Perforin-mediated target-cell death and immune homeostasis

Pediatric gliomas immunity challenges and immunotherapy advances

Pediatric gliomas, the most frequent brain tumors in children, are characterized by heterogeneity and a unique tumor immune microenvironment. They are categorized into different subtypes, including low-grade gliomas like pilocytic astrocytomas and high-grade gliomas such as diffuse midline gliomas and diffuse intrinsic pontine gliomas, each exhibiting distinct immunological profiles. The tumor immune microenvironment in pediatric gliomas is shaped by cellular and non-cellular components, including immune cells, cytokines, and the extracellular matrix, involved in tumor progression, immune evasion, and response to therapy. While pediatric low-grade gliomas often display an immunosuppressed microenvironment, high-grade gliomas are characterized by complex immune infiltrates and intricate immunosuppressive mechanisms. The blood-brain barrier further obscures immune cell recruitment and therapeutic delivery. Despite advances in understanding adult gliomas, the immunobiology of pediatric tumors is poorly investigated, with limited data on the interactions between glioma cells and immune populations such as T and natural killer cells, as well as tumor-associated macrophages. Herein, we provide an update of the current knowledge on tumor immune microenvironment interactions in pediatric gliomas, highlighting the immunosuppressive mechanisms and emerging immunotherapeutic strategies aiming at overcoming these barriers to improve clinical outcomes for affected children.

N6-methyladenosine RNA base modification regulates NKG2D-dependent and cytotoxic genes expression in natural killer cells

BACKGROUND

Breast cancer (BC) is the most commonly diagnosed cancer in women. N6-methyladenosine (m6A) is the most prevalent internal modification in mammalian mRNAs and plays a crucial role in various biological processes. However, its function in Natural killer (NK) cells in BC remains unclear. NK cells are essential for cancer immunosurveillance. This study aims to assess m6A levels in transcripts involved in the NKG2D cytotoxicity signaling pathway in NK cells of BC patients compared to controls and find out its impact on mRNA levels. Additionally, it evaluates how deliberately altering m6A levels in NK cells affects mRNA and protein expression of NKG2D pathway genes and NK cell functionality.

METHODS

m6A methylation in transcripts of NKG2D-pathway-related genes in BC patients and controls was determined using methylated RNA immunoprecipitation-reverse transcription-PCR (MERIP-RT-PCR). To deliberately alter m6A levels in primary cultured human NK cells, the m6A demethylases, FTO and ALKBH5, were knocked out using the CRISPR-CAS9 system, and FTO was inhibited using Meclofenamic acid (MA). The impact of m6A alteration on corresponding mRNA and protein levels was assessed using RT-qPCR and Western blot analysis or flow cytometry, respectively. Additionally, NK cell functionality was evaluated through degranulation and 51Cr release cytotoxicity assays.

RESULTS

Transcripts of NKG2D, an activating receptor that detects stressed non-self tumour cells, had significantly higher m6A levels in the 3' untranslated region (3'UTR) accompanied by a marked reduction in their corresponding mRNA levels in BC patients compared to controls. Conversely, transcripts of ERK2 and PRF1 exhibited significantly lower m6A levels escorted with higher mRNA expression in BC patients relative to controls. The mRNA levels of PI3K, PAK1 and GZMH were also significantly elevated in BC patients. Furthermore, artificially increasing transcripts' m6A levels via MA in cultured primary NK cells reduced mRNA levels of NKG2D pathway genes and death receptor ligands but did not affect protein expression or NK cell functionality.

CONCLUSION

Transcripts with higher m6A levels in the 3'UTR region were less abundant, and vice versa. However, changes in mRNA levels of the target genes didn't impact their corresponding protein levels or NK cell functionality.

Modeling Tumor Microenvironment Complexity In Vitro: Spheroids as Physiologically Relevant Tumor Models and Strategies for Their Analysis

Drug delivery to solid tumors is challenged by multiple physiological barriers arising from the tumor microenvironment, including dense extracellular matrix, cellular heterogeneity, hypoxic gradients, and elevated interstitial fluid pressure. These features hinder the uniform distribution and accumulation of therapeutics, reducing treatment efficacy. Despite their widespread use, conventional two-dimensional monolayer cultures fail to reproduce these complexities, contributing to the poor translational predictability of many preclinical candidates. Three-dimensional multicellular tumor spheroids have emerged as more representative in vitro models that capture essential features of tumor architecture, stromal interactions, and microenvironmental resistance mechanisms. Spheroids exhibit spatially organized regions of proliferation, quiescence, and hypoxia, and can incorporate non-tumor cells to mimic tumor-stroma crosstalk. Advances in spheroid analysis now enable detailed evaluation of drug penetration, cellular migration, cytotoxic response, and molecular gradients using techniques such as optical and confocal imaging, large-particle flow cytometry, biochemical viability assays, and microfluidic integration. By combining physiological relevance with analytical accessibility, spheroid models support mechanistic studies of drug transport and efficacy under tumor-like conditions. Their adoption into routine preclinical workflows has the potential to improve translational accuracy while reducing reliance on animal models.

Molecular mechanism of host-yeast interactions and prevention by nanoformulation approaches

Fungal infections are a major source of morbidity and mortality in people with compromised immune systems, such as those with human immunodeficiency virus, cancer, organ transplant recipients, and patients undergoing chemotherapy in healthcare settings. According to a recent World Health Organization (WHO) fungal priority pathogens list, Cryptococcus spp., Candida spp., Aspergillus spp., and Candida auris cause severe invasive infections in human. These opportunistic pathogens cause a significant number of mycoses, which affect over a billion people annually. Around two million infections can be fatal, especially for those with compromised immune systems. To diagnose and treat mycoses, we need to understand the complex interactions between the fungus and the host during pathogenesis, the virulence-causing traits of the fungus, and how the host fights infection through the immune system. Although several antifungal drugs are available against fungal infections, their effectiveness is highly variable, with adverse effects. In addition, the increasing resistance to traditional antifungal treatments poses serious risks to the healthcare industry. Therefore, new therapeutic strategies are required to combat these potentially fatal fungal infections. Nanostructure-based formulations can improve the therapeutic efficacy of conventional medications by broadening their activities, decreasing toxicity, enhancing bioactivity, and improving biodistribution. The review highlights host and fungus interaction and how nanoformulations can be targeted against fungal infections.

Enhancing NK Cell Antitumor Activity With Natural Compounds: Research Advances and Molecular Mechanisms

In recent years, immunotherapy has become a novel antitumor strategy in addition to traditional surgery, radiotherapy, and chemotherapy and has exhibited promising results in clinical applications. Despite significant breakthroughs in immunotherapy, such as immune checkpoint blockade and CAR-T cell therapy, it remains necessary to develop more efficacious, safer, and cheaper immunotherapeutic drugs due to factors including small reaction populations, acquired resistance, adverse side effects, and high costs. Natural killer (NK) cells are preeminent cytotoxic lymphocytes of the innate immune system that act as the first line of defense against tumors and synergistically enhance the adaptive immune response of T lymphocytes. Therefore, boosting the antitumor function of NK cells is an important direction in the development of immunotherapy. For decades, various immunotherapies such as adoptive cell therapy, antibody drugs, cytokines supplement, and chemical immunomodulators have been developing rapidly to improve the function of NK cells. Compared to biological immunotherapy, immunomodulators derived from natural products have outstanding advantages of low immunogenicity, multi-targeting, and cost-effectiveness. Currently, increasing attention is being focused on discovering NK cell-stimulating agents from natural products, such as polysaccharides, alkaloids, terpenoids, saponins, phenolics, and quinones. This review aims to categorize and summarize the comprehensive research progress on these natural products, discuss their potential molecular mechanisms in regulating NK cells, and explore their clinical applications as standalone treatments or in combination with conventional chemotherapy regimens.

Vitamin D exerts endogenous control over TH2 cell fate and immune plasticity

Circulating Vitamin D (Vit-D) has emerged as a potent immune modulator in asthma, yet its direct impact on TH2 cell regulation, the central effectors of allergic inflammation, remains unclear. Preliminary transcriptomic analysis of neonatal cord blood revealed that gestational Vit-D deficiency corresponds to elevated adaptive and innate immune responses, driven by TH2 immunity and antimicrobial responses related to asthma inflammation. To elucidate cell-specific molecular mechanisms of Vit-D, we differentiated murine TH2 cells in vitro under conditions mimicking Vit-D sufficiency and deficiency. Our findings demonstrate that Vit-D exposure promotes intracellular calcium ion homeostasis while suppressing prominent inflammatory cytokines characteristic of asthma. Conversely, Vit-D deficiency reprograms TH2 cell lineage commitment, inducing overexpression of cytolytic molecules and major histocompatibility complex (MHC) class I molecules-traits typically associated with cytotoxicity rather than the canonical helper function. Our findings underscore Vit-D's role in stabilizing TH2 cell function and fate, offering insights into asthma and autoimmune disorders.

