PD-L1 Interaction Research Articles

P53 ABNORMAL ENDOMETRIAL CANCERS – ANALYSIS OF PD-1 CO-EXPRESSION BY CD4 HELPER AND CD8 CYTOTOXIC T-CELL SUBTYPES IN THE TUMOR MICROENVIRONMENT

Abstract Introduction/Objective Endometrial cancer is classified into four molecular subtypes of which the p53 abnormal variant is biologically aggressive. Programmed cell death protein 1 (PD-1) is a cell surface receptor and a vital inhibitor of the immune response. Programmed death ligand 1 (PD-L1) is a trans-membrane co-inhibitory factor of the immune response. PD-1 / PDL-1 interaction inhibits the activation and survival of T cells and decreases cytokine secretion. Some cancer cells express PD-L1, which then bind to PD-1 expressed on tumor specific T cells, and escape destruction by the T cells. The CD4/CD8 T cell immune response in the p53 abnormal variant has not been adequately evaluated with respect to the PD-1/PD-L1 pathway. Understanding this immune microenvironment is important to assess the potential use of anti-PD-1 targeted tumor therapy. Methods/Case Report Twenty cases of p53 abnormal endometrial cancers were obtained. All cases were PDL-1 +ve by immunohistochemistry. Two dual stains were performed - PD-1/CD4 and PD-1/CD8 antibodies. Six high-power fields (40x objective) with the greatest concentration of lymphocytes were counted. The total number of CD4 or CD8-only cells was recorded for each of the two stained slides for each case. The total number of PD- 1/CD4 and PD-1/CD8 positive cells were counted and recorded. The results were tabulated, and a paired t-test statistical analysis was performed to compare the total number of CD4 and CD8 cells and the percentage of PD-1/CD4 cells with the percentage of PD-1/CD8 positive cells. Results (if a Case Study enter NA) A statistically significant increase in the number of CD8 (Mean = 383) compared to CD4 cells (Mean = 317) was seen in the tumor microenvironment (p-value=0.0023). Evaluating PD-1 expression, the converse was true, and the percentage of PD-1/CD4 cells (Mean = 13.035%) was increased compared to the percentage of PD-1/CD8 cells (Mean = 9.205%), achieving statistical significance (p-value=0.0116). Conclusion The statistically significant increase in CD8 cells in the tumor and its stroma suggests that a robust cytotoxic response is being mounted to this high-risk molecular variant. The concurrent increase in CD4/PD-1 positive lymphocytes provides an appropriate microenvironment for the use of anti-PD-1 immunotherapy, since blockade of PD-1 on CD4 helper T cells may augment the tumor ablative cytotoxic properties of the CD8 positive lymphocytes. This includes reinvigoration of exhausted CD8+ T cells. Anti-PD-1 may also prevent the inhibition of PD-1 positive CD8 cells.

Generating Immunological Memory Against Cancer by Camouflaging Gold-Based Photothermal Nanoparticles in NIR-II Biowindow for Mimicking T-Cells.

Photothermal therapy (PTT) against cancer not only directly ablates tumors but also induces tumor immunogenic cell death (ICD). However, the antitumor immune response elicited by ICD is insufficient to prevent relapse and metastasis because of the immunosuppressive tumor microenvironment (TME). A biomimetic nanoplatform (bmNP) mimicking cytotoxic lymphocytes (CTLs) for combinational photothermal-immunotherapy to effectively regulate the immunosuppressive TME is reported here. The bmNP is constructed by wrapping the T-cell membrane onto a new type of photothermal agents, spherical Au-based PNCs (sAuPNCs). Similar to T-cells, the bmNP enhanced accumulation at the tumor site by targeting the tumor via adhesion proteins on T-cell membrane. The obtained sAuPNCs have a wide absorption band in the second near-infrared (NIR-II) region with a high photothermal conversion efficiency (PCE) up to about 75% and excellent photostability. The bmNP with a smaller size is more superior compete with T-cells to bond with tumor cells via PD-1/PD-L1 interaction to effectively block the PD-1 checkpoint of T-cells for preventing T-cell exhaustion. Furthermore, in vivo studies reveal the immunological memory effect is significantly elicited in mice received bmNPs therapy. Collectively, bmNPs show great potential in photothermal-enhanced immunotherapy.

