Antitumor activity of mixed heat shock protein/peptide vaccine and cyclophosphamide plus interleukin-12 in mice sarcoma

Pro-inflammatory responses after peptide-based cancer immunotherapy

Therapeutic vaccinations are designed to prevent cancer by inducing immune responses against tumor antigens. in cancer cells, tumor-associated antigens (TAA) or tumor-specific (mutated) derived peptides are presented within the clefts of main histocompatibility complex (MHC) class I or class II molecules, they either activate cytotoxic T-lymphocytes (CTLs), CD4+ T or CD8+ T lymphocytes, which release cytokines that can suppress tumor cells growth. In cancer immunotherapies, CD8+ T lymphocytes are a major mediator of tumor repression. The effect of peptide-based vaccinations on cytokines in the activating CD8+ T cell against targeted tumor antigens is the subject of this review. It is believed that peptide-based vaccines increased IFN-γ, TNF-α, IL-2, and IL-12, secreting CTL line by interacting with dendritic cell (DC), supposed to stimulate immune system. Additionally, mechanisms of CTL activation and dysfunction were also studied. According to most of the data resulted from in vivo and in vitro research works, it is assumed that peptide-based vaccines increased IFN-γ, TNF-α, IL-2, and IL-12.

Profile of Serum Heat Shock Protein-27 Level in Patients with Salivary Gland Tumor

Statement of the Problem

Heat shock protein 27 (HSP₂₇) plays important roles in many cellular processes and has been implicated in different types of diseases such as cancers.

Purpose

This study aimed to evaluate the serum level of HSP₂₇ in patients with salivary gland tumors and to determine its possible correlation with the prognosis of the disease.

Materials and Method

This cross-sectional study was performed on 60 patients with sali-vary gland tumor including 16 pleomorphic adenoma, 33 adenoid cystic carcinoma, 6 mu-coepidermoid carcinoma, 5 acinic cell carcinoma, and 28 healthy control subjects. The con-trol cases were healthy blood donors who matched the study group in age and sex. Serum samples were obtained from the clotted blood and HSP₂₇concentrations were measured with sandwich enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed by using one-way ANOVA, post Hoc test, independent sample t-test, and ROC analysis. A p value of less than 0.05 was considered as significant.

Results

The mean serum level of HSP₂₇ was 3956.1±3830.1 (pg/ml) in patients with malig-nant salivary gland tumor, which was significantly higher than that in benign salivary gland tumor (752.2±485.6) and healthy controls (602.3±575.8) (p <0.001). However, there was no significant difference in the HSP₂₇ serum levels between the patients with benign salivary gland tumors and healthy controls (p= 0.2). No association was detected between the mean serum levels of HSP₂₇ and clinicopathologic factors such as age, sex, stage and nodal metas-tasis (p > 0.05), except for the tumor size (p= 0.04).

Conclusion

The HSP₂₇ concentration increased in patients with malignant salivary gland tumors. Moreover, the HSP₂₇ level was correlated with tumor growth, invasiveness, and diagnosability. Yet, larger clinical studies are required to explore its prognostic value.

GP96 and SMP30 Protein Priming of Dendritic Cell Vaccination Induces a More Potent CTL Response against Hepatoma

Heat-shock protein (HSP) GP96 is a well-known adjuvant in immunotherapy. It belongs to the HSP90 family. Our previous study demonstrated that DC pulsed with recombinant senescence marker protein 30 (SMP30) could induce cytotoxic T lymphocytes (CTLs) against liver cancer cells in vitro. In this study, SMP30 and GP96 were subcloned into lentiviruses and transfected into DCs from healthy donors. We included six groups: the GP96-SMP30 group, GP96 group, SMP30 group, DC group, empty vector control group, and hepatoma extracted protein group. We used ELISA to detect cytokines and flow cytometry to assess CD80 and CD86 on DCs and the effect of CTLs. Our vector design was considered successful and further studied. In the SMP30 group, DC expresses more CCR7 and CD86 than the control group; in the SMP30+GP96 group, DC express more CCR7, CD86, and CD80 than the control group. Transfected DCs secreted more TNF-α and interferon-β and induced more CTLs than control DCs. SMP30 + GP96 effectively stimulated the proliferation of T cells compared with control treatment (P < 0.01). We detected the cytokines TNF-α, TNF-β, IL-12, and IFN (α, β, and γ) via ELISA (Figure 5) and verified the killing effect via FCM. Four E : T ratios (0 : 1, 10 : 1, 20 : 1, and 40 : 1) were tested. The higher the ratio was, the better the effects were. We successfully constructed a liver cancer model and tested the CTL effect in each group. The GP96 + SMP30 group showed a better effect than the other groups. GP96 and SMP30 can stimulate DCs together and produce more potent antitumor effects. Our research may provide a new efficient way to improve the therapeutic effect of DC vaccines in liver cancer.

