Inhibitory Domain Research Articles

A phase 3, randomized study of adjuvant rilvegostomig plus chemotherapy in resected biliary tract cancer: ARTEMIDE-Biliary01.

TPS4199 Background: Biliary tract cancer (BTC) is a rare but aggressive heterogenous group of gastrointestinal cancers that arise from the intra- or extrahepatic bile ducts (cholangiocarcinoma [CCA]) or the gallbladder (GBC). In early-stage disease following curative resection, adjuvant chemotherapy with a fluoropyrimidine- or gemcitabine-based regimen is usually recommended, however, recurrence rates remain high (e.g. in the BILCAP study, 5-year recurrence-free survival with adjuvant capecitabine was 34%). Immunotherapy is efficacious as adjuvant therapy in other cancer types. Results from the TOPAZ-1 and KEYNOTE-966 studies support combining immunotherapy and chemotherapy in advanced BTC, including in locally advanced non-metastatic disease. Furthermore, dual inhibition of programmed cell death-1 (PD-1) or programmed cell death ligand-1 (PD-L1) and the novel immune checkpoint, T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), has shown promising results across multiple tumor types without major increases in high-grade toxicity compared with PD-1 or PD-L1 inhibition alone. Rilvegostomig is an anti-PD-1/-TIGIT bi-specific monoclonal antibody that appears active and well tolerated in non-small-cell lung cancer. ARTEMIDE-Biliary01 will investigate the efficacy of rilvegostomig plus standard of care adjuvant chemotherapy in patients with BTC after curative intent resection. Methods: ARTEMIDE-Biliary01 (NCT06109779) is a Phase 3, randomized, double-blind, placebo-controlled, multicenter, global study to assess the efficacy and tolerability of rilvegostomig IV every three weeks versus placebo in combination with investigator's choice of chemotherapy (capecitabine, S-1 [tegafur/gimeracil/oteracil] or gemcitabine/cisplatin) as adjuvant treatment in patients with BTC after curative intent resection. This study will enroll approximately 750 adults with histologically confirmed adenocarcinoma of the biliary tract (intrahepatic or extrahepatic CCA or muscle-invasive GBC) after macroscopically complete resection (R0 or R1) and an ECOG PS of 0–1. Key exclusion criteria include locally advanced, unresectable, or metastatic disease at initial diagnosis and any anti-cancer therapy for BTC prior to surgery. The primary endpoint is recurrence-free survival, and the key secondary endpoint is overall survival. Additional endpoints include progression-free survival following recurrence, patient-reported tolerability, and safety. Enrollment has begun, and approximately 200 sites will be recruiting globally across Asia, Australia, Europe, North America, and South America. Clinical trial information: NCT06109779 .

PVRIG is Expressed on Stem-Like T Cells in Dendritic Cell-Rich Niches in Tumors and Its Blockade May Induce Immune Infiltration in Non-Inflamed Tumors.

Cancers that are poorly immune infiltrated pose a substantial challenge, with current immunotherapies yielding limited clinical success. Stem-like memory T cells (TSCM) have been identified as a subgroup of T cells that possess strong proliferative capacity and that can expand and differentiate following interactions with dendritic cells (DCs). In this study, we explored the pattern of expression of a recently discovered inhibitory receptor poliovirus receptor-related immunoglobulin domain protein (PVRIG) and its ligand, poliovirus receptor-related ligand 2 (PVRL2), in the human tumor microenvironment. Using spatial and single-cell RNA transcriptomics data across diverse cancer indications, we found that among the T-cell checkpoints, PVRIG is uniquely expressed on TSCM and PVRL2 is expressed on DCs in immune aggregate niches in tumors. PVRIG blockade could therefore enhance TSCM-DC interactions and efficiently drive T-cell infiltration to tumors. Consistent with these data, following PVRIG blockade in patients with poorly infiltrated tumors, we observed immune modulation including increased tumor T-cell infiltration, T-cell receptor (TCR) clonality, and intratumoral T-cell expansion, all of which were associated with clinical benefit. These data suggest PVRIG blockade as a promising strategy to induce potent antitumor T-cell responses, providing a novel approach to overcome resistance to immunotherapy in immune-excluded tumors.

