HSP70-based anti-cancer immunotherapy

Sensitive detection of HSP70 using a current-amplified biosensor based on antibody-loaded PS-AuNPs@Cys/Au modified ITO chip

A biosensing electrochemical platform for heat shock protein 70 (HSP70) has been developed by integrating a three-electrode indium tin oxide (ITO) on a chip. The platform includes modifications to the reference electrode and working electrode for the detection of HSP70. The new platform is constructed by assembly of HSP70 antibody on PS-AuNPs@Cys/Au indium tin oxide (ITO) electrode to create a high HSP70 sensitive surface. The PS-AuNPs@Cys/Au indium tin oxide (ITO) electrode is obtained by immersing the ITO electrode into the PS-AuNPs@Cys solution and performing constant potential deposition at -1.4 V (Ag/AgCl). The PS-AuNPs@Cys/Au film deposited on ITO glass provides a desirable substrate for the immobilization of the HSP70 antibody and improves the loading of antibody between PS-AuNPs@Cys/Au and the electrode resulting in a significant amplification. Under optimal conditions, the fabricated sensor demonstrates a linear range extending from 0.1 ng mL- 1 to 1000 ng mL- 1, with an impressive detection limit of 25.7 pg mL- 1 (S/N = 3). The developed immunoassay method successfully detected the HSP70 content in normal human blood samples and outperformed the ELISA method commonly used for clinical sample analysis.

Heat Shock Proteins, a Double-Edged Sword: Significance in Cancer Progression, Chemotherapy Resistance and Novel Therapeutic Perspectives

Heat shock proteins (Hsps) are involved in one of the adaptive mechanisms protecting cells against environmental and metabolic stress. Moreover, the large role of these proteins in the carcinogenesis process, as well as in chemoresistance, was noticed. This review aims to draw attention to the possibilities of using Hsps in developing new cancer therapy methods, as well as to indicate directions for future research on this topic. In order to discuss this matter, a thorough review of the latest scientific literature was carried out, taking into account the importance of selected proteins from the Hsp family, including Hsp27, Hsp40, Hsp60, Hsp70, Hsp90 and Hsp110. One of the more characteristic features of all Hsps is that they play a multifaceted role in cancer progression, which makes them an obvious target for modern anticancer therapy. Some researchers emphasize the importance of directly inhibiting the action of these proteins. In turn, others point to their possible use in the design of cancer vaccines, which would work by inducing an immune response in various types of cancer. Due to these possibilities, it is believed that the use of Hsps may contribute to the progress of oncoimmunology, and thus help in the development of modern anticancer therapies, which would be characterized by higher effectiveness and lower toxicity to the patients.

Recent advances in cancer cell bionic nanoparticles for tumour therapy

Nanoparticle-based drug delivery systems have found extensive use in delivering oncology therapeutics; however, some delivery vehicles still exhibit rapid immune clearance, lack of biocompatibility and insufficient targeting. In recent years, bionanoparticles constructed from tumour cell membranes have gained momentum as tumour-targeting therapeutic agents. Cancer cell membrane-coated nanoparticles (CCMCNPs) typically consist of a drug-loaded nanoparticle core coated with cancer cell membrane. CCMCNPs retain homologous tumour cell surface antigens, receptors and proteins, and it has been shown that the modified nanoparticles exhibit better homologous targeting, immune escape and biocompatibility. CCMCNPs are now widely used in a variety of cancer treatments, including photothermal, photodynamic and sonodynamic therapies, chemotherapy, immunotherapy, chemodynamical therapy or other combination therapies. This article presents different therapeutic approaches using multimodal antitumour therapy-combination of two or more therapies that treat tumours synergistically-based on tumour cell membrane systems. The advantages of CCMCNPs in different cancer treatments in recent years are summarised, thus, providing new strategies for cancer treatment research.