A new antisarcoma strategy: multisubtype heat shock protein/peptide immunotherapy combined with PD-L1 immunological checkpoint inhibitors

Osteosarcoma, a common malignant tumor in orthopedics, often has a very poor prognosis after lung metastasis. Immunotherapy has not achieved much progress in the treatment because of the characteristics of solid tumors and immune environment of osteosarcoma. The tumor environment is rather essential for sarcoma treatment. Our previous study demonstrated that heat shock proteins could be used as antitumor vaccines by carrying tumor antigen peptides, and we hypothesize that an anti-osteosarcoma effect may be increased with an immune check point inhibitor (PD-L1 inhibitor) as a combination treatment strategy. The present study prepared a multisubtype mixed heat shock protein osteosarcoma vaccine (mHSP/peptide vaccine) and concluded that the mHSP/peptide vaccine was more effective than a single subtype heat shock protein, like Grp94. Therefore, we used the mHSP/peptide vaccine in combination with a PD-L1 inhibitor to treat osteosarcoma, and the deterioration of osteosarcoma was effectively hampered. The mechanism of combined therapy was investigated, and AKT expression participates with sarcoma lung metastasis. This study proposed an antisarcoma strategy via stimulation of the immune system as a further alternative approach for sarcoma treatment and elucidated the mechanism of combined therapy.

Tumor targeting nanoparticle E749-57-HSP110-RGD elicits potent anti-tumor immune response in a CD8-dependent manner in cervical cancer-bearing mouse model

Our previous research verified that HSP (heat shock protein) 110 could enhance the anti-tumor effect of HPV16 E7_49-57 epitope. In this study, to optimize the immunotherapy of this vaccine type, we developed and evaluated the anti-tumor immunity of a nanoparticle vaccine format assembling with E7_49-57-HSP110 fusion expression plasmid and RGD-GGG-K₁₈ polypeptide. The nanoparticle vaccine was self-assembled from positively charged RGD-GGG-K₁₈ polypeptide and negatively charged fusion expression plasmid pIRES2-3× E7-HSP110-EGFP. The particle size, stability, expression of E7_49-57-HSP110 fusion protein and the target ability of nanoparticle were determined, respectively. Specific CTL responses were determined by E7 tetramer staining and cytotoxicity assay in TC-1 tumor-bearing mice (CD4/CD8 knockout). The preventive and therapeutic experiments of nanoparticle vaccine were investigated in TC-1 tumor-bearing mice. Results showed that the RGD-GGG-K₁₈ polypeptide and pIRES2-3× E7-HSP110-EGFP plasmid self-assembled nanoparticles about 100 nanometers in diameter when the charge ratios of peptide/plasmid were 2. The nanoparticles effectively entered TC-1 cells directed by RGD target-peptide, and correctly expressed the E7-HSP110 fusion protein. The HSP110 effectively facilitated nanoparticles activating CD8⁺T cells than nanoparticles without HSP110, including the CD8⁺ T cell number and the IFN-γ level; in contrast, the CD4⁺T cells immune response remained indiscriminate among the mice groups. This nanoparticle formulation inhibited tumor growth and prolonged the survival duration in the prophylactic and therapeutic mouse models. Therefore, the RGD-based tumor-targeting nanoparticle expressing E7_49-57-HSP110 fusion protein can efficiently evoke anti-tumor activity and thus suggests it might be a favorable candidate for cervical cancer immunotherapy.

