Granzyme B Research Articles

Death and survival of gut CD4 T cells following HIV-1 infection ex vivo

Abstract The gastrointestinal (GI) tract is ground zero for the massive and sustained CD4 T cell depletion during acute HIV-1 infection. To date, the molecular mechanisms governing this fundamental pathogenic process remain unclear. HIV-1 infection in the GI tract is associated with chronic inflammation due to a disrupted epithelial barrier that results in microbial translocation. Here, we utilized the Lamina Propria Aggregate Culture model to demonstrate that the profound induction of Granzyme B (GZB) by bacteria in primary gut CD4 T cells ex vivo significantly contributes to HIV-1-mediated CD4 T cell death. Counterintuitively, a substantial fraction of gut GZB+ CD4 T cells harboring high levels of HIV-1 infection survive via a pathway linked to CD120b/TNFR2. Our findings underscore novel mechanisms governing the death and survival of gut CD4 T cells during HIV-1 infection that could inform strategies to counter HIV-1 pathogenesis and persistence in this critical tissue compartment.

HLA-G expression associates with immune evasion muscle-invasive urothelial cancer and drives prognostic relevance.

Urothelial bladder cancer is frequent and exhibits diverse prognoses influenced by molecular subtypes, urothelial subtype histology, and immune microenvironments. HLA-G, known for immune regulation, displays significant membranous expression in tumor tissues. We studied the protein expression of Human Leucocyte Antigen G (HLA-G) in 241 Muscle-Invasive Bladder Cancer (MIBC) patients, elucidating its potential clinical and biological significance. Protein expression levels were evaluated and correlated with molecular subtypes, histological characteristics, immune microenvironment markers, and survival outcomes. High HLA-G expression associates with poor overall survival (OS) and diseasespecific survival (DSS), independent of clinicopathological parameters. HLA-G expression varies among molecular subtypes and Urothelial Subtype Histology, e.g., elevated expression levels in basal/squamous MIBC and those with sarcomatoid differentiation. Notably, HLA-G is increased in MIBC with an immune evasive microenvironment (high PD-L1 tumor cell expression, NK cell depletion, granzyme B (GZMB)/CD8 ratio reduction, MHC class I (MHCI) expression reduction) that are characterized by immunosuppressive features and poor prognosis. Furthermore, HLA-G correlates with elevated levels of other immune checkpoint proteins (TIGIT, LAG3, CTLA-4), indicating its role in immune evasion. Our findings underscore HLA-G's role as a potential prognostic marker and interesting immunotherapeutic target in MIBC. Its impact on immune evasion mechanisms and broad expression, coupled with associations withpoor survival and distinct tumor phenotypes, positions HLA-G as a promising protein for further exploration in developing targeted immunotherapies for MIBC patients.

Clinical Significance of Granzyme B Gene Expression in Pathological Stage II/III Gastric Cancer After Curative Gastrectomy.

Granzyme B (GZMB) is mainly produced by natural killer (NK) cells and activated CD8-positive T cells to induce tumor cell apoptosis. We analyzed the significance of GZMB expression in gastric cancer (GC) tissues from patients with pathological (p)Stage II/III GC after curative resection. Patients with pStage II/III GC who received curative resection (n=253) were included and the expression levels of GZMB in GC tissues and in the adjacent normal mucosa were measured using quantitative real-time polymerase chain reaction. The expression levels in GC tissues and clinicopathological features and overall survival (OS) were compared in these patients. GZMB expression levels were significantly higher in GC tissues than in the adjacent normal mucosa. GZMB expression levels in GC tissues were not associated with any clinicopathological features. The 5-year OS rate in the high-GZMB expression group was significantly better than that in the low-expression group (5-year survival rate 72.0% vs. 55.7%; p=0.009). Furthermore, on multivariate analysis, high-GZMB expression was an independent factor for better OS (hazard ratio=0.652; 95% confidence interval=0.432-0.987; p=0.043). In patients with locally advanced GC after curative resection, GZMB expression in GC tissue may be a useful prognostic marker.

