Immunological effects of the anti-programmed death-1 antibody on human peripheral blood mononuclear cells

Awareness and Knowledge About Preventive Vaccinations Among Patients with Hematological Malignancies

BACKGROUND

Patients with hematological malignancies, including multiple myeloma (MM) and chronic lymphocytic leukemia (CLL), are at an increased risk of severe infections due to both disease- and therapy-related immunosuppression. This cross-sectional study evaluated awareness of infection risks and vaccination uptake among 150 adults with various hematological malignancies from major Polish centers.

METHODS

All participants completed a 30-item questionnaire capturing demographic data, treatment history, infection frequency, and vaccination attitude. Statistical analyses utilized Chi-square and Fisher's exact tests, with p < 0.05 considered statistically significant.

RESULTS

Respondents had a median age of 57 years (range, 30-79), and 65.3% were female. MM was the most common diagnosis (64.7%), followed by CLL (4.0%) and other hematological malignancies (31.3%). Nearly all participants (99.3%) acknowledged their increased susceptibility to infections. Frequent infections (≥2 in the past 6 months) were significantly associated with transfusion dependency (p = 0.0001) and a history of hematopoietic stem cell transplantation (HSCT, p = 0.009). Although 69.3% expressed willingness to be vaccinated, 23.3% declined COVID-19 vaccination due to insufficient cancer-specific safety data. Higher education and urban residence correlated with greater acceptance of vaccines (p < 0.05).

CONCLUSIONS

Our findings underscore the critical need for targeted educational strategies and robust vaccination guidelines in this immunocompromised population. Enhanced patient education and timely implementation of tailored vaccination regimens could reduce infection-related morbidity and improve the tolerability of cancer treatments.

A Rare Presentation of Malignant Melanoma of the Face: A Case Report

Melanoma is a malignant neoplasm of melanoblasts, which are the precursors of the melanocytes arising from the neural crest cells. Melanomas can occur at various sites like the skin, eyes, upper esophagus, and meninges due to the migration of neural crest cells. Usually, the prognostic factors are decided based on the Breslow index. This case report describes a 61-year-old female who presented with the complaint of pinkish irregular swelling over the left side of her face for six months. The patient had a surgical resection, and the condition was determined to be invasive melanoma following confirmation by magnetic resonance imaging (MRI) and histological examination. Through our case report, we aim to shed light on the existing protocol for managing malignant melanoma while also exploring new aspects of presentation and multidisciplinary action.

Combining Anti-epidermal Growth Factor Receptor (EGFR) Therapy with Immunotherapy in Metastatic Colorectal Cancer (mCRC)

INTRODUCTION

Monoclonal antibodies binding the EGFR, such as cetuximab and panitumumab, have been extensively used as targeted therapy for the treatment of mCRC. However, in clinical practice, it has been found that these treatment options have some limitations and fail to fully exploit their immunoregulatory activities. Meanwhile, because of the limited effects of current treatments, immunotherapy is being widely studied for patients with mCRC. However, previous immunotherapy trials in mCRC patients have had unsatisfactory outcomes as monotherapy. Thus, combinatorial treatment strategies are being researched.

AREAS COVERED

The authors retrieved relevant documents of combination therapy for mCRC from PubMed and Medline. This review elaborates on the knowledge of immunomodulatory effects of anti-EGFR therapy alone and in combination with immunotherapy for mCRC.

EXPERT OPINION

Although current treatment options have improved median overall survival (OS) for advanced disease to 30 months, the prognosis remains challenging for those with metastatic disease. More recently, the combination of anti-EGFR therapy with immunotherapy has been shown activity with complementary mechanisms. Hence, anti-EGFR therapy in combination with immunotherapy may hold the key to improving the therapeutic effect of refractory mCRC.

Attenuated Toxoplasma gondii enhances the antitumor efficacy of anti-PD1 antibody by altering the tumor microenvironment in a pancreatic cancer mouse model

PURPOSE

To investigate whether attenuated Toxoplasma is efficacious against solid tumors of pancreatic cancer and whether attenuated Toxoplasma improves the antitumor activity of αPD-1 antibody on pancreatic cancer.

METHODS

The therapeutic effects of attenuated Toxoplasma NRTUA strain monotherapy and combination therapy of NRTUA with anti-PD-1 antibody on PDAC tumor volume and tumor weight of Pan02 tumor-bearing mice were investigated. We characterized the effects of combination therapy of NRTUA with anti-PD-1 antibody on tumor-infiltrating lymphocytes and tumor-specific IFN-γ by using immunohistochemistry, flow cytometry and ELISA. The antitumor mechanisms of combination therapy of NRTUA with anti-PD-1 antibody were investigated via depletion of CD8+ T cells and IL-12.