Heat-shock proteins in diagnosis and treatment: an overview of different biochemical and immunological functions

Heat-shock proteins (HSPs) have been involved in different functions including chaperone activity, protein folding, apoptosis, autophagy and immunity. The HSP families have powerful effects on the stimulation of innate immune responses through Toll-like receptors and scavenger receptors. Moreover, HSP-mediated phagocytosis directly enhances the processing and presentation of internalized antigens via the endocytic pathway in adaptive immune system. These properties of HSPs have been used for development of prophylactic and therapeutic vaccines against infectious and noninfectious diseases. Several studies also demonstrated the relationship between HSPs and drug resistance as well as their use as a novel biomarker for detecting tumors in patients. The present review describes different roles of HSPs in biology and medicine especially biochemical and immunological aspects.

Antibody-drug conjugates targeting TROP-2 and incorporating SN-38: A case study of anti-TROP-2 sacituzumab govitecan

Antibody-drug conjugates (ADCs) that exploit the active metabolite SN-38, which is derived from the popular anticancer drug, irinotecan (a camptothecin that inhibits the nuclear topoisomerase I enzyme, inducing double-stranded DNA breaks during the mitotic S-phase of affected cells), represent a substantial advance in the ADC field. SN-38 has been conjugated to a humanized antibody against trophoblast cell surface antigen 2 (TROP-2), which is involved in cancer signaling pathways and has increased expression by many cancer cell types, yielding the ADC sacituzumab govitecan. By conjugating a higher number of SN-38 molecules to the immunoglobulin (drug-to-antibody ratio = 7-8:1), and giving higher (10 mg/kg) and repeated therapy cycles (Days 1 and 8 of 21-day cycles), enhanced drug uptake by the targeted cancer cells is achieved. Based on a unique conjugation method, the lactone ring of the SN-38 molecule is stabilized and the molecule is protected from glucuronidation, a process that contributes to the untoward late diarrhea experienced with irinotecan. Finally, while the ADC is internalized, the use of a moderately stable linker permits release of SN-38 in an acidic environment of the tumor cell and its microenvironment, contributing to a bystander effect on neighboring cancer cells. Here, we discuss the development of sacituzumab govitecan and clinical results obtained using it for the management of patients with advanced, refractive breast, lung, and urinary bladder cancers. Sacituzumab govitecan, which is undergoing accelerated approval review by the US Food and Drug Administration while also being studied in Phase 3 clinical studies, was granted Breakthrough Therapy status from the FDA for advanced, refractory, metastatic triple-negative breast cancer patients.

LOX and ACSL5 as potential relapse markers for pancreatic cancer patients

Pancreatic cancer is one of the most malignant diseases and has a poor prognosis. The screening and validation of biomarkers with predictive value for prognosis and treatment efficacy are important. To identify potential prognostic markers of pancreatic cancer patients, we conducted a study that included 99 pancreatic cancer patients. Three patients with PFS>18 months were enrolled in the treat group, and three patients with PFS<12 months were enrolled in the control group. Differentially expressed genes (DEGs) between these two groups were analyzed by whole-genome expression microarray. A total of 178 DEGs were identified, including 110 up-regulated and 68 down-regulated genes. Next, 24 candidate genes were selected for validation by qPCR based on fold change and previous studies. The results showed that the mRNA levels of four candidate genes, including ACSL5, SLC44A4, LOX, and TOX3, were correlated with PFS. Immunohistochemical staining was performed to validate the protein expression levels of these four markers. The results showed that patients with LOX ^high, ACSL5 ^low and TOX3 ^low expression had a significantly shorter PFS than those with LOX ^low, ACSL5 ^high and TOX3 ^high expression. Multivariable analysis revealed differentiation, tumor stage, LOX expression, and ACSL5 expression were independent prognostic factors for PFS. Then, we use the TCGA database to explore the underlying mechanism of LOX influence pancreatic cancer progression. Protein-protein interaction network of ACSL5 was established by STRING to uncover the potential regulation mechanism. Our findings reveal that LOX and ACSL5 are potential prognostic markers for the prognosis of pancreatic cancer patients.

