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HIF1A+CSF3R+ neutrophils-dominated hypoxic niche induced metabolic reprogramming for neoadjuvant therapy resistance in NSCLC.

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the frequently occurring cancers characterized by molecular heterogeneity and multiple immune cell infiltration patterns, which are associated with treatment sensitivity and resistance. However, the specific microenvironmental cells and their mechanisms that lead to treatment resistance in patients need to be explored in greater depth. METHODS: On the basis of patients receiving neoadjuvant therapy in our center, a multicenter, multicohort NSCLC spatial transcriptome, single-cell transcriptome, T-cell receptor repertoire sequencing, bulk RNA transcriptome, phosphorylated proteome, genome mutation, and clinical data were included for a comprehensive assessment of the therapeutic and prognostic impact of HIF1A+ CSF3R+ neutrophils in NSCLC. In vitro experiments validated the functional phenotype of HIF1A+ CSF3R+ neutrophils and co-localization interactions with other cellular subpopulations. Gradient boosting machine (GBM) constructed region of interest (ROI) models for evaluation. Computer-aided drug design (CADD) was used to predict targeted small molecule drugs, and in vivo mouse models were constructed to assess the effectiveness of the combination treatment regimen. RESULTS: Centered on HIF1A+ CSF3R+ neutrophils, recruited exhausted T cells and stromal cells form a hypoxic niche within the tumor region, which was enriched in non-response patients. ROI composed of these specific cellular subpopulations, associated with senescence and glycolysis, accurately predicting NSCLC progression, prognosis, and microenvironment composition. CADD analysis identified that platycodin-D2 specifically targeted CSF3R, reducing HIF1A expression and inhibiting neutrophil activity. Combining navitoclax, platycodin-D2 with anti-programmed cell death protein 1 (PD-1) significantly suppressed tumor proliferation and improved the immunosuppressive microenvironment. CONCLUSION: Our study emphasized the role of HIF1A+ CSF3R+ neutrophils in immunotherapeutic resistance of NSCLC, constructed a microenvironmental immune dysregulation network in a hypoxic ecological niche with HIF1A+ CSF3R+ neutrophils as the center. Platycodin-D2 specifically targeted HIF1A+ CSF3R+ neutrophils, enhancing the efficacy of anti-PD-1 therapy in NSCLC.

Humans↗

Spatial habitat radiomics predicts tertiary lymphoid structure status and identifies an IDO1+ migratory dendritic cell axis in breast cancer.

BACKGROUND: Tertiary lymphoid structures (TLS) are spatially organized immune niches associated with therapeutic response and favorable outcomes in breast cancer (BC). However, TLS assessment currently relies on invasive tissue-based analyses, and the biological mechanisms underlying imaging-based TLS prediction remain poorly understood. METHODS: We developed and validated a spatial heterogeneity-based radiomic TLS signature (shTLS) using dynamic contrast-enhanced MRI to non-invasively predict TLS status across multicenter BC cohorts. Spatial habitat radiomics were used to capture intratumoral and peritumoral immune-related heterogeneity. Integrated multi-omics analyses, including transcriptomics, pathomics, genomics, single-cell RNA sequencing, immunohistochemistry, and multiplex immunofluorescence, were performed to biologically interpret shTLS-defined subgroups. Functional drug-sensitivity assays were conducted to assess therapeutic implications. RESULTS: The shTLS model achieved robust predictive performance across independent cohorts and molecular subtypes. High shTLS scores were associated with immune-inflamed tumors characterized by spatially clustered activated T cells and dendritic cells (DCs). In contrast, shTLS-low tumors exhibited an immunosuppressive spatial niche with peripheral accumulation of CD4+ PD-1+ T cells and plasma cells, increased immune-tumor separation, and enhanced inflammatory and immunoregulatory signaling. An indoleamine 2,3-dioxygenase 1 (IDO1)-associated immunoregulatory program was observed in the shTLS-low tumors, which appeared to be preferentially expressed by LAMP3+CCR7+ migratory DCs. Pharmacologic inhibition of IDO1 enhanced chemotherapy and CDK4/6 inhibitor sensitivity in vitro. CONCLUSION: This study establishes spatial radiomics as a non-invasive approach to decode TLS-associated immune ecosystems and supports the presence of an IDO1-associated immunosuppressive phenotype, providing biological insight and translational rationale for patient stratification and future combination strategies.