Haemophagocytic lymphohistiocytosis (HLH) with concurrent Hodgkin's Disease

Haemophagocytic lymphohistiocytosis (HLH) is a condition of uncontrolled immune activation caused by genetic defects or triggered by infections, malignancies, autoimmune diseases, drugs, pregnancy or post-transplant immunosuppression. This case describes a young man presenting with clinical jaundice and abnormal blood tests, including raised inflammatory markers, abnormal liver function, low haemoglobin (65 g/L) and a low white blood cell count (3.08×109/L). He met five out of eight HLH criteria and tested positive for Epstein-Barr virus (EBV) PCR (58 011 IU/mL). His bone marrow biopsy showed EBV-driven Hodgkin's lymphoma. He was initially treated with the HLH-94 protocol and later switched to ABVD chemotherapy (adriamycin, bleomycin, vinblastine and dacarbazine). He steadily recovered despite a prolonged hospital stay. He was discharged to complete his remaining cycles of chemotherapy as an outpatient with a plan of having a positron emission tomography (PET) scan after two cycles of chemotherapy.

Establishment and characterisation of a novel canine mast cell tumour cell line (C18)

BACKGROUND

Mast cell tumour (MCT) is a life-threatening neoplasm commonly found in dogs worldwide. The outcome of treatment for dogs with cutaneous MCT is currently poor, mainly because of the tumour's aggressiveness and the heterogeneity in tumour behaviour. This study established a novel canine MCT cell line and compared with three reference canine MCT cell lines (CMMC, VIMC and CoMS) in terms of their characteristics and tumour sensitivity to immune cell-mediated cytotoxicity.

RESULTS

Of 18 MCT samples, only one cell line derived from high grade cutaneous MCT was established and referred to as C18 cell line. The C18 cell line could be maintained for over 100 passages while they still exhibited c-kit, tryptase, FcεRIα and FcεRIβ expression. The C18 had the longest doubling time and smallest tumour spheroid size when compared to the other three reference cell lines. The C18 also had c-kit internal tandem duplication (ITD) in exon 11 and nine single nucleotide polymorphisms (SNPs) in five genes, namely c-kit, HYAL4, SEL1L, SPAM1 and TRAF3. For a comparison of tumour sensitivity to immune cell-mediated cytotoxicity, the percentages of early and total apoptotic cells were significantly increased in all four cell lines. However, the percentages of viable cells were significantly decreased only in C18.

CONCLUSION

In conclusion, a novel canine cutaneous MCT cell line was successfully established, in terms of its characteristics, growth behavior and interaction with PBMCs. The C18 cell line holds a potential promise for advancing studies and developing new therapeutic strategies.

Development of chimeric Nanobody-Granzyme B functionalized ferritin nanoparticles for precise tumor therapy

T-cell lymphomas (TCLs) are heterogeneous malignancies with limited treatment options and poor outcomes. The efficacy of traditional T-cell therapies, including chimeric antigen receptor (CAR) T cells, is often constrained by immunosuppressive factors and the tumor microenvironment. On the other hand, although direct Granzyme B (GrB) administration can effectively induce tumor cell apoptosis, it lacks universal tumor targeting and efficient cellular entry mechanisms. To address these limitations, we developed a novel nanoparticle-based therapy for the precise targeting of TCL tumor cells and the delivery of GrB. We fused nanobody (Nb) targeting CD30 and CD5 with GrB and coupled them to human ferritin (h-HFn) using the Gv/Sd system, creating a novel therapeutic nanoparticle named BiCD30/5-GF, which specifically targets CD30 and CD5 receptors on TCL tumor cells. The Nb-GrB conjugation enhances tumor targeting, while a Gv/Sd linker coupled to h-HFn further improves cellular transport and targeting. Additionally, the multimerization of GrB enhances its effectiveness. These nanoparticles demonstrated superior binding affinity and cytotoxicity in vitro compared to conventional treatments. In vivo studies on tumor-bearing mice showed significant tumor suppression and prolonged survival following treatment with BiCD30/5-GF nanoparticles. We also extended similar nanoparticle strategies for gastric cancer therapy, targeting FGFR4-expressing tumor cells. Our findings highlight the potential of engineered nanoparticles as effective and targeted therapeutic agents across various tumor types, offering promising prospects for clinical translation in cancer treatment.

Enhanced Anti-Tumor Effects of Natural Killer Cell-Derived Exosomes Through Doxorubicin Delivery to Hepatocellular Carcinoma Cells: Cytotoxicity and Apoptosis Study

Exosomes are nanosized extracellular vesicles secreted by various cells, including natural killer (NK) cells, and are known for their low toxicity, high permeability, biocompatibility, and strong targeting ability. NK cell-derived exosomes (NK-exos) contain cytotoxic proteins that enhance tumor-targeting efficiency, making them suitable for treating solid tumors such as hepatocellular carcinoma (HCC). Despite their potential in drug delivery, the mechanisms of drug-loaded NK-exos, particularly those loaded with doxorubicin (NK-exos-Dox), remain unclear in HCC. This study explored the anti-tumor effects of NK-exos-Dox against Hep3B cells in vitro. NK-exos-Dox expressed exosome markers (CD9 and CD63) and cytotoxic proteins (granzyme B and perforin) and measured 170-220 nm in size. Compared to NK-exos, NK-exos-Dox enhanced cytotoxicity and apoptosis in Hep3B cells by upregulating pro-apoptotic proteins (Bax, cytochrome c, cleaved caspase 3, and cleaved PARP) and inhibiting the anti-apoptotic protein (Bcl-2). These findings suggest that NK-exos-Dox significantly boost anti-tumor effects by activating specific cytotoxic molecules, offering promising therapeutic opportunities for solid tumor treatment, including HCC.

Unveiling the Interplay Between Dendritic Cells and Natural Killer Cells as Key Players in Leishmania Infection

Leishmaniasis is a group of parasitic diseases whose etiological agent is the protozoa Leishmania. These diseases afflict impoverished populations in tropical and subtropical regions and affect wild and domestic animals. Canine leishmaniasis is a global disease mostly caused by L. infantum. Dogs are recognized as a good reservoir since harbor the infection long before developing the disease, facilitating parasite transmission. Furthermore, there is growing evidence that dogs may also be the reservoir of the American Leishmania spp. as L. amazonensis. The innate immune response is the first defense line against pathogens, which includes natural killer (NK) and dendritic cells (DCs). By recognizing and ultimately destroying infected cells, and by secreting immune mediators that favor inflammatory microenvironments, NK cells take the lead in the infectious process. When interacting with Leishmania parasites, DCs become activated and play a key role in driving the host immune response. While activated DCs can modulate NK cell activity, Leishmania parasites can directly activate NK cells by interacting with innate immune receptors. Once activated, NK cells can engage in a bidirectional interplay with DCs. However, the complexity of these interactions during Leishmania infection makes it challenging to fully understand the underlying processes. To further explore this, the present study investigated the dynamic interplay established between monocyte-derived DCs (moDCs) and putative NK (pNK) cells of dogs during Leishmania infection. Findings indicate that the crosstalk between moDCs exposed to L. infantum or L. amazonensis and pNK cells enhances chemokine upregulation, potentially attracting other leukocytes to the site of infection. pNK cells activated by L. infantum infected DCs upregulate IL-10, which can lead to a regulatory immune response while moDCs exposed to L. amazonensis induced pNK cells to overexpress IFN-γ and IL-13, favoring a mix of pro- and anti-inflammatory response. In addition, parasite-derived extracellular vesicles (EVs) can modulate the host immune response by stimulating the upregulation of anti-inflammatory cytokines and perforin release, which may impact infection outcomes. Thus, Leishmania and parasitic EVs can influence the bidirectional interplay between canine NK cells and DCs.

Immune responses to avian influenza viruses in chickens

Chickens are a key species in both the manifestation of avian influenza and the potential for zoonotic transmission. Avian influenza virus (AIV) infection in chickens can range from asymptomatic or mild disease with low pathogenic AIVs (LPAIVs) to systemic fatal disease with high pathogenic AIVs (HPAIVs). During AIV infection in chickens, Toll-like receptor 7 and melanoma differentiation-associated gene 5 are upregulated to detect the single-stranded ribonucleic acid genomes of AIV, triggering a signaling cascade that produces interferons (IFNs) and pro-inflammatory cytokines. These inflammatory mediators induce the expression of antiviral proteins and recruit immune system cells, such as macrophages and dendritic cells, to the infection site. AIV evades these antiviral responses primarily through its non-structural protein 1, which suppresses type I IFNs, influencing viral pathogenicity. The uncontrolled release of pro-inflammatory cytokines may contribute to the pathogenicity and high mortality associated with HPAIV infections. AIV modulates apoptosis in chicken cells to enhance its replication, with variations in apoptosis pathways influenced by viral strain and host cell type. The presentation of AIV antigens to T and B cells leads to the production of neutralizing antibodies and the targeted destruction of infected cells by CD8+ T cells, respectively, which enhances protection and establishes immunological memory. This review explores the diverse innate and adaptive immune responses in chickens to different AIVs, focusing on the dynamics of these responses relative to protection, susceptibility, and potential immunopathology. By understanding these immune mechanisms, informed strategies for controlling AIV infection and improving chicken health can be developed.