T-cell Homing Therapy for Reducing Regulatory T Cells and Preserving Effector T-cell Function in Large Solid Tumors

Purpose: Infused autologous tumor-infiltrating lymphocytes (TIL) and tumor-targeted chimeric antigen receptor (CAR) T cells typically surround malignant lesions or penetrate small tumor nodules but fail to penetrate large solid tumors, significantly compromising their antitumor impact. Strategies to overcome this primary challenge are largely required.Experimental Design: We tested the effects of IL12 plus doxorubicin on T-cell penetration and efficacy in solid tumors in a murine lung cancer model, a murine breast carcinoma lung metastasis model, and two human xenograft tumor models bearing large tumors (>10 mm).Results: Intriguingly, this simple approach increased the numbers, the distribution, and the depth of penetration of infused CD8+ T cells in these tumors, including both TILs and CAR T cells. This combined treatment halted tumor progression and significantly extended survival time. Studies of the underlying mechanism revealed multiple effects. First, the combined treatment maintained the high ratios of immune-stimulatory receptors to immune-inhibitory receptors on infiltrated CD8+ T cells, reduced the accumulation of immunosuppressive regulatory T cells, and enhanced the numbers of T-bet+ effector T cells in the tumors. Second, doxorubicin induced chemokines CXCL9 and CXCL10, which may attract NKG2D+CD8+ T cells to tumors, and this effect was boosted by IL12-induced IFNγ accumulation in tumors, promoting the penetration of NKG2D+CD8+ T cells.Conclusions: The deep penetration of infused T cells associated with combined IL12 plus doxorubicin yielded striking therapeutic effects in murine and human xenograft solid tumors. This approach might broaden the application of T-cell therapy to a wider range of solid tumors. Clin Cancer Res; 24(12); 2920-34. ©2018 AACRSee related commentary by Berraondo et al., p. 2716.

Immunotherapy in Sarcoma: Future Horizons

Immunologic approaches to cancer are over a century old. Over the years, the strategy has been fine-tuned from inciting infections in subjects to inhibiting negative regulatory signals from the innate immune system. Sarcomas are among the first tumors to be considered for immune interventions. From Coley's toxin to cytokine-based therapies to adoptive cell therapy, there have been numerous immunotherapeutic investigations in this patient population. A promising strategy includes adoptive T cell therapy which has been studied in small cohorts of synovial sarcoma, a subtype that is known to widely express the cancer testis antigen, NY-ESO-1. Additionally, recent data in metastatic melanoma and renal cell carcinoma demonstrate the utility and tremendous efficacy of immune checkpoint blockade with increased rates of durable responses compared to standard therapies. Responses in traditionally "non-immunogenic" tumors, such as lung and bladder cancers, provide ample rationale for the study of immune checkpoint inhibitors in sarcoma. While immunotherapy has induced some responses in sarcomas, further research will help clarify optimal patient selection for future clinical trials and new combinatorial immunotherapeutic strategies.

The relationship between the antitumor effect of the IL-12 gene therapy and the expression of Th1 cytokines in an HPV16-positive murine tumor model

Objective. The goal of the present study was to investigate the effect of IL-12 expressed in plasmid on the Th1 cytokine profile in an experimental HPV16-positive murine tumor model and the association with the IL-12's antitumor effect. Methods. Mice were injected with BMK-16/myc cells to establish HPV16-positive tumor and then pNGVL3-mIL-12 plasmid; pcDNA3 plasmid or PBS was injected directly into tumor site. The antitumor effect of the treatment was evaluated and the cytokines expression profile in each tumor tissue was analyzed. Results. Treatment with pNGVL3-mIL-12 plasmid had a significant antitumor effect, and a Th2-Th3-type cytokines prolife was detected in the murine tumor model with expression of the cytokines IL-10, IL-4, and TGF-β1. However, after the tumor was treated with three intratumoral injections of plasmid containing IL-12 cDNA, it showed a cytokine profile associated with Th1 with expression of IL-2, IL-12, and IFN-γ cytokines and reduced expression of IL-10, IL-4, and TGF-β1. Conclusions. The treatment with the IL-12 gene in the experimental HPV16-positive tumor model promoted the activation of the cellular immune response via expression of a Th1-type cytokine profile and was associated with the inhibition of tumor growth. Thus, IL-12 treatment represents a novel approach for gene therapy against cervical cancer.

