Immune Cells in Cancer Therapy and Drug Delivery

Bioinspired microrobots: Opportunities and challenges in targeted cancer therapy

Chemotherapy is still the most effective technique to treat many forms of cancer. However, it also carries a high risk of side effects. Numerous nanomedicines have been developed to avoid unintended consequences and significant negative effects of conventional therapies. Achieving targeted drug delivery also has several challenges. In this context, the development of microrobots is receiving considerable attention of formulation scientists and clinicians to overcome such challenges. Due to their mobility, microrobots can infiltrate tissues and reach tumor sites more quickly. Different types of microrobots, like custom-made moving bacteria, microengines powered by small bubbles, and hybrid spermbots, can be designed with complex features that are best for precise targeting of a wide range of cancers. In this review, we mainly focus on the idea of how microrobots can quickly target cancer cells and discuss specific advantages of microrobots. A brief summary of the microrobots' drug loading and release behavior is provided in this manuscript. This manuscript will assist clinicians and other medical professionals in diagnosing and treating cancer without surgery.

Association of Angiogenesis Gene Expression With Cancer Prognosis and Immunotherapy Efficacy

Background: Several new blood vessels are formed during the process of tumor development. These new blood vessels provide nutrients and water for tumour growth, while spreading tumour cells to distant areas and forming new metastases in different parts of the body. The available evidence suggests that tumour angiogenesis is closely associated with the tumour microenvironment and is regulated by a variety of pro-angiogenic factors and/or angiogenic inhibitors.

Methods: In the present study, a comprehensive characterization of angiogenesis genes expression was performed in a pan-cancer analysis across the 33 human cancer types. Further, genetic data from several public databases were also used in the current study. An angiogenesis score was assigned to The Cancer Genome Atlas (TCGA) pan-cancer data, with one angiogenesis score as per sample for each tumour.

Results: It was found that angiogenesis genes vary across cancer types, and are associated with a number of genomic and immunological features. Further, it was noted that macrophages and iTreg infiltration were generally higher in tumours with high angiogenesis scores, whereas lymphocytes and B cells showed the opposite trend. Notably, NK cells showed significantly different correlations among cancer types. Furthermore, results of the present study showed that a high angiogenesis score was associated with poor survival and aggressive types of cancer in most of the cancer types.

Conclusion: In conclusion, the current study evidently showed that the expression of angiogenesis genes is a key feature of tumour biology that has a major impact on prognosis of patient with cancers.

Global dynamics of SARS-CoV-2/cancer model with immune responses

The world is going through a critical period due to a new respiratory disease called coronavirus disease 2019 (COVID-19). This disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Mathematical modeling is one of the most important tools that can speed up finding a drug or vaccine for COVID-19. COVID-19 can lead to death especially for patients having chronic diseases such as cancer, AIDS, etc. We construct a new within-host SARS-CoV-2/cancer model. The model describes the interactions between six compartments: nutrient, healthy epithelial cells, cancer cells, SARS-CoV-2 virus particles, cancer-specific CTLs, and SARS-CoV-2-specific antibodies. We verify the nonnegativity and boundedness of its solutions. We outline all possible equilibrium points of the proposed model. We prove the global stability of equilibria by constructing proper Lyapunov functions. We do some numerical simulations to visualize the obtained results. According to our model, lymphopenia in COVID-19 cancer patients may worsen the outcomes of the infection and lead to death. Understanding dysfunctions in immune responses during COVID-19 infection in cancer patients could have implications for the development of treatments for this high-risk group.

Tumor Associated Macrophages and TAMs-Based Anti-Tumor Nanomedicines

As an important part of tumor microenvironment, tumor associated macrophages (TAMs) play a vital role in the occurrence, development, invasion, and metastasis of many malignant tumors and can significantly promote the formation of tumor blood vessels and lymphatic vessels, hence TAMs are greatly associated with poor prognosis. The research on nanomedicine has achieved huge progress, and nano-drugs have been widely utilized to treat various diseases through different mechanisms. Therefore, developing nano-drugs that are based on TAMs-associated anti-tumor mechanisms to effectively suppress tumor growth is expected to be a promising research filed. This paper introduces relevant information about TAMs in terms of their origin, and their roles in tumor genesis, development and metastasis. Furthermore, TAMs-related anti-tumor nano-drugs are summarized. Specifically, a wide range of nano-drugs targeting at TAMs are introduced, and categorized according to their therapeutic mechanisms toward tumors. Additionally, various nano delivery platforms using TAMs as cell carriers which aim at inhibiting tumor growth are reviewed. These two parts elucidate that the exploration of nanomedicine is essential to the study on TAMs-related anti-tumor strategies. This review is also intended to provide novel ideas for in-depth investigation on anti-tumor molecular mechanisms and nano-drug delivery systems based on TAMs.

