PD-L1 regulates inflammatory programs of macrophages from human pluripotent stem cells.

Programmed death ligand 1 (PD-L1) serves as a pivotal immune checkpoint in both the innate and adaptive immune systems. PD-L1 is expressed in macrophages in response to IFNγ. We examined whether PD-L1 might regulate macrophage development. We established PD-L1 KO (CD274 -/- ) human pluripotent stem cells and differentiated them into macrophages and observed a 60% reduction in CD11B+CD45+ macrophages in CD274 -/- ; this was orthogonally verified, with the PD-L1 inhibitor BMS-1166 reducing macrophages to the same fold. Single-cell RNA sequencing further confirmed the down-regulation of the macrophage-defining transcription factors SPI1 and MAFB Furthermore, CD274 -/- macrophages reduced the level of inflammatory signals such as NF-κB and TNF, and chemokine secretion of the CXCL and CCL families. Anti-inflammatory TGF-ß was up-regulated. Finally, we identified that CD274 -/- macrophages significantly down-regulated interferon-stimulated genes despite the presence of IFNγ in the differentiation media. These data suggest that PD-L1 regulates inflammatory programs of macrophages from human pluripotent stem cells.

Detection of antibodies against SARS-CoV-2 Spike protein by screen-printed carbon electrodes modified by colloidal gold nanoparticles.

In this work, electrochemical bioanalytical systems for the determination of antibodies against the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike protein (anti-rS) is reported. Environmentally friendly chemicals were applied in the synthesis of gold nanoparticles (AuNPs). The AuNPs were integrated onto the screen-printed carbon electrodes (SPE), and the biological recognition part was based on recombinant SARS-CoV-2 Spike protein (rS), which during the immobilization was cross-linked by glutaraldehyde. Immobilized rS protein based biological recognition part enabled selective recognition of anti-rS antibodies. The current flux of AuNPs reduction (at +200 mV) in a pure phosphate buffer (PB) was employed as the transduction signal. It has been reported that the formation of anti-rS layers on the surface of AuNPs delays the electrode response time (ts), tracked at the current flux density values of 80 µA cm-2. Using the AuNP-modified SPE, we demonstrated a rapid anti-rS detection within a detection limit of 2 ng mL-1 (0.125 binding antibody units mL-1, 17 pM). This system can be applied to track the response of immune system towards SARS-CoV-2 infection and monitoring of Coronavirus Disease 2019 (COVID-19).

Aspectos prácticos sobre la determinación de PD-L1 en el tratamiento de carcinoma urotelial. Consenso del grupo de uropatología de la SEAP / Practical aspects of PD-L1 assessment in the treatment of urothelial carcinoma: Consensus of the uropathology group of the SEAP

La reciente llegada de nuevos fármacos de inmunoterapia para el tratamiento del carcinoma urotelial hace necesario establecer criterios para armonizar la determinación de PD-L1 mediante inmunohistoquímica como factor pronóstico y para la selección de pacientes a tratar. En este escenario, un grupo de uropatólogos de la Sociedad Española de Anatomía Patológica, junto con un oncólogo médico como colaborador externo subespecializado en urooncología, ha elaborado este documento de recomendaciones basadas en la evidencia disponible. En la determinación de PD-L1 son especialmente relevantes la selección de la muestra analizada, su procesamiento, la plataforma de inmunohistoquímica y anticuerpo empleados, así como el algoritmo que se aplique para la lectura. Todos estos aspectos deben indicarse en el informe de resultados, que debería poder ser fácilmente interpretable en un contexto de rápida evolución de terapias inmunológicas.(AU)

The recent addition of novel immunotherapy drugs for the treatment of urothelial carcinoma makes it necessary the establishment of criteria to harmonize the immunohistochemical assessment of PD-L1, both as a prognostic factor and for the selection of patients to be treated. In this scenario, a group of uropathologists from the Spanish Society of Pathological Anatomy, together with a medical oncologist as an external collaborator subspecialized in uro-oncology, have prepared this document of recommendations based on the available evidence. During PD-L1 assessment it is especially relevant the selection of the sample, its processing, the immunohistochemical platform and antibody used, and the algorithm applied in the interpretation of results. All these aspects must be indicated in the results report, which should be easily interpretable in a context of rapid evolution of immunological therapies.(AU)

Severe Immune-Related Enteritis after In Utero Exposure to Pembrolizumab.