Tumor-repopulating cell-derived microparticles elicit cascade amplification of chemotherapy-induced antitumor immunity to boost anti-PD-1 therapy

Immune checkpoint blockade (ICB) therapy, particularly antibodies targeting the programmed death receptor 1 (PD-1) and its ligand (PD-L1), has revolutionized cancer treatment. However, its efficacy as a standalone therapy remains limited. Although ICB therapy in combination with chemotherapy shows promising therapeutic responses, the challenge lies in amplifying chemotherapy-induced antitumor immunity effectively. This relies on efficient drug delivery to tumor cells and robust antigen presentation by dendritic cells (DCs). Here, we developed tumor-repopulating cell (TRC)-derived microparticles with exceptional tumor targeting to deliver doxorubicin (DOX@3D-MPs) for improve anti-PD-1 therapy. DOX@3D-MPs effectively elicit immunogenic tumor cell death to release sufficient tumor antigens. Heat shock protein 70 (HSP70) overexpressed in DOX@3D-MPs contributes to capturing tumor antigens, promoting their phagocytosis by DCs, and facilitating DCs maturation, leading to the activation of CD8+ T cells. DOX@3D-MPs significantly enhance the curative response of anti-PD-1 treatment in large subcutaneous H22 hepatoma, orthotopic 4T1 breast tumor and Panc02 pancreatic tumor models. These results demonstrate that DOX@3D-MPs hold promise as agents to improve the response rate to ICB therapy and generate long-lasting immune memory to prevent tumor relapse.

Heat shock proteins: Biological functions, pathological roles, and therapeutic opportunities

The heat shock proteins (HSPs) are ubiquitous and conserved protein families in both prokaryotic and eukaryotic organisms, and they maintain cellular proteostasis and protect cells from stresses. HSP protein families are classified based on their molecular weights, mainly including large HSPs, HSP90, HSP70, HSP60, HSP40, and small HSPs. They function as molecular chaperons in cells and work as an integrated network, participating in the folding of newly synthesized polypeptides, refolding metastable proteins, protein complex assembly, dissociating protein aggregate dissociation, and the degradation of misfolded proteins. In addition to their chaperone functions, they also play important roles in cell signaling transduction, cell cycle, and apoptosis regulation. Therefore, malfunction of HSPs is related with many diseases, including cancers, neurodegeneration, and other diseases. In this review, we describe the current understandings about the molecular mechanisms of the major HSP families including HSP90/HSP70/HSP60/HSP110 and small HSPs, how the HSPs keep the protein proteostasis and response to stresses, and we also discuss their roles in diseases and the recent exploration of HSP related therapy and diagnosis to modulate diseases. These research advances offer new prospects of HSPs as potential targets for therapeutic intervention.

Dendritic cell-based vaccine: the state-of-the-art vaccine platform for COVID-19 management

INTRODUCTION

A correlation between new coronaviruses and host immunity, as well as the role of defective immune function in host response, would be extremely helpful in understanding coronavirus disease (COVID-19) pathogenicity, and a coherent structure of treatments and vaccines. As existing vaccines may be inadequate for new viral variants emerging in various regions of the world, it is a vital requirement for fresh and effective therapeutic alternatives.

AREA COVERED

Immunotherapy may give a viable protective option for COVID-19, a disease that is currently a big burden on global health and economic systems. Herein, we have outlined three dendritic cell (DC)-based vaccines for COVID-19 which are in human clinical trials and have shown encouraging outcomes.

EXPERT OPINION

With existing knowledge of the virus, and the nature of DC, DC-based vaccines may be proven to be effective in inducing long-lasting protective immunity, especially T cell responses.

The underlying molecular mechanism of intratumoral radiofrequency hyperthermia-enhanced chemotherapy of pancreatic cancer

Background

To investigate the underlying molecular mechanisms of radiofrequency hyperthermia (RFH)-enhanced direct chemotherapy of pancreatic cancers.