KV4.3 PROTECTS AGAINST OXIDATIVE CAMKII ACTIVATION IN HEART FAILURE

Objective: Oxidative stress causes excessive CaMKII activation in heart failure which exacerbates cardiac dysfunction. We determined whether restoration of down-regulated membrane Kv4.3 expression in ventricular myocytes can block oxidative CaMKII activation in heart failure. Design and method: Heart failure was induced in mice by severe thoracic aortic banding. Transjugular injection of AAV-Kv4.3 was performed in mice 1 week after banding. Fluorescence spectra were measured using F-4600 spectrophotometer (Hitachi). The slit width and excitation wavelength were set to 5 mm and 270 nm, respectively. Emission spectra were increased from 280 nm to 400 nm (step = 1nm). The spectra of purified proteins were examined, including CaMKII, CaMKII and Ca2+/CaM, CaMKII and Kv4.3, CaMKII, Kv4.3, and Ca2+/CaM. Results: Dissociation of Kv4.3 from Kv4.3-CaMKII molecular complex or down-regulation of Kv4.3 in mouse ventricular myocytes enhanced H2O2-induced CaMKII oxidation and autophosphorylation. Only non-oxidized and unphosphorylated forms of CaMKII have been detected from the Kv4.3 immunoprecipitates in ventricular myocytes with H2O2 Incubation. Fluorescence spectra assay showed that Kv4.3 prevented the transformational change of inactive CaMKII to its active conformation in the presence of Ca2+/CaM and H2O2. In vivo transfection with AAV9-Kv4.3 had no impact on reactive oxygen species in heart failure myocardium but effectively suppressed CaMKII oxidation and activation. Conclusions: Kv4.3 is a potent native suppressor for oxidative CaMKII activation by binding to the regulatory domain and preventing the opening of inhibitory domain in response to Ca2+/CaM and H2O2.

Silencing Ditylenchus destructor cathepsin L-like cysteine protease has negative pleiotropic effect on nematode ontogenesis

Ditylenchus destructor is a migratory plant-parasitic nematode that severely harms many agriculturally important crops. The control of this pest is difficult, thus efficient strategies for its management in agricultural production are urgently required. Cathepsin L-like cysteine protease (CPL) is one important protease that has been shown to participate in various physiological and pathological processes. Here we decided to characterize the CPL gene (Dd-cpl-1) from D. destructor. Analysis of Dd-cpl-1 gene showed that Dd-cpl-1 gene contains a signal peptide, an I29 inhibitor domain with ERFNIN and GNFD motifs, and a peptidase C1 domain with four conserved active residues, showing evolutionary conservation with other nematode CPLs. RT-qPCR revealed that Dd-cpl-1 gene displayed high expression in third-stage juveniles (J3s) and female adults. In situ hybridization analysis demonstrated that Dd-cpl-1 was expressed in the digestive system and reproductive organs. Silencing Dd-cpl-1 in 1-cell stage eggs of D. destructor by RNAi resulted in a severely delay in development or even in abortive morphogenesis during embryogenesis. The RNAi-mediated silencing of Dd-cpl-1 in J2s and J3s resulted in a developmental arrest phenotype in J3 stage. In addition, silencing Dd-cpl-1 gene expression in female adults led to a 57.43% decrease in egg production. Finally, Dd-cpl-1 RNAi-treated nematodes showed a significant reduction in host colonization and infection. Overall, our results indicate that Dd-CPL-1 plays multiple roles in D. destructor ontogenesis and could serve as a new potential target for controlling D. destructor.

Cleavage-independent activation of ancient eukaryotic gasdermins and structural mechanisms.

Gasdermins (GSDMs) are pore-forming proteins that execute pyroptosis for immune defense. GSDMs are two-domain proteins activated by proteolytic removal of the inhibitory domain. In this work, we report two types of cleavage-independent GSDM activation. First, TrichoGSDM, a pore-forming domain-only protein from the basal metazoan Trichoplax adhaerens, is a disulfides-linked autoinhibited dimer activated by reduction of the disulfides. The cryo-electron microscopy (cryo-EM) structure illustrates the assembly mechanism for the 44-mer TrichoGSDM pore. Second, RCD-1-1 and RCD-1-2, encoded by the polymorphic regulator of cell death-1 (rcd-1) gene in filamentous fungus Neurospora crassa, are also pore-forming domain-only GSDMs. RCD-1-1 and RCD-1-2, when encountering each other, form pores and cause pyroptosis, underlying allorecognition in Neurospora. The cryo-EM structure reveals a pore of 11 RCD-1-1/RCD-1-2 heterodimers and a heterodimerization-triggered pore assembly mechanism. This study shows mechanistic diversities in GSDM activation and indicates versatile functions of GSDMs.