Inhibition of GZMB activity ameliorates cognitive dysfunction by reducing demyelination in diabetic mice

BackgroundDiabetic cognitive dysfunction (DCD) has attracted increased attention, but its precise mechanism remains to be explored. Oligodendrocytes form myelin sheaths that wrap around axons. Granzyme B (GZMB) can cause axonal degeneration of the central nervous system. However, the role of GZMB in diabetic cognitive dysfunction (DCD) has not been reported. This study aimed to investigate whether GZMB promotes demyelination and participates in DCD by regulating the endoplasmic reticulum stress function of oligodendrocytes. MethodsStreptozotocin was injected intraperitoneally to establish a diabetic model in C57BL/6 mice. The mice were randomly divided into four groups: control group, diabetic group, diabetic + SerpinA3N group, and diabetic + saline treatment group. We performed the Morris water maze test to assess the learning and memory abilities of the mice. An immunofluorescence assay was performed to detect the expression sites of GZMB and OLIG2 in the hippocampal CA1 region. Luxol Fast Blue staining and electron microscopy were performed to detect the myelin number and myelin plate densities. Immunohistochemistry was used to detect the expression levels of MBP and CNPase. Protein blotting was used to assess the expression levels of GZMB, PERK, p-PERK, eIF2α, p-eIF2α, NLRP3, Caspase-1, GSDMD-N, IL-1β, and IL-18 as well as MBP and CNPase. ResultsThe GZMB inhibitor SerpinA3N reduces escape latency and increases the traversing platforms and residence time in the target area, improving DCD in mice. It also reduces endoplasmic reticulum stress in hippocampal oligodendrocytes and focal prolapse, further promoting MBP and CNPase expression and reducing demyelination. ConclusionsOur findings suggest that inhibition of GZMB activity modulates oligodendrocyte endoplasmic reticulum stress and pyroptosis, reduces demyelination, and ameliorates diabetes-related cognitive impairment.

Cigarette Smoking Is Associated With Lower Chance of Hepatitis B Surface Antigen Seroclearance and Altered Host Immunity.

Cigarette smoking is associated with worse clinical outcomes in patients with chronic hepatitis B (CHB) infection, but the effects on hepatitis B surface antigen (HBsAg) seroclearance are unclear. This study aimed to investigate the effect of active smoking on HBsAg seroclearance (SC) and its impact on peripheral blood lymphocytes in patients with CHB infection. Longitudinal follow-up data was retrieved in 7833 antiviral-treated CHB subjects identified from a centralised electronic patient record database (Part 1). Phenotypic analysis of peripheral blood mononuclear cells (PBMCs) from 27 CHB-infected patients (6 active smokers; 13 with SC) was performed by flow cytometry to assess programmed death-1 (PD-1) expression and proportion of regulatory T cells (CD4+CD25+CD127lo). Effector function of HBV-specific T cells was examined by comparing granzyme B (GZMB) and transforming growth factor beta (TGFβ) production in undepleted PBMCs and Treg-depleted PBMCs after 7 days invitro stimulation with HBV envelope protein overlapping peptides (Part 2). Over a median follow-up of 5 years, smoking was associated with lower probability of SC (aHR 0.70, 95% CI 0.57-0.87). PD-1 expression was increased in CD4+T cells, CD8+T cells and CD20+B cells among smokers compared to non-smokers and positively correlated with pack years (all p < 0.05). Treg depletion led to partial functional recovery of HBV-specific T cells, with significantly bigger magnitude in smokers (p = 0.0451, mean difference = 4.68%) than non-smokers (p = 0.012, mean difference = 4.2%). Cigarette smoking is associated with lower chance of HBsAg seroclearance, higher PD-1 expression on lymphocytes, and impairment of effector functions of HBV-specific T cells in CHB.

Causal association of immune effector proteins with sepsis: A Mendelian randomization study.

Sepsis is an infection-induced systemic inflammatory response syndrome. Immune regulation plays a crucial role in sepsis. We looked into the link between immune effector-related proteins and sepsis in this study by using both univariate and multivariate Mendelian randomization (MR) analyses. We accessed and collected data from the Integrative Epidemiology Unit's Open About Sepsis genome-wide association study database. The 6 immune effector-associated proteins each contained 10,534,735 single-nucleotide polymorphisms from 3301 samples. Using the weighted median, MR-Egger, simplex, inverse-variance weighting, and weighted mode methods, univariate MR then investigated the link between complement factor H-related protein-5 (CFHR5), Fc epsilon receptor II (FCER2), granzyme B (GZMB), major histocompatibility complex, class II, DQ alpha (HLA-DQA2), mannose-binding lectin 2 (MBL2), or myeloperoxidase (MPO) and sepsis. In the inverse-variance weighted results, the P values of all 6 immune effector-related proteins were <0.05, suggesting a possible causal relationship between them and sepsis. MBL2 (odds ratio [OR] = 1.046) was a risk factor for sepsis, while the other proteins (FCER2: OR = 0.922; GZMB: OR = 0.908; CFHR5: OR = 0.858; HLA-DQA2: OR = 0.896; MPO: OR = 0.875) were safety factors. By revealing a causal link between sepsis and CFHR5, FCER2, GZMB, HLA-DQA2, MBL2, or MPO, our study offers an essential resource for additional investigations on the subject.