Method

Rat ductal PaCa cell line DSL-6A/C1 and orthotopic pancreatic cancers of Lewis rats were divided into four study groups with various treatments: i) phosphate-buffered saline (PBS) as a control; ii) RFH alone; iii) intratumoral chemotherapy alone (gemcitabine); and (iv) combination therapy of gemcitabine plus intratumoral RFH at 42 ​°C for 30 ​min. In the in-vitro confirmation experiments, the viability and apoptosis of DSL-6A/C1 cells in each treatment group were evaluated using cell live/dead staining, flow cytometry, and Western blot. In the in vivo validation experiments, related proteins were evaluated by immunohistochemistry (IHC) staining of tumors.

Results

Of the in-vitro experiments, the lowest cell viability and more apoptotic cells were shown in the group with combination therapy compared to other treatments. Western blot data showed elevated Bax/Bcl-2, Caspase-3, and HSP70 expressions in DSL cells with combination therapy, compared to other treatments. Of the in vivo experiments, IHC staining detected the significantly increased expressions of HSP70, IL-1β, TNF-ɑ, Bax, and Caspase-3 in pancreatic cancer tissues of the animal group treated by combination therapy of gemcitabine with RFH.

Conclusion

Molecular imaging-guided interventional RFH can significantly enhance the chemotherapeutic effect on pancreatic cancers via potential molecular mechanisms of up-regulating Bax/caspase-3-dependent apoptosis pathways.

Advanced bioactive nanomaterials for biomedical applications

Bioactive materials are a kind of materials with unique bioactivities, which can change the cellular behaviors and elicit biological responses from living tissues. Bioactive materials came into the spotlight in the late 1960s when the researchers found that the materials such as bioglass could react with surrounding bone tissue for bone regeneration. In the following decades, advances in nanotechnology brought the new development opportunities to bioactive nanomaterials. Bioactive nanomaterials are not a simple miniaturization of macroscopic materials. They exhibit unique bioactivities due to their nanoscale size effect, high specific surface area, and precise nanostructure, which can significantly influence the interactions with biological systems. Nowadays, bioactive nanomaterials have represented an important and exciting area of research. Current and future applications ensure that bioactive nanomaterials have a high academic and clinical importance. This review summaries the recent advances in the field of bioactive nanomaterials, and evaluate the influence factors of bioactivities. Then, a range of bioactive nanomaterials and their potential biomedical applications are discussed. Furthermore, the limitations, challenges, and future opportunities of bioactive nanomaterials are also discussed.

Natural killer cell‑based immunotherapy for lung cancer: Challenges and perspectives (Review)

Despite the marked success of molecular targeted therapy in lung cancer in this era of personalized medicine, its efficacy has been limited by the presence of resistance mechanisms. The prognosis of patients with lung cancer remains poor, and there is an unmet need to develop more effective therapies to improve clinical outcomes. The increasing insight into the human immune system has led to breakthroughs in immunotherapy and has prompted research interest in employing immunotherapy to treat lung cancer. Natural killer (NK) cells, which serve as the first line of defense against tumors, can induce the innate and adaptive immune responses. Therefore, the use of NK cells for the development of novel lung-cancer immunotherapy strategies is promising. A growing number of novel approaches that boost NK cell antitumor immunity and expand NK cell populations ex vivo now provide a platform for the development of antitumor immunotherapy. The present review outlined the biology of NK cells, summarized the role of NK cells in lung cancer and the effect of the tumor microenvironment on NK cells, highlighted the potential of NK cell-based immunotherapy as an effective therapeutic strategy for lung cancer and discussed future directions.