Immune checkpoint blockade has become standard treatment for many types of cancer. Such therapy is indicated most often in patients with advanced or metastatic disease but has been increasingly used as adjuvant therapy in those with early-stage disease. Adverse events include immune-related organ inflammation resembling autoimmune diseases. We describe a case of severe immune-related gastroenterocolitis in a 4-month-old infant who presented with intractable diarrhea and failure to thrive after in utero exposure to pembrolizumab. Known causes of the symptoms were ruled out, and the diagnosis of pembrolizumab-induced immune-related gastroenterocolitis was supported by the results of histopathological assays, immunophenotyping, and analysis of the level of antibodies against programmed cell death protein 1 (PD-1). The infant's condition was successfully treated with prednisolone and infliximab.

Comparative analysis of clinical and immunological profiles across Omicron BA.5.2 subvariants using next-generation sequencing in a Chinese cohort.

Objective: The Omicron BA.5.2 variant of SARS-CoV-2 has undergone several evolutionary adaptations, leading to multiple subvariants. Rapid and accurate characterization of these subvariants is essential for effective treatment, particularly in critically ill patients. This study leverages Next-Generation Sequencing (NGS) to elucidate the clinical and immunological features across different Omicron BA.5.2 subvariants. Methods: We enrolled 28 patients infected with the Omicron variant, hospitalized in Zhangjiajie People's Hospital, Hunan, China, between January 20, 2023, and March 31, 2023. Throat swabs were collected upon admission for NGS-based identification of Omicron subvariants. Clinical data, including qSOFA scores and key laboratory tests, were collated. A detailed analysis of lymphocyte subsets was conducted to ascertain the extent of immune cell damage and disease severity. Results: Patients were infected with various Omicron subvariants, including BA.5.2.48, BA.5.2.49, BA.5.2.6, BF.7.14, DY.1, DY.2, DY.3, and DY.4. Despite having 43 identical mutation sites, each subvariant exhibited unique marker mutations. Critically ill patients demonstrated significant depletion in total lymphocyte count, T cells, CD4, CD8, B cells, and NK cells (P < 0.05). However, there were no significant differences in clinical and immunological markers across the subvariants. Conclusion: This study reveals that critically ill patients infected with different Omicron BA.5.2 subvariants experience similar levels of cellular immune dysfunction and inflammatory response. Four mutations - ORF1a:K3353R, ORF1a:L3667F, ORF1b:S997P, S:T883I showed correlation with immunological responses although this conclusion suffers from the small sample size. Our findings underscore the utility of NGS in the comprehensive assessment of infectious diseases, contributing to more effective clinical decision-making.

IL-1ß+ macrophages fuel pathogenic inflammation in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with high resistance to therapies1. Inflammatory and immunomodulatory signals co-exist in the pancreatic tumour microenvironment, leading to dysregulated repair and cytotoxic responses. Tumour-associated macrophages (TAMs) have key roles in PDAC2, but their diversity has prevented therapeutic exploitation. Here we combined single-cell and spatial genomics with functional experiments to unravel macrophage functions in pancreatic cancer. We uncovered an inflammatory loop between tumour cells and interleukin-1ß (IL-1ß)-expressing TAMs, a subset of macrophages elicited by a local synergy between prostaglandin E2 (PGE2) and tumour necrosis factor (TNF). Physical proximity with IL-1ß+ TAMs was associated with inflammatory reprogramming and acquisition of pathogenic properties by a subset of PDAC cells. This occurrence was an early event in pancreatic tumorigenesis and led to persistent transcriptional changes associated with disease progression and poor outcomes for patients. Blocking PGE2 or IL-1ß activity elicited TAM reprogramming and antagonized tumour cell-intrinsic and -extrinsic inflammation, leading to PDAC control in vivo. Targeting the PGE2-IL-1ß axis may enable preventive or therapeutic strategies for reprogramming of immune dynamics in pancreatic cancer.

RSV awareness, risk perception, causes, and terms: Comment.

This correspondence discusses on res awpiratory syncytial virus areness, risk perception and causes. Important limitations and possible furture direction for researching are mentioned.

Omentin-1 ameliorates the progress of osteoarthritis by promoting IL-4-dependent anti-inflammatory responses and M2 macrophage polarization.

Osteoarthritis (OA) is a prevalent joint disease commonly associated with aging and obesity, which can lead to pain, stiffness, joint dysfunction, and disability. Omentin-1 (also called intelectin-1) is a newly discovered adipokine, which plays a protective role in suppressing the secretion of pro-inflammatory cytokines. Based on data from the Gene Expression Omnibus (GEO) dataset and clinical samples obtained at our institution revealed, determined that omentin-1 and IL-4 (an anti-inflammatory cytokine) levels were significantly lower in OA patients than in normal controls. Omentin-1 was shown to induce IL-4-depedent anti-inflammatory responses and M2 macrophage polarization in OA synovial fibroblasts via the PI3K, ERK, and AMPK pathways. Administering omentin-1 was shown to block cartilage degradation and bone erosion resulting from anterior cruciate ligament transection by inhibiting the production of pro-inflammatory cytokines and promoting M2 macrophage polarization in vivo. Our findings indicate omentin-1 as a promising therapeutic avenue for the treatment for OA.

Novel insights into IL-37: an anti-inflammatory cytokine with emerging roles in anti-cancer process.

Interleukin-37 (IL-37) is a newly discovered member of IL-1 family. The cytokine was proved to have extensive protective effects in infectious diseases, allergic diseases, metabolic diseases, autoimmune diseases and tumors since its discovery. IL-37 was mainly produced by immune and some non-immune cells in response to inflammatory stimulus. The IL-37 precursors can convert into the mature forms after caspase-1 cleavage and activation intracellularly, and then bind to Smad-3 and transfer to the nucleus to inhibit the production and functions of proinflammatory cytokines; extracellularly, IL-37 binds to cell surface receptors to form IL-37/IL-18Rα/IL-1R8 complex to exert immunosuppressive function via inhibiting/activating multiple signal pathways. In addition, IL-37 can attenuate the pro-inflammatory effect of IL-18 through directly or forming an IL-37/IL-18BP/IL-18Rß complex. Therefore, IL-37 has the ability to suppress innate and acquired immunity of the host, and effectively control inflammatory stimulation, which was considered as a new hallmark of cancer. Specifically, it is concluded that IL-37 can inhibit the growth and migration of tumor cells, prohibit angiogenesis and mediate the immunoregulation in tumor microenvironment, so as to exert effective anti-tumor effects. Importantly, latest studies also showed that IL-37 may be a novel therapeutic target for cancer monitoring. In this review, we summarize the immunoregulation roles and mechanisms of IL-37 in anti-tumor process, and discuss its progress so far and potential as tumor immunotherapy.

CD8 T cell tolerance results from eviction of immature autoreactive cells from the thymus.

CD8 T cell tolerance is thought to result from clonal deletion of autoreactive thymocytes before they differentiate into mature CD8 T cells in the thymus. However, we report that, in mice, CD8 T cell tolerance instead results from premature thymic eviction of immature autoreactive CD8 thymocytes into the periphery, where they differentiate into self-tolerant mature CD8 T cells. Premature thymic eviction is triggered by T cell receptor (TCR)-driven down-regulation of the transcriptional repressor Gfi1, which induces expression of sphingosine-1-phosphate receptor-1 (S1P1) on negatively selected immature CD8 thymocytes. Thus, premature thymic eviction is the basis for CD8 T cell tolerance and is the mechanism responsible for the appearance in the periphery of mature CD8 T cells bearing autoreactive TCRs that are absent from the thymus.

Targeting of intracellular oncoproteins with peptide-centric CARs.

The majority of oncogenic drivers are intracellular proteins, constraining their immunotherapeutic targeting to mutated peptides (neoantigens) presented by individual human leukocyte antigen (HLA) allotypes1. However, most cancers have a modest mutational burden that is insufficient for generating responses using neoantigen-based therapies2,3. Neuroblastoma is a paediatric cancer that harbours few mutations and is instead driven by epigenetically deregulated transcriptional networks4. Here we show that the neuroblastoma immunopeptidome is enriched with peptides derived from proteins essential for tumorigenesis. We focused on targeting the unmutated peptide QYNPIRTTF discovered on HLA-A*24:02, which is derived from the neuroblastoma-dependency gene and master transcriptional regulator PHOX2B. To target QYNPIRTTF, we developed peptide-centric chimeric antigen receptors (PC-CARs) through a counter panning strategy using predicted potentially cross-reactive peptides. We further proposed that PC-CARs can recognize peptides on additional HLA allotypes when presenting a similar overall molecular surface. Informed by our computational modelling results, we show that PHOX2B PC-CARs also recognize QYNPIRTTF presented by HLA-A*23:01, the most common non-A2 allele in people with African ancestry. Finally, we demonstrate potent and specific killing of neuroblastoma cells expressing these HLAs in vitro and complete tumour regression in mice. These data suggest that PC-CARs have the potential to expand the pool of immunotherapeutic targets to include non-immunogenic intracellular oncoproteins and allow targeting through additional HLA allotypes in a clinical setting.