Dual-specificity tyrosine phosphorylation-regulated kinase 1A promotes the inclusion of amyloid precursor protein exon 7

Extracellular amyloid plaques made of Amyloid-β (Aβ) derived from amyloid precursor protein (APP) is one of the major neuropathological hallmarks of Alzheimer’s disease (AD). There are three major isoforms of APP, APP770, APP751, and APP695 generated by alternative splicing of exons 7 and 8. Exon 7 encodes the Kunitz protease inhibitor (KPI) domain. Its inclusion generates APP isoforms containing KPI, APPKPI+, which is elevated in AD and Down syndrome (DS) brains and associated with increased Aβ deposition. Dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A) phosphorylates many splicing factors and regulates the alternative splicing of pre-mRNA. It is upregulated in DS and AD brain. However, it is not yet clear whether Dyrk1A could regulate APP alternative splicing. In the present study, we overexpressed or knocked down Dyrk1A in cultured cells and observed that Dyrk1A promoted the inclusion of both APP exons 7 and 8. Moreover, a significant increase in APP exon7 inclusion was also detected in the forebrain and hippocampus of human Dyrk1A transgenic mice – Tg/Dyrk1A. Screening for splicing factors regulated by Dyrk1A revealed that serine/arginine-rich protein 9G8 inhibited APP exon7 inclusion and interacted with APP pre-mRNA. In vitro, expression of exon 7 facilitated APP cleavage. In human Dyrk1A transgenic mice, we also found an increase in Aβ production. These findings suggest that Dyrk1A inhibits the splicing factor 9G8 and promotes APP exon 7 inclusion, leading to more APPKPI+ expression and APP cleavage and potentially contributing to Aβ production in vivo.

Abstract CT053: Exploration of potential biomarkers correlated with efficacy of ociperlimab (anti-TIGIT) plus tislelizumab (anti-PD-1) in 1L PD-L1+ non-small cell lung cancer (NSCLC)