Humans↗

The B7 family of ligands and its receptors: new pathways for costimulation and inhibition of immune responses.

T cell activation is dependent upon signals delivered through the antigen-specific T cell receptor and accessory receptors on the T cell. A primary costimulatory signal is delivered through the CD28 receptor after engagement of its ligands, B7-1 (CD80) or B7-2 (CD86). Engagement of CTLA-4 (CD152) by the same B7-1 or B7-2 ligands results in attenuation of T cells responses. Recently, molecular homologs of CD28 and CTLA-4 receptors and their B7-like ligands have been identified. ICOS is a CD28-like costimulatory receptor with a unique B7-like ligand. PD-1 is an inhibitory receptor, with two B7-like ligands. Additional members of B7 and CD28 gene families have been proposed. Integration of signals through this family of costimulatory and inhibitory receptors and their ligands is critical for activation of immune responses and tolerance. Understanding these pathways will allow development of new strategies for therapeutic intervention in immune-mediated diseases.

Abatacept↗

A Phase II Feasibility Study Combining Pembrolizumab and Metformin in Patients with Metastatic Head and Neck Cancer.

PURPOSE: Survival for recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) remains low with <20% immunotherapy response. Metformin increases tumor-infiltrating CD8+ T and natural killer (NK) cells, which harbor PD-1. In this phase II clinical trial (NCT04414540), we combined metformin and pembrolizumab to evaluate the overall response rate (ORR) in R/M HNSCC and assess NK-cell activity. PATIENTS AND METHODS: Eligible patients were randomized 1:1 into two arms: (i) metformin extended-release (ER) dose escalation to 2,000 mg over 14 days followed by combination with pembrolizumab 200 mg every 3 weeks or (ii) pembrolizumab 200 mg every 3 weeks followed by combination with metformin ER 2,000 mg daily. The primary endpoint was ORR per RECIST 1.1. Nineteen evaluable patients were planned to estimate the proportion of approximately 32% ORR. Safety was evaluated according to Common Terminology Criteria for Adverse Events v5.0. The distribution, activation, and cytotoxic function of NK cells were analyzed via flow cytometry. RESULTS: Twenty-one patients were enrolled; 76% were male, 52% were smokers, and the median age was 64 years. Ten patients had oropharyngeal tumors, of which nine were p16+. Eighteen patients were evaluable for response, including four complete and five partial responses for an ORR of 50% [95% confidence interval (29-71)]. Combination therapy was well tolerated with no unexpected adverse events (AE). Five grade 3 AEs occurred: nausea, diarrhea, fatigue, and weight loss. Metformin led to increased peripheral NK-cell maturation and cytotoxic ability. CONCLUSIONS: The combination of metformin and pembrolizumab was well tolerated with mild gastrointestinal AEs and promising activity, warranting further investigation in a randomized trial.

Humans↗

Clinical effects of long-term use of neutralized dialysate for continuous ambulatory peritoneal dialysis.