Deconstruction of rheumatoid arthritis synovium defines inflammatory subtypes.

Rheumatoid arthritis is a prototypical autoimmune disease that causes joint inflammation and destruction1. There is currently no cure for rheumatoid arthritis, and the effectiveness of treatments varies across patients, suggesting an undefined pathogenic diversity1,2. Here, to deconstruct the cell states and pathways that characterize this pathogenic heterogeneity, we profiled the full spectrum of cells in inflamed synovium from patients with rheumatoid arthritis. We used multi-modal single-cell RNA-sequencing and surface protein data coupled with histology of synovial tissue from 79 donors to build single-cell atlas of rheumatoid arthritis synovial tissue that includes more than 314,000 cells. We stratified tissues into six groups, referred to as cell-type abundance phenotypes (CTAPs), each characterized by selectively enriched cell states. These CTAPs demonstrate the diversity of synovial inflammation in rheumatoid arthritis, ranging from samples enriched for T and B cells to those largely lacking lymphocytes. Disease-relevant cell states, cytokines, risk genes, histology and serology metrics are associated with particular CTAPs. CTAPs are dynamic and can predict treatment response, highlighting the clinical utility of classifying rheumatoid arthritis synovial phenotypes. This comprehensive atlas and molecular, tissue-based stratification of rheumatoid arthritis synovial tissue reveal new insights into rheumatoid arthritis pathology and heterogeneity that could inform novel targeted treatments.

CD47 masks pro-phagocytic ligands in cis on tumor cells to suppress antitumor immunity.

Cancer cells often overexpress CD47, which triggers the inhibitory receptor SIRPα expressed on macrophages, to elude phagocytosis and antitumor immunity. Pharmacological blockade of CD47 or SIRPα is showing promise as anticancer therapy, although CD47 blockade has been associated with hematological toxicities that may reflect its broad expression pattern on normal cells. Here we found that, in addition to triggering SIRPα, CD47 suppressed phagocytosis by a SIRPα-independent mechanism. This mechanism prevented phagocytosis initiated by the pro-phagocytic ligand, SLAMF7, on tumor cells, due to a cis interaction between CD47 and SLAMF7. The CD47-SLAMF7 interaction was disrupted by CD47 blockade and by a first-in-class agonist SLAMF7 antibody, but not by SIRPα blockade, thereby promoting antitumor immunity. Hence, CD47 suppresses phagocytosis not only by engaging SIRPα, but also by masking cell-intrinsic pro-phagocytic ligands on tumor cells and knowledge of this mechanism may influence the decision between CD47 blockade or SIRPα blockade for therapeutic purposes.

Oncolymphology: Immune Interactions and Cancer.

The proposed term "oncolymphology" encompasses the intimate relationship between cancer growth and the immune responses.

Immunogenicity and Safety of a SARS-CoV-2 Inactivated Vaccine KCONVAC in Chinese Children: Randomized, Double-blind, Placebo-controlled Phase 1 and 2 Trials.

BACKGROUND: It is important to extend the indication of severe acute respiratory syndrome coronavirus 2 vaccine to children to improve the vaccine intake rate and reduce infection in this population. METHODS: In 2 phase 1 and phase 2 randomized, double-blind and placebo-controlled trials, 84 and 480 Chinese healthy children 3 to 17 years old were enrolled, respectively, and randomized in 3:1 ratio to receive 2 doses of a severe acute respiratory syndrome coronavirus 2 inactivated vaccine, KCONVAC or placebo. The 2 doses were given 28 days apart. Adverse events (AEs) were recorded through Day 28 after each dosing. Live virus neutralizing antibody and receptor binding domain antibody (RBD-IgG) were tested before vaccination and after the second dose. RESULTS: Two doses of the vaccine, KCONVAC, elicited geometric mean titers of 142-150 for neutralizing antibody and 4154-4253 for RBD-IgG 28 days after the second dose. Seroconversion rates were 100% after 2 doses for both antibodies in both trials. The predominant AEs were injection-site pain, cough and fever. Most AEs were grade 1 or 2 in intensity. Five participants reported 6 vaccination-unrelated serious AEs in the phase 2 trial. CONCLUSIONS: Two doses of this study vaccine, KCONVAC, were well tolerated and immunogenic in children 3 to 17 years of age.