MEST promotes immune escape in gastric cancer by downregulating MHCI expression via SHP2

BackgroundImmune escape is a major obstacle to T-cell-based immunotherapy for cancers such as gastric cancer (GC). Mesoderm-specific transcript (MEST) is a tumor-promoting factor that regulates multiple oncogenic signaling pathways. However, the role of MEST-mediated immune escape is unclear. MethodsBioinformatics analysis of MEST expression and enrichment pathways were performed Quantitative reverse transcription PCR (qPCR) or western blot was used to detect the expression of MEST, Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2), Major histocompatibility class I (MHCI)-related genes. Cell function was assessed by Cell Counting Kit (CCK)-8, Transwell, Lactate dehydrogenase (LDH) kit, flow cytometry, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry (IHC). Xenograft nude mice and immune-reconstructed mice were used to test the effects of different treatments on tumor growth and immune escape in vivo. ResultsMEST was upregulated in GC and promoted tumor proliferation, migration, and invasion. Rescue experiments revealed that TNO155 treatment or knockdown of SHP2 promoted the killing ability of CD8+ T cells and the expression of granzyme B (GZMB) and interferon-gamma (IFN-γ), and MEST overexpression reversed the effect. In vivo experiments confirmed that MEST promoted tumor growth, knockdown of MEST inhibited immune escape in GC, and that combination treatment with anti-PD-1 improved anti-tumor activity. ConclusionIn this study, we demonstrated that MEST inhibited IFN-γ secretion from CD8+ T cells by up-regulating SHP2, thereby downregulating MHCI expression in GC cells to promote immune escape and providing a new T cell-based therapeutic potential for GC.

Granzyme B Expression in Conjunctiva of Patients with Pterygium.

Pterygium is often associated with chronic ultraviolet (UV) radiation exposure and characterized by the overgrowth of conjunctiva and extracellular matrix (ECM) remodeling. Notably, several studies in the skin have demonstrated that chronic UV radiation can upregulate Granzyme B (GrB) expression and increase ECM degradation. The aim of this study was to compare GrB expression between pterygium and healthy controls and to further link this GrB expression to mast cells. Post-mortem pterygium tissues and conjunctival tissues from age-matched controls were used to assess GrB expression via immunofluorescence and microscopy. We found a significantly higher density of GrB+ cells from pterygium specimens compared to healthy controls. Furthermore, many of the GrB+ cells in pterygium specimens co-expressed tryptase, a mast cell marker. These findings suggest a role for conjunctival mast cell-secreted GrB in the pathogenesis of pterygium and highlight GrB as a possible therapeutic target in delaying or halting pterygium progression.

Circulating CD8 + LGALS9 + T Cell Population Exhibiting Low Cytotoxic Characteristics are Decreased in Patients with Systemic Lupus Erythematosus.

LGALS9, also known as Galectin-9 and a member of the β-galactosidase family, plays a crucial role in immune regulation. However, its expression and function in CD8 T cells, as well as its association with cytotoxic T lymphocytes (CTL), remain unclear. This study aims to investigate LGALS9 expression patterns in human circulating CD8 T lymphocytes and elucidate its clinical significance in Systemic Lupus Erythematosus (SLE). Blood samples from 56 healthy controls and 50 new-onset SLE patients were collected. Flow cytometry was utilized to analyze LGALS9 expression in circulating CD8 T lymphocytes via intracellular staining. Compared to LGALS9 + CD8 + T cells, LGALS9-CD8 + T cells showed increased secretion of Granzyme B (GZMB) and Perforin, along with elevated expression levels of GPR56, CX3CR1, KLRD1, KLRF1, PD1, and CD29. A higher proportion of Tn (naive T cells) and TCM (central memory T cells) showed LGALS9 positivity, compared to TEM (effector memory T cells) and TEMRA (terminally differentiated effector memory T cells re-expressing CD45RA). Clinically, the downregulation of LGALS9 expression was significant in SLE patients. LGALS9 + CD8 + T cells exhibited an Area Under the Curve (AUC) of 0.6916, while CX3CR1 + in LGALS9 + CD8 + T cells had an AUC of 0.6478, and KLRF1 + had an AUC of 0.6419, for distinguishing SLE from healthy individuals. In conclusion, CD8 + LGALS9 + T cells display characteristics of low cytotoxicity, and their reduction is evident in SLE patients, potentially implicating them in SLE pathogenesis and providing diagnostic assistance.