Discovery of Daclatasvir as a potential PD-L1 inhibitor from drug repurposing

This study employed a drug repositioning strategy to discover novel PD-L1 small molecule inhibitors. 3D-QSAR pharmacophore models were establishedand subsequently validated through various means to select a robust model, Hypo-1, suitable for virtual screening. Hypo1 was used toscreen a library of 7,475 compounds from the Drugbank database, leading to the identification of 283 molecules following molecular docking with PD-L1.19 compounds underwent HTRF assays, with 15 showing varying degrees of inhibition of the PD-1/PD-L1 interaction. Compounds2202,2204,2207, and2208were further confirmed to bind to PD-L1 using SPR experiments. Among them, compound2204(Daclatasvir, KD = 11.4 μM) showeda higher affinity for human PD-L1 than the control compound BMS-1. In the HepG2/Jurkat cell co-culture model, Daclatasvir effectively activated Jurkat cells to kill HepG2 cells. In the mouse H22 hepatocellular tumor model, Daclatasvir significantly inhibited tumor growth (TGI = 53.4 % at a dose of 100 mg/kg). Its anti-tumor effect was more pronounced when combined with Lenvatinib (TGI = 85.1 %). Flow cytometry analysis of splenocytes and tumor cells indicated that Daclatasvir activated the immune system in both models. In summary, Daclatasvir was identified as a novel PD-L1small molecule inhibitor.

FcγR3A polymorphism influences natural killer cell activation and response to anti-PD-L1 (avelumab) in gestational trophoblastic neoplasia

BackgroundLow-risk gestational trophoblastic neoplasia (GTN) are currently receiving monochemotherapy as first-line therapy. In the case of a resistance, a second-line mono- or polychemotherapy is proposed. As an alternative to these toxic and historic chemotherapy agents, the efficacy of the anti-PD-L1 monoclonal antibody (avelumab) was assessed in the TROPHIMMUN phase II trial Cohort A. Avelumab yielded a 53% cure rate with an acceptable tolerance profile, including normal further pregnancy and delivery. Beyond the blockade of PD-1/PD-L1 interactions, avelumab effect could rely on the induction of antibody-dependent cell-mediated cytotoxicity (ADCC) mediated by FcγR3A-expressing natural killer (NK) cells. ObjectiveThis translational study aimed at testing whether ADCC is involved in avelumab efficacy on GTN and if FcγR3A affinity polymorphism could help predicting the response to avelumab in GTN. Study DesignThe expression of PD-L1 by the tumor and the phenotype of NK cells infiltrating GTN were verified by performing transcriptomic and proteomic analyses. Then, JEG-3 choriocarcinoma cells were cocultured with human NK cells in presence and absence of avelumab. The impact of FcγR3A functional polymorphism was assessed on the activation status of NK cells and the viability of JEG-3 choriocarcinoma cells. Finally, the data from TROPHIMMUN trial were reanalyzed to determine the impact of the FcγR3A polymorphism of patients on their response to avelumab. ResultsWe confirmed that FcγR3A+ NK cells infiltrated PD-L1-expressing GTN. In vitro, avelumab-coated JEG-3 choriocarcinoma cells induced NK cell activation, which promoted the destruction of JEG-3 cells. NK cell activation was abolished when the Fc portion of avelumab was removed, demonstrating the importance of Fcγ receptor in this process. Using this model of ADCC, we demonstrated that high-affinity FcγR3A polymorphism on NK cells was associated with better in vitro response to avelumab. In line with this result, patients from the TROPHIMMUN trial homozygous for the high affinity FcγR3A polymorphism had better clinical response to avelumab. ConclusionsOur work demonstrates that ADCC contributes to the therapeutic effect of avelumab in GTN and that the individual patient response is impacted by the FcγR3A polymorphism. The FcγR3A polymorphism could be used as a biomarker to identify patients diagnosed with monochemoresistant GTN who are most likely to respond to avelumab.

