Ultrasound-mediated delivery of doxorubicin to the brain results in immune modulation and improved responses to PD-1 blockade in gliomas.

Given the marginal penetration of most drugs across the blood-brain barrier, the efficacy of various agents remains limited for glioblastoma (GBM). Here we employ low-intensity pulsed ultrasound (LIPU) and intravenously administered microbubbles (MB) to open the blood-brain barrier and increase the concentration of liposomal doxorubicin and PD-1 blocking antibodies (aPD-1). We report results on a cohort of 4 GBM patients and preclinical models treated with this approach. LIPU/MB increases the concentration of doxorubicin by 2-fold and 3.9-fold in the human and murine brains two days after sonication, respectively. Similarly, LIPU/MB-mediated blood-brain barrier disruption leads to a 6-fold and a 2-fold increase in aPD-1 concentrations in murine brains and peritumoral brain regions from GBM patients treated with pembrolizumab, respectively. Doxorubicin and aPD-1 delivered with LIPU/MB upregulate major histocompatibility complex (MHC) class I and II in tumor cells. Increased brain concentrations of doxorubicin achieved by LIPU/MB elicit IFN-γ and MHC class I expression in microglia and macrophages. Doxorubicin and aPD-1 delivered with LIPU/MB results in the long-term survival of most glioma-bearing mice, which rely on myeloid cells and lymphocytes for their efficacy. Overall, this translational study supports the utility of LIPU/MB to potentiate the antitumoral activities of doxorubicin and aPD-1 for GBM.

Anti-PD-1 cis-delivery of low-affinity IL-12 activates intratumoral CD8+T cells for systemic antitumor responses.

Immune checkpoint blockade (ICB) therapies function by alleviating immunosuppression on tumor-infiltrating lymphocytes (TILs) but are often insufficient to fully reactivate these dysfunctional TILs. Although interleukin 12 (IL-12) has been used in combination with ICB to improve efficacy, this remains limited by severe toxicity associated with systemic administration of this cytokine. Here, we engineer a fusion protein composed of an anti-PD-1 antibody and a mouse low-affinity IL-12 mutant-2 (αPD1-mIL12mut2). Systemic administration of αPD1-mIL12mut2 displays robust antitumor activities with undetectable toxicity. Mechanistically, αPD1-mIL12mut2 preferentially activates tumor-infiltrating PD-1+CD8+T cells via high-affinity αPD-1 mediated cis-binding of low-affinity IL-12. Additionally, αPD1-mIL12mut2 treatment exerts an abscopal effect to suppress distal tumors, as well as metastasis. Collectively, αPD1-mIL12mut2 treatment induces robust systemic antitumor responses with reduced side effects.

SIRPG expression positively associates with an inflamed tumor microenvironment and response to PD-1 blockade.

BACKGROUND: This study aimed to investigate the relationship between signal regulatory protein gamma (SIRPG) and tumor immune microenvironment phenotypes or T cell mediated-adaptive antitumor immunity, and its predictive value for response to PD-1 blockade in cancers. METHODS: Pan-cancer analysis of SIRPG expression and immune deconvolution was performed using transcriptomic data across 33 tumor types. Transcriptomic and clinical data from 157 patients with non-small-cell lung cancer (NSCLC) and melanoma received PD-1 blockade were analyzed. Expression characteristics of SIRPG were investigated using single-cell RNA sequencing (scRNA-seq) data of 103,599 cells. The effect of SIRPG expression was evaluated via SIRPG knockdown or overexpression in Jurkat T cells. RESULTS: The results showed that most cancers with high SIRPG expression had significantly higher abundance of T cells, B cells, NK cells, M1 macrophages and cytotoxic lymphocytes and increased expression level of immunomodulatory factors regulating immune cell recruitment, antigen presentation, T cell activation and cytotoxicity, but markedly lower abundance of neutrophils, M2 macrophages, and myeloid-derived suppressor cells. High SIRPG expression was associated with favorable response to PD-1 blockade in both NSCLC and melanoma. scRNA-seq data suggested SIRPG was mainly expressed in CD8+ exhausted T and CD4+ regulatory T cells, and positively associated with immune checkpoint expression including PDCD1 and CTLA4. In vitro test showed SIRPG expression in T cells could facilitate expression of PDCD1 and CTLA4. CONCLUSION: High SIRPG expression is associated with an inflamed immune phenotype in cancers and favorable response to PD-1 blockade, suggesting it would be a promising predictive biomarker for PD-1 blockade and novel immunotherapeutic target.