Damage-associated molecular patterns in tumor radiotherapy

Radiotherapy is one of the most common modalities for the treatment of cancer. One of the most promising effects of radiotherapy is immunologic cell death and the release of danger alarms, which are known as damage-associated molecular patterns (DAMPs). DAMPs are able to trigger cancer cells and other cells within tumor microenvironment (TME), either for suppression or promotion of tumor growth. Heat shock proteins (HSPs) including HSP70 and HSP90, high mobility group box 1 (HMGB1), and adenosine triphosphate (ATP) and its metabolites such as adenosine are the most common danger alarms that are released after radiotherapy-induced immunologic cell death. Some DAMPs including adenosine is able to interact with both cancer cells as well as other cells in TME to promote tumor growth and resistance to radiotherapy. However, others are able to trigger anti-tumor immunity or both tumor suppressive and immunosuppressive mechanisms depending on affected cells. In this review, we explain the mechanisms behind the release of radiation-induced DAMPs, and its consequences on cells within tumor. Targeting of these mechanisms may be in favor of tumor control in combination with radiotherapy and radioimmunotherapy.

Mimetic Heat Shock Protein Mediated Immune Process to Enhance Cancer Immunotherapy

Inspired by heat shock proteins (HSPs), a self-assembly nanochaperone (nChap) is developed as a novel nanovaccine for boosting antitumor immune responses. Taking advantage of HSP-like microdomains and surface-decorated mannose, this nChap can efficiently capture antigens and ferry them into the dendritic cells (DCs). Subsequently, the nChap can blast lysosomes by transforming the structure and property of surface microdomains, thereby promoting antigen escape and enhancing their cross-presentation in cytoplasm. As a result, the nChap-based nanovaccine can elicit both CD4+ and CD8+ T cell-based immune responses and shows an excellent preventive effect on melanoma. Further combination of the nanovaccine with antiprogrammed death-1 (anti-PD-1) checkpoint blockade offers effective inhibition on the growth of already-established melanoma. Therefore, this nC ap-based nanovaccine provides a simple and robust strategy in mimicking HSPs to realize structure-assisted antigen capture, surface-receptor-mediated DC internalization, and both activation of humoral immunity and cellular immunity, promising for efficient cancer immunotherapy.

HSP70/IL-2 Treated NK Cells Effectively Cross the Blood Brain Barrier and Target Tumor Cells in a Rat Model of Induced Glioblastoma Multiforme (GBM)

Natural killer (NK) cell therapy is one of the most promising treatments for Glioblastoma Multiforme (GBM). However, this emerging technology is limited by the availability of sufficient numbers of fully functional cells. Here, we investigated the efficacy of NK cells that were expanded and treated by interleukin-2 (IL-2) and heat shock protein 70 (HSP70), both in vitro and in vivo. Proliferation and cytotoxicity assays were used to assess the functionality of NK cells in vitro, after which treated and naïve NK cells were administrated intracranially and systemically to compare the potential antitumor activities in our in vivo rat GBM models. In vitro assays provided strong evidence of NK cell efficacy against C6 tumor cells. In vivo tracking of NK cells showed efficient homing around and within the tumor site. Furthermore, significant amelioration of the tumor in rats treated with HSP70/Il-2-treated NK cells as compared to those subjected to nontreated NK cells, as confirmed by MRI, proved the efficacy of adoptive NK cell therapy. Moreover, results obtained with systemic injection confirmed migration of activated NK cells over the blood brain barrier and subsequent targeting of GBM tumor cells. Our data suggest that administration of HSP70/Il-2-treated NK cells may be a promising therapeutic approach to be considered in the treatment of GBM.

MTBHsp70-exFPR1-pulsed Dendritic Cells Enhance the Immune Response against Cervical Cancer

Cervical cancer is the most common malignancy of the female reproductive system. Dendritic cell (DC)-based immunological therapy is a novel treatment for this cancer. DCs are specialized antigen-presenting cells (APCs) in the human immune system, and they can activate the T cells used in tumor immunological therapy. In this study, we developed a novel immunotherapeutic peptide by linking the Mycobacterium tuberculosis (MTB) heat shock protein 70 (Hsp70) functional peptide to the extracellular domain of FPR1, a protein overexpressed in cervical cancer, to obtain an MTBHsp70-exFPR1 fusion protein. Our experiments confirmed that the MTBHsp70-exFPR1 protein could promote DC maturation and induce the secretion of IL-12p70, IL-1β, and TNF-α. The antitumor effect of human cytotoxic T lymphocytes (CTLs) activated by autologous DCs was assessed in NOG mice. These results indicate that DCs pulsed with MTBHsp70-exFPR1 can enhance antitumor immunity against cervical cancer, providing a novel immune therapeutic strategy.