New benzophenone analogs from Nigrospora sphaerica and their inhibitory activity against PD-1/PD-L1 interactions

Four newly identified benzophenone analogs [nigrophenone A–D (1–4)] and a pyrrolidinone analog [nigropyrrolidinone (5)], alongside thirteen known congeners (6–18), were isolated from Nigrospora sphaerica. Transcriptome analysis revealed that 6 might have the potential to modulate T-cell immunity. Quantitative measurements of the binding affinities between eighteen natural molecules and the immunological checkpoint receptors PD-1 and PD-L1 were performed using Surface Plasmon Resonance (SPR). The results of SPR analysis showed that 1–18 have KD values ranging from 1.8 to 99.5 μM for PD-1 and from 10.6 to 99.5 μM for PD-L1. Competitive inhibition studies, employing SPR and ELISA assays, have indicated that compounds 6, 10, 15, and 18 are capable of inhibiting the PD-1/PD-L1 interaction. Additionally, compound 6 exhibited notable in vitro anticancer potency through the augmentation of activating signals and the upregulation of PD-1 expression on CD8+ T cells, concurrently elevating the secretion of IFN-γ and IL-2, thereby inhibiting the proliferation of LLC and MC38 cells and promoting MC38 apoptosis. Moreover, compound 6 modulates the PI3K/Akt pathway, which is a key downstream effector of the PD-1/PD-L1 axis. These compounds are considered promising candidates for more in-depth exploration because they could significantly inhibit PD-1/PD-L1 interactions in tumor immunotherapy.

Discovery of 2-Aryl-4-aminoquinazolin-Based LSD1 Inhibitors to Activate Immune Response in Gastric Cancer.

LSD1 (histone lysine-specific demethylase 1) has been gradually disclosed to act as an immunomodulator to enhance antitumor immune response. Despite the identification of numerous potent LSD1 inhibitors, there remains a lack of LSD1 inhibitors approved for marketing. Novel LSD1 inhibitors with different mechanisms are therefore needed. Herein, we reported a series of novel quinazoline-based LSD1 inhibitors. Among them, compound Z-1 exhibited the best LSD1 inhibitory activity (IC50 = 0.108 μM). Z-1 also acted as a selective and cellular active as an LSD1 inhibitor. Furthermore, Z-1 promoted response of gastric cancer cells to T-cell killing effect by decreasing PD-L1 expression and further attenuated the PD-1/PD-L1 interaction. In vivo, Z-1 exhibited significant suppression effect on the growth of gastric cancer cells without obvious toxicity. Therefore, Z-1 represents a potential novel immunomodulator that targets LSD1, providing a lead compound with new function mechanism for gastric cancer treatment.

Preparation and effects of functionalized liposomes targeting breast cancer tumors using chemotherapy, phototherapy, and immunotherapy