Heat-shock proteins as dendritic cell-targeting vaccines--getting warmer

Heat-shock proteins (hsp) provide a natural link between innate and adaptive immune responses by combining the ideal properties of antigen carriage (chaperoning), targeting and activation of antigen-presenting cells (APC), including dendritic cells (DC). Targeting is achieved through binding of hsp to distinct cell surface receptors and is followed by antigen internalization, processing and presentation. An improved understanding of the interaction of hsp with DC has driven the development of numerous hsp-containing vaccines, designed to deliver antigens directly to DC. Studies in mice have shown that for cancers, such vaccines generate impressive immune responses and protection from tumour challenge. However, translation to human use, as for many experimental immunotherapies, has been slow partly because of the need to perform trials in patients with advanced cancers, where demonstration of efficacy is challenging. Recently, the properties of hsp have been used for development of prophylactic vaccines against infectious diseases including tuberculosis and meningitis. These hsp-based vaccines, in the form of pathogen-derived hsp-antigen complexes, or recombinant hsp combined with selected antigens in vitro, offer an innovative approach against challenging diseases where broad antigen coverage is critical.

Hsp70 chaperone-based gel composition as a novel immunotherapeutic anti-tumor tool

The recent advances in designing Hsp70-based anti-cancer vaccines and the ability of the chaperone to penetrate inside a living cell prompted us to develop a non-invasive method for the treatment of surface tumors. We designed hydrogel-containing gel-forming substances and human recombinant Hsp70 and applied them on the surface of a 7-day-old B16F10 melanoma tumor. According to the results of histochemistry, Hsp70 diffused through skin layer inside the B16 tumor, and this transport was proved by biochemical data. The application of Hsp70 gel reduced the rate of tumor growth by 64% and prolonged the life of animals by 46%. Increased survival was correlated with the enhancement of B16-specific cytotoxicity and up-regulation of gamma-interferon production. Taken together, the data confirm the anti-tumor effect of pure recombinant Hsp70 delivered intratumorally and demonstrate the relevance of a novel non-invasive technology of Hsp70-based therapy.

Deregulated systemic IL-10/IL-12 balance in advanced and poor prognosis paediatric soft tissue sarcomas

CONTEXT

The roles of interleukin 10 (IL-10) and IL-12 in regulation of cancer growth and Th1/Th2 immune responses towards cancer are unclear.

OBJECTIVE

To establish the prognostic significance of serum IL-10 and IL-12 in paediatric soft tissue sarcomas (STS).

MATERIALS AND METHODS

ELISA determinations of cytokines were performed as pre-treatment in 59 children with STS and 30 healthy controls.

RESULTS

Elevated IL-10 and decreased IL-12 serum levels correlated with advanced disease, poor response to chemotherapy and poor outcome. IL-10 ≥ 9.5 pg/ml, IL-12 ≤ 65 pg/ml and lymph nodes involvement independently predicted poor overall survival (OS) in multivariate Cox analysis.

CONCLUSION

Serum IL-10/IL-12 balance determination may facilitate to assess risk groups and prognosis in childhood STS.

Comparison of the expression of 5 heat shock proteins in benign and malignant salivary gland tumor tissues

The objective of this study was to analyze the significance and potential value of heat shock proteins (HSPs) in salivary gland tumors. We found that expression of HSP60, HSP70, HSP86 and HSP84 were all upregulated in both salivary gland benign tumors and malignant tumors, and that the expression of HSP70, HSP86 and HSP84 was more greatly overexpressed in the malignant tumors (each P<0.01). For HSP27, expression was upregulated both in malignant and benign tumors, with less expression observed in malignant tumors (P<0.01). In malignant tumors, expression of HSP27 was negatively correlated with the age of the patients, size of the tumor tissue, occurrence of neural invasion and metastasis (each P<0.05). Additionally, in malignant tumors, HSP70 and HSP86 were both positively correlated with occurrence site, neural invasion and metastasis (each P<0.05), while HSP60 was only negatively correlated with the age of the patients (P<0.05). HSP86 was also positively correlated with malignant degree (P<0.01). In malignant tumors, the proliferation index (PI), which was marked by proliferating cell nuclear antigen (PCNA; PCNA-PI) was 49.95±14.569, which was significantly higher compared with that in benign tumors (P<0.001), which was in accordance with the upregulation of HSP70, HSP86 or HSP84; however, an adverse correlation was found between HSP27 expression and PCNA (each P<0.05). In conclusion, these results suggest that HSPs are involved in the occurrence and development of salivary gland tumors. HSP70, HSP86 and HSP84 retained the higher multiplication capability of the malignant tumor cells, however, HSP27 did not. Thus, the upregulation of HSP70, HSP86 and HSP84 and the downregulation of HSP27 may all be used as biomarkers of the occurrence and development of malignant salivary gland tumors. Moreover, the extremely high expression of HSP86 and HSP84 in benign tumors indicates the malignant transformation potential.