Epithelial ovarian cancer: feasibility of image-guided intratumoral radiofrequency hyperthermia-enhanced direct gene therapy

The aim of this study was to develop an interventional oncologic technique, "Image-guided intratumoral radiofrequency hyperthermia (RFH)-enhanced herpes simplex virus-thymidine kinase (HSV-TK) gene therapy of ovarian cancer. This study consisted of three portions: (1) serial in-vitro experiments to establish "proof-of-principle" of this novel technique using human ovarian cancer cells; (2) serial in-vivo experiments to validate technical feasibility using animal models with the same orthotopic ovarian cancers; and (3) serial investigations into the underlying bio-molecular mechanisms of this technique. We included four subject groups: (i) combination therapy with RFH+HSV-TK gene therapy; (ii) gene therapy-only; (iii) RFH-only; and (iv) Phosphate-buffered saline (PBS). For in-vitro experiments, confocal microscopy and MTS assays were performed to quantify HSV-TK gene expression and assess cell viability. For in-vivo experiments, bioluminescence optical and ultrasound imaging were used to assess therapeutic effectiveness. These results were correlated with subsequent pathologic/laboratory studies to further elucidate the biologic mechanisms of this technique. In in-vitro experiments, combination therapy resulted in the lowest cell proliferation and greatest increase in HSV-TK gene expression among four subject groups. In in-vivo experiments, combination therapy lead to significant decreases of bioluminescence signals and sizes of tumors in combination therapy by optical and ultrasound imaging. Pathology/laboratory examinations confirmed the significantly increased expression of Bax, Caspase-3, HSP70, IL-2, and CD94 in cancer tissues subjected to combination therapy. "Image-guided intratumoral RFH-enhanced direct gene therapy" is an effective interventional oncologic technique which functions through apoptotic/anti-tumor immunity pathways. This technical development may open new avenues for treating ovarian cancer.

The Yin and Yang of Myeloid Derived Suppressor Cells

In recent years, most of our knowledge about myeloid derived suppressor cells (MDSCs) has come from cancer studies, which depicts Yin side of MDSCs. In cancer, inherent immunosuppressive action of MDSCs favors tumor progression by inhibiting antitumor immune response. However, recently Yang side of MDSCs has also been worked out and suggests the role in maintenance of homeostasis during non-cancer situations like pregnancy, obesity, diabetes, and autoimmune disorders. Continued work in this area has armored the biological importance of these cells as master regulators of immune system and prompted scientists all over the world to look from a different perspective. Therefore, explicating Yin and Yang arms of MDSCs is obligatory to use it as a double edged sword in a much smarter way. This review is an attempt toward presenting a synergistic coalition of all the facts and controversies that exist in understanding MDSCs, bring them on the same platform and approach their "Yin and Yang" nature in a more comprehensive and coherent manner.

An update on the discovery and development of selective heat shock protein inhibitors as anti-cancer therapy

INTRODUCTION

Over the years, not a single HSP inhibitor has progressed into the post-market phase of drug development despite the success recorded in various pre-clinical and clinical studies. The inability of existing drugs to specifically target oncogenic HSPs has majorly accounted for these setbacks. Recent combinatorial strategies that incorporated computer-aided drug design (CADD) techniques are geared towards the development of highly specific HSP inhibitors with increased activities and minimal toxicities. Areas covered: In this review, strategic therapeutic approaches that have recently aided the development of selective HSP inhibitors were highlighted. Also, the significant contributions of CADD techniques over the years were discussed in detail. This article further describes promising computational paradigms and their applications towards the discovery of highly specific inhibitors of oncogenic HSPs. Expert opinion: The recent shift towards highly selective and specific HSP inhibition has shown great promise as evidenced by the development of paralog/isoform-selective HSP drugs. It could be further augmented with computer-aided drug design strategies, which incorporate reliable methods that would greatly enhance the design and optimization of novel inhibitors with improved activities and minimal toxicities.