Breast cancer therapy has significantly advanced by targeting the programmed cell death-ligand 1/programmed cell death-1 (PD-L1/PD-1) pathway. BMS-202 (a smallmolecule PD-L1 inhibitor) induces PD-L1 dimerization to block PD-1/PD-L1 interactions, allowing the T-cell-mediated immune response to kill tumor cells. However, immunotherapy alone has limited effects. Clinically approved photodynamic therapy (PDT) activates immunity and selectively targets malignant cells. However, PDT aggravates hypoxia, which may compromise its therapeutic efficacy and promote tumor metastasis. We designed a tumor-specific delivery nanoplatform of liposomes that encapsulate the hypoxia-sensitive antitumor drug tirapazamine (TPZ) and the small-molecule immunosuppressant BMS. New indocyanine green (IR820)-loaded polyethylenimine-folic acid (PEI-FA) was complexed with TPZ and BMS-loaded liposomes via electrostatic interactions to form lipid nanocomposites. This nanoplatform can be triggered by near-infrared irradiation to induce PDT, resulting in a hypoxic tumor environment and activation of the prodrug TPZ to achieve efficient chemotherapy. The in vitro and in vivo studies demonstrated excellent combined PDT, chemotherapy, and immunotherapy effects on the regression of distant tumors and lung metastases, providing a reference method for the preparation of targeted agents for treating breast cancer.Graphical abstract

Synthesis and immunotherapy efficacy of a PD-L1 small-molecule inhibitor combined with its 131I-iodide labelled isostructural compound

Although antibody-based immune checkpoint blockades have been successfully used in antitumor immunotherapy, the low response rate is currently the main problem. In this work, a small-molecule programmed cell death-ligand (PD-L1) inhibitor, LG-12, was developed and radiolabeled with 131I to obtain the chemically and biologically identical radiopharmaceutical [131I]LG-12, which aimed to improve the antitumor effect by combination of LG-12 and [131I]LG-12. LG-12 showed high inhibitory activity to PD-1/PD-L1 interaction. The results of cell uptake and biodistribution studies indicated that [131I]LG-12 could specifically bind to PD-L1 in B16-F10 tumors. It could induce immunogenic cell death and the release of high mobility group box 1 and calreticulin. The combination of [131I]LG-12 and LG-12 could significantly inhibit tumor growth and resulted in enhanced antitumor immune response. This PD-L1 small-molecule inhibitor based combination strategy has great potential for tumor treatment.

Design, synthesis, and antitumor activity evaluation of 1,2,3-triazole derivatives as potent PD-1/PD-L1 inhibitors

A series of 1,2,3-triazole derivatives targeting the PD-1/PD-L1 pathway were designed, synthesized, and evaluated both in vitro and in vivo. Among them, compound III-4 demonstrated exceptional inhibitory activity against the interaction of PD-1/PD-L1 and showed great binding affinity with hPD-L1, with an IC50 value of 2.9 nM and a KD value of 3.33 nM. In the co-culture of Hep3B/OS-8/hPD-L1 cells and CD3+ T cells assay, III-4 relieved the inhibition of PD-L1 on PD-1 and promoted the expression of IFN-γ, which shared a comparable effect to that of the PD-1 monoclonal antibody Pembrolizumab (5 μg/mL). Moreover, compound III-5, an ester prodrug derived from III-4, demonstrated significant antitumor effects in the hPD-L1-MC38 C57BL/6 mouse model (TGI: 49.6 %) by oral administration. These findings suggest that compound III-5 holds promise as an inhibitor of the PD-1/PD-L1 interaction for cancer immunotherapy.

VSTM2A reverses immunosuppression in colorectal cancer by antagonizing the PD-L1/PD-1 interaction

Immunoglobulin (Ig) VSTM2A (V-set and transmembrane domain containing 2A) is a top-ranked secretory protein frequently silenced during colorectal carcinogenesis; however, its role in immune modulation remains largely unknown. Bioinformatic and immunohistochemistry analysis of human colorectal specimens and Vstm2a+/- knockout mice indicated that VSTM2A positively correlated with CD8a and immune infiltration in both physiological and pathological conditions. We then utilized liquid chromatography-mass spectrometry to pinpoint programmed death ligand 1 (PD-L1) as a membrane receptor of VSTM2A. A series of invitro biochemistry assays further revealed the binding pattern and kinetics between VSTM2A and PD-L1 proteins through their IgV domains ata dissociation constant of 0.7-2.5nM. Recombinant VSTM2A protein inhibited the PD-1/PD-L1 interaction and induced NFAT response element (RE) luciferase activity dose dependently. Furthermore, interleukin (IL)-2 production from DO11.10 Tcells upon co-culture with mouse non-T splenocytes was upregulated in the presence of VSTM2A conditioned medium. Finally, tumor killing assay and exvivo data from human peripheral blood mononuclear cells and autologous dendritic cell-T cell co-culture demonstrated that VSTM2A significantly enhanced immune activation via the release of granzyme B and interferon (IFN)-γ cytokines. In conclusion, our study demonstrates the tumor-extrinsic role of VSTM2A in sterically blocking the PD-L1/PD-1 interaction at a picomole to nanomole affinity, which leads to the enhanced anti-tumor effect of cytotoxic Tcells.