Construction of cancer-on-a-chip for drug screening

Cancer-on-a-chip has effectively contributed to the development of drug screening, holding great promise for more convenient and reliable drug development as well as personalized drug administration.

Migration of Cytotoxic T Lymphocytes in 3D Collagen Matrices

CD8+ cytotoxic T lymphocytes (CTL) and natural killer cells are the main cytotoxic killer cells of the human body to eliminate pathogen-infected or tumorigenic cells (also known as target cells). To find their targets, they have to navigate and migrate through complex biological microenvironments, a key component of which is the extracellular matrix (ECM). The mechanisms underlying killer cell's navigation are not well understood. To mimic an ECM, we use a matrix formed by different collagen concentrations and analyze migration trajectories of primary human CTLs. Different migration patterns are observed and can be grouped into three motility types: slow, fast, and mixed. The dynamics are well described by a two-state persistent random walk model, which allows cells to switch between slow motion with low persistence and fast motion with high persistence. We hypothesize that the slow motility mode describes CTLs creating channels through the collagen matrix by deforming and tearing apart collagen fibers and that the fast motility mode describes CTLs moving within these channels. Experimental evidence supporting this scenario is presented by visualizing migrating T cells following each other on exactly the same track and showing cells moving quickly in channel-like cavities within the surrounding collagen matrix. Consequently, the efficiency of the stochastic search process of CTLs in the ECM should strongly be influenced by a dynamically changing channel network produced by the killer cells themselves.

Engineering microrobots for targeted cancer therapies from a medical perspective

Systemic chemotherapy remains the backbone of many cancer treatments. Due to its untargeted nature and the severe side effects it can cause, numerous nanomedicine approaches have been developed to overcome these issues. However, targeted delivery of therapeutics remains challenging. Engineering microrobots is increasingly receiving attention in this regard. Their functionalities, particularly their motility, allow microrobots to penetrate tissues and reach cancers more efficiently. Here, we highlight how different microrobots, ranging from tailor-made motile bacteria and tiny bubble-propelled microengines to hybrid spermbots, can be engineered to integrate sophisticated features optimised for precision-targeting of a wide range of cancers. Towards this, we highlight the importance of integrating clinicians, the public and cancer patients early on in the development of these novel technologies.

Immune cells as tumor drug delivery vehicles

This review article describes the use of immune cells as potential candidates to deliver anti-cancer drugs deep within the tumor microenvironment. First, the rationale of using drug carriers to target tumors and potentially decrease drug-related side effects is discussed. We further explain some of the current limitations when using nanoparticles for this purpose. Next, a comprehensive step-by-step description of the migration cascade of immune cells is provided as well as arguments on why immune cells can be used to address some of the limitations associated with nanoparticle-mediated drug delivery. We then describe the benefits and drawbacks of using red blood cells, platelets, granulocytes, monocytes, macrophages, myeloid-derived suppressor cells, T cells and NK cells for tumor-targeted drug delivery. An additional section discusses the versatility of nanoparticles to load anti-cancer drugs into immune cells. Lastly, we propose increasing the circulatory half-life and development of conditional release strategies as the two main future pillars to improve the efficacy of immune cell-mediated drug delivery to tumors.