Topical heat shock protein 70 prevents imiquimod-induced psoriasis-like inflammation in mice

Psoriasis is a chronic inflammatory skin disease with systemic manifestations and potential genetic etiology. The newest treatments utilize antibodies against one of several cytokines known to underlie the inflammatory signaling molecules that produce the skin and systemic symptoms. However, these agents must be regularly injected, and they may compromise the normal responses of the immune system. Furthermore, they do not address the causes of the abnormal immunoregulatory responses of the disease because the etiology is not yet completely understood. In this short-term treatment study, the potential anti-inflammatory activity of an alfalfa-derived Hsp70-containing skin cream (aHsp70) was tested on imiquimod (IMQ)-induced psoriasis-like lesions in wild-type mice. Treatment of the mice with the aHsp70 skin cream simultaneously with the imiquimod application mitigated the induction of psoriatic-like lesions and correlated with altered expression of various skin cytokines.

Methods for improving the immunogenicity and efficacy of cancer vaccines

INTRODUCTION

Cancer vaccines represent one of the oldest immunotherapy strategies. A variety of tumor-associated antigens have been exploited to investigate their immunogenicity as well as multiple strategies for vaccine administration. These efforts have led to the development of several clinical trials in tumors with different histological origins to test the clinical efficacy of cancer vaccines. However, suboptimal clinical results have been reported mainly due to the lack of optimized strategies to induce strong and sustained systemic tumor antigen-specific immune responses.

AREAS COVERED

We provide an overview of different types of cancer vaccines that have been developed and used in the context of clinical studies. Moreover, we review different preclinical and clinical strategies pursued to enhance the immunogenicity, stability, and targeting at tumor site of cancer vaccines.

EXPERT OPINION

Additional and appropriate preclinical studies are warranted to optimize the immunogenicity and delivery of cancer vaccines. The appropriate choice of target antigens is challenging; however, the exploitation of neoantigens generated from somatic mutations of tumor cells represents a promising approach to target highly immunogenic tumor-specific antigens. Remarkably, the investigation of the combination of cancer vaccines with immunomodulating agents able to skew the tumor microenvironment from immunosuppressive to immunostimulating will dramatically improve their clinical efficacy.

Necroptotic cancer cells-mimicry nanovaccine boosts anti-tumor immunity with tailored immune-stimulatory modality

Recent breakthroughs in cancer immunotherapy offer new paradigm-shifting therapeutic options for combating cancer. Personalized therapeutic anti-cancer vaccines training T cells to directly fight against tumor cells endogenously offer tremendous benefits in working synergistically with immune checkpoint inhibitors. Biomimetic nanotechnology offers a versatile platform to boost anticancer immunity by efficiently co-delivering optimized immunogenic antigen materials and adjuvants to antigen presenting cells (APC). Necroptotic tumor cells can release danger associated molecule patterns (DAMPs) like heat shock proteins, being more immunogenic than naïve tumor cells. Here, nano-size "artificial necroptotic cancer cell" (αHSP70p-CM-CaP) composing of phospholipid bilayer and a phosphate calcium core was designed as a flexible vaccine platform for co-delivering cancer membrane proteins (CM), DAMPs signal-augmenting element α-helix HSP70 functional peptide (αHSP70p) and CpG to both natural killer (NK) cells and APC. Mechanically, immunogenic B16OVA tumor cells membrane-associated antigens and αHSP70p were reconstituted in artificial outer phospholipid bilayer membrane via one-step hydration and CpG encapsulated in the phosphate calcium core. The resulted αHSP70p-CM-CaP exhibited 30 nm in diameter with the immunogenic membrane proteins reserved in the particles to produce synergistic effect on bone marrow derived dendritic cells maturation and antigen-presentation. Following αHSP70p-CM-CaP vaccination, efficient lymph node trafficking and multi-epitope-T cells response was observed in mice. Vitally, αHSP70p-CM-CaP was also able to induce expansion of IFN-γ-expressing CD8⁺ T cells and NKG2D⁺ NK cells subsets. Most promisingly, αHSP70p-CM-CaP vaccination led to the killing of target cells and tumor regression in vivo when combined with anti-PD-1 antibody treatment on mice B16OVA melanoma models. Altogether, we demonstrated proof-of-concept evidence for the feasibility, capability and safety of a nanovaccine platform towards efficient personalized anticancer application.