Abstract Background: PD-L1 expression was associated with anti-immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) + anti-PD-(L)1 treatment, in which a high PD-L1 subgroup showed improved efficacy. We investigated if anti-TIGIT mechanism of action (MOA)-related markers were associated with the efficacy of ociperlimab + tislelizumab in Cohort 3 (1L PD-L1+ NSCLC) of the phase 1/1b AdvanTIG-105 trial (NCT04047862) and evaluated a potential patient-enrichment strategy based on tumor tissue gene expression profile (GEP). Methods: Tumor tissue GEP was tested using TruSeq RNA Access technology. Ventana SP263 PD-L1 immunohistochemistry (IHC) assay was used to evaluate PD-L1 expression. Median progression-free survival (mPFS) by investigator was calculated descriptively by Kaplan-Meier methodology. 95% confidence intervals for mPFS were generated using the Brookmeyer method. The primary inferential PFS comparison used unstratified log-rank test with 2-sided descriptive P-values. Results: At data cutoff (Feb 2, 2023), 24 of 45 patients had GEP results. Anti-TIGIT MOA-related genes and signatures correlated with ociperlimab + tislelizumab treatment response. Patients with high (H) vs low (L) expression of TIGIT, CD226, CCR8, or a tumor-associated macrophage (TAM) signature had significantly longer mPFS (Table). Dual biomarkers combining both anti-PD-L1 (PD-L1 IHC) and one of the anti-TIGIT MOA-related factors (TIGIT, CCR8, TAM signature GEP) identified subgroups of PD-L1 H + TIGIT MOA-related factor H patients with improved PFS vs other subgroups (Table). A highly overlapped PD-L1 H + TIGIT H + CCR8 H + TAM signature H patient population was observed in dual biomarker analyses. Conclusions: Anti-TIGIT MOA-related genes and signatures correlated with efficacy in ociperlimab + tislelizumab-treated 1L PD-L1+ NSCLC. Combining anti-TIGIT MOA-related factors with PD-L1 expression identified a subgroup of patients with improved efficacy. TABLE 1. NAND Table. Efficacy Analyses in Patient Subgroups TIGITa CD226b CCR8b TAMb Subgroup H L H L H L H L n 8 16 12 12 12 12 12 12 mPFS, months (95% CI) NR (2.6, NR) 5.26 (2.07, 11.86) NR (4.21, NR) 4.68 (1.41, 15.05) 15.21 (2.6, NR) 4.7 (1.71, 7.16) 15.21 (4.21, NR) 4.17 (1.71, 5.45) PFS, P-value 0.0326 0.0327 0.0131 0.0153 PD-L1c + TIGITb PD-L1c + CCR8b PD-L1c + TAMb Subgroup TIGITHPD-L1H TIGITHPD-L1L TIGITLPD-L1H TIGITL PD-L1L CCR8HPD-L1H CCR8HPD-L1L CCR8LPD-L1H CCR8L PD-L1L TAMHPD-L1H TAMHPD-L1L TAMLPD-L1H TAML PD-L1L n 8 4 8 4 11 1 5 7 9 3 7 5 mPFS, months (95% CI) NR (1.41,NR) 4.76 (2.6,NR) 8.62 (2.07,NR) 2.94 (1.25,NR) NR (1.41,NR) 2.6 (NR,NR) 5.19 (2.07,NR) 4.21 (1.25,7.16) 23.89 (1.41,NR) 5.32 (4.21,NR) 5.29 (2.07,NR) 2.6 (1.25,NR) Cutoff: aTop 1/3; bMedian; cTC≥25% Citation Format: Se Hyun Kim, Jiayuan Zhang, Wei Tan, Han Yan, Tian Tian, Hao Zheng, Ziqi Zhou, Ruihua Wang, Yun Zhang, Zhirong Shen, Hye Ryun Kim, Diansheng Zhong, Shun Lu. Exploration of potential biomarkers correlated with efficacy of ociperlimab (anti-TIGIT) plus tislelizumab (anti-PD-1) in 1L PD-L1+ non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT053.

Abstract LB153: Spatial transcriptomics of mouse parathyroid gland cells expressing an activating variant of gcm2

Abstract Tumors of one or multiple parathyroid glands and elevated serum calcium and parathyroid hormone (PTH) are the common characteristics of primary hyperparathyroidism (PHPT). Genes associated with familial PHPT (hereditary parathyroid tumors) include - MEN1, CDKN1B, CDC73, RET, MAX and GCM2. The glial cells missing 2 (GCM2) gene functions as a transcription factor that is essential for parathyroid gland development. Heterozygous germline missense variants located within the C-terminal conserved inhibitory domain (CCID) of GCM2 have been reported in a subset of patients with familial PHPT. In functional assays, these missense variants enhance the transcriptional activity of GCM2, suggesting that GCM2 could act as a proto-oncogene in parathyroid neoplasia. A recurrent germline activating missense variant of GCM2, p.Y394S in patients with familial PHPT has been reported in various publications. To study the direct contribution of this missense variant in parathyroid neoplasia, we used the CRISPR/Cas9 system to generate a heterozygous germline knock-in of p.Y392S in the mouse Gcm2 gene (which corresponds to the human variant p.Y394S in GCM2). In GCM2-binding site mediated luciferase reporter assays, the mouse Gcm2 variant p.Y392S also exhibited the transcription enhancing effect that was observed for the human GCM2 p.Y394S variant. However, mice with this variant (Gcm2 +/Y392S) did not show obvious parathyroid tumors. Because the mouse Gcm2 variant p.Y392S exhibited enhanced transcriptional activity, we performed spatial transcriptomics of parathyroid glands from wildtype (WT) and Gcm2 +/Y392S mice to examine differentially expressed transcripts in parathyroid cells with the p.Y392S variant of Gcm2. Using the 10X Genomics Visium platform, spatially resolved RNA-seq analysis was performed on parathyroid gland cells of WT and Gcm2 +/Y392S mice specifically marked by the expression of Pth and Gcm2. Spatial transcriptomics and Pathway analysis was performed to evaluate transcripts with more than 2-fold increased expression in parathyroid cells from the p.Y392S variant of Gcm2 compared to WT. Further investigation of these genes and pathways in mouse and human parathyroid cells can provide insights into the functional consequences of GCM2 activating variants and the pathophysiology of parathyroid tumorigenesis. Citation Format: Priyanka Bolel, Jeremie O. Pina, Fabio R. Faucz, Lee S. Weinstein, Sunita K. Agarwal. Spatial transcriptomics of mouse parathyroid gland cells expressing an activating variant of gcm2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB153.