Murine hepatoma treatment with mature dendritic cells stimulated by Trichinella spiralis excretory/secretory products

Excretory/Secretory Products (ESPs) of the nematode Trichinella spiralis contain antitumor-active substances that inhibit tumor growth. Mature dendritic cells (DCs) play a critical role in the antitumor immunity of the organism. As pathogen-derived products, it ought to be discussed whether T. spiralis ESPs will reduce the antitumor effect of mature DCs from the host before it is applied to patients' tumors. Therefore, the aim of this work was to evaluate the immunological effect of DCs stimulated by T. spiralis ESPs in H22 tumor-bearing mice. H22 tumor model mice in this study were randomly divided into four groups according to the treatment: PBS control group, ESP group, DCs group, and DCs stimulated with T. spiralis ESP (ESP+DCs group). The antitumor effect was evaluated by tumor inhibition rate and cytokine detection using ELISA. The results showed significant inhibition in tumor growth in the ESP+DCs, DCs and ESP groups when compared with the PBS control group (p < 0.01, p < 0.01, and p < 0.05, respectively). However, no significant difference was observed on tumor inhibition rates between the ESP+DCs and DCs groups. The decrease in IL-4, IL-6, and IL-10, and the increase in IFN-γ between the DCs and ESP+DCs groups were also not significant. Therefore, DCs stimulated by ESP did not reduce the antitumor effect of mature DCs, which demonstrated that the T. spiralis ESP would not affect the antitumor effect of mature DCs by modulating the immune response of the host, and that ESPs are safe in antitumor immunology when applied in a tumor model mice.

The Impact of COVID-19 on Cancer Risk and Treatment

Millions of people are being infected with COVID-19 around the globe. Though the majority of them will recover, cancer patients remain at a higher risk to SARS-CoV-2 infection and its related severe outcomes. Understanding how viruses contribute to human cancers provides us with new opportunities for preventing or treating virus-associated cancers. However, a limited amount of research has been done to date in the context of how viral infections impact cancer at the cellular level and vice versa. Therefore, in light of the COVID-19 global infection, this review highlights the need for better understanding of the biology of viral infections in cancer patients, to enable novel therapies to co-target viral infections and cancer.

Neutrophils, as "Trojan horses", participate in the delivery of therapeutical PLGA nanoparticles into a tumor based on the chemotactic effect

Inspired by the fact that leukocytes have innate phagocytic functions and oriented migration capabilities in response to chemoattractants, we have unveiled that endogenous neutrophils as “Trojan horses”, participate in the delivery of nanoparticles in an “in vivo self-armed assembly” manner. Neutrophils were the main population to preferentially sequester the intravenous administrated nanoparticles with an average size of 260 nm. The pre-implantation of CXCL1-laden hydrogels could trigger and induce a targeted signal to attract an influx of neutrophils carrying the therapeutic goods to the desired position. In mouse models of melanoma, the combinatorial regimen of using the PLGA nanoparticles with the CXCL1 hydrogels exhibited superior tumor inhibition capability. This work leveraged the natural phagocytosis of neutrophile and the chemotactic effect of chemokines for targeted delivery. We believe this strategy will improve the therapeutic efficiency of nanoparticle-based delivery systems, especially when the chemokines are implanted at sites of surgical tumor removal, during cancer treatment at the clinic.

Molecular Aspects and Future Perspectives of Cytokine-Based Anti-cancer Immunotherapy

Cytokine-based immunotherapy is a promising field in the cancer treatment, since cytokines, as proteins of the immune system, are able to modulate the host immune response toward cancer cell, as well as directly induce tumor cell death. Since a low dose monotherapy with some cytokines has no significant therapeutic results and a high dose treatment leads to a number of side effects caused by the pleiotropic effect of cytokines, the problem of understanding the influence of cytokines on the immune cells involved in the pro- and anti-tumor immune response remains a pressing one. Immune system cells carry CD makers on their surface which can be used to identify various populations of cells of the immune system that play different roles in pro- and anti-tumor immune responses. This review discusses the functions and specific CD markers of various immune cell populations which are reported to participate in the regulation of the immune response against the tumor. The results of research studies and clinical trials investigating the effect of cytokine therapy on the regulation of immune cell populations and their surface markers are also discussed. Current trends in the development of cancer immunotherapy, as well as the role of cytokines in combination with other therapeutic agents, are also discussed.