Plasma proteome profiling reveals dynamic of cholesterol marker after dual blocker therapy.

Dual blocker therapy (DBT) has the enhanced antitumor benefits than the monotherapy. Yet, few effective biomarkers are developed to monitor the therapy response. Herein, we investigate the DBT longitudinal plasma proteome profiling including 113 longitudinal samples from 22 patients who received anti-PD1 and anti-CTLA4 DBT therapy. The results show the immune response and cholesterol metabolism are upregulated after the first DBT cycle. Notably, the cholesterol metabolism is activated in the disease non-progressive group (DNP) during the therapy. Correspondingly, the clinical indicator prealbumin (PA), free triiodothyronine (FT3) and triiodothyronine (T3) show significantly positive association with the cholesterol metabolism. Furthermore, by integrating proteome and radiology approach, we observe the high-density lipoprotein partial remodeling are activated in DNP group and identify a candidate biomarker APOC3 that can reflect DBT response. Above, we establish a machine learning model to predict the DBT response and the model performance is validated by an independent cohort with balanced accuracy is 0.96. Thus, the plasma proteome profiling strategy evaluates the alteration of cholesterol metabolism and identifies a panel of biomarkers in DBT.

[Progress in PD-1/PD-L1, PD-L2 signaling pathway and its role in host anti-tuberculosis immunity].

Programmed cell death 1 (PD-1) and its ligands, PD-L1 and PD-L2, expressed on a variety of immune cells, play multiple regulatory roles in the host immune response to Mycobacterium tuberculosis infection. In this study, we reviewed that the regulatory roles of PD-1/PD-L1, PD-L2 signaling in the host adaptive immune response, such as the innate response of macrophages, and the interaction between T cells and macrophages in response to MTB. In addition, during MTB infection, PD-1/PD-L1, PD-L2 signaling is also involved in the host inflammatory response, as well as the potential roles of PD-1/PD-L1, PD-L2 in the diagnosis and treatment of tuberculosis.

Therapeutic role of interferon-γ in experimental autoimmune encephalomyelitis is mediated through a tolerogenic subset of splenic CD11b+ myeloid cells.

Cumulative evidence has established that Interferon (IFN)-γ has both pathogenic and protective roles in Multiple Sclerosis and the animal model, Experimental Autoimmune Encephalomyelitis (EAE). However, the underlying mechanisms to the beneficial effects of IFN-γ are not well understood. In this study, we found that IFN-γ exerts therapeutic effects on chronic, relapsing-remitting, and chronic progressive EAE models. The frequency of regulatory T (Treg) cells in spinal cords from chronic EAE mice treated with IFN-γ was significantly increased with no effect on Th1 and Th17 cells. Consistently, depletion of FOXP3-expressing cells blocked the protective effects of IFN-γ, indicating that the therapeutic effect of IFN-γ depends on the presence of Treg cells. However, IFN-γ did not trigger direct in vitro differentiation of Treg cells. In vivo administration of blocking antibodies against either interleukin (IL)-10, transforming growth factor (TGF)-ß or program death (PD)-1, revealed that the protective effects of IFN-γ in EAE were also dependent on TGF-ß and PD-1, but not on IL-10, suggesting that IFN-γ might have an indirect role on Treg cells acting through antigen-presenting cells. Indeed, IFN-γ treatment increased the frequency of a subset of splenic CD11b+ myeloid cells expressing TGF-ß-Latency Associated Peptide (LAP) and program death ligand 1 (PD-L1) in a signal transducer and activator of transcription (STAT)-1-dependent manner. Furthermore, splenic CD11b+ cells from EAE mice preconditioned in vitro with IFN-γ and myelin oligodendrocyte glycoprotein (MOG) peptide exhibited a tolerogenic phenotype with the capability to induce conversion of naïve CD4+ T cells mediated by secretion of TGF-ß. Remarkably, adoptive transfer of splenic CD11b+ cells from IFN-γ-treated EAE mice into untreated recipient mice ameliorated clinical symptoms of EAE and limited central nervous system infiltration of mononuclear cells and effector helper T cells. These results reveal a novel cellular and molecular mechanism whereby IFN-γ promotes beneficial effects in EAE by endowing splenic CD11b+ myeloid cells with tolerogenic and therapeutic activities.