Modulators of MAPK pathway activity during filamentous growth in Saccharomyces cerevisiae.

Mitogen-activated protein kinase (MAPK) pathways control the response to intrinsic and extrinsic stimuli. In the budding yeast Saccharomyces cerevisiae, cells undergo filamentous growth, which is regulated by the fMAPK pathway. To better understand the regulation of the fMAPK pathway, a genetic screen was performed to identify spontaneous mutants with elevated activity of an fMAPK pathway-dependent growth reporter (ste4 FUS1-HIS3). In total, 159 mutants were isolated and analyzed by secondary screens for invasive growth by the plate-washing assay and filament formation by microscopy. Thirty-two mutants were selected for whole-genome sequencing, which identified new alleles in genes encoding known regulators of the fMAPK pathway. These included gain-of-function alleles in STE11, which encodes the MAPKKK, as well as loss-of-function alleles in KSS1, which encodes the MAP kinase, and loss-of-function alleles in RGA1, which encodes a GTPase-activating protein (GAP) for CDC42. New alleles in previously identified pathway modulators were also uncovered in ALY1, AIM44, RCK2, IRA2, REG1, and in genes that regulate protein folding (KAR2), glycosylation (MNN4), and turnover (BLM10). Mutations leading to C-terminal truncations in the transcription factor Ste12p were also uncovered that resulted in elevated reporter activity, identifying an inhibitory domain of the protein from residues 491 to 688. We also find that a diversity of filamentous growth phenotypes can result from combinatorial effects of multiple mutations and by loss of different regulators of the response. The alleles identified here expand the connections surrounding MAPK pathway regulation and reveal new features of proteins that function in the signaling cascade.

Subtilisin-like proteases from Fusarium graminearum induce plant cell death and contribute to virulence.

Fusarium head blight (FHB), caused by Fusarium graminearum, causes huge annual economic losses in cereal production. To successfully colonize host plants, pathogens secrete hundreds of effectors that interfere with plant immunity and facilitate infection. However, the roles of most secreted effectors of F. graminearum in pathogenesis remain unclear. We analyzed the secreted proteins of F. graminearum and identified 255 candidate effector proteins by liquid chromatography-mass spectrometry (LC-MS). Five subtilisin-like family proteases (FgSLPs) were identified that can induce cell death in Nicotiana benthamiana leaves. Further experiments showed that these FgSLPs induced cell death in cotton (Gossypium barbadense) and Arabidopsis (Arabidopsis thaliana). A signal peptide and light were not essential for the cell death-inducing activity of FgSLPs. The I9 inhibitor domain and the entire C-terminus of FgSLPs were indispensable for their self-processing and cell death-inducing activity. FgSLP-induced cell death occurred independent of the plant signal transduction components BRI-ASSOCIATED KINASE 1 (BAK1), SUPPRESSOR OF BIR1 1 (SOBIR1), ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1), and PHYTOALEXIN DEFICIENT 4 (PAD4). Reduced virulence was observed when FgSLP1 and FgSLP2 were simultaneously knocked out. This study reveals a class of secreted toxic proteins essential for F. graminearum virulence.