Gene expression profile of immunoregulatory cytokines secreted from bone marrow and adipose derived human mesenchymal stem cells in early and late passages

Mesenchymal Stem Cells (MSCs) have therapeutic potential in a variety of diseases; however, the safety and efficacy of their use remain ambiguous. Clinical applications of MSCs are under intensive investigation due to their immunomodulatory features and lack of immune reactivity. Therefore, having a clear perspective on the exact mechanisms underlying the regulation of cytokine secretion in different microenvironments seems crucially important.In the current study, samples from human bone marrow and adipose were collected, and peripheral blood mononuclear cells (PBMCs) were isolated and cultured in conventional medium. After MSC expansion, the cells from passage 3 (P3) and passage 9 (P9) were utilized to identify MSC cell surface markers and their differentiation capacity. The P3, P5, P7, and P9 cells were used for RNA extraction to qualify the expression of the main immunomodulatory cytokines IDO, VCAM-1, TGF-β, IL-6, IL-10, and PGE2 at mRNA levels. The results indicate that VCAM-1 expression in the subcultures was reduced in bone marrow-derived MSCs. After an increase in P5, P7, and P9, IL-6 expression was reduced. In adipose-derived MSCs, the mRNA levels of IL-10 in higher passages were decreased compared with P3; other studied cytokines had no significant changes in their expression levels in either bone marrow or adipose-derived MSCs. Based on these results, it can be concluded that a suitable source for MSCs in cell therapy with stable expression of main cytokines, even in higher subcultures, appears to be adipose-derived MSCs with the exception of IL-10 secretion.

Silk peptide treatment potentiates natural killer cell activity in vitro and induces natural killer cell maturation and activation in mouse splenocytes

Context: Silk peptide from cocoons of silkworm (Bombyx mori L., Bombycidae) has been employed as a biomedical material and exhibits various bioactivities, including immune-modulating activity. Objective: We analyzed whether silk peptide exerts direct modulating effects on NK cells using an NK cell line in vitro and ex vivo splenocytes. We also attempted to delineate the mechanism underlying the modulation. Material and methods: In vitro activity of silk peptide on NK cells was determined by measurement of cytolytic activity against K562 cells at an effector-to-target ratio of 5:1 after incubation of NK-92MI cells with silk peptide (0-2000 μg/mL) for 48 and 72 h. Ex vivo activity of silk peptide on mouse splenic NK cells was determined similarly by using YAC-1 cells. Results: Treatment of NK-92MI NK cells with silk peptide (500-2000 μg/mL) significantly increased cytolytic activity on target cells by 2- to 4-fold. The same concentrations (500-2000 μg/mL) of silk peptide treatment also significantly enhanced the cytolytic activity of splenic NK cells against YAC-1 cells. Silk peptide treatment of IL-2-stimulated splenocytes induced enhanced expression of Th1, 2 and 17 cytokines including TNF-α, IFN-γ, IL-6, IL-4 and IL-17. Finally, ex vivo treatment with silk peptide on mouse splenocytes significantly enhanced the degree of NK cell maturation in a dose-dependent manner from 3.49 to 23.79%. Discussion and conclusions: These findings suggest that silk peptide stimulates NK cells, thereby influencing systemic immune functions and improving natural immunity. Thus, silk peptide could be useful as a complementary therapy in cancer patients.

Salmonella Immunotherapy Improves the Outcome of CHOP Chemotherapy in Non-Hodgkin Lymphoma-Bearing Mice

We have previously shown that Salmonella immunotherapy is effective to treat B-cell non-Hodgkin lymphoma (B-NHL) in mice. However, this model involves animals with high tumor burden, whereas in the clinics B-NHL patients are usually treated with chemotherapy (CHOP: cyclophosphamide, doxorubicin, vincristine, and prednisone) as first-line therapy prior to immunotherapy. Recently, we have described a NHL-B preclinical model using CHOP chemotherapy to achieve MRD in immunocompetent animals that closely resemble patients' conditions. In this work, we assessed the efficacy of Salmonella immunotherapy in B-NHL-bearing mice undergoing chemotherapy. Salmonella administration significantly delayed tumor growth and prolonged survival of chemotherapy-treated NHL-bearing animals. Mice receiving the CHOP-Salmonella combined therapy showed increased numbers of tumor-infiltrating leukocytes and a different profile of cytokines and chemokines expressed in the tumor microenvironment. Further, Salmonella immunotherapy in CHOP-treated animals also enhanced NK cells cytotoxic activity as well as induced systemic lymphoma-specific humoral and cellular responses. Chemotherapy treatment profoundly impacted on the general health status of recipient animals, but those receiving Salmonella showed significantly better overall body condition. Altogether, the results clearly demonstrated that Salmonella immunotherapy could be safely used in individuals under CHOP treatment, resulting in a better prognosis. These results give strong support to consider Salmonella as a neoadjuvant therapy in a clinical setting.