Diagnostic testing for hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome caused by severe systemic hyperinflammation. HLH can be rapidly fatal if unrecognized or inadequately treated. It is important that clinicians are able to utilize diagnostic testing to assess for HLH and determine the underlying causes including possible inborn errors of immunity (IEI). This article summarizes many of the tools available to aid with the diagnostic evaluation of patients with possible HLH and underlying IEI.

Immune microenvironment features underlying the superior efficacy of neoadjuvant immunochemotherapy over chemotherapy in local advanced gastric cancer

Background

The therapeutic efficacy of neoadjuvant immunotherapy combined with chemotherapy (Io+Chemo) is superior than chemotherapy alone (Chemo). However, the mechanism of Io+Chemo superiority remains to be further elucidated.

Methods

The study included 128 patients with resectable stage II-III gastric cancer, in which 63 were given neoadjuvant Io+Chemo, and 65 Chemo alone. Patients given Io+Chemo were treated with 2-4 cycles of PD-(L)1 inhibitor (Pembrolizumab, Sintililimab or Nivolumab) with S-1 and oxaliplatin (SOX) or capecitabine and oxaliplatin (XELOX) before surgical resection. Patients given Chemo were treated with 2-4 cycles of SOX or XELOX before surgical resection. Tumor tissues were evaluated for tumor-infiltrating immune cells (TIICs) using immunohistochemistry and QuPath software quantitative analysis, for detecting T, B, NK, plasma cells, and macrophages. The relationship between TIICs and different neoadjuvant treatment regimens and pathological responses was also explored.

Results

Compared with Chemo, Io+Chemo induced higher rates of pathological complete response (33.3 vs. 9.2%, p=0.001) and major pathological response (MPR) (49.2 vs. 30.8%, p=0.033). Compared with Chemo group, density of CD4+(1904.8 vs. 1530), CD8+(1982.9 vs. 1124.4), CD20+(1115.6 vs. 574), CD38+(1580.4 vs. 1128), CD138+(1237.2 vs. 496.4), and CD56+ (596.8 vs. 159) cells was increased 24.5%, 76.4%, 94.4%, 40.1%, and 149.2% respectively, whereas CD163+ macrophages (994.4 vs. 1706) was decreased 41.7% in Io+Chemo group.

Conclusions

Our study favors neoadjuvant Io+Chemo over Chemo and reveals Io+Chemo can induce the formation of an immune-activated microenvironment that make Io+Chemo superior to Chemo.

Tumor microenvironment in primary central nervous system lymphoma (PCNSL)

Primary central nervous system lymphoma (PCNSL) is one of the rare lymphomas limited to the central nervous system. With the availability of immunotherapy, the tumor microenvironment (TME) attracts much attention nowadays. However, the systematic studies on the TME of PCNSL are lacking. By reviewing the existing research, we found that the TME of PCNSL is infiltrated with abundant TAMs and TILs, among which cytotoxic T cells (CTLs) and M2-polarized macrophages are principal. However, the counts of immune cells infiltrated in the TME of PCNSL are significantly lower than systemic diffuse large B-cell lymphoma (DLBCL). In addition, PCNSL can attract the infiltration of immunosuppressive cells and the loss of HLA I/II expression, overexpress inhibitory immune checkpoints, and release immunosuppressive cytokines to form an immunosuppressive TME. The immunosuppressive effect of TME in PCNSL is significantly stronger than that in systemic DLBCL. These characteristics of TME highlight the immunosuppression of PCNSL.

Circular RNA circPHLPP2 promotes tumor growth and anti-PD-1 resistance through binding ILF3 to regulate IL36γ transcription in colorectal cancer

BACKGROUND

Most Colorectal Cancer (CRC) patients exhibit limited responsiveness to anti-programmed cell death protein 1 (PD-1) therapy, with the underlying mechanisms remaining elusive. Circular RNAs (circRNAs) play a significant role in tumorigenesis and development, with potential applications in tumor screening and predicting treatment efficacy. However, there are few studies exploring the role of circRNAs in CRC immune evasion.

METHODS

circRNA microarrays were used to identify circPHLPP2. RT-qPCR was used to examine the associations between the expression level of circPHLPP2 and the clinical characteristics of CRC patients. MTS assay, clone formation experiment, subcutaneous tumor implantation and multicolor flow cytometry were used to confirm the biological function of circPHLPP2. RAN-seq, RT-qPCR, and WB experiments were performed to investigate the downstream signaling pathways involved in circPHLPP2. RNA pull-down, RNA immunoprecipitation (RIP) and immunofluorescence staining were performed to identify the proteins associated with circPHLPP2.

RESULTS

circPHLPP2 is up-regulated in CRC patients who exhibit resistance to anti-PD-1 based therapy. circPHLPP2 significantly promotes the proliferation and tumor growth of CRC cells. Knockdown of circPhlpp2 enhances the efficacy of anti-PD-1 in vivo. Mechanistically, the specific interaction between circPHLPP2 and ILF3 facilitates the nuclear accumulation of ILF3, which subsequently enhances the transcription of IL36γ. This process reduces NK cell infiltration and impairs NK cells' granzyme B and IFN-γ production, thereby promoting tumor progression.

CONCLUSIONS

Overall, our findings reveal a novel mechanism by which circRNA regulates CRC immune evasion. circPHLPP2 may serve as a prognostic biomarker and potential therapeutic target for CRC patients.

Exploring the Complexity of Pan-Cancer: Gene Convergences and in silico Analyses

Cancer is a complex and multifaceted group of diseases characterized by highly intricate mechanisms of tumorigenesis and tumor progression, which complicates diagnosis, prognosis, and treatment. In recent years, targeted therapies have gained prominence by focusing on specific mutations and molecular features unique to each tumor type, offering more effective and personalized treatment options. However, it is equally critical to explore the genetic commonalities across different types of cancer, which has led to the rise of pan-cancer studies. These approaches help identify shared therapeutic targets across various tumor types, enabling the development of broader and potentially more widely applicable treatment strategies. This review aims to provide a comprehensive overview of key concepts related to tumors, including tumorigenesis processes, the tumor microenvironment, and the role of extracellular vesicles in tumor biology. Additionally, we explore the molecular interactions and mechanisms driving tumor progression, with a particular focus on the pan-cancer perspective. To achieve this, we conducted an in silico analysis using publicly available datasets, which facilitated the identification of both common and divergent genetic and molecular patterns across different tumor types. By integrating these diverse areas, this review offers a clearer and deeper understanding of the factors influencing tumorigenesis and highlights potential therapeutic targets.

Immunotherapeutic strategies to induce inflection in the immune response: therapy for cancer and COVID-19

Cancer has agonized the human race for millions of years. The present decade witnesses biological therapeutics to combat cancer effectively. Cancer Immunotherapy involves the use of therapeutics for manipulation of the immune system by immune agents like cytokines, vaccines, and transfection agents. Recently, this therapeutic approach has got vast attention due to the current pandemic COVID-19 and has been very effective. Concerning cancer, immunotherapy is based on the activation of the host's antitumor response by enhancing effector cell number and the production of soluble mediators, thereby reducing the host's suppressor mechanisms by induction of a tumour killing environment and by modulating immune checkpoints. In the present era, immunotherapies have gained traction and momentum as a pedestal of cancer treatment, improving the prognosis of many patients with a wide variety of haematological and solid malignancies. Food supplements, natural immunomodulatory drugs, and phytochemicals, with recent developments, have shown positive trends in cancer treatment by improving the immune system. The current review presents the systematic studies on major immunotherapeutics and their development for the effective treatment of cancers as well as in COVID-19. The focus of the review is to highlight comparative analytics of existing and novel immunotherapies in cancers, concerning immunomodulatory drugs and natural immunosuppressants, including immunotherapy in COVID-19 patients.

Hemophagocytic lymphohistiocytosis: current treatment advances, emerging targeted therapy and underlying mechanisms

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly progressing, life-threatening syndrome characterized by excessive immune activation, often presenting as a complex cytokine storm. This hyperactive immune response can lead to multi-organ failure and systemic damage, resulting in an extremely short survival period if left untreated. Over the past decades, although HLH has garnered increasing attention from researchers, there have been few advancements in its treatment. The cytokine storm plays a crucial role in the treatment of HLH. Investigating the detailed mechanisms behind cytokine storms offers insights into targeted therapeutic approaches, potentially aiding in early intervention and improving the clinical outcome of HLH patients. To date, there is only one targeted therapy, emapalumab targeting interferon-γ, that has gained approval for primary HLH. This review aims to summarize the current treatment advances, emerging targeted therapeutics and underlying mechanisms of HLH, highlighting its newly discovered targets potentially involved in cytokine storms, which are expected to drive the development of novel treatments and offer fresh perspectives for future studies. Besides, multi-targeted combination therapy may be essential for disease control, but further trials are required to determine the optimal treatment mode for HLH.

