhanced cell death in vivo upon combined SLP vaccination and cisplatin treatment. In vivo neutralization of TNFα significantly reduced the antitumor responses induced by the combined treatment.Conclusion: Taken together, our data show that peptide vaccination with cisplatin treatment leads to decreased tumor cell proliferation and TNFα-induced enhanced cisplatin-mediated killing of tumor cells, together resulting in superior tumor eradication. Clin Cancer Res; 21(4); 781–94. ©2014 AACR.

Cisplatin-induced cell death enhances T-cell activation by upregulating CD70, CD80 and CD86 costimulatory molecules.

Categorizations of proteins released upon cisplatin treatment of tumor cells.

Supplemental Video 3. TC-1 cells were in vitro cultured wer treated with TNFα (250iU). Cell death was followed for 22 hours using Annexin-V staining and automated imaging on a BD pathway 855 imager. Every hour a picture was taken.

Supplemental Video 1. TC-1 cells were in vitro cultured and left untreated.Cell death was followed for 22 hours using Annexin-V staining and automated imaging on a BD pathway 855 imager. Every hour a picture was taken.

Cisplatin treatment does not affect the expression of costimulatory molecules on tumor cells, total myeloid cells of spleen and TDLN in vivo.

The maximum tolerated dose (MTD) of cisplatin does not induce liver or organ toxicity.

Effects of cisplatin on the tumor microenvironment.

Certain cytotoxic chemotherapeutic drugs are immunogenic, stimulating tumor immunity through mechanisms that are not completely understood. Here we show how the DNA-damaging drug cisplatin modulates tumor immunity. At the maximum tolerated dose (MTD), cisplatin cured 50% of mice with established murine TC-1 or C3 tumors, which are preclinical models of human papillomavirus (HPV)-associated cancer. Notably, the curative benefit of cisplatin relied entirely upon induction of tumor-specific CD8+ T cells. Mechanistic investigations showed that cisplatin stimulated tumor infiltration of inflammatory antigen-presenting cells (APC) expressing relatively higher levels of the T-cell costimulatory ligands CD70, CD80, and CD86. Cell death triggered by cisplatin was associated with the release of at least 19 proteins in the tumor environment that could act as damage-associated molecular patterns and upregulate costimulatory molecules, either alone or in concert, but the responsible proteins remain unknown. Essentially, the curative effect of cisplatin was abrogated in mice lacking expression of CD80 and CD86 on APCs. Furthermore, cisplatin treatment was improved by CTLA-4 blockade, which increases the availability of CD80/86 to bind to CD28. In contrast, there was no effect of CD27 stimulation, which replaces CD70 interaction. At the cisplatin MTD, cure rates could also be increased by vaccination with synthetic long peptides, whereas cures could also be achieved at similar rates at 80% of the MTD with reduced side effects. Our findings reveal an essential basis for the immunogenic properties of cisplatin, which are mediated by the induction of costimulatory signals for CD8+ T-cell–dependent tumor destruction. Cancer Res; 76(20); 6017–29. ©2016 AACR.