The critical roles of endoplasmic reticulum chaperones and unfolded protein response in tumorigenesis and anticancer therapies

Cancer progression is characterized by rapidly proliferating cancer cells that are in need of increased protein synthesis. Therefore, enhanced endoplasmic reticulum (ER) activity is required to facilitate the folding, assembly and transportation of membrane and secretory proteins. These functions are carried out by ER chaperones. It is now becoming clear that the ER chaperones have critical functions outside of simply facilitating protein folding. For example, cancer progression requires glucose regulated protein (GRP) 78 for cancer cell survival and proliferation, as well as angiogenesis in the microenvironment. GRP78 can translocate to the cell surface acting as a receptor regulating oncogenic signaling and cell viability. Calreticulin, another ER chaperone, can translocate to the cell surface of apoptotic cancer cells and induce immunogenic cancer cell death and antitumor responses in vivo. Tumor-secreted GRP94 has been shown to elicit antitumor immune responses when used as antitumor vaccines. Protein disulfide isomerase is another ER chaperone that demonstrates pro-oncogenic and pro-survival functions. Because of intrinsic alterations of cellular metabolism and extrinsic factors in the tumor microenvironment, cancer cells are under ER stress, and they respond to this stress by activating the unfolded protein response (UPR). Depending on the severity and duration of ER stress, the signaling branches of the UPR can activate adaptive and pro-survival signals, or induce apoptotic cell death. The protein kinase RNA-like ER kinase signaling branch of the UPR has a dual role in cancer proliferation and survival, and is also required for ER stress-induced autophagy. The activation of the inositol-requiring kinase 1α branch promotes tumorigenesis, cancer cell survival and regulates tumor invasion. In summary, perturbance of ER homeostasis has critical roles in tumorigenesis, and therapeutic modulation of ER chaperones and/or UPR components presents potential antitumor treatments.

A CpG oligodeoxynucleotide potentiates the anti-tumor effect of HSP65-Her2 fusion protein against Her2 positive B16 melanoma in mice

Although being promising tumor vaccine candidates in animal models, heat shock protein (HSP)-based tumor vaccines have not yet succeeded in the clinical trials, implying the necessity to be formulated with appropriate adjutants to enhance their immunogenicity. In this study, we investigated whether a B-class CpG ODN (BW006), a TLR9 agonist, could facilitate HSP65-Her2, a recombinant protein between mycobacterial HSP65 and Her2-derived peptide, to induce vigorous anti-tumor activity against Her2 positive tumors in mice both prophylactically and therapeutically. It was found that BW006 could enhance prophylactic and therapeutic effect of HSP65-Her2 with improved survival of the mice bearing Her2(+) B16 melanoma and HSP65-Her2 specific Th1 response.

Sarcomas and the immune system: implications for therapeutic strategies

Soft-tissue sarcomas are a heterogeneous group of tumors that are capable of generating host immune responses. Historically the role of antitumor immunity was first studied in soft-tissue sarcomas. Subsequent in vitro studies, preclinical models, and clinical observations have provided ample evidence for an immunologic approach to sarcoma treatment. Initial clinical trials involving vaccines and adoptive immunotherapy have demonstrated promising results. The continued search for sarcoma tumor-associated antigens as specific targets is central to the clinical translation of effective immunotherapies.