Inhibitory CARs fail to protect from immediate T cell cytotoxicity

Chimeric antigen receptors equipped with an inhibitory signaling domain (iCARs) have been proposed as strategy to increase on-tumor specificity of CAR-T cell therapies. iCARs inhibit T cell activation upon antigen recognition and thereby program a Boolean NOT-gate within the CAR-T cell. If cancer cells do not express the iCAR target antigen while it is highly expressed on healthy tissue, CAR/iCAR coexpressing T cells are supposed to kill cancer cells but not healthy cells expressing the CAR antigen. In this study we employed a well-established reporter cell system to demonstrate high potency of iCAR constructs harboring BTLA-derived signaling domains. We then created CAR/iCAR-combinations for the clinically relevant antigen pairs B7-H3/CD45 and CD123/CD19 and show potent reporter cell suppression by iCARs targeting CD45 or CD19. In primary human T cells αCD19-iCARs were capable of suppressing T cell proliferation and cytokine production. Surprisingly, the iCAR failed to veto immediate CAR-mediated cytotoxicity. Likewise, T cells overexpressing PD1 or BTLA did not show impaired cytotoxicity towards ligand-expressing target cells, indicating that inhibitory signaling by these receptors does not mediate protection against cytotoxicity by CAR-T cells. Future approaches employing iCAR-equipped CAR-T cells for cancer therapy should therefore monitor off-tumor reactivity and potential CAR/iCAR-T cell dysfunction.

Novel homozygous CARD11 variants in two patients with combined immunodeficiency and atopic skin disease

BackgroundCaspase recruitment domain family, member 11 (CARD11) is an important protein which plays a fundamental role in the activation of NF-κβ pathway in lymphocytes. CARD11 deficiency can be inherited in either autosomal dominant or autosomal recessive forms and present with different phenotypes including combined immunodeficiency, atopic dermatitis, and other variable manifestations. The present report describes clinical phenotypes and immunological defects of two unrelated patients with missense homozygous variants in CARD11 presenting with combined immunodeficiency (CID) and atopic skin disease resembling that reported in dominant negative CARD11 deficiency. The patients underwent next generation sequencing, immunophenotyping of T and B subsets by flow cytometry, T cell stimulation, and evaluation of CARD11 expression.ResultsBoth patients had features suggesting CID including repeated pneumoniae with ICU admissions, chronic diarrhea, and itchy atopic skin disease. Patient-1 has homozygous missense variant in the C terminal domain (c.2839G > A, p.Glu947Lys), and patient-2 has homozygous variant in the inhibitory domain (c.1073C > G, p.Pro568Arg). Both have profound defects in Tregs with normal recent thymic emigrants, memory, and naïve CD4+ T cells. However, in response to stimulation, T cells failed to upregulate the expression of CD25. CARD11 expression by flow cytometry was decreased rather than abolished as previously described in patients with autosomal recessive CARD11 deficiency. B cells showed marked deficiency of switched memory and increase in transitional B cells.ConclusionMissense variants causing CARD11 deficiency may affect the protein function rather than the expression and can result in a phenotype combining the atopic skin disease and the features of CID.

Essential role of CD155 glycosylation in functional binding to DNAM-1 on natural killer cells.

The cluster of differentiation 155 (CD155) is highly expressed on tumor cells and augments or inhibits the cytotoxic activities of natural killer (NK) cells and T cells through its receptor ligands DNAX accessory molecule 1 (DNAM-1) and T-cell immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), respectively. Although CD155 is heavily glycosylated, the role of glycosylation of CD155 in the cytotoxic activity of effector lymphocytes remains unknown. Here, we show that the N-linked glycosylation at residue 105 (N105 glycosylation) in the first Ig-like domain of CD155 is involved in the binding of CD155 to both DNAM-1 and TIGIT. The N105 glycosylation also plays an essential role to induce signaling in both DNAM-1 and TIGIT reporter cells. Moreover, we show that the N105 glycosylation of CD155 contributes preferentially to the DNAM-1-mediated activating signal over the TIGIT-mediated inhibitory signal in NK cells. Our results demonstrated the important role of the N105 glycosylation of CD155 in DNAM-1 and TIGIT functions and shed new light on the understanding of tumor immune responses.

T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain as a promising immune checkpoint target for the treatment of SLE.

