• MeSH
• CD8-Positive T-Lymphocytes cytology   immunology   MeSH
• T-Lymphocytes, Cytotoxic * MeSH
• Gene Expression MeSH
• HIV Infections immunology   MeSH
• HIV * immunology   pathogenicity   MeSH
• Immune Checkpoint Inhibitors * analysis   MeSH
• Clinical Trials as Topic MeSH
• Humans MeSH
• CD4-CD8 Ratio MeSH
• Flow Cytometry MeSH
• Gene Expression Profiling MeSH
• Check Tag
• Humans MeSH

Trichothecene mycotoxins have a strong immunosuppressive effect, which may even escape host immune surveillance and damage the immune repair to show an "immune evasion" effect. Increasing lines of evidence have shown that hypoxia and hypoxia-inducible factors (HIFs) are key mediators of trichothecenes, and these toxins appear to be closely related to the "immune evasion" mechanisms. Therefore, we used RAW264.7 cell model to explore the association of T-2 toxins with "immune evasion" process and hypoxia, as well as their cross-linking effects induced by T-2 toxin. Our results showed that HIF-1α is an important toxicity target of T-2 toxin, which could induce intracellular hypoxia. T-2 toxin induced an "immune evasion" process by activating the PD-1/PD-L1 signaling pathway. Interestingly, when HIF-1α activation was blocked, the "immune evasion" process regulated by PD-1/PD-L1 signaling was activated, resulting in the cells damage, suggesting that hypoxia induced by T-2 toxin plays a protective role for RAW264.7 cell damage. Thus, our work shows that HIF-1α inhibits T-2 toxin-mediated "immune evasion" process by negatively regulating PD-1/PD-L1signaling. This study contributes to a better understanding of the immunotoxicity mechanism of trichothecenes.

• MeSH
• B7-H1 Antigen metabolism   MeSH
• Programmed Cell Death 1 Receptor metabolism   MeSH
• Hypoxia-Inducible Factor 1, alpha Subunit pharmacology   MeSH
• Hypoxia MeSH
• Humans MeSH
• T-2 Toxin * toxicity   MeSH
• Trichothecenes * toxicity   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

INTRODUCTION: Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many malignancies in recent years. However, immune-related adverse events (irAE) are a frequent concern in clinical practice. The safety profile of ICI for the treatment of malignancies in patients diagnosed with autoimmune and cholestatic liver disease (AILD) remains unclear. Due to this uncertainty, these patients were excluded from ICI clinical trials and ICI are withheld from this patient group. In this retrospective multicenter study, we assessed the safety of ICI in patients with AILD. METHODS: We contacted tertiary referral hospitals for the identification of AILD patients under ICI treatment in Europe via the European Reference Network on Hepatological Diseases (ERN RARE-LIVER). Fourteen centers contributed data on AILD patients with malignancies being treated with ICI, another three centers did not treat these patients with ICI due to fear of irAEs. RESULTS: In this study, 22 AILD patients under ICI treatment could be identified. Among these patients, 12 had primary biliary cholangitis (PBC), five had primary sclerosing cholangitis (PSC), four had autoimmune hepatitis (AIH), and one patient had an AIH-PSC variant syndrome. Eleven patients had hepatobiliary cancers and the other 11 patients presented with non-hepatic tumors. The applied ICIs were atezolizumab (n=7), durvalumab (n=5), pembrolizumab (n=4), nivolumab (n=4), spartalizumab (n=1), and in one case combined immunotherapy with nivolumab plus ipilimumab. Among eight patients who presented with grade 1 or 2 irAEs, three demonstrated liver irAEs. Cases with grades ≥ 3 irAEs were not reported. No significant changes in liver tests were observed during the first year after the start of ICI. DISCUSSION: This European multicenter study demonstrates that PD-1/PD-L1 inhibitors appear to be safe in patients with AILD. Further studies on the safety of more potent dual immune checkpoint therapy are needed. We conclude that immunotherapy should not categorically be withheld from patients with AILD.

• MeSH
• B7-H1 Antigen MeSH
• Programmed Cell Death 1 Receptor MeSH
• Hepatitis, Autoimmune * drug therapy   MeSH
• Cholestasis * MeSH
• Immune Checkpoint Inhibitors adverse effects   MeSH
• Humans MeSH
• Neoplasms * MeSH
• Nivolumab adverse effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH

Cancers arising from germline DNA mismatch repair deficiency or polymerase proofreading deficiency (MMRD and PPD) in children harbour the highest mutational and microsatellite insertion-deletion (MS-indel) burden in humans. MMRD and PPD cancers are commonly lethal due to the inherent resistance to chemo-irradiation. Although immune checkpoint inhibitors (ICIs) have failed to benefit children in previous studies, we hypothesized that hypermutation caused by MMRD and PPD will improve outcomes following ICI treatment in these patients. Using an international consortium registry study, we report on the ICI treatment of 45 progressive or recurrent tumors from 38 patients. Durable objective responses were observed in most patients, culminating in a 3 year survival of 41.4%. High mutation burden predicted response for ultra-hypermutant cancers (>100 mutations per Mb) enriched for combined MMRD + PPD, while MS-indels predicted response in MMRD tumors with lower mutation burden (10-100 mutations per Mb). Furthermore, both mechanisms were associated with increased immune infiltration even in 'immunologically cold' tumors such as gliomas, contributing to the favorable response. Pseudo-progression (flare) was common and was associated with immune activation in the tumor microenvironment and systemically. Furthermore, patients with flare who continued ICI treatment achieved durable responses. This study demonstrates improved survival for patients with tumors not previously known to respond to ICI treatment, including central nervous system and synchronous cancers, and identifies the dual roles of mutation burden and MS-indels in predicting sustained response to immunotherapy.

• MeSH
• Survival Analysis MeSH
• B7-H1 Antigen antagonists & inhibitors   MeSH
• Child MeSH
• Adult MeSH
• Immune Checkpoint Inhibitors pharmacology   therapeutic use   MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Biomarkers, Tumor MeSH
• Tumor Microenvironment MeSH
• Neoplasms drug therapy   MeSH
• DNA Repair genetics   MeSH
• Prospective Studies MeSH
• DNA Replication genetics   MeSH
• Retrospective Studies MeSH
• Germ-Line Mutation * MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: The anti-PD-1 monoclonal antibody pembrolizumab has been shown to be associated with a good response in patients with metastatic gastric cancer. Excellent therapeutic results of pembrolizumab have been shown in patients with tumours showing a high microsatellite instability (MSI) and Epstein–Barr virus (EBV) positivity. GOAL: This is a retrospective study of 40 bioptic specimens from the patients, who underwent gastrectomy for gastric carcinoma. The goal of the study was to identify biomarkers (EBV, MLH-1, PDL-1 expression) that are potentially relevant for selecting the patients, who may benefit from PD-1 inhibition therapy. METHODS: Immunohistochemical (IHC) expression of PDL-1 and MSI, cytogenetic FISH amplification of the HER-2/neu gene and polymerase chain reaction of EBV RNA, including charge quantification, were performed in selected patients with metastatic or advanced gastric cancer. RESULTS: EBV-encoded RNA was detected in nine patients. None of them exhibited Her-2 overexpression or CMV infection. PD-L1 was detected in twelve patients. Ten patients were MLH1 positive. All nine cases of EBV infection showed a high expression of PD-L1 and MLH-1 (Tab. 1, Ref. 14).

• MeSH
• B7-H1 Antigen analysis   immunology   MeSH
• Biomarkers * analysis   MeSH
• Gene Expression MeSH
• Epstein-Barr Virus Infections diagnosis   immunology   MeSH
• Clinical Laboratory Techniques methods   MeSH
• Middle Aged MeSH
• Humans MeSH
• Microsatellite Instability MeSH
• MutL Protein Homolog 1 analysis   immunology   MeSH
• Stomach Neoplasms * immunology   physiopathology   MeSH
• Specimen Handling MeSH
• Receptor, ErbB-2 analysis   immunology   MeSH
• Retrospective Studies MeSH
• Aged MeSH
• Patient Selection MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Aged MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: SOT201 and its murine surrogate mSOT201 are novel cis-acting immunocytokines consisting of a humanized/murinized/, Fc-silenced anti-programmed cell death protein 1 (PD-1) monoclonal antibody (mAb) fused to an attenuated human interleukin (IL)-15 and the IL-15Rα sushi+ domain. Murine mPD1-IL2v is a conjugate of a murinized, Fc silenced anti-PD-1 mAb bearing human IL-2 with abolished IL-2Rα binding. These immunocytokines spatiotemporally reinvigorate PD-1+ CD8+ tumor-infiltrating lymphocytes (TILs) via cis-activation and concomitantly activate the innate immunity via IL-2/15Rβγ signaling. METHODS: Human peripheral blood mononuclear cell and cell lines were used to evaluate cis/trans activity of SOT201. Anti-PD-1 mAb responsive (MC38, CT26) and resistant (B16F10, CT26 STK11 KO) mouse tumor models were used to determine the anticancer efficacy, and the underlying immune cell activity was analyzed via single-cell RNA sequencing and flow cytometry. The expansion of tumor antigen-specific CD8+ T cells by mSOT201 or mPD1-IL2v and memory CD8+ T-cell generation in vivo was determined by flow cytometry. RESULTS: SOT201 delivers attenuated IL-15 to PD-1+ T cells via cis-presentation, reinvigorates exhausted human T cells and induces higher interferon-γ production than pembrolizumab in vitro. mSOT201 administered as a single dose exhibits strong antitumor efficacy with several complete responses in all tested mouse tumor models. While mPD1-IL2v activates CD8+ T cells with a 50-fold higher potency than mSOT201 in vitro, mSOT201 more effectively reactivates effector exhausted CD8+ T cells (Tex), which demonstrate higher cytotoxicity, lower exhaustion and lower immune checkpoint transcriptional signatures in comparison to mPD1-IL2v in MC38 tumors in vivo. This can be correlated with a higher rate of complete responses in the MC38 tumor model following mSOT201 treatment when compared with mPD1-IL2v. mSOT201 increased the relative number of tumor antigen-specific CD8+ T cells, and unlike mPD1-IL2v stimulated greater expansion of adoptively transferred ovalbumin-primed CD8+ T cells simultaneously limiting the peripheral CD8+ T-cell sink, leading to the development of memory CD8+ T cells in vivo. CONCLUSIONS: SOT201 represents a promising therapeutic candidate that preferentially targets PD-1+ TILs, delivering balanced cytokine activity for reviving CD8+ Tex cells in tumors. SOT201 is currently being evaluated in the Phase I clinical study VICTORIA-01 (NCT06163391) in patients with advanced metastatic cancer.

