Therapeutic cancer vaccines trigger CD4 + and CD8 + T cell responses capable of established tumor eradication. Current platforms include DNA, mRNA and synthetic long peptide (SLP) vaccines, all... Show moreTherapeutic cancer vaccines trigger CD4 + and CD8 + T cell responses capable of established tumor eradication. Current platforms include DNA, mRNA and synthetic long peptide (SLP) vaccines, all aiming at robust T cell responses. SLPs linked to the Amplivant (R) adjuvant (Amplivant-SLP) have shown effective delivery to dendritic cells, resulting in improved immunogenicity in mice. We have now tested virosomes as a delivery vehicle for SLPs. Virosomes are nanoparticles made from influenza virus membranes and have been used as vaccines for a variety of antigens. Amplivant-SLP virosomes induced the expansion of more antigen-specific CD8 + T memory cells in ex vivo experiments with human PBMCs than Amplivant-SLP conjugates alone. The immune response could be further improved by including the adjuvants QS-21 and 3D-PHAD in the virosomal membrane. In these experiments, the SLPs were anchored in the membrane through the hydrophobic Amplivant adjuvant. In a therapeutic mouse model of HPV16 E6/E7(+) cancer, mice were vaccinated with virosomes loaded with either Amplivant-conjugated SLPs or lipid-coupled SLPs. Vaccination with both types of virosomes significantly improved the control of tumor outgrowth, leading to elimination of the tumors in about half the animals for the best combinations of adjuvants and to their survival beyond 100 days. Show less
Pardieck, I.N.; Sluis, T.C. van der; Gracht, E.T.I. van der; Veerkamp, D.M.B.; Behr, F.M.; Duikeren, S. van; ... ; Arens, R. 2022
Vaccination regimens and the number of doses required for optimal immunity and protection are critical factors in the translation of vaccines. Here the authors show administration of a three dose... Show moreVaccination regimens and the number of doses required for optimal immunity and protection are critical factors in the translation of vaccines. Here the authors show administration of a three dose protocol of a single T cell epitope to the SARS-CoV-2 spike protein induces a robust CD8(+) T cell response and confers protection in a lethal murine challenge model of infection.Understanding the mechanisms and impact of booster vaccinations are essential in the design and delivery of vaccination programs. Here we show that a three dose regimen of a synthetic peptide vaccine elicits an accruing CD8(+) T cell response against one SARS-CoV-2 Spike epitope. We see protection against lethal SARS-CoV-2 infection in the K18-hACE2 transgenic mouse model in the absence of neutralizing antibodies, but two dose approaches are insufficient to confer protection. The third vaccine dose of the single T cell epitope peptide results in superior generation of effector-memory T cells and tissue-resident memory T cells, and these tertiary vaccine-specific CD8(+) T cells are characterized by enhanced polyfunctional cytokine production. Moreover, fate mapping shows that a substantial fraction of the tertiary CD8(+) effector-memory T cells develop from re-migrated tissue-resident memory T cells. Thus, repeated booster vaccinations quantitatively and qualitatively improve the CD8(+) T cell response leading to protection against otherwise lethal SARS-CoV-2 infection. Show less
Pardieck, I.N.; Duikeren, S. van; Veerkamp, D.M.B.; Brasem, D.J.; Redeker, A.; Bergen, J. van; ... ; Arens, R. 2022
Human cytomegalovirus (HCMV) is an ubiquitous herpesvirus that can cause serious morbidity and mortality in immunocompromised or immune-immature individuals. A vaccine that induces immunity to CMV... Show moreHuman cytomegalovirus (HCMV) is an ubiquitous herpesvirus that can cause serious morbidity and mortality in immunocompromised or immune-immature individuals. A vaccine that induces immunity to CMV in these target populations is therefore highly needed. Previous attempts to generate efficacious CMV vaccines primarily focused on the induction of humoral immunity by eliciting neutralizing antibodies. Current insights encourage that a protective immune response to HCMV might benefit from the induction of virus-specific T cells. Whether addition of antiviral T cell responses enhances the protection by antibody-eliciting vaccines is however unclear. Here, we assessed this query in mouse CMV (MCMV) infection models by developing synthetic vaccines with humoral immunity potential, and deliberately adding antiviral CD8(+) T cells. To induce antibodies against MCMV, we developed a DNA vaccine encoding either full-length, membrane bound glycoprotein B (gB) or a secreted variant lacking the transmembrane and intracellular domain (secreted (s)gB). Intradermal immunization with an increasing dose schedule of sgB and booster immunization provided robust viral-specific IgG responses and viral control. Combined vaccination of the sgB DNA vaccine with synthetic long peptides (SLP)-vaccines encoding MHC class I-restricted CMV epitopes, which elicit exclusively CD8(+) T cell responses, significantly enhanced antiviral immunity. Thus, the combination of antibody and CD8(+) T cell-eliciting vaccines provides a collaborative improvement of humoral and cellular immunity enabling enhanced protection against CMV. Show less