Increased pathogenicity and pro-inflammatory capabilities of mucosal-associated invariant T cells involved in Oral Lichen Planus

BackgroundMucosal-associated invariant T (MAIT) cells assume pivotal roles in numerous autoimmune inflammatory maladies. However, scant knowledge exists regarding their involvement in the pathological progression of oral lichen planus (OLP). The focus of our study was to explore whether MAIT cells were altered across distinct clinical types of OLP.MethodsThe frequency, phenotype, and partial functions of MAIT cells were performed by flow cytometry, using peripheral blood from 18 adults with non-erosive OLP and 22 adults with erosive OLP compared with 15 healthy adults. We also studied the changes in MAIT cells in 15 OLP patients receiving and 10 not receiving corticosteroids. Surface proteins including CD4, CD8, CD69, CD103, CD38, HLA-DR, Tim-3, Programmed Death Molecule-1 (PD-1), and related factors released by MAIT cells such as Granzyme B (GzB), interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-17A, and IL-22 were detected.ResultsWithin non-erosive OLP patients, MAIT cells manifested an activated phenotype, evident in an elevated frequency of CD69+ CD38+ MAIT cells (p < 0.01). Conversely, erosive OLP patients displayed an activation and depletion phenotype in MAIT cells, typified by elevated CD69 (p < 0.01), CD103 (p < 0.05), and PD-1 expression (p < 0.01). Additionally, MAIT cells exhibited heightened cytokine production, encompassing GzB, IFN-γ, and IL-17A in erosive OLP patients. Notably, the proportion of CD103+ MAIT cells (p < 0.05) and GzB secretion (p < 0.01) by MAIT cells diminished, while the proportion of CD8+ MAIT cells (p < 0.05) rose in OLP patients with corticosteroid therapy.ConclusionsMAIT cells exhibit increased pathogenicity and pro-inflammatory capabilities in OLP. Corticosteroid therapy influences the expression of certain phenotypes and functions of MAIT cells in the peripheral blood of OLP patients.

Upregulation of granzyme B and C-X3-C motif receptor 1 in circulating plasmablasts was negatively regulated by Notch signal in patients with systemic lupus erythematosus.

As one molecule related to cytotoxicity, surface expression of C-X3-C motif receptor 1 (CX3CR1) was highly correlated with intracellular granzyme B (GZMB) in NK and cytolytic T cells. However, the expression of CX3CR1 and GZMB in B cells has not been clarified, and their clinical significance in systemic lupus erythematosus (SLE) remains unclear. This study aimed to clarify the changes and clinical significance of peripheral blood B cells expressing GZMB and/or CX3CR1 in SLE. Peripheral blood was collected from 39 SLE patients and 48 healthy controls. We found that GZMB and CX3CR1 expression varied in different B-cell subsets, with plasmablasts possessing the highest positive percentages, consistent with bioinformatics prediction. GZMB+ and CX3CR1+ percentages in circulating B cells and plasmablasts were increased in SLE patients. CX3CR1 was upregulated on B cells after in vitro stimulation. Notch intracellular domain (NICD) expression was significantly decreased in plasmablasts of SLE patients and CX3CR1 in plasmablasts was downregulated with the addition of JAG1. In conclusion, GZMB and CX3CR1 were increased in B cells and in plasmablasts of SLE patients and CX3CR1 was negatively regulated by Notch signal in plasmablasts, which may be involved in SLE pathogenesis.

Granzyme B Promotes Proliferation, Migration and EMT Process in Gastric Cancer.