RESULTS

NRTUA strain treatment inhibited tumor growth in a subcutaneous mouse model of PDAC through activating dendritic cells and increasing CD8+ T cell infiltration in the tumor microenvironment. More importantly, combination therapy of NRTUA with anti-PD-1 antibody elicited a significant antitumor immune response and synergistically controlled tumor growth in Pan02 tumor-bearing mice. Specifically, the combination treatment led to elevation of CD8+ T cell infiltration mediated by dendritic cell-secreted IL-12 and to tumor-specific IFN-γ production in the PDAC tumor microenvironment. Also, the combination treatment markedly reduced the immunosuppressive myeloid-derived suppressor cell population in PDAC mice.

CONCLUSION

These findings could provide a novel immunotherapy approach to treating solid tumors of PDAC and overcoming resistance to anti-PD-1 agents in PDAC tumors.

Immune normalization strategy against suboptimal health status: safe and efficacious therapy using mixed-natural killer cells

"Immune normalization" has emerged as a new paradigm in immunotherapy, which is proposed in cancer patients instead of conventional "immune-enhancement" therapy. Immune normalization may also be implemented in cancer prevention of "sub-healthy" individuals. We established in vitro cultured mixed-natural killer (NKM) cells to achieve immune normalization. The in vitro cytotoxicity of NKM cells was tenfold higher than that of peripheral blood mononuclear cells (PBMCs). The cytotoxicity of NKM cells was negatively correlated with the proportion of T-helper cells (cluster of differentiation: CD3+CD4+ T), and positively correlated with the proportion of NK cells (especially CD56^brightCD16^bright NK cells). Then, we defined "sub-healthy individuals" after measuring Programmed cell death protein-1 (PD-1) expression in PBMCs from 95 donors aged > 50 years. Furthermore, we evaluated the potential clinical application of NKM-cell therapy in 11 patients with malignant lymphoma, one patient with pancreatic cancer, and four sub-healthy individuals. NKM-cell therapy elicited good tolerance and side-effects were not found. In sub-healthy individuals, the proportion of CD3⁺PD-1⁺ T cells and CD3⁺CD8⁺PD-1⁺ T cells was reduced significantly after NKM-cell treatment. We demonstrated that a new method using NKM cells was safe and efficacious as adjuvant treatment for cancer patients as well as therapy for sub-healthy individuals. Normalization of the peripheral immune system through NKM-cell therapy could expand its scope of application in different disorders.

Resistance to Immune Checkpoint Inhibitors Secondary to Myeloid-Derived Suppressor Cells: A New Therapeutic Targeting of Haematological Malignancies

Myeloid-derived suppressor cells (MDSCs) are a set of immature myeloid lineage cells that include macrophages, granulocytes, and dendritic cell precursors. This subpopulation has been described in relation to the tumour processes at different levels, including resistance to immunotherapy, such as immune checkpoint inhibitors (ICIs). Currently, multiple studies at the preclinical and clinical levels seek to use this cell population for the treatment of different haematological neoplasms, together with ICIs. This review addresses the different points in ongoing studies of MDSCs and ICIs in haematological malignancies and their future significance in routine clinical practice.

Cutaneous Malignant Melanoma: A Review of Early Diagnosis and Management

Cutaneous melanoma (CM) is a malignant tumor formed from pigment-producing cells called melanocytes. It is one of the most aggressive and fatal forms of skin malignancy. In the last decades, CM's incidence has gradually risen, with 351,880 new cases in 2015. Since the 1960s, its incidence has increased steadily, in 2019, with approximately 96,000 new cases. A greater understanding of early diagnosis and management of CM is urgently needed because of the high mortality rates due to metastatic melanoma. Timely detection of melanoma is crucial for successful treatment, but diagnosis with histopathology may also pose a significant challenge to this objective. Early diagnosis and management are essential and contribute to better survival rates of the patient. To better control this malignancy, such information is expected to be particularly useful in the early detection of possible metastatic lesions and the development of new therapeutic approaches. This article reviews the available information on the early diagnosis and management of CM and discusses such information's potential in facilitating the future prospective.

Nanoparticle-Delivered HIV Peptides to Dendritic Cells a Promising Approach to Generate a Therapeutic Vaccine

Finding a functional cure for HIV-1 infection will markedly decrease the social and economic burden of this disease. In this work, we have taken advantage of the antigen presenting cell role of human dendritic cells (DCs) to try to induce an immune response to HIV-derived peptide delivered to DCs using two different polycationic nanoparticles: a G4 PAMAM dendrimer modified to a 70/30 ratio of hydroxyl groups/amines and a cyclodextrin derivative. We have studied peptide delivery using a fluorescence peptide and have studied the immune response generation by cytokine determination and flow cytometry. We have found a robust delivery of the antigenic peptide to DCs and activated dendritic cell-mediated peripheral blood mononuclear cells (PBMCs) proliferation using the mixed lymphocyte reaction. However, no expression of markers indicating activation of either B or T lymphocytes was observed. Moreover, the release of the pro-inflammatory cytokine TNF-α or IL-2 was only observed when DCs treated with either the dendrimer or the dendriplex containing the peptide. Antigenic peptide delivery to DCs is a promising approach to generate a vaccine against HIV-1 infection. However, more studies, including the simultaneous delivery of several antigenic peptides from different viral proteins, can markedly improve the immune response.

Targeting Myeloid-Derived Suppressor Cell, a Promising Strategy to Overcome Resistance to Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) are starting to transform the treatment for patients with advanced cancer. The extensive application of these antibodies for various cancer obtains exciting anti-tumor immune response by activating T cells. Although the encouraging clinical benefit in patients receiving these immunostimulatory agents are observed, numbers of patients still derive limited response or even none for reasons unknown, sometimes at the cost of adverse reactions. Myeloid-derived suppressor cells (MDSCs) is a heterogeneous immature population of myeloid cells partly influencing the efficacy of immunotherapies. These cells not only directly suppress T cell but mediate a potently immunosuppressive network within tumor microenvironment to attenuate the anti-tumor response. The crosstalk between MDSCs and immune cells/non-immune cells generates several positive feedbacks to negatively modulate the tumor microenvironment. As such, the recruitment of immunosuppressive cells, upregulation of immune checkpoints, angiogenesis and hypoxia are induced and contributing to the acquired resistance to ICIs. Targeting MDSCs could be a potential therapy to overcome the limitation. In this review, we focus on the role of MDSCs in resistance to ICIs and summarize the therapeutic strategies targeting them to enhance ICIs efficiency in cancer patients.

Targeting Myeloid-Derived Suppressor Cell, a Promising Strategy to Overcome Resistance to Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) are starting to transform the treatment for patients with advanced cancer. The extensive application of these antibodies for various cancer obtains exciting anti-tumor immune response by activating T cells. Although the encouraging clinical benefit in patients receiving these immunostimulatory agents are observed, numbers of patients still derive limited response or even none for reasons unknown, sometimes at the cost of adverse reactions. Myeloid-derived suppressor cells (MDSCs) is a heterogeneous immature population of myeloid cells partly influencing the efficacy of immunotherapies. These cells not only directly suppress T cell but mediate a potently immunosuppressive network within tumor microenvironment to attenuate the anti-tumor response. The crosstalk between MDSCs and immune cells/non-immune cells generates several positive feedbacks to negatively modulate the tumor microenvironment. As such, the recruitment of immunosuppressive cells, upregulation of immune checkpoints, angiogenesis and hypoxia are induced and contributing to the acquired resistance to ICIs. Targeting MDSCs could be a potential therapy to overcome the limitation. In this review, we focus on the role of MDSCs in resistance to ICIs and summarize the therapeutic strategies targeting them to enhance ICIs efficiency in cancer patients.

Antitumor activity of the PD-1/PD-L1 binding inhibitor BMS-202 in the humanized MHC-double knockout NOG mouse

Recently, the first series of small molecule inhibitors of PD-1/PD-L1 were reported by Bristol-Myers Squibb (BMS), which were developed using a homogeneous time-resolved fluorescence (HTRF)-based screening investigation of the PD-1/PD-L1 interaction. Additional crystallographic and biophysical studies showed that these compounds inhibited the interaction of PD-1/PD-L1 by inducing the dimerization of PD-L1, in which each dimer binds one molecule of the stabilizer at its interface. However, the immunological mechanism of the antitumor effect of these compounds remains to be elucidated. In the present study, we focused on BMS-202 (a representative of the BMS compounds) and investigated its antitumor activity using in vitro and in vivo experiments. BMS-202 inhibited the proliferation of strongly PD-L1-positive SCC-3 cells (IC₅₀ 15 μM) and anti-CD3 antibody-activated Jurkat cells (IC₅₀ 10 μM) in vitro. Additionally, BMS-202 had no regulatory effect on the PD-1 or PD-L1 expression level on the cell surface of these cells. In an in vivo study using humanized MHC-double knockout (dKO) NOG mice, BMS-202 showed a clear antitumor effect compared with the controls; however, a direct cytotoxic effect was revealed to be involved in the antitumor mechanism, as there was no lymphocyte accumulation in the tumor site. These results suggest that the antitumor effect of BMS-202 might be partly mediated by a direct off-target cytotoxic effect in addition to the immune response-based mechanism. Also, the humanized dKO NOG mouse model used in this study was shown to be a useful tool for the screening of small molecule inhibitors of PD-1/PD-L1 binding that can inhibit tumor growth via an immune-response-mediated mechanism.