Supplementary Figure Legends and Supplementary Materials and Methods

High serum levels of interleukin‐6 (IL‐6) correlate with poor prognosis and chemotherapy resistance in several cancers. The underlying mechanisms and its effects on immunotherapy are largely unknown. To address this, we developed a human papillomavirus type 16 (HPV16)‐associated tumor model expressing IL‐6 to investigate the impact of tumor‐expressed IL‐6 during cisplatin chemotherapy and HPV16 synthetic long peptide vaccination as immunotherapy. The effects of tumor‐produced IL‐6 on tumor growth, survival and the tumor microenvironment were analyzed. Our data demonstrated that tumor‐produced IL‐6 conferred resistance to cisplatin and therapeutic vaccination. This was not caused by a changed in vitro or in vivo growth rate of tumor cells, or a changed sensitivity of tumor cells to chemotherapy or T‐cell‐mediated killing. Furthermore, no overt differences in the frequencies of tumor‐infiltrating subsets of T cells or CD11b+ myeloid cells were observed. IL‐6, however, affected the systemic and local function of myeloid cells, reflected by a strong reduction of major histocompatibility complex (MHC) class II expression on all major myeloid cell subtypes. Resistance to both therapies was associated with a changed intratumoral influx of MHC class II+ myeloid cells toward myeloid cells with no or lower MHC class II expression. Importantly, while these IL‐6‐mediated effects provided resistance to the immunotherapy and chemotherapy as single therapies, their combination still successfully mediated tumor control. In conclusion, IL‐6‐mediated therapy resistance is caused by an extrinsic mechanism involving an impaired function of intratumoral myeloid cells. The fact that resistance can be overcome by combination therapies provides direction to more effective therapies for cancer., What's new? Interleukin‐6 (IL‐6) cytokine has multiple effects on hematopoiesis and immune function and typically circulates at low levels. In cancer, however, IL‐6 serum levels are significantly elevated, with suspected impacts on tumor behavior. In this study, using a mouse model of human papillomavirus‐induced cancer with IL‐6 expression, the authors show that tumor‐produced IL‐6 confers resistance to both chemotherapy and immunotherapy. Resistance was associated with impaired myeloid cell maturation, with no evidence of involvement of mechanisms intrinsic to tumor cells. Resistance was overcome by combining chemotherapy and immunotherapy, providing insight into a potentially effective therapeutic approach for cancers with IL‐6‐mediated resistance.

Immune checkpoint therapy (ICT) has the potency to eradicate cancer but the mechanisms that determine effective versus non-effective therapy-induced immune responses are not fully understood. Here, using high-dimensional single-cell profiling we examined whether T cell states in the blood circulation could predict responsiveness to a combined ICT, sequentially targeting OX40 costimulatory and PD-1 inhibitory pathways, which effectively eradicated syngeneic mouse tumors. Unbiased assessment of transcriptomic alterations by single-cell RNA sequencing and profiling of cell-surface protein expression by mass cytometry revealed unique activation states for therapy-responsive CD4+ and CD8+ T cells. Effective ICT elicited T cells with dynamic expression of distinct NK cell and chemokine receptors, and these cells were systemically present in lymphoid tissues and in the tumor. Moreover, NK cell receptor-expressing CD8+ T cells were also present in the peripheral blood of immunotherapy-responsive cancer patients. Targeting of the NK cell and chemokine receptors in tumor-bearing mice showed their functional importance for therapy-induced anti-tumor immunity. These findings provide a better understanding of ICT and highlight the use of dynamic biomarkers on effector CD4+ and CD8+ T cells to improve cancer immunotherapy.

Understanding the mechanisms and impact of booster vaccinations can facilitate decisions on vaccination programmes. This study shows that three doses of the same synthetic peptide vaccine eliciting an exclusive CD8+ T cell response against one SARS-CoV-2 Spike epitope protected all mice against lethal SARS-CoV-2 infection in the K18-hACE2 transgenic mouse model in the absence of neutralizing antibodies, while only a second vaccination with this T cell vaccine was insufficient to provide protection. The third vaccine dose of the single T cell epitope peptide resulted in superior generation of effector-memory T cells in the circulation and tissue-resident memory T (TRM) cells, and these tertiary vaccine-specific CD8+ T cells were characterized by enhanced polyfunctional cytokine production. Moreover, fate mapping showed that a substantial fraction of the tertiary effector-memory CD8+ T cells developed from remigrated TRM cells. Thus, repeated booster vaccinations quantitatively and qualitatively improve the CD8+ T cell response leading to protection against otherwise lethal SARS-CoV-2 infection.SummaryA third dose with a single T cell epitope-vaccine promotes a strong increase in tissue-resident memory CD8+ T cells and fully protects against SARS-CoV-2 infection, while single B cell epitope-eliciting vaccines are unable to provide protection.