Granzyme B (GZMB), a critical member of the Gr gene family, is known to play an essential role in diverse physiological and pathological processes such as inflammation, acute and chronic inflammatory diseases, and cancer progression. In this study, we delve deeper into the role of GZMB within the context of gastric cancer (GC) to examine its expression patterns and functional implications. To accomplish this, we applied a combination of quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry techniques. These methodologies allowed us to accurately gauge GZMB expression levels in GC tissues and investigate their correlation with various clinical-pathological variables. Our secondary focus was to discern the regulatory influence of GZMB on GC cell biology. We used an array of assays including cell counting kit-8 (CCK-8), colony formation, 5-ethynyl-2'-deoxyuridine, and migration assays. The effect of GZMB on gastric cancer progression was further validated through a subcutaneous xenograft mouse model. Our findings underscored that GZMB mRNA and protein levels were upregulated in GC tissues, a feature that showed a significant correlation with GC staging. We also discovered that a decrease in GZMB expression via knockdown experiments suppressed the proliferation and migration capabilities of GC cells. This effect was manifested through diminished expression levels of epithelial-mesenchymal transition (EMT) markers. In stark contrast, the overexpression of GZMB through plasmid transfection appeared to enhance the proliferation and migration abilities of GC cells. This was coupled with an upregulation in EMT expression. Our study concludes by emphasizing that GZMB promotes the growth, migration, and EMT processes in gastric cancer. In vitro, cell-based experiments and in vivo xenograft mouse models confirm this. Our findings provide a more comprehensive understanding of GZMB's role in gastric cancer pathogenesis, potentially opening doors for novel therapeutic strategies targeting this molecular pathway.

Granzyme B PET Imaging for Assessment of Disease Activity in Inflammatory Bowel Disease.

Developing a noninvasive imaging method to detect immune system activation with a high temporal resolution is key to improving inflammatory bowel disease (IBD) management. In this study, granzyme B (GZMB), typically released from cytotoxic T and natural killer cells, was targeted using PET with 68Ga-NOTA-GZP (where GZP is β-Ala-Gly-Gly-Ile-Glu-Phe-Asp-CHO) to detect early intestinal inflammation in murine models of colitis. Methods: Bioinformatic analysis was used to assess the potential of GZMB as a biomarker for detecting IBD and predicting response to treatment. Human active and quiescent Crohn disease and ulcerative colitis tissues were stained for GZMB. We used IL-10-/- mice treated with dextran sulfate sodium (DSS) as an IBD model, wild-type C57BL/6J mice as a control, and anti-tumor necrosis factor as therapy. We used a murine GZMB-binding peptide conjugated to a NOTA chelator (NOTA-GZP) labeled with 68Ga as the PET tracer. PET imaging was conducted at 1, 3, and 4 wk after colitis induction to evaluate temporal changes. Results: Bioinformatic analysis showed that GZMB gene expression is significantly upregulated in human ulcerative colitis and Crohn disease compared with the noninflamed bowel by 2.98-fold and 1.92-fold, respectively; its expression is lower by 2.16-fold in treatment responders than in nonresponders. Immunofluorescence staining of human tissues demonstrated a significantly higher GZMB in patients with active than with quiescent IBD (P = 0.032).68Ga-NOTA-GZP PET imaging showed significantly increased bowel uptake in IL-10-/- mice with DSS-induced colitis compared with vehicle-treated IL-10-/- mice (SUVmean, 0.75 vs. 0.24; P < 0.001) and both vehicle- and DSS-treated wild-type mice (SUVmean, 0.26 and 0.37; P < 0.001). In the IL-10-/- DSS-induced colitis model, the bowel PET probe uptake decreased in response to treatment with tumor necrosis factor-α (SUVmean, 0.32; P < 0.001). There was a 4-fold increase in colonic uptake of 68Ga-NOTA-GZP in the colitis model compared with the control 1 wk after colitis induction. The uptake gradually decreased to approximately 2-fold by 4 wk after IBD induction; however, the inflamed bowel uptake remained significantly higher than control at all time points (week 4 SUVmean, 0.23 vs. 0.08; P = 0.001). Conclusion: GZMB is a promising biomarker to detect active IBD and predict response to treatment. This study provides compelling evidence to translate GZMB PET for imaging IBD activity in clinical settings.