PD-1 knockout on cytotoxic primary murine CD8+ T cells improves their motility in retrovirus infected mice.

Cytotoxic T lymphocyte (CTL) motility is an important feature of effective CTL responses and is impaired when CTLs become exhausted, e.g. during chronic retroviral infections. A prominent T cell exhaustion marker is programmed cell death protein 1 (PD-1) and antibodies against the interaction of PD-1 and PD-ligand 1 (PD-L1) are known to improve CTL functions. However, antibody blockade affects all PD-1/PD-L1-expressing cell types, thus, the observed effects cannot be attributed selectively to CTLs. To overcome this problem, we performed CRISPR/Cas9 based knockout of the PD-1 coding gene PDCD1 in naïve Friend Retrovirus (FV)-specific CTLs. We transferred 1,000 of these cells into mice where they proliferated upon FV-infection. Using intravital two-photon microscopy we visualized CTL motility in the bone marrow and evaluated cytotoxic molecule expression by flow cytometry. Knockout of PDCD1 improved the CTL motility at 14 days post infection and enhanced the expression of cytotoxicity markers. Our data show the potential of genetic tuning of naive antiviral CTLs and might be relevant for future designs of improved T cell-mediated therapies.

Expression of CD39 is associated with T cell exhaustion in ovarian cancer and its blockade reverts T cell dysfunction.

Immune exhaustion is a hallmark of ovarian cancer. Using multiparametric flow cytometry, the study aimed to analyze protein expression of novel immunological targets on CD3+ T cells isolated from the peripheral blood (n = 20), malignant ascites (n = 16), and tumor tissue (n = 6) of patients with ovarian cancer (OVCA). The study revealed an increased proportion of effector memory CD8+ T cells in OVCA tissue and malignant ascites. An OVCA-characteristic PD-1high CD8+ T cell population was detected, which differed from PD-1lowCD8+ T cells by increased co-expression of TIGIT, CD39, and HLA-DR. In addition, these OVCA-characteristic CD8+ T cells showed reduced expression of the transcription factor TCF-1, which may also indicate reduced effector function and memory formation. On the contrary, the transcription factor TOX, which significantly regulates terminal T cell-exhaustion, was found more frequently in these cells. Further protein and gene analysis showed that CD39 and CD73 were also expressed on OVCA tumor cells isolated from solid tumors (n = 14) and malignant ascites (n = 9). In the latter compartment, CD39 and CD73 were also associated with the expression of the "don't eat me" molecule CD24 on tumor cells. Additionally, ascites-derived CD24+EpCAM+ tumor cells showed a higher frequency of CD39+ or CD73+ cells. Furthermore, CD39 expression was associated with unfavorable clinical parameters. Expression of CD39 on T cells was upregulated through CD3/CD28 stimulation and its blockade by a newly developed nanobody construct resulted in increased proliferation (eFluor), activation (CD25 and CD134), and production of cytotoxic cytokines (IFN-γ, TNF-α, and granzyme-B) of CD8+ T cells.