Molecular insight into binding affinities and blockade effects of selected flavonoid compounds on the PD-1/PD-L1 pathway.

This study investigated the binding mechanisms of the flavonoids apigenin (Api), kaempferol (Kmp), and quercetin (Que) to the PD-L1 dimer using a combination of molecular modeling and experimental techniques. The binding free energy results demonstrated that the flavonoids could tightly bind to the PD-L1 dimer, with the binding abilities following the trend Que > Kmp > Api. Key residues Ile54, Tyr56, Met115, Ala121, and Tyr123 were identified as important for binding. The flavonoids primarily bind to the C-, F-, and G-sheet domains. The spontaneous formation of the complex systems was mainly driven by hydrophobic forces. Dynamic cross-correlation matrix and secondary structure analyses further indicated that the studied flavonoids could stably interact with the binding sites. ELISA results showed that the flavonoids could effectively block PD-1/PD-L1 interactions, although the inhibitory activity of Api was weaker. Therefore, flavonols might be more effective inhibitors compared to flavones. The findings of this study are expected to contribute to the development of novel flavonoids targeting the PD-1/PD-L1 pathway.

Miniprotein engineering for inhibition of PD-1/PD-L1 interaction.

Miniproteins constitute an excellent basis for the development of structurally demanding functional molecules. The engrailed homeodomain, a three-helix-containing miniprotein, was applied as a scaffold for constructing programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) interaction inhibitors. PD-L1 binders were initially designed using the computer-aided approach and subsequently optimized iteratively. The conformational stability was assessed for each obtained miniprotein using circular dichroism spectroscopy, indicating that numerous mutations could be introduced. The formation of a sizable hydrophobic surface at the inhibitor that fits the molecular target imposed the necessity for the incorporation of additional charged amino acid residues to retain its appropriate solubility. Finally, the miniprotein effectively binding to PD-L1 (KD = 51.4 nM) that inhibits PD-1/PD-L1 interaction in cell-based studies with EC50 = 3.9 μM, was discovered.

Peptide Blockers of PD-1-PD-L1 Interaction Reinvigorate PD-1-Suppressed T Cells and Curb Tumor Growth in Mice.

The programmed cell death protein 1 (PD-1) plays a critical role in cancer immune evasion. Blocking the PD-1-PD-L1 interaction by monoclonal antibodies has shown remarkable clinical efficacy in treating certain types of cancer. However, antibodies are costly to produce, and antibody-based therapies can cause immune-related adverse events. To address the limitations associated with current PD-1/PD-L1 blockade immunotherapy, we aimed to develop peptide-based inhibitors of the PD-1/PD-L1 interaction as an alternative means to PD-1/PD-L1 blockade antibodies for anti-cancer immunotherapy. Through the functional screening of peptide arrays encompassing the ectodomains of PD-1 and PD-L1, followed by the optimization of the hit peptides for solubility and stability, we have identified a 16-mer peptide, named mL7N, with a remarkable efficacy in blocking the PD-1/PD-L1 interaction both in vitro and in vivo. The mL7N peptide effectively rejuvenated PD-1-suppressed T cells in multiple cellular systems designed to recapitulate the PD-1/PD-L1 interaction in the context of T-cell receptor signaling. Furthermore, PA-mL7N, a chimera of the mL7N peptide coupled to albumin-binding palmitic acid (PA), significantly promoted breast cancer cell killing by peripheral blood mononuclear cells ex vivo and significantly curbed tumor growth in a syngeneic mouse model of breast cancer. Our work raises the prospect that mL7N may serve as a prototype for the development of a new line of peptide-based immunomodulators targeting the PD-1/PD-L1 immune checkpoint with potential applications in cancer treatment.

Design, synthesis, and evaluation of antitumor activity of 2-arylmethoxy-4-(2-fluoromethyl-biphenyl-3-ylmethoxy) benzylamine derivatives as PD-1/PD-l1 inhibitors

A series of novel 2-arylmethoxy-4-(2-fluoromethyl-biphenyl-3-ylmethoxy) benzylamine derivatives was designed, synthesized, and evaluated for their antitumor effects as PD-1/PD-L1 inhibitors both in vitro and in vivo. Firstly, the ability of these compounds to block the PD-1/PD-L1 immune checkpoint was assessed using the homogeneous time-resolved fluorescence (HTRF) assay. Two of the compounds can strongly block the PD-1/PD-L1 interaction, with IC50 values of less than 10 nM, notably, compound HD10 exhibited significant clinical potential by inhibiting the PD-1/PD-L1 interaction with an IC50 value of 3.1 nM. Further microscale thermophoresis (MST) analysis demonstrated that HD10 had strong interaction with PD-L1 protein. Co-crystal structure (2.7 Å) analysis of HD10 in complex with the PD-L1 protein revealed a strong affinity between the compound and the target PD-L1 dimer. This provides a solid theoretical basis for further in vitro and in vivo studies. Next, a typical cell-based experiment demonstrated that HD10 could remarkably prevent the interaction of hPD-1 293 T cells from human recombinant PD-L1 protein, effectively restoring T cell function, and promoting IFN-γ secretion in a dose-dependent manner. Moreover, HD10 was effective in suppressing tumor growth (TGI = 57.31 %) in a PD-1/PD-L1 humanized mouse model without obvious toxicity. Flow cytometry, qPCR, and immunohistochemistry data suggested that HD10 inhibits tumor growth by activating the immune system in vivo. Based on these results, it seems likely that HD10 is a promising clinical candidate that should be further investigated.

N-methylmorpholine incorporation into the structure of biphenyl leads to the bioactive inhibitor of PD-1/PD-L1 interaction

We present new small-molecular probes targeting the human PD-L1 protein. The molecules were designed by incorporating a newly discovered N-methylmorpholine substituent into a known biphenyl-based structure. Four prototype derivatives of 4-methyl-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-carbonitrile (STD4), comprising a morpholine substituent fused with a biphenyl core at different orientations were first verified for their potential binding to PD-L1 using the molecular docking method. A more favorable 7-phenyl derivative of STD4 was then equipped with an amide bond, pyridine, and either a tris(hydroxymethyl)aminomethane or serinol tail leading to two final molecules. Among them, compound 1c showed activity in three bioassays, i.e., the homogenous time-resolved fluorescence (HTRF) assay, immune checkpoint blockade (ICB) assay, and T-cell activation (TCA) assay. Our work shows that morpholine can substitute for dioxane and becomes a promising component in PD-L1-targeting molecules. This finding unlocks new avenues for optimizing PD-L1-targeting compounds, presenting exciting prospects for future developments in this field.