• MeSH
• Programmed Cell Death 1 Receptor * antagonists & inhibitors   MeSH
• CD8-Positive T-Lymphocytes immunology   MeSH
• Immune Checkpoint Inhibitors pharmacology   MeSH
• Interleukin-15 * genetics   pharmacology   MeSH
• Humans MeSH
• Mice MeSH
• Cell Line, Tumor MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

In search of a potent small molecular PD-L1 inhibitor, we designed and synthesized a compound based on a 2-hydroxy-4-phenylthiophene-3-carbonitrile moiety. Ligand's performance was tested in vitro and compared side-by-side with a known PD-L1 antagonist with a proven bioactivity BMS1166. Subsequently, we modified both compounds to allow 18F labeling that could be used for PET imaging. Radiolabeling, which is used in drug development and diagnosis, was applied to investigate the properties of those ligands and test them against tissue sections with diverse expression levels of PD-L1. We confirmed biological activity toward hPD-L1 for this inhibitor, comparable with BMS1166, while holding enhanced pharmacological properties.

• MeSH
• B7-H1 Antigen * MeSH
• Immune Checkpoint Inhibitors * MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: Immune checkpoint inhibitors (ICIs), including those targeting PD-1, are currently used in a wide range of tumors, but only 20-40% of patients achieve clinical benefit. The objective of our study was to find predictive peripheral blood-based biomarkers for ICI treatment. METHODS: In 41 patients with advanced malignant melanoma (MM) and NSCLC treated with PD-1 inhibitors, we analyzed peripheral blood-based immune subsets by flow cytometry before treatment initialization and the second therapy dose. Specifically, we assessed basic blood differential count, overall T cells and their subgroups, B cells, and myeloid-derived suppressor cells (MDSC). In detail, CD4 + and CD8 + T cells were assessed according to their subtypes, such as central memory T cells (TCM), effector memory T cells (TEM), and naïve T cells (TN). Furthermore, we also evaluated the predictive value of CD28 and ICOS/CD278 co-expression on T cells. RESULTS: Patients who achieved disease control on ICIs had a significantly lower baseline proportion of CD4 + TEM (p = 0.013) and tended to have a higher baseline proportion of CD4 + TCM (p = 0.059). ICI therapy-induced increase in Treg count (p = 0.012) and the proportion of CD4 + TN (p = 0.008) and CD28 + ICOS- T cells (p = 0.012) was associated with disease control. Patients with a high baseline proportion of CD4 + TCM and a low baseline proportion of CD4 + TEM showed significantly longer PFS (p = 0.011, HR 2.6 and p ˂ 0.001, HR 0.23, respectively) and longer OS (p = 0.002, HR 3.75 and p ˂ 0.001, HR 0.15, respectively). Before the second dose, the high proportion of CD28 + ICOS- T cells after ICI therapy initiation was significantly associated with prolonged PFS (p = 0.017, HR 2.51) and OS (p = 0.030, HR 2.69). Also, a high Treg count after 2 weeks of ICI treatment was associated with significantly prolonged PFS (p = 0.016, HR 2.33). CONCLUSION: In summary, our findings suggest that CD4 + TEM and TCM baselines and an early increase in the Treg count induced by PD-1 inhibitors and the proportion of CD28 + ICOS- T cells may be useful in predicting the response in NSCLC and MM patients.