The long-term effects of neutralized dialysate used in continuous ambulatory peritoneal dialysis (CAPD) were evaluated in 8 well-controlled patients. Twelve milliliters of 8.4% sodium bicarbonate was added to Dianeal PD-1 immediately before every administration. The final pH was 6.8 and the concentration of sodium bicarbonate was 6 mmol/l. The final sodium level was 138 mEq/l. This dialysate was used for 5 months. For 2 months before and 3 months after this period, Dianeal PD-2 was used as the dialysate for comparison. Blood bicarbonate levels significantly improved during the use of the neutralized dialysate. Blood sodium, chloride and magnesium levels and the effluent volume significantly increased. Sodium balance improved during the period when neutralized dialysate was used. Total leukocyte counts in the effluent decreased, and leukocyte viability increased. Abdominal distention, abdominal pain during instillation, nausea and headache improved. No side effects, including peritonitis, occurred during the trial of neutralized dialysate. The results suggest that this dialysate was less irritating to the peritoneal membrane than the control dialysate and that the therapeutic effects were satisfactory.

Blood Urea Nitrogen↗

Soluble immune-checkpoint factors: a potential immunotherapy biomarker.

There is unmet need for additional biomarkers to better select patients with non-small cell lung cancer (NSCLC) that are likely to benefit from immunotherapy in order to improve patient outcomes, reduce patient toxicity, and relieve the growing burden of healthcare costs. In this issue of the JCI, Hayashi and colleagues evaluated soluble forms of the immune checkpoint molecules PD-L1, PD-1, and CTLA-4 in the plasma of patients with advanced NSCLC who had been treated with anti-PD-1/L1 therapy. The findings suggest that these soluble immune-checkpoint factors may provide a complementary biomarker to PD-L1 IHC, although application into the clinic may not be straightforward.

Humans↗

Multiomic study of cutaneous T-cell lymphoma reveals single-cell clonal evolution in progression and therapy resistance.

Cutaneous T-cell lymphoma (CTCL) remains a challenging disease due to its significant heterogeneity, therapy resistance, and relentless progression. Multiomics technologies offer the potential to provide uniquely precise views of disease progression and response to therapy. Here, we present a comprehensive multiomics view of CTCL clonal evolution, incorporating exome, whole-genome, epigenome, bulk, single-cell T-cell receptor, and single-cell RNA sequencing of 99 clinically annotated serial skin, peripheral blood, and lymph node samples from 34 patients with CTCL. We leveraged this extensive data set to define the molecular underpinnings of CTCL progression in individual patients at single-cell resolution with the goal of identifying clinically useful biomarkers and therapeutic targets. Our studies identified recurrent progression-associated clonal genomic alterations; we highlight mutation of CCR4, phosphoinositide 3-kinase inhibitor signaling, and programmed cell death protein 1 (PD-1) checkpoint pathways as evasion tactics deployed by malignant T cells. We identified a gain-of-function mutation in STAT3 (D661Y) and demonstrated, using cleavage under targets and release using nuclease (CUT&RUN) and RNA sequencing, that it enhances binding to and transcription of genes in Rho GTPase pathways. With our previous work implicating this pathway in histone deacetylase inhibitor-resistant CTCL, these data provide further support for a previously unrecognized role for Rho GTPase pathway dysregulation in CTCL progression. Recurrent progression-associated mutations were common in the epigenetic modifier EZH2, suggesting that EZH2 inhibition may benefit patients with CTCL. Our findings support an approach in which genomic analysis is widely used for improved disease monitoring, biomarker-informed clinical trial design, and genome-guided therapeutic decision-making. Moreover, these molecular changes present new opportunities for therapeutic targeting in this challenging and incurable cancer.

Multiomics↗

Heavy chain ferritin activates regulatory T cells by induction of changes in dendritic cells.