PD-1/PD-L1 interaction score and NKT-like cell infiltration predict immunotherapy efficacy in non-small cell lung cancer patients

ObjectiveThe currently available biomarkers are insufficient to accurately predict the immunotherapy response in patients. This work attempted to investigate effects of PD-1/PD-L1 interaction score combined with NKT-like cell infiltration level in tumor microenvironment on predicting immunotherapy efficacy. Methods24 non-small cell lung cancer (NSCLC) patients who underwent immunotherapy were analyzed using multiplex immunofluorescence to quantitatively assess positive cells of target biomarkers and their spatial localization. Correlation between PD-1/PD-L1 interaction score in combination with NKT-like cell infiltration level and immunotherapy response was analyzed. The predictive performance of two individual biomarkers and combined novel biomarkers in immunotherapy efficacy was assessed through receiver operating characteristic curve analysis. Relationships between these factors and patient survival prognosis were analyzed using Kaplan–Meier curves. ResultsAmong responders, PD-1/PD-L1 interaction score and NKT-like cell infiltration level were significantly higher than nonresponders (P < 0.05), and PD-1/PD-L1 interaction score and NKT-like cell infiltration level could effectively identify the population with immunotherapy response, with area under the curves (AUCs) of 0.7571 and 0.8643, respectively. Combination of the two had the best performance in predicting the efficacy of immunotherapy (AUC = 0.9070). High PD-1/PD-L1 interaction scores and high levels of NKT-like cell infiltration significantly improved progression-free survival (HR = 0.2544, P = 0.0053) and overall survival (HR = 0.2820, P = 0.0053) in patients. ConclusionsCombination of PD-1/PD-L1 interaction score and NKT-like cell infiltration level had favorable performance in predicting immunotherapy response in NSCLC patients, contributing to accurately identify patients who may benefit from immunotherapy.

Design, synthesis, pharmacological evaluation, and computational study of benzo[d] isothiazol-based small molecule inhibitors targeting PD-1/PD-l1 interaction

Blockade of the programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway is an attractive strategy for immunotherapy, but the clinical application of small molecule PD-1/PD-L1 inhibitors remains unclear. In this work, based on BMS-202 and our previous work YLW-106, a series of compounds with benzo[d]isothiazol structure as scaffold were designed and synthesized. Their inhibitory activity against PD-1/PD-L1 interaction was evaluated by a homogeneous time-resolved fluorescence (HTRF) assay. Among them, LLW-018 (27c) exhibited the most potent inhibitory activity with an IC50 value of 2.61 nM. The cellular level assays demonstrated that LLW-018 exhibited low cytotoxicity against Jurkat T and MDA-MB-231. Further cell-based PD-1/PD-L1 blockade bioassays based on PD-1 NFAT-Luc Jurkat cells and PD-L1 TCR Activator CHO cells indicated that LLW-018 could interrupt PD-1/PD-L1 interaction with an IC50 value of 0.88 μM. Multi-computational methods, including molecular docking, molecular dynamics, MM/GBSA, MM/PBSA, Metadynamics, and QM/MM MD were utilized on PD-L1 dimer complexes, which revealed the binding modes and dissociation process of LLW-018 and C2-symmetric small molecule inhibitor LCH1307. These results suggested that LLW-018 exhibited promising potency as a PD-1/PD-L1 inhibitor for further investigation.

TimiGP-Response: the pan-cancer immune landscape associated with response to immunotherapy.

Accumulating evidence suggests that the tumor immune microenvironment (TIME) significantly influences the response to immunotherapy, yet this complex relationship remains elusive. To address this issue, we developed TimiGP-Response (TIME Illustration based on Gene Pairing designed for immunotherapy Response), a computational framework leveraging single-cell and bulk transcriptomic data, along with response information, to construct cell-cell interaction networks associated with responders and estimate the role of immune cells in treatment response. This framework was showcased in triple-negative breast cancer treated with immune checkpoint inhibitors targeting the PD-1:PD-L1 interaction, and orthogonally validated with imaging mass cytometry. As a result, we identified CD8+ GZMB+ T cells associated with responders and its interaction with regulatory T cells emerged as a potential feature for selecting patients who may benefit from these therapies. Subsequently, we analyzed 3,410 patients with seven cancer types (melanoma, non-small cell lung cancer, renal cell carcinoma, metastatic urothelial carcinoma, hepatocellular carcinoma, breast cancer, and esophageal cancer) treated with various immunotherapies and combination therapies, as well as several chemo- and targeted therapies as controls. Using TimiGP-Response, we depicted the pan-cancer immune landscape associated with immunotherapy response at different resolutions. At the TIME level, CD8 T cells and CD4 memory T cells were associated with responders, while anti-inflammatory (M2) macrophages and mast cells were linked to non-responders across most cancer types and datasets. Given that T cells are the primary targets of these immunotherapies and our TIME analysis highlights their importance in response to treatment, we portrayed the pan-caner landscape on 40 T cell subtypes. Notably, CD8+ and CD4+ GZMK+ effector memory T cells emerged as crucial across all cancer types and treatments, while IL-17-producing CD8+ T cells were top candidates associated with immunotherapy non-responders. In summary, this study provides a computational method to study the association between TIME and response across the pan-cancer immune landscape, offering resources and insights into immune cell interactions and their impact on treatment efficacy.

Novel Bifunctional Conjugates Targeting PD-L1/PARP7 as Dual Immunotherapy for Potential Cancer Treatment.

Bifunctional conjugates targeting PD-L1/PARP7 were designed, synthesized, and evaluated for the first time. Compounds B3 and C6 showed potent activity against PD-1/PD-L1 interaction (IC50 = 0.426 and 0.342 μM, respectively) and PARP7 (IC50 = 2.50 and 7.05 nM, respectively). They also displayed excellent binding affinity with hPD-L1, approximately 100-200-fold better than that of hPD-1. Both compounds restored T-cell function, leading to the increase of IFN-γ secretion. In the coculture assay, B3 and C6 enhanced the killing activity of MDA-MB-231 cells by Jurkat T cells in a concentration-dependent manner. Furthermore, B3 and C6 displayed significant in vivo antitumor efficacy in a melanoma B16-F10 tumor mouse model, more than 5.3-fold better than BMS-1 (a PD-L1 inhibitor) and RBN-2397 (a PARP7i clinical candidate) at the dose of 25 mg/kg, without observable side effects. These results provide valuable insight and understanding for developing bifunctional conjugates for potential anticancer therapy.

Spatial proteomic landscape of primary and relapsed hepatocellular carcinoma reveals immune escape characteristics in early relapse.

Surgical resection serves as the principal curative strategy for hepatocellular carcinoma (HCC), yet the incidence of postoperative recurrence remains alarmingly high. However, the spatial molecular structural alterations contributing to postoperative recurrence in HCC are still poorly understood. We employed imaging mass cytometry to profile the in-situ expression of 33 proteins within 358,729 single cells of 92 clinically annotated surgical specimens from 46 patients who were treated with surgical resections for primary and relapsed tumors. We revealed the recurrence progression of HCC was governed by the dynamic spatial distribution and functional interplay of diverse cell types across adjacent normal, tumor margin, and intratumor regions. Our exhaustive analyses revealed an aggressive, immunosuppression-related spatial ecosystem in relapsed HCC. Additionally, we illustrated the prominent implications of the TME of tumor margins in association with relapse HCC. Moreover, we identified a novel subpopulation of dendritic cells (PDL1+CD103+ DCs) enriched in the peritumoral area that correlated with early postoperative recurrence, which was further validated in an external cohort. Through the analysis of scRNA-seq data, we found the interaction of PDL1+CD103+ DCs with regulatory T cells and exhausted T cells enhanced immunosuppression and immune escape via multiple ligand-receptor pathways. We comprehensively depicted the spatial landscape of single-cell dynamics and multicellular architecture within primary and relapsed HCC. Our findings highlight spatial organization is a prominent determinant of HCC recurrence and provide a valuable insight into the immune evasion mechanisms driving recurrence.