Identifying the association between polymorphisms in the GZMB and IFIH1 genes and psoriasis in Egyptians

ABSTRACT Objectives This study aims to examine whether the genetic variants in the genes for Granzyme B (GZMB) and Interferon Induced with Helicase C domain 1 (IFIH1) were associated with psoriasis. Background Psoriasis, a papulosquamous skin disease, was initially thought of as a disorder primarily of epidermal keratinocytes but is now recognized as one of the most common immune-mediated disorders. It is caused by the interplay between multiple genetic and environmental risk factors. Subjects and methods This case-control study has 65 participants with psoriasis and 65 healthy controls. Real-time PCR was used to genotype GZMB (rs8192917) and IFIH1 (rs35667974). Results Genotype occurrence and allelic spreading for both SNPs are in Hardy – Weinberg equilibrium. The genotype and allele distributions of rs35667974 showed no differences between the studied groups. Regarding rs8192917, compared to Group II, there is a statistically significant rise in the CC genotype and C allele in Group I. Higher PASI scores are detected in the C/C and C/T genotypes more than the T/T genotype. Univariate and multivariate analyses revealed that BMI, catalase, MDA, and rs8192917 (C/C) are associated with psoriasis. Conclusion GZMB rs8192917 was significantly related to psoriasis risk; its C allele is likewise associated with psoriasis vulnerability. However, our investigation found no link between rs35667974 and psoriasis.

Dual-Responsive Nanomedicine Activates Programmed Antitumor Immunity through Targeting Lymphatic System.

Effective antitumor immunotherapy depends on evoking a cascade of cancer-immune cycles with lymph nodes (LNs) as the initial sites for activating antitumor immunity, making drug administration through the lymphatic system highly attractive. Here, we describe a nanomedicine with dual responsiveness to pH and enzyme for a programmed activation of antitumor immune through the lymphatic system. The proposed nanomedicine can release the STING agonist diABZI-C2-NH2 in the LNs' acidic environment to activate dendritic cells (DCs) and T cells. Then, the remaining nanomedicine hitchhikes on the activated T cells (PD-1+ T cells) through binding to PD-1, resulting in an effective delivery into tumor tissues owing to the tumor-homing capacity of PD-1+ T cells. The enzyme matrix metalloproteinase-2 (MMP-2) being enriched in tumor tissue triggers the release of PD-1 antibody (aPD-1) which exerts immune checkpoint blockade (ICB) therapy. Eventually, the nanomedicine delivers a DNA methylation inhibitor GSK-3484862 (GSK) into tumor cells, and then the latter combines with granzyme B (GZMB) to trigger tumor cell pyroptosis. Consequently, the pyroptotic tumor cells induce robust immunogenic cell death (ICD) enhancing the DCs maturation and initiating the cascading antitumor immune response. Study on a 4T1 breast tumor mouse model demonstrates the prominent antitumor therapeutic outcome of this nanomedicine through creating a positive feedback loop of cancer-immunity cycles including immune activation in LNs, T cell-mediated drug delivery, ICB therapy, and tumor cell pyroptosis-featured ICD.

Glutamine promotes human CD8+ T cells and counteracts imiquimod-induced T cell hyporesponsiveness

T cells protect tissues from cancer. Although investigations in mice showed that amino acids (AA) critically regulate Tcell immunity, this remains poorly understood in humans. Here, we describe the AA composition of interstitial fluids in keratinocyte-derived skin cancers (KDSCs) and study the effect of AA on Tcells using models of primary human cells and tissues. Gln contributed to ∼15% of interstitial AAs and promoted interferon gamma (IFN-γ), but not granzyme B (GzB) expression, in CD8+ Tcells. Furthermore, the Toll-like receptor 7 agonist imiquimod (IMQ), a common treatment for KDSCs, down-regulated the metabolic gatekeepers c-MYC and mTORC1, as well as the AA transporter ASCT2 and intracellular Gln, Asn, Ala, and Asp in Tcells. Reduced proliferation and IFN-γ expression, yet increased GzB, paralleled IMQ effects on AA. Finally, Gln was sufficient to promote IFN-γ-production in IMQ-treated Tcells. Our findings indicate that Gln metabolism can be harnessed for treating KDSCs.