Three-dimensional silk fibroin scaffolded co-culture of human neuroblastoma and innate immune cells

Neuroblastoma (NB) is the most common pediatric extracranial solid tumor. It accounts for 50 % of cancers diagnosed in infants less than 1 year old, and 10 % of all pediatric cancer deaths in the United States. High-risk patients have a less than 50 % 5-year survival rate with current treatment strategies. The complex tumor microenvironment of NB makes the development of treatment strategies for high-risk patients challenging. There is increasing evidence that intratumoral immune suppression plays an important role in the progression and invasion of NB tumors. Few three-dimensional (3D) cancer models include components of the innate immune system. This work develops a preclinical 3D NB-immune co-culture model using SK-N-AS NB cells, NK-92 natural killer cells, and THP-1 derived macrophages, co-cultured on porous 3D silk scaffolds to provide tumor architecture. Conditioned media and indirect co-culturing showed changes in SK-N-AS gene expression associated with immunoregulatory signaling, and changes in NK-92 gene expression that are associated with reduced cytotoxicity. This motivated the development of a 3D direct co-culture system in which NB cells were seeded prior to immune cells to allow incorporation and deposition of extracellular matrix within the construct. Immune cells were then incorporated into the model to achieve direct co-culture with SK-N-AS cells. Changes in THP-1 macrophage polarization toward a more M2-like phenotype were observed in 3D direct co-culture, as well as altered NK-92 cell protein secretion and cytotoxic activity. Preliminary testing of immunotherapeutics within the model was conducted on both NB-macrophage and NB-NK co-cultures, but the model demonstrated limited response to immunotherapeutics. This work lays the foundation for building high-throughput therapeutic screening models for the improved treatment NB and other solid tumors.

Killing of xenogenous and virally infected homogenous target cells by shrimp lymphocyte-like haemocytes

Haemocytes play a crucial role in the invertebrate's immune system. In our lab, five subpopulations of shrimp haemocytes were identified in the past: hyalinocytes, granulocytes, semi-granulocytes and two subpopulations of non-phagocytic cells. In the latter two subpopulations, their characteristics such as having small cytoplasmic rims and not adhering to plastic cell-culture plates are very similar to those of mammalian lymphocytes. Therefore, they were designated lymphocyte-like haemocytes. Although little is known about their function, we hypothesize, based on their morphology, that they may have a cytotoxic activity like natural killer cells, with the ability to recognize and kill target cells. In our study, K562 cells and Sf9 cells were used as xenogenous target cells to detect the cytotoxic activity of the shrimp non-adherent lymphocyte-like haemocytes. Non-adherent haemocytes were collected and mixed with K562 cells and Sf9 cells at a 5:1 ratio and the binding activity was examined under a microscope. The binding rate of non-adherent haemocytes to K562 cells and Sf9 cells reached 6.6 % and 2.4 % after 240 min of culture, respectively. Then, the killing activity of non-adherent haemocytes was detected by an EMA staining (fluorescence microscopy), which showed 3.75 % dead K562 cells and 1.025 % dead Sf9 cells, and by Sytox® blue staining (flow cytometry), which showed 4.97 % of dead K562 cells. Next, a killing assay was developed to visualize the killing activity of shrimp non-adherent haemocytes. Non-adherent haemocytes were pre-labeled in blue (CellTracker blue) and K562/Sf9 cells in green (CFSE); dead cells were differentially stained red with ethidium bromide. The cytotoxic activity increased and reached a level of 2.59 % in K562 cells and 0.925 % in Sf9 cells at 120 min after co-culture. Furthermore, in the co-cultures of non-adherent haemocytes with K562 cells and Sf9 cells, upregulation of the gene and protein expression of the cytotoxic molecules torso-like protein and granzyme B was observed by RT-qPCR at 240 min and western blotting at 180 min. Additionally, non-adherent haemocytes were co-cultured with WSSV-inoculated shrimp ovary and lymphoid organ cells to detect the cytotoxicity to homogenous target cells. The binding activity started at 60 min in both the ovary and lymphoid organ cultures and reached at 240 min 50.62 % and 40.7 %, respectively. The killing activity was detected by EMA staining and the percentage of dead ovary and lymphoid organ cells increased respectively from 10.84 % to 6.89 % at 0 min to 13.09 % and 8.37 % at 240 min. In conclusion, we demonstrated the existence of cytotoxic activity of shrimp lymphocyte-like haemocytes against xenogenous cells from mammals and insects and against WSSV-infected homogenous shrimp cells.

Nivolumab Reaches Brain Lesions in Patients with Recurrent Glioblastoma and Induces T-cell Activity and Upregulation of Checkpoint Pathways

Glioblastoma (GBM) is an aggressive brain tumor with poor prognosis. Although immunotherapy is being explored as a potential treatment option for patients with GBM, it is unclear whether systemic immunotherapy can reach and modify the tumor microenvironment in the brain. We evaluated immune characteristics in patients receiving the anti-PD-1 immune checkpoint inhibitor nivolumab 1 week prior to surgery, compared with control patients receiving salvage resection without prior nivolumab treatment. We observed saturating levels of nivolumab bound to intratumorally and tissue-resident T cells in the brain, implicating saturating levels of nivolumab reaching brain tumors. Following nivolumab treatment, significant changes in T-cell activation and proliferation were observed in the tumor-resident T-cell population, and peripheral T cells upregulated chemokine receptors related to brain homing. A strong nivolumab-driven upregulation in compensatory checkpoint inhibition molecules, i.e., TIGIT, LAG-3, TIM-3, and CTLA-4, was observed, potentially counteracting the treatment effect. Finally, tumor-reactive tumor-infiltrating lymphocytes (TIL) were found in a subset of nivolumab-treated patients with prolonged survival, and neoantigen-reactive T cells were identified in both TILs and blood. This indicates a systemic response toward GBM in a subset of patients, which was further boosted by nivolumab, with T-cell responses toward tumor-derived neoantigens. Our study demonstrates that nivolumab does reach the GBM tumor lesion and enhances antitumor T-cell responses both intratumorally and systemically. However, various anti-inflammatory mechanisms mitigate the clinical efficacy of the anti-PD-1 treatment.

PlexinB1 Inactivation Reprograms Immune Cells in the Tumor Microenvironment, Inhibiting Breast Cancer Growth and Metastatic Dissemination

Semaphorin-plexin signaling plays a major role in the tumor microenvironment (TME). In particular, Semaphorin 4D (SEMA4D) has been shown to promote tumor growth and metastasis; however, the role of its high-affinity receptor Plexin-B1 (PLXNB1), which is expressed in the TME, is poorly understood. In this study, we directly targeted PLXNB1 in the TME of triple-negative murine breast carcinoma to elucidate its relevance in cancer progression. We found that primary tumor growth and metastatic dissemination were strongly reduced in PLXNB1-deficient mice, which showed longer survival. PLXNB1 loss in the TME induced a switch in the polarization of tumor-associated macrophages (TAM) toward a pro-inflammatory M1 phenotype and enhanced the infiltration of CD8+ T lymphocytes both in primary tumors and in distant metastases. Moreover, PLXNB1 deficiency promoted a shift in the Th1/Th2 balance of the T-cell population and an antitumor gene signature, with the upregulation of Icos, Perforin-1, Stat3, and Ccl5 in tumor-infiltrating lymphocytes (TILs). We thus tested the translational relevance of TME reprogramming driven by PLXNB1 inactivation for responsiveness to immunotherapy. Indeed, in the absence of PLXNB1, the efficacy of anti-PD-1 blockade was strongly enhanced, efficiently reducing tumor growth and distant metastasis. Consistent with this, pharmacological PLXNB1 blockade by systemic treatment with a specific inhibitor significantly hampered breast cancer growth and enhanced the antitumor activity of the anti-PD-1 treatment in a preclinical model. Altogether, these data indicate that PLXNB1 signaling controls the antitumor immune response in the TME and highlight this receptor as a promising immune therapeutic target for metastatic breast cancers.

NK cell based immunotherapy against oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), a major subtype of head and neck cancers, presents significant challenges due to its aggressive feature and limited therapeutic efficacy of conventional treatments. In response to these challenges, Natural Killer (NK) cells, a vital component of the innate immune system, are being explored for their therapeutic potential in OSCC due to their inherent ability to target and eliminate cancer cells without prior sensitization. This review uniquely focuses on the evolving role of NK cells specifically in OSCC, incorporating recent advancements in CAR-NK cell engineering and personalized therapy approaches that have not been comprehensively covered in previous reviews. The mechanisms through which NK cells exert cytotoxic effects on tumor cells include direct killing through the engagement of natural cytotoxic receptors and antibody-dependent cellular cytotoxicity (ADCC), making them promising agents in cancer immunotherapy. Additionally, the article explores recent advancements in engineering NK cells to enhance their antitumor activity, such as the modification with chimeric antigen receptors (CARs) to target specific tumor antigens. Clinical implications of NK cell-based therapies, including the challenges of integrating these treatments with existing protocols and the potential for personalized therapy, are examined. The review highlights the promise of NK cell therapies in improving outcomes for OSCC patients and outlines future directions for research in this dynamic field of oncological immunotherapy.