Gracht, E.T.I. van der; Beyrend, G.; Abdelaal, T.; Pardieck, I.N.; Wesselink, T.H.; Haften, F.J. van; ... ; Arens, R. 2021
Factors that govern the complex formation of memory T cells are not completely understood. A better understanding of the development of memory T cell heterogeneity is however required to enhance... Show moreFactors that govern the complex formation of memory T cells are not completely understood. A better understanding of the development of memory T cell heterogeneity is however required to enhance vaccination and immunotherapy approaches. Here we examined the impact of pathogen- and tissue-specific cues on memory CD8(+) T cell heterogeneity using high-dimensional single-cell mass cytometry and a tailored bioinformatics pipeline. We identified distinct populations of pathogen-specific CD8(+) T cells that uniquely connected to a specific pathogen or associated tomultiple types of acute and persistent infections. In addition, the tissue environment shaped the memory CD8(+) T cell heterogeneity, albeit to a lesser extent than infection. The programming of memory CD8(+) T cell differentiation during acute infection is eventually superseded by persistent infection. Thus, the plethora of distinct memory CD8(+) T cell subsets that arise upon infection is dominantly sculpted by the pathogen-specific cues and further shaped by the tissue environment. Show less
Nejad, E.B.; Labrie, C.; Sluis, T.C. van der; Duikeren, S. van; Franken, K.L.M.C.; Roosenhoff, R.; ... ; Burg, S.H. van der 2020
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... Show moreHigh 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. Show less
Qiao, X.H.; Zanden, S.Y. van der; Wander, D.P.A.; Borras, D.M.; Song, J.Y.; Li, X.Y.; ... ; Neefjes, J. 2020
The anthracycline doxorubicin (Doxo) and its analogs daunorubicin (Daun), epirubicin (Epi), and idarubicin (Ida) have been cornerstones of anticancer therapy for nearly five decades. However, their... Show moreThe anthracycline doxorubicin (Doxo) and its analogs daunorubicin (Daun), epirubicin (Epi), and idarubicin (Ida) have been cornerstones of anticancer therapy for nearly five decades. However, their clinical application is limited by severe side effects, especially dose-dependent irreversible cardiotoxicity. Other detrimental side effects of anthracyclines include therapy-related malignancies and infertility. It is unclear whether these side effects are coupled to the chemotherapeutic efficacy. Doxo, Daun, Epi, and Ida execute two cellular activities: DNA damage, causing double-strand breaks (DSBs) following poisoning of topoisomerase II (Topo II), and chromatin damage, mediated through histone eviction at selected sites in the genome. Here we report that anthracycline-induced cardiotoxicity requires the combination of both cellular activities. Topo II poisons with either one of the activities fail to induce cardiotoxicity in mice and human cardiac microtissues, as observed for aclarubicin (Acla) and etoposide (Etop). Further, we show that Doxo can be detoxified by chemically separating these two activities. Anthracycline variants that induce chromatin damage without causing DSBs maintain similar anticancer potency in cell lines, mice, and human acute myeloid leukemia patients, implying that chromatin damage constitutes a major cytotoxic mechanismof anthracyclines. With these anthracyclines abstained from cardiotoxicity and therapy-related tumors, we thus uncoupled the side effects from anticancer efficacy. These results suggest that anthracycline variants acting primarily via chromatin damage may allow prolonged treatment of cancer patients and will improve the quality of life of cancer survivors. Show less