• MeSH
• Inducible T-Cell Co-Stimulator Protein metabolism   MeSH
• Programmed Cell Death 1 Receptor antagonists & inhibitors   MeSH
• CD28 Antigens MeSH
• CD8-Positive T-Lymphocytes immunology   drug effects   metabolism   MeSH
• Adult MeSH
• Immune Checkpoint Inhibitors * therapeutic use   pharmacology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Melanoma * drug therapy   immunology   blood   pathology   MeSH
• Lung Neoplasms * drug therapy   immunology   blood   pathology   MeSH
• Carcinoma, Non-Small-Cell Lung * drug therapy   immunology   blood   pathology   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: Nivolumab is a human monoclonal antibody against programmed cell death receptor-1 (PD-1) able to rescue quiescent tumor infiltrating cytotoxic T lymphocytes (CTLs) restoring their ability to kill target cells expressing specific tumor antigen-derived epitope peptides bound to homologue human leukocyte antigen (HLA) molecules. Nivolumab is currently an active but expensive therapeutic agent for metastatic non-small cell lung cancer (mNSCLC), producing, in some cases, immune-related adverse events (irAEs). At the present, no reliable biomarkers have been validated to predict either treatment response or adverse events in treated patients. METHODS: We performed a retrospective multi-institutional analysis including 119 patients with mNSCLC who received PD-1 blockade since November 2015 to investigate the predictive role of germinal class I HLA and DRB1 genotype. We investigated the correlation among patients' outcome and irAEs frequency with specific HLA A, B, C and DRB1 alleles by reverse sequence-specific oligonucleotide (SSO) DNA typing. RESULTS: A poor outcome in patients negative for the expression of two most frequent HLA-A alleles was detected (HLA: HLA-A*01 and or A*02; progression-free survival (PFS): 7.5 (2.8 to 12.2) vs 15.9 (0 to 39.2) months, p=0.01). In particular, HLA-A*01-positive patients showed a prolonged PFS of 22.6 (10.2 to 35.0) and overall survival (OS) of 30.8 (7.7 to 53.9) months, respectively. We also reported that HLA-A and DRB1 locus heterozygosis (het) were correlated to a worse OS if we considered het in the locus A; in reverse, long survival was correlated to het in DRB1. CONCLUSIONS: This study demonstrate that class I and II HLA allele characterization to define tumor immunogenicity has relevant implications in predicting nivolumab efficacy in mNSCLC and provide the rationale for further prospective trials of cancer immunotherapy.

• MeSH
• Alleles MeSH
• Survival Analysis MeSH
• HLA Antigens metabolism   MeSH
• Immune Checkpoint Inhibitors pharmacology   therapeutic use   MeSH
• Humans MeSH
• Lung Neoplasms genetics   mortality   MeSH
• Carcinoma, Non-Small-Cell Lung genetics   mortality   MeSH
• Retrospective Studies MeSH
• Aged MeSH
• Treatment Outcome MeSH
• Germ-Line Mutation genetics   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH

Immune checkpoint blockade (ICB) using monoclonal antibodies against programmed cell death protein 1 (PD-1) or programmed death-ligand 1 (PD-L1) is the treatment of choice for cancer immunotherapy. However, low tissue permeability, immunogenicity, immune-related adverse effects, and high cost could be possibly improved using alternative approaches. On the other hand, synthetic low-molecular-weight (LMW) PD-1/PD-L1 blockers have failed to progress beyond in vitro studies, mostly due to low binding affinity or poor pharmacological characteristics resulting from their limited solubility and/or stability. Here, we report the development of polymer-based anti-human PD-L1 antibody mimetics (α-hPD-L1 iBodies) by attaching the macrocyclic peptide WL12 to a N-(2-hydroxypropyl)methacrylamide copolymer. We characterized the binding properties of iBodies using surface plasmon resonance, enzyme-linked immunosorbent assay, flow cytometry, confocal microscopy, and a cellular ICB model. We found that the α-hPD-L1 iBodies specifically target human PD-L1 (hPD-L1) and block the PD-1/PD-L1 interaction in vitro, comparable to the atezolizumab, durvalumab, and avelumab licensed monoclonal antibodies targeting PD-L1. Our findings suggest that iBodies can be used as experimental tools to target hPD-L1 and could serve as a platform to potentiate the therapeutic effect of hPD-L1-targeting small molecules by improving their affinity and pharmacokinetic properties.

• MeSH
• B7-H1 Antigen * antagonists & inhibitors   immunology   metabolism   MeSH
• Immune Checkpoint Inhibitors * pharmacology   chemistry   MeSH
• Humans MeSH
• Antibodies, Monoclonal chemistry   pharmacology   MeSH
• Cell Line, Tumor MeSH
• Polymers chemistry   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH