Multiple-purpose immunotherapy for cancer

Inflammation Control and Immunotherapeutic Strategies in Comprehensive Cancer Treatment

Tumor growth and expansion are determined by the immunological tumor microenvironment (TME). Typically, early tumorigenic stages are characterized by the immune system not responding or weakly responding to the tumor. However, subsequent tumorigenic stages witness the tumor promoting its growth and metastasis by stimulating tumor-protective (pro-tumor) inflammation to suppress anti-tumor immune responses. Here, we propose the pivotal role of inflammation control in a successful anti-cancer immunotherapy strategy, implying that available and novel immunotherapeutic modalities such as inflammation modulation, antibody (Ab)-based immunostimulation, drug-mediated immunomodulation, cancer vaccination as well as adoptive cell immunotherapy and donor leucocyte transfusion could be applied in cancer patients in a synergistic manner to amplify each other's clinical effects and achieve robust anti-tumor immune reactivity. In addition, the anti-tumor effects of immunotherapy could be enhanced by thermal and/or oxygen therapy. Herein, combined immune-based therapy could prove to be beneficial for patients with advanced cancers, as aiming to provide long-term tumor cell/mass dormancy by restraining compensatory proliferation of surviving cancer cells observed after traditional anti-cancer interventions such as surgery, radiotherapy, and metronomic (low-dose) chemotherapy. We propose the Inflammatory Prognostic Score based on the blood levels of C-reactive protein and lactate dehydrogenase as well as the neutrophil-to-lymphocyte ratio to effectively monitor the effectiveness of comprehensive anti-cancer treatment.

The new progress in cancer immunotherapy

The cross talk between immune and non-immune cells in the tumor microenvironment leads to immunosuppression, which promotes tumor growth and survival. Immunotherapy is an advanced treatment that boosts humoral and cellular immunity rather than using chemotherapy or radiation-based strategy associated with non-specific targets and toxic effects on normal cells. Immune checkpoint inhibitors and T cell-based immunotherapy have already exhibited significant effects against solid tumors and leukemia. Tumor cells that escape immune surveillance create a major obstacle to acquiring an effective immune response in cancer patients. Tremendous progress had been made in recent years on a wide range of innate and adaptive immune checkpoints which play a significant role to prevent tumorigenesis, and might therefore be potential targets to suppress tumor cells growth. This review aimed to summarize the underlying molecular mechanisms of existing immunotherapy approaches including T cell and NK-derived immune checkpoint therapy, as well as other intrinsic and phagocytosis checkpoints. Together, these insights will pave the way for new innate and adaptive immunomodulatory targets for the development of highly effective new therapy in the future.

Immunotherapy and immunoengineering for breast cancer; a comprehensive insight into CAR-T cell therapy advancements, challenges and prospects

BACKGROUND

Breast cancer (BC) is a highly prevalent solid cancer with a high-rise infiltration of immune cells, turning it into a significant candidate for tumor-specific immunotherapies. Chimeric antigen receptor (CAR)-T cells are emerging as immunotherapeutic tools with genetically engineered receptors to efficiently recognize and attack tumor cells that express specific target antigens. Technological advancements in CAR design have provided five generations of CAR-T cells applicable to a wide range of cancer patients while boosting CAR-T cell therapy safety. However, CAR-T cell therapy is ineffective against breast cancer because of the loss of specified antigens, the immunosuppressive nature of the tumor and CAR-T cell-induced toxicities. Next-generation CAR-T cells actively pass through the tumor vascular barriers, persist for extended periods and disrupt the tumor microenvironment (TME) to block immune escape.

CONCLUSION

CAR-T cell therapy embodies advanced immunotherapy for BC, but further pre-clinical and clinical assessments are recommended to achieve maximized efficiency and safety.

Antitumor and immunoregulatory activities of a novel polysaccharide from Astragalus membranaceus on S180 tumor-bearing mice

The Astragalus membranaceus polysaccharide (APS4) with direct cytotoxicity on various cancer cells has been prepared in our previous study, while the underlying therapeutic role of APS4 on solid tumors in vivo hasn't been investigated yet. Therefore, in this paper, the lymphocytes-mediated antitumor and immunoregulatory activities of APS4 were researched by establishing S180 tumor-bearing mice model. Flow cytometry analysis revealed that APS4 could effectively regulate the percentages of CD3⁺, CD4⁺, CD8⁺ T cells and CD19⁺ B cells in thymus, peripheral blood and spleen of S180 tumor-bearing mice, dose-dependently. H&E staining and cell cycle determination of solid tumors manifested that APS4 treatment could significantly inhibit the growth of solid tumors by inducing cells apoptosis. Furthermore, two-dimensional electrophoresis and western blot analysis further demonstrated that APS4 could activate antitumor-related immune cells and promote anaerobic metabolism of tumor microenvironment, thereby causing the apoptosis of S180 tumor cells. These data implicated that APS4 could be used as a potential dietary supplement for immune enhancement.