BackgroundHigh serum interleukin (IL-6) levels may cause resistance to immunotherapy by modulation of myeloid cells in the tumor microenvironment. IL-6 signaling blockade is tested in cancer, but as this inflammatory cytokine has pleiotropic effects, this treatment is not always effective.MethodsIL-6 and IL-6R blockade was applied in an IL-6-mediated immunotherapy-resistant TC-1 tumor model (TC-1.IL-6) and immunotherapy-sensitive TC-1.control. Effects on therapeutic vaccination-induced tumor regression, recurrence and survival as well on T cells and myeloid cells in the tumor microenvironment were studied. The effects of IL-6 signaling in macrophages under therapy conditions were studied in Il6rafl/fl×LysMcre+ mice.ResultsOur therapeutic vaccination protocol elicits a strong tumor-specific CD8+ T-cell response, leading to enhanced intratumoral T-cell infiltration and recruitment of tumoricidal macrophages. Blockade of IL-6 signaling exacerbated tumor outgrowth, reflected by fewer complete regressions and more recurrences after therapeutic vaccination, especially in TC-1.IL-6 tumor-bearing mice. Early IL-6 signaling blockade partly inhibited the development of the vaccine-induced CD8+ T-cell response. However, the main mechanism was the malfunction of macrophages during therapy-induced tumor regression. Therapy efficacy was impaired in Il6rafl/fl×LysMcre+ but not cre-negative control mice, while no differences in the vaccine-induced CD8+ T-cell response were found between these mice. IL-6 signaling blockade resulted in decreased expression of suppressor of cytokine signaling 3, essential for effective M1-type function in macrophages, and increased expression of the phagocytic checkpoint molecule signal-regulatory protein alpha by macrophages.ConclusionIL-6 signaling is critical for macrophage function under circumstances of immunotherapy-induced tumor tissue destruction, in line with the acute inflammatory functions of IL-6 signaling described in infections.

Background The capacity of cytomegalovirus (CMV) to elicit long-lasting strong T cell responses, and the ability to engineer the genome of this DNA virus positions CMV-based vaccine vectors highly suitable as a cancer vaccine platform. Defined immune thresholds for tumor protection and the factors affecting such thresholds have not well been investigated in cancer immunotherapy. We here determined using CMV as a vaccine platform whether critical thresholds of vaccine-specific T cell responses can be established that relate to tumor protection, and which factors control such thresholds. Methods We generated CMV-based vaccine vectors expressing the E7 epitope and tested these in preclinical models of HPV16-induced cancer. Vaccination was applied via different doses and routes (intraperitoneal (IP), subcutaneous (SC) and intranasal (IN)). The magnitude, kinetics and phenotype of the circulating tumor-specific CD8+ T cell response were determined. Mice were subsequently challenged with tumor cells, and the tumor protection was monitored. Results Immunization with CMV-based vaccines via the IP or SC route eliciting vaccine-induced CD8+ T cell responses of > 0.3% of the total circulating CD8 T cell population fully protects mice against lethal tumor challenge. However, low dose inoculations via the IP or SC route or IN vaccination elicited vaccine-induced CD8+ T cell responses that did not reach protective thresholds for tumor protection. In addition, whereas weak pre-existing immunity did not alter the protective thresholds of the vaccine-specific T cell response following subsequent immunization with CMV-based vaccine vectors, strong pre-existing immunity inhibited the development of vaccine-induced T cells and their control on tumor progression. Conclusions This study highlight the effectiveness of CMV-based vaccine vectors, and shows that demarcated thresholds of vaccine-specific T cells could be defined that correlate to tumor protection. Together, these results may hold importance for cancer vaccine development to achieve high efficacy in vaccine recipients. Electronic supplementary material The online version of this article (10.1186/s40425-019-0500-9) contains supplementary material, which is available to authorized users.