Immune checkpoint inhibitors induce acute interstitial nephritis in mice with increased urinary MCP1 and PD-1 glomerular expression.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) induce acute interstitial nephritis (AIN) in 2-5% of patients, with a clearly higher incidence when they are combined with platinum derivatives. Unfortunately, suitable disease models and non-invasive biomarkers are lacking. To fill this gap in our understanding, we investigated the renal effects of cisplatin and anti-PD-L1 antibodies in mice, assessing PD-1 renal expression and cytokine levels in mice with AIN, and then we compared these findings with those in AIN-diagnosed cancer patients. METHODS: Twenty C57BL6J mice received 200 µg of anti-PD-L1 antibody and 5 mg/kg cisplatin intraperitoneally and were compared with those receiving cisplatin (n = 6), anti-PD-L1 (n = 7), or saline (n = 6). After 7 days, the mice were euthanized. Serum and urinary concentrations of TNFα, CXCL10, IL-6, and MCP-1 were measured by Luminex. The kidney sections were stained to determine PD-1 tissue expression. Thirty-nine cancer patients with AKI were enrolled (AIN n = 33, acute tubular necrosis (ATN) n = 6), urine MCP-1 (uMCP-1) was measured, and kidney sections were stained to assess PD-1 expression. RESULTS: Cisplatin and anti PD-L1 treatment led to 40% AIN development (p = 0.03) in mice, accompanied by elevated serum creatinine and uMCP1. AIN-diagnosed cancer patients also had higher uMCP1 levels than ATN-diagnosed patients, confirming our previous findings. Mice with AIN exhibited interstitial PD-1 staining and stronger glomerular PD-1 expression, especially with combination treatment. Conversely, human AIN patients only showed interstitial PD-1 positivity. CONCLUSIONS: Only mice receiving cisplatin and anti-PDL1 concomitantly developed AIN, accompanied with a more severe kidney injury. AIN induced by this drug combination was linked to elevated uMCP1, consistently with human AIN, suggesting that uMCP1 can be potentially used as an AIN biomarker.

Exploring novel immunotherapy biomarker candidates induced by cancer deformation.

Triple-negative breast cancer (TNBC) demands urgent attention for the development of effective treatment strategies due to its aggressiveness and limited therapeutic options [1]. This research is primarily focused on identifying new biomarkers vital for immunotherapy, with the aim of developing tailored treatments specifically for TNBC, such as those targeting the PD-1/PD-L1 pathway. To achieve this, the study places a strong emphasis on investigating Ig genes, a characteristic of immune checkpoint inhibitors, particularly genes expressing Ig-like domains with altered expression levels induced by "cancer deformation," a condition associated with cancer malignancy. Human cells can express approximately 800 Ig family genes, yet only a few Ig genes, including PD-1 and PD-L1, have been developed into immunotherapy drugs thus far. Therefore, we investigated the Ig genes that were either upregulated or downregulated by the artificial metastatic environment in TNBC cell line. As a result, we confirmed the upregulation of approximately 13 Ig genes and validated them using qPCR. In summary, our study proposes an approach for identifying new biomarkers applicable to future immunotherapies aimed at addressing challenging cases of TNBC where conventional treatments fall short.

Multi-omic analysis identifies hypoalbuminemia as independent biomarker of poor outcome upon PD-1 blockade in metastatic melanoma.

We evaluated the prognostic value of hypoalbuminemia in context of various biomarkers at baseline, including clinical, genomic, transcriptomic, and blood-based markers, in patients with metastatic melanoma treated with anti-PD-1 monotherapy or anti-PD-1/anti-CTLA-4 combination therapy (n = 178). An independent validation cohort (n = 79) was used to validate the performance of hypoalbuminemia compared to serum LDH (lactate dehydrogenase) levels. Pre-treatment hypoalbuminemia emerged as the strongest predictor of poor outcome for both OS (HR = 4.01, 95% CI 2.10-7.67, Cox P = 2.63e-05) and PFS (HR = 3.72, 95% CI 2.06-6.73, Cox P = 1.38e-05) in univariate analysis. In multivariate analysis, the association of hypoalbuminemia with PFS was independent of serum LDH, IFN-γ signature expression, TMB, age, ECOG PS, treatment line, treatment type (combination or monotherapy), brain and liver metastasis (HR = 2.76, 95% CI 1.24-6.13, Cox P = 0.0131). Our validation cohort confirmed the prognostic power of hypoalbuminemia for OS (HR = 1.98, 95% CI 1.16-3.38; Cox P = 0.0127) and was complementary to serum LDH in analyses for both OS (LDH-adjusted HR = 2.12, 95% CI 1.2-3.72, Cox P = 0.00925) and PFS (LDH-adjusted HR = 1.91, 95% CI 1.08-3.38, Cox P = 0.0261). In conclusion, pretreatment hypoalbuminemia was a powerful predictor of outcome in ICI in melanoma and showed remarkable complementarity to previously established biomarkers, including high LDH.