Clinically feasible and prospective immunotherapeutic interventions in multidirectional comprehensive treatment of cancer

INTRODUCTION

The immune system is able to exert both tumor-destructive and tumor-protective functions. Immunotherapeutic technologies aim to enhance immune-based anti-tumor activity and (or) weaken tumor-protective immunity.

AREAS COVERED

Cancer vaccination, antibody (Ab)-mediated cytotoxicity, Ab-based checkpoint molecule inhibition, Ab-based immunostimulation, cytokine therapy, oncoviral therapy, drug-mediated immunostimulation, exovesicular therapy, anti-inflammatory therapy, neurohormonal immunorehabilitation, metabolic therapy, as well as adoptive cell immunotherapy, could be coherently used to synergize and amplify each other in achieving robust anti-cancer responses in cancer patients. Tumor-specific immunotherapy applied at early stages is capable of eliminating remaining tumor cells after surgery, thus preventing the development of minimal residual disease. Patients with advanced disease stages could benefit from combined immunotherapy, which would be aimed at providing tumor cell/mass dormancy. Traditional therapeutic anti-cancer interventions (chemoradiotherapy, hyperthermia, anti-hormonal therapy) could significantly enhance tumor sensitivity to anti-cancer immunotherapy. It is important that lower-dose (metronomic) chemotherapy regimens, which are well-tolerated by normal cells, could advance immune-mediated control over tumor growth.

EXPERT OPINION

We envisage that combined immunotherapy regimens in the context of traditional treatment could become the mainstream modality for treating cancers in all phases of the tumorigenesis. The effectiveness of the anti-cancer treatment could be monitored by the following blood parameters: C-reactive protein, lactate dehydrogenase, and neutrophil-to-lymphocyte ratio.

Antibody-Based Immunotherapeutic Strategies for the Treatment of Hematological Malignancies

As the most common type of cancer in the world, hematological malignancies (HM) account for 10% of all annual cancer deaths and have attracted more attention. Conventional treatments, such as chemotherapy, radiotherapy, and hematopoietic stem cell transplantation (HSCT), could relieve patients suffering HM. However, serious side effects and high costs bring patients both physical complaints and mental pressure. Recently, compared with conventional therapeutic strategies for HM patients, antibody-based immunotherapies, including cancer vaccines, oncolytic virus therapies, monoclonal antibody treatments, and CAR-T cell therapies, have displayed longer survival time and fewer adverse reactions, even though specific efficacy and safety of these antibody-based immunotherapies still need to be evaluated and improved. This review summarized the advantages of antibody-based immunotherapies over conventional treatments, as well as its existing difficulties and solutions, thereby enhancing the understanding and applications of antibody-based immunotherapies in HM treatment.

Attaining threshold antibody cytotoxicity for selective tumor cell destruction: an opinion article

We propose a novel immunotherapeutic paradigm that justifies application of several antibodies to various membrane-associated antigens to achieve a critical threshold density of immune complexes on the surface of cancer cells sufficient for triggering downstream cytolytic pathways. Indeed, some cancer-associated antigens (such as cancer/testis antigens) were found to be expressed on many cancer (but not normal) cells, with their baseline membrane expression levels being originally quite low for some of them, or even further down-regulated due to immune-driven cell selection. To achieve the mandatory threshold density of membrane-associated immune complexes on malignant cells, the concept stipulates combined application of antibodies specific for a cancer-associated antigen along with antibodies against an antigen expressed not only on tumor, but also on normal cells. In the proposed scenario it is of vital importance that the latter antibodies should be applied in suboptimal dosage to exclude the destruction of normal cells devoid of a cancer-associated antigen. Malignant cells often co-express antigens not present concurrently on normal cells at high levels. In such cases, suboptimal dosages of antibodies specific for those antigens could also be applied to achieve cumulative effect leading to selective destruction of tumour cells. Hence, the described immunotherapeutic technology could be used metaphorically speaking as a kind of ‘immunological knife’, which is capable of highly selective destruction of cancer cells without destroying normal cells.

Monoclonal antibodies in cancer immunotherapy

Nowadays, in cancer treatments, immunotherapy which can be classified as a cancer type specific therapy is more popular than non-specific therapy methods such as surgery, radiotherapy and chemotherapy. The main aim of immunotherapy is to enable patients' immune system to target cancer cells and destroy them. The mainly used treatment methods in cancer immunotherapy are cancer vaccines, adoptive cell therapy, cytokines and monoclonal antibodies. In this review, we discuss the immunotherapy approaches, especially monoclonal antibodies which are mostly used in cancer immunotherapy in clinical applications.