Heavy chain ferritin (H-ferritin) is a component of the iron-binding protein, ferritin. We have previously shown that H-ferritin inhibits anti-CD3-stimulated lymphocyte proliferation and that this was due to increased production of interleukin-10 (IL-10). In the present study we have shown that induction of IL-10 production was due to effects of H-ferritin on adherent antigen-presenting cells (APCs) in blood and monocyte-derived dendritic cells (MoDCs). IL-10 was produced by a subpopulation of CD4 T cells, which expressed the CD25 component of the IL-2 receptor and the CTLA-4 receptor characteristic of regulatory T cells. The changes induced in MoDCs were compared with those induced by CD40L and their significance tested by inhibition with monoclonal antibodies. These studies indicated that H-ferritin induced relatively greater expression of CD86 and B7-H1 on MoDCs and that monoclonal antibodies against their receptors, CTLA-4 and programmed death receptor-1 (PD-1), inhibited IL-10 production from the regulatory T cells. H-ferritin did not appear to induce direct production of the cytokines IL-2, IL-4, IL-6, IL-10, IL-12, or interferon-gamma from the DCs. These results are consistent with the thesis that H-ferritin induces B7-H1 and CD86 (B7-2) on APCs, which in turn induce IL-10 production from regulatory T cells. This is possibly one mechanism by which melanoma cells may induce changes in APCs in the vicinity of the tumor and result in suppression of immune responses by induction of regulatory T cells.

CD4-Positive T-Lymphocytes↗

Development and validation of blood-based diagnostic biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) using EpiSwitch&#xae; 3-dimensional genomic regulatory immuno-genetic profiling.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating, multifactorial disorder characterised by profound fatigue, post-exertional malaise, cognitive impairments, and autonomic dysfunction. Despite its significant impact on quality of life, ME/CFS lacks definitive diagnostic biomarkers, complicating diagnosis and management. Recent evidence highlights potential blood tests for ME/CFS biomarkers in immunological, genetic, metabolic, and bioenergetic domains. Chromosome conformations (CCs) are potent epigenetic regulators of gene expression and cross-tissue exosome signalling. We have previously developed an epigenetic assay, EpiSwitch&#xae;, that employs an algorithm-based CCs analysis. Using EpiSwitch&#xae; technology, we have shown the presence of disease-specific CCs in peripheral blood mononuclear cells (PBMCs) of patients with amyotrophic lateral sclerosis (ALS), rheumatoid arthritis (RA), prostate and colorectal cancers, diffuse Large B-cell lymphoma and severe COVID-19. In a recent paper, we have identified a profile of systemic chromosome conformations in cancer patients reflective of the predisposition to respond to immune checkpoint inhibitors, PD-1/PD-L1 antagonists, with 85% accuracy. In this Retrospective case/control study (EPI-ME, Epigenetic Profiling Investigation in Myalgic Encephalomyelitis), we used whole blood samples retrospectively collected from n&#x2009;=&#x2009;47 patients with severe ME/CFS and n&#x2009;=&#x2009;61 age-matched healthy control patients to perform whole-genome 3D DNA screening for CCs correlating to ME/CFS diagnosis. We identified a 200-marker model for ME/CFS diagnosis (Episwitch&#xae;CFS test). First testing on the retrospective independent validation cohort demonstrated a strong systemic ME/CFS signal with a sensitivity of 92% and a specificity of 98%.Pathways analysis revealed several likely contributors to the pathology of ME/CFS, including interleukins, TNF&#x3b1;, neuroinflammatory pathways, toll-like receptor signalling and JAK/STAT. Comparison with pathways involved in the action of Rituximab and glatiramer acetate (Copaxone) (therapies with potential in ME/CFS treatment) identified IL2 as a shared pathway with clear patient clustering, indicating a possibility of a potential responder group for targeted treatment.

Humans↗

Malaria: Factors affecting disease severity, immune evasion mechanisms, and reversal of immune inhibition to enhance vaccine efficacy.