Immune checkpoints (ICs) play a pivotal role in orchestrating immune regulation, crucial for the maintenance of immune tolerance and prevention of autoimmune diseases. One noteworthy example among these immune regulators is T cell immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT). The TIGIT pathway's inhibition or the absence of TIGIT has been linked to the hyperactivation and excessive proliferation of T cells, rendering individuals more susceptible to autoimmune diseases and exacerbating inflammatory responses. Conversely, the activation of TIGIT has exhibited promising outcomes in ameliorating autoimmune disorders, as observed in murine models of systemic lupus erythematosus (SLE). Consequently, a judicious exploration of the co-inhibitory axis appears warranted for the effective management of pathogenic immune responses in SLE. In light of compelling evidence, this review undertakes a comprehensive examination of TIGIT's characteristics within the context of autoimmunity, offering insights into its potential as a therapeutic target for SLE.

Identification and expression analysis of genomic regions associated with the traits contributing to lodging tolerance in wheat (Triticum aestivum L.)

Crop lodging, either stem breaking/stem bending or root lodging, is a major concern for farmers worldwide. In the present study, meta-QTLs, ortho-MQTLs and candidate genes related to lodging and its associated traits were identified using 836 of the 1269 known QTLs retrieved from 107 QTL mapping studies published during 1998–2022. The study resulted in the identification of 86 MQTLs with an average confidence interval (CI) of 1.66 cM (4.26-fold reduction) as against a CI of > 7.08 cM in the initial QTLs. Out of 86 MQTLs, a subset of 12 MQTLs demonstrated stability and robustness, earning them the title of breeders’ MQTLs. These selections were made based on criteria such as the number of initial QTLs involved, small CI, high LOD scores, and PVE values. Furthermore, leveraging synteny and collinearity facilitated the identification of 10 ortho-MQTLs shared between wheat and maize. Further, in silico expression analysis allowed the detection of 53 significantly expressed candidate genes encoding different proteins/products including the following: F-box protein, GDSL lipase/esterases, SANT/Myb domain transcription factor, pectin esterase inhibitor domain, glycoside hydrolase family, protein kinase domain, zinc finger domain, cytochrome P450, UDP-glucuronosyl/UDP-glucosyltransferase, glycosyltransferase 61 etc. In addition, 26 lodging tolerance genes from Arabidopsis, rice, and maize were also utilized to identify 34 wheat homologues in wheat MQTL regions. Among these, three genes TraesCS2D02G256600 (TaEREB114-2D), TraesCS7B02G340100 (TaIRX14-7B), and TraesCS1B02G347600 (TaGA2ox4-1B) were prioritized for qRT-PCR-based expression analysis in one lodging-tolerant (i.e., WH-1105) and one lodging-susceptible (i.e., WH-1184) variety. When comparing these two varieties, we found higher relative expression levels of these three genes in the second basal internode at the milky endosperm stage of the lodging-tolerant variety. The MQTLs, ortho-MQTLs, and candidate genes (CGs) identified in this study can be utilized for marker-assisted selection to improve lodging tolerance and enhance our understanding of the molecular basis of lodging tolerance in wheat.

Combination of oligo-fractionated irradiation with nivolumab can induce immune modulation in gastric cancer

BackgroundTumor-associated antigen (TAA)-specific CD8(+) T cells are essential for nivolumab therapy, and irradiation has been reported to have the potential to generate and activate TAA-specific CD8(+) T cells. However, mechanistic...

Combining TIGIT blockade with IL-15 stimulation is a promising immunotherapy strategy for lung adenocarcinoma.

T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an immune checkpoint molecule that suppresses CD8+ T-cell function in cancer. However, the expression profile and functional significance of TIGIT in the immune microenvironment of lung adenocarcinoma (LUAD) remain elusive. Interleukin (IL)-15 has emerged as a promising candidate for enhancing CD8+ T-cell mediated tumour eradication. Exploring therapeutic strategies that combine IL-15 with TIGIT blockade in LUAD is warranted. We investigated the regulatory network involving coinhibitory TIGIT and CD96, as well as costimulatory CD226 in LUAD using clinical samples. The potential role of TIGIT in regulating the pathogenesis of LUAD was addressed through a murine model with transplanted tumours constructed in Tigit-/- mice. The therapeutic strategy that combines TIGIT blockade with IL-15 stimulation was verified using a transplanted tumour murine model and a patient-derived organoid (PDO) model. The frequency of TIGIT+ CD8+ T cells was significantly increased in LUAD. Increased TIGIT expression indicated poorer prognosis in LUAD patients. Furthermore, the effector function of TIGIT+ CD8+ tumour-infiltrating lymphocytes (TILs) was impaired in LUAD patients and TIGIT inhibited antitumour immune response of CD8+ TILs in tumour-bearing mice. Mechanistically, IL-15 enhanced the effector function of CD8+ TILs but stimulated the expression of TIGIT on CD8+ TILs concomitantly. The application of IL-15 combined with TIGIT blockade showed additive effects in enhancing the cytotoxicity of CD8+ TILs and thus further increased the antitumour immune response in LUAD. Our findings identified TIGIT as a promising therapeutic target for LUAD. LUAD could benefit more from the combined therapy of IL-15 stimulation and TIGIT blockade.