Recent advances in cell-mediated nanomaterial delivery systems for photothermal therapy

Cell-mediated “Trojan Horse” delivery vehicles overcome the drug delivery barriers to transport nano-agents enhancing the efficiency of photothermal therapy.

B-cell populations are expanded in breast cancer patients compared with healthy controls

BACKGROUND

Historically, humoral immunity was considered unimportant in anti-tumor immunity, and the differentiation and anti-tumor activity of B cells in breast cancer are poorly understood. However, it was recently discovered that B cells participate in tumor immunity through both antibody production and immunosuppressive mechanisms. We analyzed the expression of B-cell differentiation markers in detail using fluorescence-activated cell sorting to investigate the relationship between B-cell subsets and breast cancer etiology.

METHODS

Blood samples were taken from breast cancer patients and healthy donors, and peripheral blood mononuclear cells were collected. B cells at various stages of differentiation were identified by the expression of combinations of the cell surface markers CD5, CD19, CD21, CD24, CD27, CD38, CD45, and IgD. Statistical analysis of the proportions of each B-cell subtype in the different patient groups was then performed.

RESULTS

Twenty-seven breast cancer patients and 12 controls were considered. The proportion of total B cells was significantly higher in cancer patients than in controls (11.51 ± 2.059 vs 8.905 ± 0.379%, respectively; p = 0.001). Breast cancer patients were then classified as High-B or Low-B for further analysis. A significantly higher proportion of memory B cells was found in the High-B group than in the Low-B or control groups (p = 0.003 and p = 0.043, respectively).

CONCLUSIONS

Breast cancer patients generally have a higher proportion of B cells than healthy controls, but this is highly variable. Analysis of the major B-cell surface markers indicates that memory B cells in particular are significantly expanded, or more robust, in breast cancer patients.

L-asparaginase isolated from Streptomyces ansochromogenes promotes Th1 profile and activates CD8+ T cells in human PBMC: an in vitro investigation

AIMS

A new L-asparaginase produced by Streptomyces ansochromogenes UFPEDA 3420 actinobacteria was used in this study against human lymphocyte cultures to evaluate the immunological profile induced by this enzyme.

METHODS AND RESULTS

Cultures of lymphocytes were stimulated with S. ansochromogenes L-asparaginase, and cytotoxicity, cell viability, cell stimulation and cytokine production were analysed. This new S. ansochromogenes L-asparaginase induced activation and proliferation of the TCD8⁺ lymphocyte subset and produced higher TNF-α, IFN-γ, IL-2 and IL-10 levels in a 24-h assay.

CONCLUSION

Streptomyces ansochromogenes L-asparaginase is a promising molecule to be used in in vivo models and to deepen preclinical tests against acute lymphoblast leukaemia.

SIGNIFICANCE AND IMPACT OF STUDY

L-asparaginase is an indispensable component of the chemotherapeutic treatment of acute lymphoblast leukaemia (ALL) and acute myeloid leukaemia (AML). Currently, drugs such as Asparaginase^® , Kidrolase^® , and Elspar^® and Erwinase^® are efficient against leukemic disease, but promote immunosuppression and other side effects in human organisms. Our purified S. ansochromogenes L-asparaginase showed promissory results inducing, in vitro, higher immunostimulation in human PBMC, especially in T CD8⁺ lymphocyte subsets.

Cell-mediated delivery of synthetic nano- and microparticles

Cell mediated delivery of synthetic nano- and microparticle based drug carriers is a very promising strategy to enhance control over the distribution of drugs and improve targeting. This article will present an overview of work, which has been done to explore cell surface modification strategies for the cellular hitchhiking of synthetic nano- and microparticles. The first part of this article will present and discuss the different types of cells that have been explored for cell mediated drug delivery. The second part of this review will discuss the various chemical strategies that have been elaborated for the conjugation or immobilization of nano- and microparticles on the surface of these cells.