Malaria is a complex parasitic disease caused by species of Plasmodium parasites. Infection with the parasites can lead to a spectrum of symptoms and disease severity, influenced by various parasite, host, and environmental factors. There have been some successes in developing vaccines against the disease recently, but the vaccine efficacies require improvement. Some issues associated with the difficulties in developing a sterile vaccine include high antigenic diversity, switching expression of the immune targets, and inhibition of immune pathways. Current vaccine research focuses on identifying conserved and protective epitopes, developing multivalent vaccines (including the whole parasite), and using more powerful adjuvants. However, overcoming the systematic immune inhibition and immune cell dysfunction/exhaustion may be required before high titers of protective antibodies can be achieved. Increased expression of surface molecules such as CD86 and MHC II on antigen-presenting cells and blocking immune checkpoint pathways (interactions of PD-1 and PD-L1; CTLA-4 and CD80) using small molecules could be a promising approach for enhancing vaccine efficacy. This assay reviews the factors affecting the disease severity, the genetics of host-parasite interaction, immune evasion mechanisms, and approaches potentially to improve host immune response for vaccine development.

Humans↗

HIV-Associated Lymphomas: Updates from Pathogenesis to Treatment Strategies.

HIV-associated lymphoma (HAL) is an aggressive malignancy directly linked to HIV infection and accounts for more than 30% of cancer-related deaths in people living with HIV (PLWH). HAL subtypes, including diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), primary effusion lymphoma (PEL), and plasmablastic lymphoma (PBL), exhibit five to ten times higher incidence rates and distinct molecular profiles compared to HIV-negative lymphomas. Pathogenesis involves HIV-driven CD4+ T-cell depletion, chronic B-cell activation, and oncogenic viral coinfection. First-line therapy combines antiretroviral therapy (ART) with chemotherapy, achieving complete remission rates of 60-70% for DLBCL using R-EPOCH and 50-60% for BL with CODOX-M/IVAC. Relapsed/refractory cases show durable responses to CD19- CAR-T therapy; however, only 10% of HAL patients are enrolled in pivotal immunotherapy trials. Severe immunosuppression necessitates PET-CT-guided de-escalation and nanoparticlebased drug delivery systems to minimize toxicity. Emerging strategies include PD-1 inhibitors and broad-spectrum antivirals targeting HIV reservoirs, underscoring the need for precision medicine that integrates tumor genomics and viral dynamics.

Humans↗

The role of Epstein-Barr virus in NK/T cell lymphoproliferative disorders: molecular mechanisms and potential therapeutic strategies.

Epstein-Barr virus (EBV) is a widely prevalent lymphotropic &#x3b3;-herpesvirus, with approximately 95% of the population showing evidence of infection at some point during their lifetime. While most infections are asymptomatic or follow a self-limiting clinical course, in certain populations, EBV can lead to a range of lymphoproliferative disorders (LPDs), particularly subtypes originating from T cells and natural killer (NK) cells, which are often characterized by highly aggressive disease progression. This review aims to systematically discuss the molecular basis of EBV infection, covering its viral biological properties, regulation of the latent and lytic cycles, key viral protein functions (e.g., LMP1, LMP2A, EBNA1), miRNA regulatory mechanisms, and the activation of various host signaling pathways (such as NF-&#x3ba;B, PI3K-AKT, JAK-STAT) that contribute to the maintenance of latent infection, cell transformation, and immune evasion. Additionally, the review focuses on the pathogenic contributions of these mechanisms in EBV-related T/NK cell lymphoproliferative diseases. Research highlights include the in-depth analysis of virus-host genome interaction mechanisms, the identification of novel molecular biomarkers, and the development of targeted therapeutic strategies (e.g., PD-1/PD-L1 immune checkpoint inhibitors, EBV-specific T cell therapy). Through this comprehensive review, it is hoped that personalized medicine and artificial intelligence-assisted multimodal decision-making will be applied to the precise prevention and treatment of EBV-related diseases.

Humans↗

Longitudinal analysis of genomic and immune differences between primary and metastatic nasopharyngeal carcinoma for precision oncology.