Human DKK1 and human HSP70 fusion DNA vaccine induces an effective anti-tumor efficacy in murine multiple myeloma

Dickkopf-1 (DKK1) is an ideal target for the immunotherapy of multiple myeloma. Heat Shock protein70 (HSP70) is a class of important molecular chaperone to promote antigen presentation. Homologous xenogeneic antigens can enhance immunogenicity and induce stronger anti-tumor immune response than that of allogeneic ones. Therefore, we constructed human DKK1 and human HSP70 DNA fusion vaccine (hDKK1-hHSP70), and then determined its anti-tumor immuno- genicity and anti-tumor effects on immunizing BALB/c mice already inoculated with NS-1 murine multiple myeloma cells in prophylactic and therapeutic models using cytotoxic T lymphocytes, enzyme-lined immunosorbent assay, flow cytometry, immunohistochemistry and Hochest staining. The side effects of vaccines were also monitored. We found that hDKK1-hHSP70 fusion vaccine could significantly inhibit tumor growth and prolonged the survival of the mice, whether prophylactic or therapeutic immunotherapy in vivo, by eliciting both humoral and cellular tumor-specific immune responses. A significant decrease of proliferation and increase of apoptosis were also observed in the tumor tissues injected with hDKK1-hHSP70 vaccine. These findings showed the xenogeneic homologous vaccination had stronger immunogenicity and minimal toxicity. Our study may provide an effective and safety immonutheraphy strategy for multiple myeloma.

STAT3-blocked whole-cell hepatoma vaccine induces cellular and humoral immune response against HCC

Background

Whole-cell tumor vaccines have shown much promise; however, only limited success has been achieved for the goal of eliciting robust tumor-specific T-cell responses.

Methods

Hepatocellular carcinoma (HCC) cells, H22 and Hepa1–6, were modified by blocking the STAT3 signaling pathway with a STAT3 decoy oligodeoxynucleotide, and the immunogenicity and possibility of using these cell lysates as a vaccine were evaluated.

Results

STAT3-blocked whole HCC cell lysates inhibited tumor growth and tumorigenesis, and prolonged the survival of tumor-bearing mice. In addition, STAT3-blocked whole HCC cell lysates stimulated the activation of T cells and natural killer (NK) cells, and enhanced the infiltration of cytotoxic CD8⁺ T cells in the tumor tissues. In addition, the maturation of dendritic cells (DCs) was enhanced, which promoted the generation of immunological memory against HCC. Furthermore, secondary immune responses could be primed as soon as these immunized mice were challenged with HCC cells, accompanied by T cell and NK cell activation and infiltration. Additionally, immunization with this vaccine decreased the generation of Tregs and the production of TGF-β and IL-10. Importantly, STAT3-blocked whole HCC cell lysates prevented HCC-mediated exhaustion of T cells and NK cells, showing low expression of checkpoint molecules such as PD-1 and TIGIT on T cells and NK cells in the immunized mice.

Conclusions

The newly generated STAT3-blocked whole-cell HCC vaccine has potential for cancer cell vaccination.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0623-0) contains supplementary material, which is available to authorized users.

Immunotherapy against metastatic bladder cancer by combined administration of granulocyte macrophage-colony stimulating factor and interleukin-2 surface modified MB49 bladder cancer stem cells vaccine

In previous studies, it has been shown that the granulocyte macrophage‐colony stimulating factor (GM‐CSF) or interleukin‐2 (IL‐2) surface modified MB49 bladder cancer stem cells (MCSCs) vaccine could induce a specific antitumor immunity and against bladder cancer in mice model respectively. However, whether combined administration of GM‐CSF and IL‐2 could produce specific immune responses to cancer stem cells (CSCs) was uncertain. MCSCs were established and characterized. GM‐CSF and IL‐2 MCSCs vaccines were prepared and bioactivity was evaluated. The therapeutic, protective, specific, and memorial immune response animal experiments were designed. Tumor‐specific cytotoxic T lymphocytes assay, enzyme linked immunosorbent assay, flow cytometry assay were performed to indentify whether vaccine caused an antitumor immunity. Streptavidin (SA)‐GM‐CSF and SA‐IL‐2 MCSCs vaccines were prepared successfully. Such vaccines inhibited the volume of tumor and prolonged the survival of the mice in animal experiments. The express of IgG or IFN‐c, the portion of dendritic cells, CD8⁺ and CD4⁺ T cells were highest in the combined vaccines group than the SA‐GM‐CSF vaccine group, the SA‐IL‐2 vaccine group, the MCSCs group and the PBS group. The combined of GM‐CSF and IL‐2 vaccines could induce better antitumor immunity than a vaccine alone.