Modulation of MHC expression by interferon-gamma and its influence on PBMC-mediated cytotoxicity in canine mast cell tumour cells

Immunotherapy is a promising alternative treatment for canine mast cell tumour (MCT). However, evasion of immune recognition by downregulating major histocompatibility complex (MHC) molecules might decline treatment efficiency. Enhancing MHC expression through interferon-gamma (IFN-γ) is crucial for effective immunotherapy. In-house and reference canine MCT cell lines derived from different tissue origins were used. The impacts of IFN-γ treatment on cell viability, expression levels of MHC molecules, as well as cell apoptosis were evaluated through the MTT assay, RT-qPCR and flow cytometry. The results revealed that IFN-γ treatment significantly influenced the viability of canine MCT cell lines, with varying responses observed among different cell lines. Notably, IFN-γ treatment increased the expression of MHC I and MHC II, potentially enhancing immune recognition and MCT cell clearance. Flow cytometry analysis in PBMCs-mediated cytotoxicity assays showed no significant differences in overall apoptosis between IFN-γ treated and untreated canine MCT cell lines across various target-to-effector ratios. However, a trend towards higher percentages of late and total apoptotic cells was observed in the IFN-γ treated C18 and CMMC cell lines, but not in the VIMC and CoMS cell lines. These results indicate a variable response to IFN-γ treatment among different canine MCT cell lines. In summary, our study suggests IFN-γ's potential therapeutic role in enhancing immune recognition and clearance of MCT cells by upregulating MHC expression and possibly promoting apoptosis, despite variable responses across different cell lines. Further investigations are necessary to elucidate the underlying mechanisms and evaluate IFN-γ's efficacy in in vivo models.

In-depth analysis of the interplay between oncogenic mutations and NK cell-mediated cancer surveillance in solid tumors

Natural killer (NK) cells play a crucial role in antitumoral and antiviral responses. Yet, cancer cells can alter themselves or the microenvironment through the secretion of cytokines or other factors, hindering NK cell activation and promoting a less cytotoxic phenotype. These resistance mechanisms, often referred to as the "hallmarks of cancer" are significantly influenced by the activation of oncogenes, impacting most, if not all, of the described hallmarks. Along with oncogenes, other types of genes, the tumor suppressor genes are frequently mutated or modified during cancer. Traditionally, these genes have been associated with uncontrollable tumor growth and apoptosis resistance. Recent evidence suggests oncogenic mutations extend beyond modulating cell death/proliferation programs, influencing cancer immunosurveillance. While T cells have been more studied, the results obtained highlight NK cells as emerging key protagonists for enhancing tumor cell elimination by modulating oncogenic activity. A few recent studies highlight the crucial role of oncogenic mutations in NK cell-mediated cancer recognition, impacting angiogenesis, stress ligands, and signaling balance within the tumor microenvironment. This review will critically examine recent discoveries correlating oncogenic mutations to NK cell-mediated cancer immunosurveillance, a relatively underexplored area, particularly in the era dominated by immune checkpoint inhibitors and CAR-T cells. Building on these insights, we will explore opportunities to improve NK cell-based immunotherapies, which are increasingly recognized as promising alternatives for treating low-antigenic tumors, offering significant advantages in terms of safety and manufacturing suitability.

Thetumor microenvironment'sinpancreatic cancer:Effects onimmunotherapy successandnovel strategiestoovercomethehostile environment

Cancer is a significant global health issue that poses a considerable burden on both patients and healthcare systems. Many different types of cancers exist that often require unique treatment approaches and therapies. A hallmark of tumor progression is the creation of an immunosuppressive environment, which poses complex challenges for current treatments. Amongst the most explored characteristics is a hypoxic environment, high interstitial pressure, and immunosuppressive cells and cytokines. Traditional cancer treatments involve radiotherapy, chemotherapy, and surgical procedures. The advent of immunotherapies was regarded as a promising approach with hopes of greatly increasing patients' survival and outcome. Although some success is seen with various immunotherapies, the vast majority of monotherapies are unsuccessful. This review examines how various aspects of the tumor microenvironment (TME) present challenges that impede the success of immunotherapies. Subsequently, we review strategies to manipulate the TME to facilitate the success of immunotherapies.

A Carbon-Caged Rhodamine Generating Nitrosoperoxycarbonate for Photoimmunotherapy

Photoimmunotherapy is a promising cancer treatment modality. While potent 1-e- oxidative species are known to induce immunogenic cell death (ICD), they are also associated with unspecific oxidation and collateral tissue damage. This difficulty may be addressed by post-generation radical reinforcement. Namely, non-oxidative radicals are first generated and subsequently activated into powerful oxidative radicals to induce ICD. Here, we developed a photo-triggered molecular donor (NPCD565) of nitrosoperoxycarbonate (ONOOCO2 -), the first of its class to our knowledge, and further evaluated its feasibility for immunotherapy. Upon irradiation of NPCD565 by light within a broad spectral region from ultraviolet to red, ONOOCO2 - is released along with a bright rhodamine dye (RD565), whose fluorescence is a reliable and convenient build-in reporter for the localization, kinetics, and dose of ONOOCO2 - generation. Upon photolysis of NPCD565 in 4T1 cells, damage-associated molecular patterns (DAMPs) indicative of ICD were observed and confirmed to exhibit immunogenicity by induced maturation of dendritic cells. In vivo studies with a bilateral tumor-bearing mouse model showcased the potent tumor-killing capability of NPCD565 of the primary tumors and growth suppression of the distant tumors. This work unveils the potent immunogenicity of ONOOCO2 -, and its donor (NPCD565) has broad potential for photo-immunotherapy of cancer.

Unique presentation of T-cell/histiocyte-rich large B cell lymphoma complicated with hemophagocytic lymphohistiocytosis: Case report and review of the literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare, lifethreatening hyperinflammatory disorder characterized by dysfunction of NK cells and cytotoxic lymphocytes. We present a rare case of a patient diagnosed with HLH who presented with persistent fever during treatment for refractory T-cell/histiocyte-rich large B-cell lymphoma (TCHRLBCL), highlighting the challenges of managing HLH in the context of refractory lymphoma. According to our review of the literature, this is the first case of HLH that developed several months into treatment for refractory TCHRLBCL and not in close temporal relation to lymphoma diagnosis.

PVALB Was Identified as an Independent Prognostic Factor for HCC Closely Related to Immunity, and Its Absence Accelerates Tumor Progression by Regulating NK Cell Infiltration

Purpose

Hepatocellular carcinoma is the most common primary liver cancer, with poor prognosis. Complex immune microenvironment of the liver is linked to the development of HCC. PVALB is a calcium-binding protein which has been described as a cancer suppressor gene in thyroid cancer and glioma. Nevertheless, the role of PVALB in HCC is unknown.

Materials and Methods

We obtained data from TCGA and GSE54236 datasets. MCP-counter, WGCNA and LASSO model were applied to identify PVALB. With UALCAN, MethSurv, and other websites, we probed the expression, methylation and survival of PVALB. LinkedOmics and GSEA were adopted for functional analysis, while TIMER, TISIDB, Kaplan-Meier plotter, TIDE databases were utilized to evaluate the relevance of PVALB to the tumor immune microenvironment and predict immunotherapy efficacy. TargetScan, DIANA, LncRNASNP2 databases and relevant experiments were employed to construct ceRNA network. Finally, molecular docking and drug sensitivity of PVALB were characterized by GeneMANIA, CTD, and so on.

Results

PVALB was recognized as a gene associated with HCC and NK cell. Its expression was down-regulated in HCC tissue, which lead to adverse prognosis. Besides, the hypomethylation of PVALB was related to its reduced expression. Notably, PVALB was tightly linked to immune, and its reduced expression attenuated the anticancer effect of NK cells via the Fas/FasL pathway, leading to a adverse outcome. The lnc-YY1AP1-3/hsa-miR-6735-5p/PVALB axis may regulate the PVALB expression. Finally, we found immunotherapy might be a viable treatment option.

Conclusion

In a word, PVALB is a prognostic indicator, whose low expression facilitates HCC progression by impacting NK cell infiltration.