INTRODUCTION: Nasopharyngeal carcinoma (NPC) is a common malignancy with a high incidence in Southern China and Southeast Asia. Distant metastasis remains a major cause of poor prognosis. This study aims to explore the genomic and immune microenvironmental changes in primary and metastatic NPC through longitudinal analysis, to provide insights for guiding precision treatment strategies. METHODS: We analyzed tumor samples from 11 male NPC patients with distant metastasis. Paired primary and metastatic samples underwent targeted whole-exome sequencing (551 genes) and RNA sequencing (289 genes). Multiplex immunohistochemistry was performed to assess immune cell composition and immune response markers. Genomic alterations and immune features were compared between primary and metastatic tumors, and their associations with clinical outcomes were evaluated. RESULTS: Metastatic tumors exhibited distinct chromosomal changes, including frequent 1q gain, while 6p gain showed a trend toward prolonged survival. Primary tumors showed stronger immune suppression characterized by increased B-cell and Treg infiltration and elevated CTLA4 and IDO1 expression, whereas metastatic lesions displayed more active immune responses. Liver metastases presented a distinct immune landscape with lower CD8+ T-cell density compared to non-liver metastases. In locoregionally advanced NPC, high expression of oncogenic genes such as EGFR and MYC correlated with shorter disease-free survival, while elevated PANCK expression and enhanced cytotoxicity were linked to better outcomes. These results delineate the molecular and immune evolution of NPC and provide a foundation for developing precision therapeutic strategies. CONCLUSION: This study identifies key molecular and immune features associated with NPC survival. Primary tumors show an immunosuppressive phenotype, suggesting potential benefits from combining CTLA4 or IDO1 inhibitors with PD-1 blockade. Liver metastases exhibit distinct immune features, supporting the need for site-specific precision therapies. These findings contribute to personalized management strategies in NPC, guiding treatment based on molecular and immune profiles.

distant metastasis↗

Myeloid-Mediated Immunoregulation and Resistance to Immune Checkpoint Inhibitor Therapy Across Squamous Cell Carcinomas: Mechanisms and Reprogramming Strategies.

Immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 have improved outcomes across squamous cell carcinomas (SCCs) of the head and neck, lung, esophagus, and skin, yet durable responses remain confined to a subset of patients in every subtype. Objective response rates vary substantially across SCCs despite overlapping genomic alterations, comparable tumor mutational burden, and high PD-L1 expression, indicating that tumor-intrinsic biomarkers alone do not explain this variability. Growing evidence points to the tumor immune microenvironment, and in particular the myeloid compartment, as a critical determinant of immunotherapy responsiveness. In this review, we synthesize current evidence on myeloid-mediated immune regulation across SCC subtypes, focusing on tumor-associated macrophages, myeloid-derived suppressor cells/tumor-associated neutrophils, and dendritic cells, and the mechanisms by which these populations impair antigen presentation, restrict T cell infiltration, and sustain immunologically "cold" tumor states. We further examine therapeutic strategies aimed at reprogramming rather than simply depleting suppressive myeloid populations, including radiation therapy, STING agonism, and myeloid-targeted agents (CSF1R, PI3K&#x3b3;, and CXCR2 inhibition), each of which has shown encouraging preclinical and early clinical activity in combination with ICI. Collectively, this evidence supports a model in which the myeloid compartment functions as an actionable, convergent determinant of ICI resistance across SCC subtypes, rather than merely a passive biomarker. We propose that through the integration of spatial and single-cell profiling of myeloid states with clinical history it will be possible to predict response to immune checkpoint therapy and personalize myeloid-directed combination strategies, though the specific biomarkers needed to match individual patients to a given myeloid-targeted approach remain to be defined. We further discuss the toxicity considerations associated with both immune checkpoint blockade and radiation-based combination approaches, the early-phase status of most myeloid-targeted agents currently in clinical development, and the extent to which mechanistic insight, derived predominantly from HNSCC, generalizes to squamous cell carcinomas arising at other anatomic sites.

dendritic cells↗

Deconstructing Exceptional Responses to Immune Checkpoint Inhibition in Recurrent or Metastatic Head and Neck Carcinoma: A Site-Specific Clinical-Biological Synthesis.