In silico exploration of deep-sea fungal metabolites as inhibitor of Ebola and Marburg VP35 and VP40.

VP30 and VP40 proteins of Ebola and Marburg viruses have been recognized as potential targets for antiviral drug development due to their essential roles in the viral lifecycle. Targeting these proteins could disrupt key stages of the viral replication process, inhibiting the viruses' ability to propagate and cause disease. The current study aims to perform molecular docking and virtual screening on deep-sea fungal metabolites targeting Marburg virus VP40 Dimer, matrix protein VP40 from Ebola virus Sudan, Ebola VP35 Interferon Inhibitory Domain, and VP35 from Marburg virus. The top ten compounds for each protein target were chosen using the glide score. All the compounds obtained indicate a positive binding interaction. Furthermore, AdmetSAR was utilized to investigate the pharmacokinetics of the inhibitors chosen. Gliotoxin was used as a ligand with Marburg virus VP40 Dimer, Austinol with matrix protein VP40 from Ebola virus Sudan, Ozazino-cyclo-(2,3-dihydroxyl-trp-tyr) with Ebola VP35 Interferon Inhibitory Domain, and Dehydroaustinol with VP35 from Marburg virus. MD modeling and MMPBSA studies were used to provide a better understanding of binding behaviors. Pre-clinical experiments can assist validate our in-silico studies and assess whether the molecule can be employed as an anti-viral drug.

Synthetic studies on the extracellular domain of the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) using Trt-K10 solubilizing tags

The T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an inhibitory immunoreceptor expressed on lymphocytes that serves as a promising target for cancer immunotherapy. In this study, facile synthetic protocols to produce the extracellular domain of TIGIT were investigated for applications of TIGIT in mirror-image screening. During the synthesis via sequential native chemical ligations, we encountered problems with significantly poor solubility of the ligated products. Introducing trityl-type solubilizing auxiliaries, which also functioned as temporary protecting groups for cysteine residues, facilitated a flexible order of ligations and efficient purification protocols. After refolding under appropriate conditions, the synthetic TIGIT showed a sufficient affinity toward its target ligand CD155.

Formin tails act as a switch, inhibiting or enhancing processive actin elongation

Formins are large, multidomain proteins that nucleate new actin filaments and accelerate elongation through a processive interaction with the barbed ends of filaments. Their actin assembly activity is generally attributed to their eponymous formin homology (FH) 1 and 2 domains; however, evidence is mounting that regions outside of the FH1FH2 stretch also tune actin assembly. Here, we explore the underlying contributions of the tail domain, which spans the sequence between the FH2 domain and the C terminus of formins. Tails vary in length from ∼0 to >200 residues and contain a number of recognizable motifs. The most common and well-studied motif is the ∼15-residue-long diaphanous autoregulatory domain. This domain mediates all or nothing regulation of actin assembly through an intramolecular interaction with the diaphanous inhibitory domain in the N-terminal half of the protein. Multiple reports demonstrate that the tail can enhance both nucleation and processivity. In this study, we provide a high-resolution view of the alternative splicing encompassing the tail in the formin homology domain (Fhod) family of formins during development. While four distinct tails are predicted, we found significant levels of only two of these. We characterized the biochemical effects of the different tails. Surprisingly, the two highly expressed Fhod-tails inhibit processive elongation and diminish nucleation, while a third supports activity. These findings demonstrate a new mechanism of modulating actin assembly by formins and support a model in which splice variants are specialized to build distinct actin structures during development.