Preclinical evaluation of two phylogenetically distant arenavirus vectors for the development of novel immunotherapeutic combination strategies for cancer treatment

BACKGROUND

Engineered arenavirus vectors have recently been developed to leverage the body's immune system in the fight against chronic viral infections and cancer. Vectors based on Pichinde virus (artPICV) and lymphocytic choriomeningitis virus (artLCMV) encoding a non-oncogenic fusion protein of human papillomavirus (HPV)16 E6 and E7 are currently being tested in patients with HPV16+ cancer, showing a favorable safety and tolerability profile and unprecedented expansion of tumor-specific CD8+ T cells. Although the strong antigen-specific immune response elicited by artLCMV vectors has been demonstrated in several preclinical models, PICV-based vectors are much less characterized.

METHODS

To advance our understanding of the immunobiology of these two vectors, we analyzed and compared their individual properties in preclinical in vivo and in vitro systems. Immunogenicity and antitumor effect of intratumoral or intravenous administration of both vectors, as well as combination with NKG2A blockade, were evaluated in naïve or TC-1 mouse tumor models. Flow cytometry, Nanostring, and histology analysis were performed to characterize the tumor microenvironment (TME) and T-cell infiltrate following treatment.

RESULTS

Despite being phylogenetically distant, both vectors shared many properties, including preferential infection and activation of professional antigen-presenting cells, and induction of potent tumor-specific CD8+ T-cell responses. Systemic as well as localized treatment induced a proinflammatory shift in the TME, promoting the infiltration of inducible T cell costimulator (ICOS)+CD8+ T cells capable of mediating tumor regression and prolonging survival in a TC-1 mouse tumor model. Still, there was evidence of immunosuppression built-up over time, and increased expression of H2-T23 (ligand for NKG2A T cell inhibitory receptor) following treatment was identified as a potential contributing factor. NKG2A blockade improved the antitumor efficacy of artARENA vectors, suggesting a promising new combination approach. This demonstrates how detailed characterization of arenavirus vector-induced immune responses and TME modulation can inform novel combination therapies.

CONCLUSIONS

The artARENA platform represents a strong therapeutic vaccine approach for the treatment of cancer. The induced antitumor immune response builds the backbone for novel combination therapies, which warrant further investigation.

Mesoporous nanoperforators as membranolytic agents via nano- and molecular-scale multi-patterning

Plasma membrane lysis is an effective anticancer strategy, which mostly relying on soluble molecular membranolytic agents. However, nanomaterial-based membranolytic agents has been largely unexplored. Herein, we introduce a mesoporous membranolytic nanoperforators (MLNPs) via a nano- and molecular-scale multi-patterning strategy, featuring a spiky surface topography (nanoscale patterning) and molecular-level periodicity in the spikes with a benzene-bridged organosilica composition (molecular-scale patterning), which cooperatively endow an intrinsic membranolytic activity. Computational modelling reveals a nanospike-mediated multivalent perforation behaviour, i.e., multiple spikes induce nonlinearly enlarged membrane pores compared to a single spike, and that benzene groups aligned parallelly to a phospholipid molecule show considerably higher binding energy than other alignments, underpinning the importance of molecular ordering in phospholipid extraction for membranolysis. Finally, the antitumour activity of MLNPs is demonstrated in female Balb/c mouse models. This work demonstrates assembly of organosilica based bioactive nanostructures, enabling new understandings on nano-/molecular patterns co-governed nano-bio interaction.

Optimising IL-2 for Cancer Immunotherapy

The key role of T cells in cancer immunotherapy is well established and is highlighted by the remarkable capacity of Ab-mediated checkpoint blockade to overcome T-cell exhaustion and amplify anti-tumor responses. However, total or partial tumor remission following checkpoint blockade is still limited to only a few types of tumors. Hence, concerted attempts are being made to devise new methods for improving tumor immunity. Currently, much attention is being focused on therapy with IL-2. This cytokine is a powerful growth factor for T cells and optimises their effector functions. When used at therapeutic doses for cancer treatment, however, IL-2 is highly toxic. Nevertheless, recent work has shown that modifying the structure or presentation of IL-2 can reduce toxicity and lead to effective anti-tumor responses in synergy with checkpoint blockade. Here, we review the complex interaction of IL-2 with T cells: first during normal homeostasis, then during responses to pathogens, and finally in anti-tumor responses.

PD-1/PD-L1 governed cross-talk of exhausted CD8+ T and memory B cells in systemic lupus erythematosus

BACKGROUND

Indeterminate readout of the quantitative interferon-γ release test (QFT) for Mycobacterium tuberculosis screening is a specific laboratory finding for systemic lupus erythematosus (SLE), which may be due to T-cell exhaustion and abnormal programmed death receptor 1 (PD-1)/programmed death-ligand 1 (PD-L1) signalling.

METHODS

We enrolled 104 patients with SLE and 225 with other rheumatic musculoskeletal diseases (RMDs) who presented to the outpatient clinic between 2020 and 2023. Twenty healthy donors served as the controls. The QFT was performed in all participants, and those with indeterminate results were compared among the groups. Immunophenotyping and functional assays were performed using blood mononuclear cells. Interferon (IFN)-γ was detected in vitro and ex vivo in patients with SLE with indeterminate or negative QFT results, before or after rituximab therapy.

RESULTS

104 patients with SLE had a significantly higher rate of indeterminate QFT results was significantly higher (17.31%) than that of 225 patients with RMD (3.56%). Patients with SLE with indeterminate QFT had more active disease (SLEDAI-2K, mean 10.94 vs 4.02, p<0.0001), including a higher incidence of active nephritis (55.56% vs 29.07%). Indeterminate QFT in SLE is mainly caused by an insufficient IFN-γ response in CD8+T cells with exhausted immunophenotypes. The abnormal interaction between exhausted PD-1 high CD8+ T cells and activated PD-L1 low memory B cells in SLE can be reversed with a PD-1 agonist or increased PD-L1 expression. Rituximab treatment indirectly reversed this IFN-γ response.

CONCLUSION

The PD-1/PD-L1 signalling pathway, which governs the crosstalk between exhausted CD8+ T cells and activated memory B cells, is a mechanistic explanation for insufficient interferon-γ response in patients with SLE.

Immunoregulatory functions and therapeutic potential of natural killer cell-derived extracellular vesicles in chronic diseases

Extracellular vesicles (EVs) have been proven to play a significant immunoregulatory role in many chronic diseases, such as cancer and immune disorders. Among them, EVs derived from NK cells are an essential component of the immune cell functions. These EVs have been demonstrated to carry a variety of toxic proteins and nucleic acids derived from NK cells and play a therapeutic role in diseases like malignancies, liver fibrosis, and lung injury. However, natural NK-derived EVs (NKEVs) have certain limitations in disease treatment, such as low yield and poor targeting. Concurrently, NK cells exhibit characteristics of memory-like NK cells, which have stronger proliferative capacity, increased IFN-γ production, and enhanced cytotoxicity, making them more advantageous for disease treatment. Recent research has shifted its focus towards engineered extracellular vesicles and their potential to improve the efficiency, specificity, and safety of disease treatments. In this review, we will discuss the characteristics of NK-derived EVs and the latest advancements in disease therapy. Specifically, we will compare different cellular sources of NKEVs and explore the current status and prospects of memory-like NK cell-derived EVs and engineered NKEVs.

Hemophagocytic Lymphohistiocytosis in Adolescents and Young Adults: Genetic Predisposition and Secondary Disease

Hemophagocytic lymphohistiocytosis (HLH) is a disorder of impaired immune regulation resulting in hyperinflammation that is ultimately fatal if not treated. HLH is categorized into familial disease, caused by genetic mutations affecting the function of cytotoxic T lymphocytes and natural killer cells, and secondary disease, triggered by infections, malignancies, rheumatologic disorders, or immune deficiency. Adolescent and young adults with HLH represent a unique population with specific diagnostic challenges. Here we review the diagnostic criteria, possible etiologies, pathophysiology, and management of HLH with focus on the adolescent population.

T cell receptor sequences are the dominant factor contributing to the phenotype of CD8+ T cells with specificities against immunogenic viral antigens

Antigen-specific CD8+ T cells mediate pathogen clearance. T cell phenotype is influenced by T cell receptor (TCR) sequences and environmental signals. Quantitative comparisons of these factors in human disease, while challenging to obtain, can provide foundational insights into basic T cell biology. Here, we investigate the phenotype kinetics of 679 CD8+ T cell clonotypes, each with specificity against one of three immunogenic viral antigens. Data were collected from a longitudinal study of 68 COVID-19 patients with antigens from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cytomegalovirus (CMV), and influenza. Each antigen is associated with a different type of immune activation during COVID-19. We find TCR sequence to be by far the most important factor in shaping T cell phenotype and persistence for populations specific to any of these antigens. Our work demonstrates the important relationship between TCR sequence and T cell phenotype and persistence and helps explain why T cell phenotype often appears to be determined early in an infection.

CD8+ T-cells target the Crimean-Congo haemorrhagic fever virus Gc protein to control the infection in wild-type mice

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a serious viral hemorrhagic fever caused by the CCHF virus (CCHFV). Spread by the bites of infected ticks or handling of viremic livestock, human disease is characterized by a non-specific febrile illness that can rapidly progress to fatal hemorrhagic disease. No vaccines or antivirals are available. Case fatality rates can vary but can be higher than 30%, although sub-clinical infections are often unrecognized and unreported. Yet, while most humans infected with CCHFV will survive the infection, often with little-to-no symptoms, the host responses that control the infection are unknown.