Background: Recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) is an aggressive malignancy with a historically poor prognosis. Although immune checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 axis have established a new first-line standard of care, durable clinical benefit is restricted to a minority of patients, while primary or acquired resistance remains a major clinical challenge. This narrative review aims to provide a conceptual clinical-biological synthesis of immunotherapy in R/M HNSCC through an anatomical and biomarker-driven lens, with a focus on characterizing potential shared features of "exceptional responders". Methods: A targeted narrative literature search was conducted across PubMed/MEDLINE and to identify key clinical trials and representative clinical reports of exceptional response to ICIs in R/M HNSCC. The literature was not systematically synthesized to construct a conceptual clinical-biological framework of response and resistance. Results: Landmark clinical data confirm durable survival benefits with frontline pembrolizumab-based regimens in selected PDL-1 positive populations compared to historical chemotherapy. Qualitative appraisal of illustrative cases and translational cohorts suggests a potential biological hypothesis: exceptional responders, defined as patients achieving unexpected, multi-year complete radiological, pathological, or metabolic remissions, often align with a favorable confluence of a pre-existing "hot" or inflamed tumor microenvironment, preserved antigen presentation machinery, and elevated antigenic novelty driven by viral oncoproteins (HPV, EBV) or high mutational/indel burdens. Conversely, primary and acquired resistance are conceptually associated with defects in antigen processing, immunosuppressive cellular barriers, and alternative immune checkpoints. Conclusions: Immunotherapy has fundamentally transformed R/M HNSCC management, yet exceptional single-agent responses remain rare. Rather than a definitive or proven biological biomarker, the proposed blueprint represents an integrative hypothesis highlighting the complex interplay of baseline immune inflammation, genomic features, and viral drivers. Translating these observations into broader clinical benefit will require validated biomarker-driven personalization and rationally designed combination regimens.

Epstein-Barr virus (EBV)↗

Long-Term Outcomes and Paired Immune and Genomic Exploratory Analyses After Neoadjuvant Dose-Dense MVAC in Muscle-Invasive Bladder Cancer: A Single-Centre Case Series.

Background/Objectives: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy has been the standard of care for muscle-invasive bladder cancer (MIBC) for two decades, yet a substantial proportion of patients derive no benefit. As antibody-drug conjugates and immune checkpoint inhibitors reshape perioperative treatment, it is unclear which patients retain meaningful benefit from platinum. We describe long-term outcomes and exploratory paired immune and genomic analyses in a single-centre cohort treated with dose-dense MVAC (dd-MVAC). Methods: We retrospectively identified 54 consecutive patients with MIBC treated with neoadjuvant dd-MVAC between November 2013 and November 2019. Forty-two underwent radical cystectomy and are assessable for pathologic response. Immunohistochemistry for CD3, CD8, FOXP3, PD-1, PD-L1, PD-L2, and NY-ESO-1 was evaluable in 31 baseline specimens and 22 paired specimens; paired genomic profiling was evaluable in 12 cases, with paired tumour mutational burden (TMB) in 10 by whole-exome sequencing and 7 by TSO-500. Paired analyses necessarily exclude patients achieving a pathologic complete response (pCR), who have no residual tumour, and most early progressors. Results: pCR was achieved in 11/42 operated patients (26%, 95% CI 15-41). Median follow-up was 87 months (IQR 24-104). Hydronephrosis was the only baseline factor associated with absence of pCR (p = 0.016). Within the operated cohort, pCR was associated with longer recurrence-free survival (log-rank p = 0.017), but the difference in overall survival did not reach significance (p = 0.121). NAC reduced intratumoral FOXP3 (q = 0.001), NY-ESO-1 (q = 0.013), PD-L2 (q = 0.013), and CD3 (q = 0.043) after correction for multiple comparisons, whereas TMB showed no significant change (TSO-500 p = 0.67; WES p = 0.86). No statistically significant association was detected between any baseline immune marker, including PD-L1, and pCR. The mutational landscape was largely concordant before and after NAC. Conclusions: This study was exploratory and was not powered to validate predictive biomarkers. In this long-term cohort, dd-MVAC was associated with measurable depletion of intratumoral immune populations in chemoresistant tumours, while paired genomic profiles remained broadly concordant. No pre-treatment biomarker identified platinum-refractory patients, but the small evaluable subsets mean these are hypothesis-generating rather than negative findings, and prospective studies with pre-specified biomarker endpoints are required.