Co-encapsulation of granzyme B and perforin in nanocapsules for tumour therapy: biomimicking immune cells

Granzyme B (GrB)-based immunotherapy is of interest for cancer treatment. However, insufficient cellular uptake and a lack of targeting remain challenges to make use of GrB for solid tumour therapy. As GrB induced cell death requires the help of perforin (PFN), we designed a system (nGPM) for the co-delivery of GrB and PFN. Therefore, GrB and PFN were loaded in a porous polymeric nanocapsule rich in acetylcholine analogues and matrix metalloproteinase-2 (MMP-2) responsive peptides. The neutrally charged nGPM nanocapsules showed as long circulating time and accumulated at the tumour sites. Once in the tumour the outside shell of nanocapsules became degraded by overexpressed MMP-2 proteases, resulting in the release of GrB and PFN. We found that the PFN complex formed small pores on the surface of tumour cells which allow GrB to enter the cytoplasm of tumour cells inducing cell apoptosis and tumour suppression significantly.

The effects of photodynamic therapy on the immune response of women with cervical high-grade squamous intraepithelial lesions

ObjectiveTo evaluate and elucidate the effects and mechanism of photodynamic therapy (PDT) on the immune response of women with cervical high-grade squamous intraepithelial lesions (HSILs). Materials and methodsImmunofluorescence staining was used to compare immune infiltration before and after PDT in 23 patients with cervical HSILs. The infiltration of immune cells into the cervical tissues of patients with different outcomes was also compared at the 6-month follow-up period. Immune cell counts in samples collected before and after treatment were compared. ResultsWe found an increased number of CD8+ T cell infiltration, an increased proportion of CD8+ T cells expressing Granzyme B (GrB), Chemokine receptor 3 (CXCR3), and CD8+ tissue-resident memory T (TRM) cells, and a decreased proportion of CD8+ T cells expressing PD-1 in patients with cervical HSIL compared to that before PDT. Moreover, at the 6-month follow-up, there was higher infiltration of CD8+ T and CD8+ TRM cells, higher expression of GrB and CXCR3, and lower expression of PD-1 on CD8+ T cells in the HPV and cervical HSIL clearance groups than in the persistent HPV infection and cervical HSIL regression groups. However, no significant difference was observed in the number of CD8+ TSCM following PDT. ConclusionPDT activates immune responses mediated by CD8+ T cells. The degree of the immune response is correlated with the prognosis of cervical HSIL.

Abstract 5974: Targeting VEGFR on tumor cells and activated vasculature through delivery of granzyme B

Abstract Anti-VEGF therapy is a key therapeutic in several cancer treatment regimens. However, none of the current therapeutics are directly cytotoxic against tumor cells. VEGF121 is the smallest isoform in the VEGF-A family of cytokines that binds to VEGF receptors R-1 and R-2. Both receptors are over-expressed on several tumor cells and the endothelium of tumor vasculature but not normal vasculature. We hypothesized that delivery of a cytotoxic payload through VEGFR-2 into tumor cells and tumor neovasculature would significantly enhance cancer therapy. Granzyme B is a key effector in immune-mediated cell killing through both caspase-dependent and -independent mechanisms. We previously reported the development of a fusion protein composed of granzyme B (GrB) and VEGF121 (GrB/VEGF121). Here, we report on GrB-Fc-VEGF121, a fusion protein incorporating a human IgG heavy chain Fc fragment for dimerization to increase the molecular weight and improve in vivo circulation and targeting potential. We expressed and purified GrB-Fc-VEGF121 from HEK-293E cells under serum-free conditions with a final yield of approximately 40 mg/L. The enzymatic activity of GrB in GrB-Fc-VEGF121 was comparable to that of commercially available human GrB. We characterized this construct against both human and mouse VEGFR+ cell lines as this ligand cross-reacts to both species. GrB-Fc-VEGF121 showed in vitro cytotoxicity in the nanomolar range against tumor and endothelial cell lines expressing high levels of VEGFR-1 or VEGFR-2, while receptor-negative cells demonstrated IC50 levels in the high micromolar range. GrB-Fc-VEGF121 internalized into VEGFR-2+ tumor and endothelial cells within 2 hours of treatment while untargeted GrB did not internalize, suggesting internalization was receptor-mediated. Treatment of VEGFR2+ cells at the respective IC50 dose resulted in &amp;gt;50% cell death via apoptosis and/or necrosis within 48 h. Ex vivo serum stability studies indicated a gradual protein loss of GrB-Fc-VEGF121 with an overall stability of about 50% over 96 hours. No toxicity was observed in mice treated with a total dose of 475 mg/kg (IP, QOD x 5), indicating that the maximum tolerated dose of GrB-Fc-VEGF121 exceeds this dose level. In vivo efficacy studies in an OVCAR8 tumor xenograft model (20 mg/kg GrB-Fc-VEGF121 x 5) resulted in significant growth inhibition of established tumors compared to vehicle controls. The number of CD31+ blood vessels and Ki-67+ proliferating tumor cells decreased significantly in treated tumors compared to controls. Pharmacokinetic studies are underway and will be reported. Thus, GrB-Fc-VEGF121 significantly reduces tumor growth in vivo with no observed toxicity against normal tissues. This tumor- and vascular-targeting agent appears to have significant potential as a new class of targeted therapeutic agents with a unique mechanism of action. Research conducted, in part, by the Clayton Foundation for Research. Citation Format: Khalid A. Mohamedali, Lawrence H. Cheung, Ana Alvarez-Cienfuegos, Walter N. Hittelman, Michael G. Rosenblum. Targeting VEGFR on tumor cells and activated vasculature through delivery of granzyme B [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5974.