METHODS

Here we investigated the role of cellular immunity in control of CCHFV infection in an immunocompetent mouse model.

FINDINGS

We found that CD8+ T-cells are crucial for efficient control of the acute infection and rapidly acquired CCHFV-specific antiviral effector functions such as production of antiviral cytokines and degranulating in response to CCHFV peptides. We further identified the minimal CD8+ T-cell epitopes in the viral Gc proteins and that infection of mice lacking IFNγ resulted in worsened disease and higher viral loads.

INTERPRETATION

Together our data suggest that CD8+ T-cells are important for control of acute CCHFV infection likely through production of antiviral cytokines.

FUNDING

This work was supported by the Intramural Research Program of the NIH.

Hemophagocytic lymphohistiocytosis with a hemizygous PRF1 c.674G>A mutation

Hemophagocytic lymphohistiocytosis(HLH) is a rare highly-fatal disease presenting with fever, hepatosplenomegaly, and pancytopenia and has a poor prognosis. Homozygous or semi-zygous or complex heterozygous variants can cause familial HLH and heterozygous carriers are frequently seen in secondary HLH. A 42-year-old male patient was admitted to the hospital for persistent fever, fatigue, and splenomegaly. Investigations revealed hypertriglyceridemia, hyperlactatemia dehydrogenaseemia, hyperferritinemia, and elevated levels of soluble cluster of differentiation 25. We found a heterozygous mutation of PRF1: c.674G>A (p.R225Q) through next-generation sequencing technology of hemophagocytic-lymphohistiocytosis-related genes. After a brief remission with dexamethasone and etoposide-based therapy, the disease relapsed quickly, and an allogeneic hematopoietic stem cell transplant was performed to achieve complete remission. To date, the patient's condition was in complete remission. Our study detected a rare missense mutation in the PRF1 gene in a patient with HLH disease and the c.674G>A mutation may be rated as a possible pathogenic variant.

Osimertinib resistance prognostic gene signature: STRIP2 is associated with immune infiltration and tumor progression in lung adenocarcinoma

OBJECTIVE

Although the use of osimertinib can significantly improve the survival time of lung adenocarcinoma (LUAD) patients with epithelial growth factor receptor mutation, eventually drug resistance will limit the survival benefit of most patients. This study aimed to develop a novel prognostic predictive signature based on genes associated with osimertinib resistance.

METHODS

The differentially expressed genes (DEGs) associated with osimertinib resistance in LUAD were screened from Gene Expression Omnibus datasets and The Cancer Genome Atlas datasets. Multivariate cox regression was used to establish a prognostic signature, and then a nomogram was developed to predict the survival probability of LUAD patients. We used ROC curve and DCA curve to evaluate its clinical prediction accuracy and net benefit. In addition, the differentially expressed genes significantly associated with prognosis were selected for immune infiltration analysis and drug sensitivity analysis, and their roles in the progression of lung adenocarcinoma were verified by in vitro experiments.

RESULTS

Our evaluation results indicated that the new nomogram had higher clinical prediction accuracy and net benefit value than the TN nomogram. Further analysis showed that patients with low STRIP2 expression had a higher level of immune response, and may be more likely to benefit from immune checkpoint inhibitors and conventional antitumor drugs. This may help to select more precise and appropriate therapy for LUAD patients with osimertinib resistance. Furthermore, in vitro experiments showed that STRIP2 promoted the LUAD cells proliferation, migration and invasion. This further demonstrates the importance of this gene signature for prognostic prediction.

CONCLUSION

We developed a reliable prognostic model based on DEGs associated with osimertinib resistance and screened for biomarker that can predict the immune response in LUAD patients, which may help in the selection of treatment regimens after osimertinib resistance.

Defining Tumor Microenvironment as a Possible Target for Effective GEP-NENs Immunotherapy-A Systematic Review

Neuroendocrine neoplasms (NENs) are a heterogenous and recurrent group of malignancies originating from neuroendocrine secretory cells diffused on all parts of the human body. Gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) account for most NENs. Considering the abundance of possible origins, locations, and tumor specifications, there is still no consensus about optimal treatment options for these neoplasms. In light of the escalating immunotherapeutic approaches, it is crucial to define indications for such therapy in GEP-NETs. Bearing in mind the significance of pathophysiological mechanisms and tumor microenvironment (TME) impact on carcinogenesis, defining TME structure and correlation with the immune system in GEP-NETs appears essential. This paper aimed to assess the characterization of the tumor immune microenvironment for a better understanding of the possible therapeutic options in GEP-NETS. The authors performed a systematic review, extracting papers from the PubMed, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among 3800 articles identified through database searching, 292 were assessed for eligibility. Ultimately, 28 articles were included in the qualitative synthesis. This paper sums up the research on the immune cell infiltrates, immune checkpoint expression, cytokine profile, neoangiogenesis, and microbiome in the TME of GEP-NETs.

Preclinical 3D-model supports an invisibility cloak for adenoid cystic carcinoma

The tumour-cell based initiation of immune evasion project evaluated the role of Gipie in adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (A-253), from ninety-six 3D-ACC and A-253-immune co-culture models using natural killer cells (NK), and Jurkat cells (JK). Abnormal ACC morphology was observed in 3D-ACC immune co-culture models. Gipie-silencing conferred a "lymphoblast-like" morphology to ACC cells, a six-fold increase in apoptotic cells (compared to unaltered ACC cells, P ≤ 0.0001), a two-fold decrease in T regulatory cells (FoxP3+/IL-2Rα+/CD25+) (P ≤ 0.0001), and a three-fold increase in activated NK cells (NKp30+/IFN-γ+) (P ≤ 0.0001) with significantly higher release of granzyme (P ≤ 0.001) and perforin (P ≤ 0.0001).

Intracellular Salmonella delivery of an exogenous immunization antigen refocuses CD8 T cells against cancer cells, eliminates pancreatic tumors and forms antitumor immunity

Introduction

Immunotherapies have shown great promise, but are not effective for all tumors types and are effective in less than 3% of patients with pancreatic ductal adenocarcinomas (PDAC). To make an immune treatment that is effective for more cancer patients and those with PDAC specifically, we genetically engineered Salmonella to deliver exogenous antigens directly into the cytoplasm of tumor cells. We hypothesized that intracellular delivery of an exogenous immunization antigen would activate antigen-specific CD8 T cells and reduce tumors in immunized mice.

Methods

To test this hypothesis, we administered intracellular delivering (ID) Salmonella that deliver ovalbumin as a model antigen into tumor-bearing, ovalbumin-vaccinated mice. ID Salmonella delivers antigens by autonomously lysing in cells after the induction of cell invasion.

Results

We showed that the delivered ovalbumin disperses throughout the cytoplasm of cells in culture and in tumors. This delivery into the cytoplasm is essential for antigen cross-presentation. We showed that co-culture of ovalbumin-recipient cancer cells with ovalbumin-specific CD8 T cells triggered a cytotoxic T cell response. After the adoptive transfer of OT-I CD8 T cells, intracellular delivery of ovalbumin reduced tumor growth and eliminated tumors. This effect was dependent on the presence of the ovalbumin-specific T cells. Following vaccination with the exogenous antigen in mice, intracellular delivery of the antigen cleared 43% of established KPC pancreatic tumors, increased survival, and prevented tumor re-implantation.

Discussion

This response in the immunosuppressive KPC model demonstrates the potential to treat tumors that do not respond to checkpoint inhibitors, and the response to re-challenge indicates that new immunity was established against intrinsic tumor antigens. In the clinic, ID Salmonella could be used to deliver a protein antigen from a childhood immunization to refocus pre-existing T cell immunity against tumors. As an off-the-shelf immunotherapy, this bacterial system has the potential to be effective in a broad range of cancer patients.

Circulating Natural Killer Cells as Prognostic Value for Non-Small-Cell Lung Cancer Patients Treated with Immune Checkpoint Inhibitors: Correlation with Sarcopenia

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of tumors. Natural killer (NK) cells can play an important role in cancer immune surveillance. The aim of this prospective observational study was to analyze peripheral blood mononuclear cells (PBMCs) in patients with advanced non-small-cell lung cancer (NSCLC) receiving ICIs in order to identify predictive factors for better survival outcomes.

METHODS

Forty-seven stage IV NSCLC patients were enrolled. Patients underwent baseline (T₀) and longitudinal (T₁) evaluations after ICIs. Peripheral immune blood cell counts were analyzed using flow cytometry.