Anti-Inflammatory Action of Heterogeneous Nuclear Ribonucleoprotein A2/B1 in Patients with Autoimmune Endocrine Disorders

Our previous studies documented that human fibroblast-limbal stem cells (f-LSCs) possess immunosuppressive capabilities, playing a role in regulating T-cell activity. This study highlights the molecular activities by which human f-LSCs can attenuate the inflammatory responses of self-reactive peripheral blood mononuclear cells (PBMCs) collected from patients with autoimmune endocrine diseases (AEDs). Anti-CD3 activated PBMCs from twenty healthy donors and fifty-two patients with AEDs were cocultured on f-LSC monolayer. 2D-DIGE proteomic experiments, mass spectrometry sequencing and functional in vitro assays were assessed in cocultured PBMCs. We identified the downmodulation of several human heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) isoforms in healthy and AED activated PBMCs upon f-LSC interaction. The reduction of hnRNPA2/B1 protein expression largely affected the cycling ki67⁺, CD25⁺, PD-1⁺ reactive cells and the double marked CD8⁺/hnRNPA2B1⁺ T cell subset. Anti-PD1 blocking experiments evoked hnRNPA2/B1 overexpression, attributing putative activation function to the protein. hnRNPA2/B2 transient silencing inverted immunopolarization of the self-reactive PBMCs from AEDs toward a M2/Th2-type background. Pharmacological inhibition and co-immunoprecipitation experiments demonstrated the involvement of NF-ĸB in hnRNPA2/B activity and turnover. Our data indicate cardinal involvement of hnRNP A2/B1 protein in peripheral mechanisms of tolerance restoration and attenuation of inflammation, identifying a novel immunoplayer potentially targetable in all AEDs.

Targeting the tumor microenvironment to overcome immune checkpoint blockade therapy resistance

The ability of immune checkpoint inhibitors (ICIs) to reactivate the killing function of the immune system to tumor cells has led to long lasting immune response presenting highly promising clinical advances. Recently, immune checkpoint inhibitors related resistance due to the specialized tumor microenvironment has also drawn a widely attention. To overcome resistance to immune checkpoint blockade therapy, understanding the relationship of this type of therapy and tumor microenvironment is necessary and critical. This review will focus on how the tumor environment influences the effectiveness of the immunotherapeutic check inhibitors. Finally, we provide a briefly succinct glimpse into the most exciting pre-clinical discoveries and ongoing clinical trials to overcome the resistance of ICIs.

Cancer Stem Cells and Immunosuppressive Microenvironment in Glioma

Glioma is one of the most common malignant tumors of the central nervous system and is characterized by extensive infiltrative growth, neovascularization, and resistance to various combined therapies. In addition to heterogenous populations of tumor cells, the glioma stem cells (GSCs) and other nontumor cells present in the glioma microenvironment serve as critical regulators of tumor progression and recurrence. In this review, we discuss the role of several resident or peripheral factors with distinct tumor-promoting features and their dynamic interactions in the development of glioma. Localized antitumor factors could be silenced or even converted to suppressive phenotypes, due to stemness-related cell reprogramming and immunosuppressive mediators in glioma-derived microenvironment. Furthermore, we summarize the latest knowledge on GSCs and key microenvironment components, and discuss the emerging immunotherapeutic strategies to cure this disease.