The anthracycline doxorubicin (Doxo) and its analogs daunorubicin (Daun), epirubicin (Epi), and idarubicin (Ida) have been cornerstones of anticancer therapy for nearly five decades. However, their... Show moreThe anthracycline doxorubicin (Doxo) and its analogs daunorubicin (Daun), epirubicin (Epi), and idarubicin (Ida) have been cornerstones of anticancer therapy for nearly five decades. However, their clinical application is limited by severe side effects, especially dose-dependent irreversible cardiotoxicity. Other detrimental side effects of anthracyclines include therapy-related malignancies and infertility. It is unclear whether these side effects are coupled to the chemotherapeutic efficacy. Doxo, Daun, Epi, and Ida execute two cellular activities: DNA damage, causing double-strand breaks (DSBs) following poisoning of topoisomerase II (Topo II), and chromatin damage, mediated through histone eviction at selected sites in the genome. Here we report that anthracycline-induced cardiotoxicity requires the combination of both cellular activities. Topo II poisons with either one of the activities fail to induce cardiotoxicity in mice and human cardiac microtissues, as observed for aclarubicin (Acla) and etoposide (Etop). Further, we show that Doxo can be detoxified by chemically separating these two activities. Anthracycline variants that induce chromatin damage without causing DSBs maintain similar anticancer potency in cell lines, mice, and human acute myeloid leukemia patients, implying that chromatin damage constitutes a major cytotoxic mechanism of anthracyclines. With these anthracyclines abstained from cardiotoxicity and therapy-related tumors, we thus uncoupled the side effects from anticancer efficacy. These results suggest that anthracycline variants acting primarily via chromatin damage may allow prolonged treatment of cancer patients and will improve the quality of life of cancer survivors. Show less
Gracht, E.T.I. van der; Schoonderwoerd, M.J.; Duikeren, S. van; Yilmaz, A.N.; Behr, F.M.; Colston, J.M.; ... ; Arens, R. 2020
Background Adenoviral vectors emerged as important platforms for cancer immunotherapy. Vaccination with adenoviral vectors is promising in this respect, however, their specific mechanisms of action... Show moreBackground Adenoviral vectors emerged as important platforms for cancer immunotherapy. Vaccination with adenoviral vectors is promising in this respect, however, their specific mechanisms of action are not fully understood. Here, we assessed the development and maintenance of vaccine-induced tumor-specific CD8(+) T cells elicited upon immunization with adenoviral vectors. Methods Adenoviral vaccine vectors encoding the full-length E7 protein from human papilloma virus (HPV) or the immunodominant epitope from E7 were generated, and mice were immunized intravenously with different quantities (10(7), 10(8) or 10(9) infectious units). The magnitude, kinetics and tumor protection capacity of the induced vaccine-specific T cell responses were evaluated. Results The adenoviral vaccines elicited inflationary E7-specific memory CD8(+) T cell responses in a dose-dependent manner. The magnitude of these vaccine-specific CD8(+) T cells in the circulation related to the development of E7-specific CD8(+) tissue-resident memory T (T-RM) cells, which were maintained for months in multiple tissues after vaccination. The vaccine-specific CD8(+) T cell responses conferred long-term protection against HPV-induced carcinomas in the skin and liver, and this protection required the induction and accumulation of CD8(+) T-RM cells. Moreover, the formation of CD8(+) T-RM cells could be enhanced by temporal targeting CD80/CD86 costimulatory interactions via CTLA-4 blockade early after immunization. Conclusions Together, these data show that adenoviral vector-induced CD8(+) T cell inflation promotes protective T-RM cell populations, and this can be enhanced by targeting CTLA-4. Show less
Nejad, E.B.; Labrie, C.; Abdulrahman, Z.; Elsas, M.J. van; Rademaker, E.; Kleinovink, J.W.; ... ; Burg, S.H. van der 2020
Background Immunotherapy of cancer is successful but tumor regression often is incomplete and followed by escape. Understanding the mechanisms underlying this acquired resistance will aid the... Show moreBackground Immunotherapy of cancer is successful but tumor regression often is incomplete and followed by escape. Understanding the mechanisms underlying this acquired resistance will aid the development of more effective treatments. Methods We exploited a mouse model where tumor-specific therapeutic vaccination results in tumor regression, followed by local recurrence and resistance. In depth studies on systemic, local and tumor intrinsic changes were performed with flow and mass cytometry, immunohistochemistry, transcriptomics and several perturbation studies with inhibitors or agonistic antibodies in mice. Main findings were recapitulated in vaccinated patients. Results Full tumor regression and cure of tumor-bearing mice is dependent on the magnitude of the vaccine-induced T-cell response. Recurrence of tumors did not involve classical immune escape mechanisms, such as antigen-presentation alterations, immune checkpoint expression, resistance to killing or local immune suppression. However, the recurrent tumors displayed a changed transcriptome with alterations in p53, tumor necrosis factor-alpha and transforming growth factor-beta signaling pathways and they became immunologically cold. Remarkably, ex