Abstract 2603: Targeting chemo-resistant ovarian cancer with a first-in-class, first-in-human immune-oncology agents containing granzyme B

Abstract Ovarian cancer (OC) is the fifth leading cause of cancer-related mortality in women. The current standard of care consists of debulking surgery with platinum-taxane maintenance chemotherapy. However, OC will recur in most patients, resulting in a five-year survival rate of 45%. In the past decades, there have been several developments in front-line maintenance therapy including bevacizumab or PARP inhibitors. While these therapies have shown effectiveness in prolonging progression free survival, this has not translated into improvements in overall survival. It is, therefore, essential to develop more effective maintenance therapies and most of the current efforts are focused on targeted approaches and immune therapeutics. Though immunotherapeutic strategies have induced durable responses in patients with melanoma, lung cancer, and other malignancies, the OC response to immunotherapy is limited as there is a significant subset of patients who do not respond. Our laboratory has developed several fully human granzyme B (GrB) based fusion proteins against key OC targets including folate receptor 1 (GrB-Fc-mov018) and fibroblast growth factor-inducible 14 (GrB-Fc-IT4) which retain high specificity of the targeting agent, combined with the GrB specific activity, a pro-apoptotic mechanism of action, and a robust in vivo efficacy. We assessed the in vitro cytotoxicity of GrB-based constructs against a panel of OC cell lines sensitive (OVCAR8, SKOV3, A2780, HeyA8) or resistant (SKOV3-TX, A2780/Cl-16, HeyA8-MDR) to common chemotherapeutic agents. SKOV3-TX cells were &amp;gt;10 fold more resistant to Paclitaxel than the parental SKOV3 cells while A2780/Cl-16 were 11-fold more resistant to Cisplatin than the parental A2780 cells. In contrast, none of the chemo-resistant cell lines showed resistance to the GrB-based constructs and the IC50 values observed were similar to those of the parental cell lines in the low nanomolar range (&amp;lt;50 nM). Moreover, target expression analysis did not show significant differences between parental and chemo-resistant cell lines. A pilot in vivo efficacy study of GrB-Fc-IT4 and GrB-Fc-mov018 against a subcutaneous, established ovarian tumor (OVCAR8) xenograft showed promising growth inhibition of established tumors compared to vehicle controls. In vivo studies evaluating the response to different treatments of mice bearing chemo-resistant ovarian tumors are ongoing. Our results suggest that the mechanism of resistance developed to conventionally used chemotherapeutic agents such as Paclitaxel, Doxorubicin, Cisplatin or Mitomycin do not confer resistance to GrB-based constructs. Hence, we speculate that GrB-based constructs could be an effective therapy in OC patients with immune-excluded tumors that have developed resistance to conventional treatment. Research conducted, in part, by the Clayton Foundation for Research. Citation Format: Ana Alvarez-Cienfuegos, Lawrence H. Cheung, Khalid A. Mohamedali, Michael G. Rosenblum. Targeting chemo-resistant ovarian cancer with a first-in-class, first-in-human immune-oncology agents containing granzyme B [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2603.