Myeloid-Derived Suppressor Cells Hinder the Anti-Cancer Activity of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICI) used for cancer immunotherapy were shown to boost the existing anti-tumor immune response by preventing the inhibition of T cells by tumor cells. Antibodies targeting two negative immune checkpoint pathways, namely cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death-ligand 1 (PD-L1), have been approved first for patients with melanoma, squamous non-small cell lung cancer (NSCLC), and renal cell carcinoma. Clinical trials are ongoing to verify the efficiency of these antibodies for other cancer types and to evaluate strategies to block other checkpoint molecules. However, a number of patients do not respond to this treatment possibly due to profound immunosuppression, which is mediated partly by myeloid-derived suppressor cells (MDSC). This heterogeneous population of immature myeloid cells can strongly inhibit anti-tumor activities of T and NK cells and stimulate regulatory T cells (Treg), leading to tumor progression. Moreover, MDSC can contribute to patient resistance to immune checkpoint inhibition. Accumulating evidence demonstrates that the frequency and immunosuppressive function of MDSC in cancer patients can be used as a predictive marker for therapy response. This review focuses on the role of MDSC in immune checkpoint inhibition and provides an analysis of combination strategies for MDSC targeting together with ICI to improve their therapeutic efficiency in cancer patients.

Cutaneous melanoma: From pathogenesis to therapy (Review)

In less than 10 years, melanoma treatment has been revolutionized with the approval of tyrosine kinase inhibitors and immune checkpoint inhibitors, which have been shown to have a significant impact on the prognosis of patients with melanoma. The early steps of this transformation have taken place in research laboratories. The mitogen‑activated protein kinase (MAPK) pathway, phosphoinositol‑3‑kinase (PI3K) pathway promote the development of melanoma through numerous genomic alterations on different components of these pathways. Moreover, melanoma cells deeply interact with the tumor microenvironment and the immune system. This knowledge has led to the identification of novel therapeutic targets and treatment strategies. In this review, the epidemiological features of cutaneous melanoma along with the biological mechanisms involved in its development and progression are summarized. The current state‑of‑the‑art of advanced stage melanoma treatment strategies and the currently available evidence of the use of predictive and prognostic biomarkers are also discussed.

Perspective on immune oncology with liquid biopsy, peripheral blood mononuclear cells, and microbiome with non-invasive biomarkers in cancer patients

Antibodies against immune checkpoint inhibitors such as anti-programmed cell death protein 1 (PD-1) and anti-programmed death ligand 1 (PD-L1) play a key role in the treatment of advanced lung cancer. To examine the clinical benefits of these agents, preclinical and clinical studies have been conducted to identify definitive biomarkers associated with cancer status. Analysis of the blood and feces of tumor patients has attracted attention in recent studies attempting to identify non-invasive biomarkers such as cytokines, soluble PD-L1, peripheral blood mononuclear cells, and gut microbiota. These factors are believed to interact with each other to produce synergistic effects and contribute to the formation of the tumor immune microenvironment through the seven steps of the cancer immunity cycle. The immunogram was first introduced as a novel indicator to define the immunity status of cancer patients. In this review, we discuss the progress in the identification of predictive biomarkers as well as future prospects for anti-PD-1/PD-L1 therapy.

Rationale for combination of therapeutic antibodies targeting tumor cells and immune checkpoint receptors: Harnessing innate and adaptive immunity through IgG1 isotype immune effector stimulation

Immunoglobulin (Ig) G1 antibodies stimulate antibody-dependent cell-mediated cytotoxicity (ADCC). Cetuximab, an IgG1 isotype monoclonal antibody, is a standard-of-care treatment for locally advanced and recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN) and metastatic colorectal cancer (CRC). Here we review evidence regarding the clinical relevance of cetuximab-mediated ADCC and other immune functions and provide a biological rationale concerning why this property positions cetuximab as an ideal partner for immune checkpoint inhibitors (ICIs) and other emerging immunotherapies. We performed a nonsystematic review of available preclinical and clinical data involving cetuximab-mediated immune activity and combination approaches of cetuximab with other immunotherapies, including ICIs, in SCCHN and CRC. Indeed, cetuximab mediates ADCC activity in the intratumoral space and primes adaptive and innate cellular immunity. However, counterregulatory mechanisms may lead to immunosuppressive feedback loops. Accordingly, there is a strong rationale for combining ICIs with cetuximab for the treatment of advanced tumors, as targeting CTLA-4, PD-1, and PD-L1 can ostensibly overcome these immunosuppressive counter-mechanisms in the tumor microenvironment. Moreover, combining ICIs (or other immunotherapies) with cetuximab is a promising strategy for boosting immune response and enhancing response rates and durability of response. Cetuximab immune activity–including, but not limited to, ADCC–provides a strong rationale for its combination with ICIs or other immunotherapies to synergistically and fully mobilize the adaptive and innate immunity against tumor cells. Ongoing prospective studies will evaluate the clinical effect of these combination regimens and their immune effect in CRC and SCCHN and in other indications.