vivo cell-sorted recurrent tumors, directly reinjected in naive hosts retained their resistance to vaccination despite a strong infiltration with tumor-specific CD8(+)T cells, similar to that of vaccine-responsive tumors. The influx of inflammatory mature myeloid effector cells in the resistant tumors, however, was impaired and this turned out to be the underlying mechanisms as restoration of inflammatory myeloid cell infiltration reinstated the sensitivity of these refractory tumors to vaccination. Notably, impaired myeloid cell infiltration after vaccination was also associated with vaccine resistance in patients. Conclusion An immunotherapy-induced disability of tumor cells to attract innate myeloid effector cells formed a major mechanism underlying immune escape and acquired resistance. These data not only stresses the importance of myeloid effector cells during immunotherapy but also demands for new studies to harness their tumoricidal activities. Show less
Tondini, E.; Arakelian, T.; Oosterhuis, K.; Camps, M.; Duikeren, S. van; Han, W.D.; ... ; Ossendorp, F. 2019
Background The clinical benefit of immunotherapeutic approaches against cancer has been well established although complete responses are only observed in a minority of patients. Combination... Show moreBackground The clinical benefit of immunotherapeutic approaches against cancer has been well established although complete responses are only observed in a minority of patients. Combination immunotherapy offers an attractive avenue to develop more effective cancer therapies by improving the efficacy and duration of the tumor-specific T-cell response. Here, we aimed at deciphering the mechanisms governing the response to PD-1/PD-L1 checkpoint blockade to support the rational design of combination immunotherapy. Methods Mice bearing subcutaneous MC-38 tumors were treated with blocking PD-L1 antibodies. To establish high-dimensional immune signatures of immunotherapy-specific responses, the tumor microenvironment was analyzed by CyTOF mass cytometry using 38 cellular markers. Findings were further examined and validated by flow cytometry and by functional in vivo experiments. Immune profiling was extended to the tumor microenvironment of colorectal cancer patients. Results PD-L1 blockade induced selectively the expansion of tumor-infiltrating CD4(+) and CD8(+) T-cell subsets, co-expressing both activating (ICOS) and inhibitory (LAG-3, PD-1) molecules. By therapeutically co-targeting these molecules on the T-AI cell subsets in vivo by agonistic and antagonist antibodies, we were able to enhance PD-L1 blockade therapy as evidenced by an increased number of T-AI cells within the tumor micro-environment and improved tumor protection. Moreover, T-AI cells were also found in the tumor-microenvironment of colorectal cancer patients. Conclusions This study shows the presence of T cell subsets in the tumor micro-environment expressing both activating and inhibitory receptors. These T-AI cells can be targeted by combined immunotherapy leading to improved survival. Show less
Beyrend, G.; Gracht, E. van der; Yilmaz, A.; Duikeren, S. van; Camps, M.; Hollt, T.; ... ; Ossendorp, F. 2019
Dendritic cells (DC) play a prominent role in the priming of CD8(+) T cells. Vaccination is a promising treatment to boost tumor-specific CD8(+) T cells which is crucially dependent on adequate... Show moreDendritic cells (DC) play a prominent role in the priming of CD8(+) T cells. Vaccination is a promising treatment to boost tumor-specific CD8(+) T cells which is crucially dependent on adequate delivery of the vaccine to DC. Upon subcutaneous (s.c.) injection, only a small fraction of the vaccine is delivered to DC whereas the majority is cleared by the body or engulfed by other immune cells. To overcome this, we studied vaccine delivery to DC via CD40-targeting using a multi-compound particulate vaccine with the aim to induce potent CD8(+) T cell responses. To this end, biodegradable poly(lactic-co-glycolic acid) nanoparticles (NP) were formulated encapsulating a protein Ag, Pam3CSK4 and Poly(I:C) and coated with an agonistic αCD40-mAb (NP-CD40). Targeting NP to CD40 led to very efficient and selective delivery to DC in vivo upon s.c. injection and improved priming of CD8(+) T cells against two independent tumor associated Ag. Therapeutic application of NP-CD40 enhanced tumor control and prolonged survival of tumor-bearing mice. We conclude that CD40-mediated delivery to DC of NP-vaccines, co-encapsulating Ag and adjuvants, efficiently drives specific T cell responses, and therefore, is an attractive method to improve the efficacy of protein based cancer vaccines undergoing clinical testing in the clinic. Show less
Rosalia, R.A.; Cruz, L.J.; Duikeren, S. van; Tromp, A.T.; Silva, A.L.; Jiskoot, W.; ... ; Ossendorp, F. 2015