An NGS-based assay for accurate detection and quantification of immune gene expression in mouse tumor models.

Tumor microenvironment (TME) is a complex dynamic system with many tumor-interacting components including tumor-infiltrating leukocytes (TILs), cancer associated fibroblasts, blood vessels, and other stromal constituents. It intrinsically affects tumor development and pharmacology of oncology therapeutics, particularly immune-oncology (IO) treatments. Accurate measurement of TME is therefore of great importance for understanding the tumor immunity, identifying IO treatment mechanisms, developing predictive biomarkers, and ultimately, improving the treatment of cancer. Here, we introduce a mouse-IO NGS-based (NGSmIO) assay for accurately detecting and quantifying the mRNA expression of 1080 TME related genes in mouse tumor models. The NGSmIO panel was shown to be superior to the commonly used microarray approach by hosting 300 more relevant genes to better characterize various lineage of immune cells, exhibits improved mRNA and protein expression correlation to flow cytometry, shows stronger correlation with mRNA expression than RNAseq with 10x higher sequencing depth, and demonstrates higher sensitivity in measuring low-expressed genes. We describe two studies; firstly, detecting the pharmacodynamic change of interferon-γ expression levels upon anti-PD-1: anti-CD4 combination treatment in MC38 and Hepa 1-6 tumors; and secondly, benchmarking baseline TILs in 14 syngeneic tumors using transcript level expression of lineage specific genes, which demonstrate effective and robust applications of the NGSmIO panel.

Comparative characterization of two monoclonal antibodies targeting canine PD-1.

Monoclonal antibodies targeting immune checkpoints have revolutionized oncology. Yet, the effectiveness of these treatments varies significantly among patients, and they are associated with unexpected adverse events, including hyperprogression. The murine research model used in drug development fails to recapitulate both the functional human immune system and the population heterogeneity. Hence, a novel model is urgently needed to study the consequences of immune checkpoint blockade. Dogs appear to be uniquely suited for this role. Approximately 1 in 4 companion dogs dies from cancer, yet no antibodies are commercially available for use in veterinary oncology. Here we characterize two novel antibodies that bind canine PD-1 with sub-nanomolar affinity as measured by SPR. Both antibodies block the clinically crucial PD-1/PD-L1 interaction in a competitive ELISA assay. Additionally, the antibodies were tested with a broad range of assays including Western Blot, ELISA, flow cytometry, immunofluorescence and immunohistochemistry. The antibodies appear to bind two distinct epitopes as predicted by molecular modeling and peptide phage display. Our study provides new tools for canine oncology research and a potential veterinary therapeutic.

IL-38 promotes the development of prostate cancer.

Introduction: Prostate Cancer (PCa) remains a significant concern in male cancer-related mortality. Tumour development is intricately regulated by the complex interactions between tumour cells and their microenvironment, making it essential to determine which is/are key factor(s) that influence the progression of PCa within the tumour microenvironment. Materials and methods: The current study utilised histopathology and immunohistochemistry to determine the expression of IL-38 in PCa and analysed the correlation between the expression level of IL-38 within PCa and clinical pathological characteristics. Results: There was a significant increase in IL-38 expression in PCa tissues compared to adjacent non-PCa tissues (P < 0.0001). In addition, IL-38 expression was significantly higher in tumour cells with a high proliferation index compared to those with a low value-added index. ROC curve analysis demonstrated that IL-38 has high specificity and sensitivity for the diagnosis of PCa (AUC=0.76). Moreover, we Probed the cellular source of IL-38 in prostate cancer tissue by immunofluorescence double staining. Additionally, within PCa, the expression of IL-38 was inversely correlated with the expression levels of CD8 and PD-1. Survival analysis revealed a significantly lower overall survival rate for PCa patients with high IL-38 expression (P=0.0069), and when IL-38 was co-expressed with CD8, the survival rate of the IL-38high/CD8low group was decreased significantly. Multivariate analysis indicated that the expression level of IL-38 and TNM staging were independent predictors of survival in PCa patients. Conclusion: These findings suggest that IL-38 plays a crucial role in the development of PCa, and the exploration of the correlation between IL-38 and various immune factors in the tumour microenvironment further reveals its mechanism of action, making it a potential target for immunotherapy in PCa.