RESULTS

Basal levels of CD3^-CD56⁺ NK cells were higher in patients with controlled disease (DC) compared to progression disease (PD) patients (127 cells/µL vs. 27.8 cells/µL, p < 0.001). Lower NK cell values were independent prognostic factors for shorter overall survival (OS) (HR 0.992; 95% CI 0.987-0.997, p < 0.001) and progression-free survival (PFS) (HR 0.988; 95% CI 0.981-0.994, p < 0.001). During the longitudinal evaluation, CD3^-CD56⁺ NK cells (138.1 cells/µL vs. 127 cells/µL, p = 0.025) and CD56^bright NK cells (27.4 cells/µL vs. 18.1 cells/µL, p = 0.034) significantly increased in the DC group. Finally, lower values of CD3^-CD56⁺ NK cells (28.3 cells/µL vs. 114.6 cells/µL, p = 0.004) and CD56^dim NK cells (13.2 cells/µL vs. 89.4 cells/µL, p < 0.001) were found in sarcopenic patients compared to patients without sarcopenia.

CONCLUSIONS

Peripheral NK cells could represent a non-invasive and useful tool to predict ICI therapy response in NSCLC patients, and the association of low NK cell levels with sarcopenia deserves even more attention in clinical evaluation.

Immunity and Immune Evasion Mechanisms of Epstein-Barr Virus

Epstein-Barr virus (EBV) is the first human oncogenic virus to be identified, which evades the body's immune surveillance through multiple mechanisms that allow long-term latent infection. Under certain pathological conditions, EBVs undergo a transition from the latent phase to the lytic phase and cause targeted dysregulation of the host immune system, leading to the development of EBV-related diseases. Therefore, an in-depth understanding of the mechanism of developing an immune response to EBV and the evasion of immune recognition by EBV is important for the understanding of the pathogenesis of EBV, which is of great significance for finding strategies to prevent EBV infection, and developing a therapy to treat EBV-associated diseases. In this review, we will discuss the molecular mechanisms of host immunological responses to EBV infection and the mechanisms of EBV-mediated immune evasion during chronic active infection.

Natural killer cell epigenetic reprogramming in tumors and potential for cancer immunotherapy

Natural killer (NK) cells are critical members of the innate lymphoid cell population and have a pivotal role in cancer eradication. NK cell maturation, development and function are tightly regulated by epigenetic modifications, which can also be recruited for cancer propagation and immune escape. NK cells have the potential to be activated against tumors through several epigenetic regulators. Given that epigenetic changes are inducible and reversible, focusing on aberrant epigenetic regulations recruited by tumor cells provides a tremendous opportunity for cancer treatment. This review presents a comprehensive picture of NK cell normal epigenetic regulation and cancer-driven epigenetic modifications. From our perspective, a better understanding of epigenetic regulators that can edit and revise NK cells' activity is a promising avenue for NK cell-based therapy in cancer management.

Development of an antibody-ligand fusion protein scFvCD16A-sc4-1BBL in Komagataella phaffii with stimulatory activity for Natural Killer cells

BACKGROUND

Natural killer (NK) cell-based immunotherapies have demonstrated substantial potential for the treatment of hematologic malignancies. However, its application is limited due to the difficulty in the production of a large number of NK cells in vitro and the insufficient therapeutic efficacy against solid tumors in vivo. Engineered antibodies or fusion proteins targeting activating receptors and costimulatory molecules of NK cells have been developed to encounter these problems. They are mostly produced in mammalian cells with high cost and long processing times. Yeast systems, such as Komagataella phaffii, present a convenient manipulation of microbial systems with the key advantages of improved folding machinery and low cost.

RESULTS

In this study, we designed an antibody fusion protein scFvCD16A-sc4-1BBL, composed of the single chain variant fragment (scFv) of anti-CD16A antibody and the three extracellular domains (ECDs) of human 4-1BBL in a single-chain format (sc) with the GS linker, aiming to boost NK cell proliferation and activation. This protein complex was produced in the K. phaffii X33 system and purified by affinity chromatography and size exclusion chromatography. The scFvCD16A-sc4-1BBL complex showed comparable binding abilities to its two targets human CD16A and 4-1BB as its two parental moieties (scFvCD16A and monomer ECD (mn)4-1BBL). scFvCD16A-sc4-1BBL specifically stimulated the expansion of peripheral blood mononuclear cell (PBMC)-derived NK cells in vitro. Furthermore, in the ovarian cancer xenograft mouse model, adoptive NK cell infusion combined with intraperitoneal (i.p) injection of scFvCD16A-sc4-1BBL further reduced the tumor burden and prolonged the survival time of mice.

CONCLUSION

Our studies demonstrate the feasibility of the expression of the antibody fusion protein scFvCD16A-sc4-1BBL in K. phaffii with favourable properties. scFvCD16A-sc4-1BBL stimulates PBMC-derived NK cell expansion in vitro and improves the antitumor activity of adoptively transferred NK cells in a murine model of ovarian cancer and may serve as a synergistic drug for NK immunotherapy in future research and applications.

Multiple Actions of Telomerase Reverse Transcriptase in Cell Death Regulation

Telomerase reverse transcriptase (TERT), a core part of telomerase, has been known for a long time only for its telomere lengthening function by reverse transcription of RNA template. Currently, TERT is considered as an intriguing link between multiple signaling pathways. The diverse intracellular localization of TERT corresponds to a wide range of functional activities. In addition to the canonical function of protecting chromosome ends, TERT by itself or as a part of the telomerase complex participates in cell stress responses, gene regulation and mitochondria functioning. Upregulation of TERT expression and increased telomerase activity in cancer and somatic cells relate to improved survival and persistence of such cells. In this review, we summarize the data for a comprehensive understanding of the role of TERT in cell death regulation, with a focus on the interaction of TERT with signaling pathways involved in cell survival and stress response.

Deciphering the complete human-monkeypox virus interactome: Identifying immune responses and potential drug targets

Monkeypox virus (MPXV) is a dsDNA virus, belonging to Poxviridae family. The outbreak of monkeypox disease in humans is critical in European and Western countries, owing to its origin in African regions. The highest number of cases of the disease were found in the United States, followed by Spain and Brazil. Understanding the complete infection mechanism of diverse MPXV strains and their interaction with humans is important for therapeutic drug development, and to avoid any future epidemics. Using computational systems biology, we deciphered the genome-wide protein-protein interactions (PPIs) between 22 MPXV strains and human proteome. Based on phylogenomics and disease severity, 3 different strains of MPXV: Zaire-96-I-16, MPXV-UK_P2, and MPXV_USA_2022_MA001 were selected for comparative functional analysis of the proteins involved in the interactions. On an average, we predicted around 92,880 non-redundant PPIs between human and MPXV proteomes, involving 8014 host and 116 pathogen proteins from the 3 strains. The gene ontology (GO) enrichment analysis revealed 10,624 common GO terms in which the host proteins of 3 strains were highly enriched. These include significant GO terms such as platelet activation (GO:0030168), GABA-A receptor complex (GO:1902711), and metalloendopeptidase activity (GO:0004222). The host proteins were also significantly enriched in calcium signaling pathway (hsa04020), MAPK signaling pathway (hsa04010), and inflammatory mediator regulation of TRP channels (hsa04750). These significantly enriched GO terms and KEGG pathways are known to be implicated in immunomodulatory and therapeutic role in humans during viral infection. The protein hubs analysis revealed that most of the MPXV proteins form hubs with the protein kinases and AGC kinase C-terminal domains. Furthermore, subcellular localization revealed that most of the human proteins were localized in cytoplasm (29.22%) and nucleus (26.79%). A few drugs including Fostamatinib, Tamoxifen and others were identified as potential drug candidates against the monkeypox virus disease. This study reports the genome-scale PPIs elucidation in human-monkeypox virus pathosystem, thus facilitating the research community with functional insights into the monkeypox disease infection mechanism and augment the drug development.

Myocarditis: causes, mechanisms, and evolving therapies

INTRODUCTION

Myocarditis is a severe lymphocyte-mediated inflammatory disorder of the heart, mostly caused by viruses and immune checkpoint inhibitors (ICIs). Recently, myocarditis as a rare adverse event of mRNA vaccines for SARS-CoV-2 has caused global attention. The clinical consequences of myocarditis can be very severe, but specific treatment options are lacking or not yet clinically proven.

AREAS COVERED

This paper offers a brief overview of the biology of viruses that frequently cause myocarditis, focusing on mechanisms important for viral entry and replication following host infection. Current and new potential therapeutic targets/strategies especially for viral myocarditis are reviewed systematically. In particular, the immune system in myocarditis is dissected with respect to infective viral and non-infective, ICI-induced myocarditis.

EXPERT OPINION

Vaccination is an excellent emerging preventative strategy for viral myocarditis, but most vaccines still require further development. Anti-viral treatments that inhibit viral replication need to be considered following viral infection in host myocardium, as lower viral load reduces inflammation severity. Understanding how the immune system continues to damage the heart even after viral clearance will define novel therapeutic targets/strategies. We propose that viral myocarditis can be best treated using a combination of antiviral agents and immunotherapies that control cytotoxic T cell activity.