chemoresistance↗

Constitutive association of SHP-1 with leukocyte-associated Ig-like receptor-1 in human T cells.

The intracellular Src homology 2 (SH2) domain-containing protein tyrosine phosphatase (SHP-1) is a negative regulator of cell signaling and contributes to the establishment of TCR signaling thresholds in both developing and mature T lymphocytes. Although there is much functional data implicating SHP-1 as a regulator of TCR signaling, the molecular basis for SHP-1 activation in T lymphocytes is poorly defined. A modification of the yeast two-hybrid system was employed to identify in T cells phosphotyrosine-containing proteins capable of binding the SH2 domains of SHP-1. From this yeast tri-hybrid screen, the p85beta subunit of phosphatidylinositol 3-kinase and the immunoreceptor tyrosine-based inhibitory motif-containing receptors, leukocyte-associated Ig-like receptor-1 (LAIR-1) and programmed death-1 (PD-1), were identified. Coimmunoprecipitation studies demonstrated that the exclusive phosphotyrosine-containing protein associated with SHP-1 in Jurkat T cells under physiological conditions is LAIR-1. Significantly, this interaction is constitutive and was detected only in the membrane-enriched fraction of cell lysates. Ligand engagement of the SH2 domains of SHP-1 is a prerequisite to activation of the enzyme, and, consistent with an association with LAIR-1, SHP-1 was found to be constitutively active in unstimulated Jurkat T cells. Importantly, a constitutive interaction between LAIR-1 and SHP-1 was also detected in human primary T cells. These results illustrate the sustained recruitment and activation of SHP-1 at the plasma membrane of resting human T cells by an inhibitory receptor. We propose that this mechanism may exert a constitutive negative regulatory role upon T cell signaling.

Amino Acid Motifs↗

CD4+CD25high regulatory cells in human peripheral blood.

Thymectomy in mice on neonatal day 3 leads to the development of multiorgan autoimmune disease due to loss of a CD(+)CD25(+) T cell regulatory population in their peripheral lymphoid tissues. Here, we report the identification of a CD4(+) population of regulatory T cells in the circulation of humans expressing high levels of CD25 that exhibit in vitro characteristics identical with those of the CD4(+)CD25(+) regulatory cells isolated in mice. With TCR cross-linking, CD4(+)CD25(high) cells did not proliferate but instead totally inhibited proliferation and cytokine secretion by activated CD4(+)CD25(-) responder T cells in a contact-dependent manner. The CD4(+)CD25(high) regulatory T cells expressed high levels of CD45RO but not CD45RA, akin to the expression of CD45RB(low) on murine CD4(+)CD25(+) regulatory cells. Increasing the strength of signal by providing either costimulation with CD28 cross-linking or the addition of IL-2 to a maximal anti-CD3 stimulus resulted in a modest induction of proliferation and the loss of observable suppression in cocultures of CD4(+)CD25(high) regulatory cells and CD4(+)CD25(-) responder cells. Whereas higher ratios of CD4(+)CD25(high) T cells are required to suppress proliferation if the PD-L1 receptor is blocked, regulatory cell function is shown to persist in the absence of the PD-1/PD-L1 or CTLA-4/B7 pathway. Thus, regulatory CD4 T cells expressing high levels of the IL-2 receptor are present in humans, providing the opportunity to determine whether alterations of these populations of T cells are involved in the induction of human autoimmune disorders.

Abatacept↗