The treatment options for cancer-surgery, radiotherapy and chemotherapy-are now supplemented with immunotherapy. Previously underappreciated but now gaining strong interest are the immune modulatory properties of the three conventional modalities. Moreover, there is a better understanding of the needs and potential of the different immune therapeutic platforms. Key to improved treatment will be the combinations of modalities that complete each other's shortcomings. Area covered: Tumor-specific T-cells are required for optimal immunotherapy. In this review, the authors focus on the correct timing of different types of chemotherapeutic agents or immune modulators and immunotherapeutic drugs, not only for the activation and expansion of tumor-specific T-cells but also to support and enhance their anti-tumor efficacy. Expert opinion: At an early phase of disease, clinical success can be obtained using single treatment modalities but at later disease stages, combinations of several modalities are required. The gain in success is determined by a thorough understanding of the direct and indirect immune effects of the modalities used. Profound knowledge of these effects requires optimal tuning of immunomonitoring. This will guide the appropriate combination of treatments and allow for correct sequencing the order and interval of the different therapeutic modalities.

Certain cytotoxic chemotherapeutic drugs are immunogenic, stimulating tumor immunity through mechanisms that are not completely understood. Here we show how the DNA-damaging drug cisplatin modulates tumor immunity. At the maximum tolerated dose (MTD), cisplatin cured 50% of mice with established murine TC-1 or C3 tumors, which are preclinical models of human papillomavirus (HPV)-associated cancer. Notably, the curative benefit of cisplatin relied entirely upon induction of tumor-specific CD8+ T cells. Mechanistic investigations showed that cisplatin stimulated tumor infiltration of inflammatory antigen-presenting cells (APC) expressing relatively higher levels of the T-cell costimulatory ligands CD70, CD80, and CD86. Cell death triggered by cisplatin was associated with the release of at least 19 proteins in the tumor environment that could act as damage-associated molecular patterns and upregulate costimulatory molecules, either alone or in concert, but the responsible proteins remain unknown. Essentially, the curative effect of cisplatin was abrogated in mice lacking expression of CD80 and CD86 on APCs. Furthermore, cisplatin treatment was improved by CTLA-4 blockade, which increases the availability of CD80/86 to bind to CD28. In contrast, there was no effect of CD27 stimulation, which replaces CD70 interaction. At the cisplatin MTD, cure rates could also be increased by vaccination with synthetic long peptides, whereas cures could also be achieved at similar rates at 80% of the MTD with reduced side effects. Our findings reveal an essential basis for the immunogenic properties of cisplatin, which are mediated by the induction of costimulatory signals for CD8+ T-cell–dependent tumor destruction. Cancer Res; 76(20); 6017–29. ©2016 AACR.

Purpose: Cancer immunotherapy, such as vaccination, is an increasingly successful treatment modality, but its interaction with chemotherapy remains largely undefined. Therefore, we explored the mechanism of synergy between vaccination with synthetic long peptides (SLP) of human papillomavirus type 16 (HPV16) and cisplatin in a preclinical tumor model for HPV16. Experimental Design: SLP vaccination in this preclinical tumor model allowed the elucidation of novel mechanisms of synergy between chemo- and immunotherapy. By analyzing the tumor immune infiltrate, we focused on the local intratumoral effects of chemotherapy, vaccination, or the combination. Results: Of several chemotherapeutic agents, cisplatin synergized best with SLP vaccination in tumor eradication, without requirement for the maximum-tolerated dose (MTD). Upon SLP vaccination, tumors were highly infiltrated with HPV-specific, tumor necrosis factor-α (TNFα)- and interferon-γ (IFNγ)–producing T cells. Upon combined treatment, tumor cell proliferation was significantly decreased compared with single treated and untreated tumors. Furthermore, we showed that TNFα strongly enhanced cisplatin-induced apoptotic tumor cell death in a JNK-dependent manner. This is consistent with upregulation of proapoptotic molecules and with enhanced cell death in vivo upon combined SLP vaccination and cisplatin treatment. In vivo neutralization of TNFα significantly reduced the antitumor responses induced by the combined treatment. Conclusion: Taken together, our data show that peptide vaccination with cisplatin treatment leads to decreased tumor cell proliferation and TNFα-induced enhanced cisplatin-mediated killing of tumor cells, together resulting in superior tumor eradication. Clin Cancer Res; 21(4); 781–94. ©2014 AACR.