A Novel Approach to Anticancer Therapy: Molecular Modules Based on the Barnase:Barstar Pair for Targeted Delivery of HSP70 to Tumor Cells

One important distinction between many tumor cell types and normal cells consists in the translocation of a number of intracellular proteins, in particular the 70 kDa heat shock protein (HSP70), to the surface of the plasma membrane. It has been demonstrated that such surface localization of HSP70 on tumor cells is recognized by cytotoxic effectors of the immune system, which increases their cytolytic activity. The mechanisms behind this interaction are not fully clear; however, the phenomenon of surface localization of HSP70 on cancer cells can be used to develop new approaches to antitumor immunotherapy. At the same time, it is known that the presence of HSP70 on a cell's surface is not a universal feature of cancer cells. Many types of tumor tissues do not express membrane-associated HSP70, which limits the clinical potential of these approaches. In this context, targeted delivery of exogenous HSP70 to the surface of cancer cells with the aim of attracting and activating the cytotoxic effectors of the immune system can be considered a promising means of antitumor immunotherapy. Molecular constructs containing recombinant mini-antibodies specific to tumor-associated antigens (in particular, antibodies specific to HER2/neu-antigen and other markers highly expressed on the surface of a wide range of cancer cells) can be used to target the delivery of HSP70 to tumor tissues. In order to assess the feasibility and effectiveness of this approach, recombinant constructs containing a mini-antibody specific to the HER2/ neu-antigen in the first module and HSP70 molecule or a fragment of this protein in the second module were developed in this study. Strong selective interaction between the modules was ensured by a cohesive unit formed by the barnase:barstar pair, a heterodimer characterized by an unusually high constant of association. During testing of the developed constructs in in vitro models the constructs exhibited targeted binding to tumor cells expressing the HER2/neu antigen and the agents had a significant stimulating effect on the cytotoxic activity of NK cells against the respective cancer cells.

MtHsp70-CLIC1-pulsed dendritic cells enhance the immune response against ovarian cancer

Approximately 80% of ovarian cancer (OC) is diagnosed at late stages, and most patients die within 5 years of diagnosis due to recurrence or drug resistance. Novel treatments are required to improve patient survival. Immune therapy against cancer is promising; however, therapeutic vaccination has been limited by the inability of tumor antigens to induce effective immune responses. Chloride intracellular channel 1 (CLIC1) was previously identified as a possible tumor marker for OC. In this study, we constructed a recombinant protein by conjugating the extracellular domain of CLIC1 to the carboxyl terminus of Mycobacterium tuberculosis heat shock protein 70 (MtHsp70). Human dendritic cells (DCs) derived from cortical blood were pulsed with the fusion protein, and the antitumor effect of human cytotoxic T lymphocytes (CTLs) stimulated by autologous DCs was assessed in NOG mice. MtHsp70-CLIC1 promoted the phenotypic maturation of human DCs and the secretion of Th1-associated cytokines in vitro. MtHsp70-CLIC1-stimulated CTLs generated a CLIC1-specific immune response both in vitro and in vivo. These results indicate that DCs pulsed with MtHsp70-CLIC1 can enhance antitumor immunity against OC, providing a novel immune therapeutic strategy.