Engineering PD-1-targeted small protein variants for in vitro diagnostics and in vivo PET imaging.

BACKGROUND: Programmed cell death 1 (PD-1) belongs to immune checkpoint proteins ensuring negative regulation of the immune response. In non-small cell lung cancer (NSCLC), the sensitivity to treatment with anti-PD-1 therapeutics, and its efficacy, mostly correlated with the increase of tumor infiltrating PD-1+ lymphocytes. Due to solid tumor heterogeneity of PD-1+ populations, novel low molecular weight anti-PD-1 high-affinity diagnostic probes can increase the reliability of expression profiling of PD-1+ tumor infiltrating lymphocytes (TILs) in tumor tissue biopsies and in vivo mapping efficiency using immune-PET imaging. METHODS: We designed a 13 kDa ß-sheet Myomedin scaffold combinatorial library by randomization of 12 mutable residues, and in combination with ribosome display, we identified anti-PD-1 Myomedin variants (MBA ligands) that specifically bound to human and murine PD-1-transfected HEK293T cells and human SUP-T1 cells spontaneously overexpressing cell surface PD-1. RESULTS: Binding affinity to cell-surface expressed human and murine PD-1 on transfected HEK293T cells was measured by fluorescence with LigandTracer and resulted in the selection of most promising variants MBA066 (hPD-1 KD = 6.9 nM; mPD-1 KD = 40.5 nM), MBA197 (hPD-1 KD = 29.7 nM; mPD-1 KD = 21.4 nM) and MBA414 (hPD-1 KD = 8.6 nM; mPD-1 KD = 2.4 nM). The potential of MBA proteins for imaging of PD-1+ populations in vivo was demonstrated using deferoxamine-conjugated MBA labeled with 68Galium isotope. Radiochemical purity of 68Ga-MBA proteins reached values 94.7-99.3% and in vitro stability in human serum after 120 min was in the range 94.6-98.2%. The distribution of 68Ga-MBA proteins in mice was monitored using whole-body positron emission tomography combined with computerized tomography (PET/CT) imaging up to 90 min post-injection and post mortem examined in 12 mouse organs. The specificity of MBA proteins was proven by co-staining frozen sections of human tonsils and NSCLC tissue biopsies with anti-PD-1 antibody, and demonstrated their potential for mapping PD-1+ populations in solid tumors. CONCLUSIONS: Using directed evolution, we developed a unique set of small binding proteins that can improve PD-1 diagnostics in vitro as well as in vivo using PET/CT imaging.

Radiotherapy and immunology.

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

A new mode for the diagnosis of angioimmunoblastic T-cell lymphoma.

In order to explore a new mode for the diagnosis of angioimmunoblastic T-cell lymphoma (AITL), 31 cases of AITL and 28 cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) were used as the study subjects. Identifying T follicular helper (TFH) cells with CD4, CD10, Bcl-6, and PD-1, identifying proliferative B cells with CD20 and EZH2, identifying proliferative follicular dendritic cells (FDCs) with CD21 and CD23, and analyzing the value of TFH/B/FDC proliferation and immunolocalization in the diagnosis of AITL. (1) Outside the inherent lymphoid follicles, simultaneous proliferation of TFH/B/FDC (a new diagnostic mode) were observed in AITL [83.87%; 26/31], with their immunolocalizations in the same site [83.87%; 26/31], while this phenomenon was not observed in 28 cases of PTCL-NOS (P<0.05). (2) The sensitivity and specificity of using this new mode to diagnose AITL were both high (83.87%, 100%), which was superior to CD2 (100%, 0%), CD3 (100%, 0%), CD4 (100%, 32.14%), CD5 (100%, 25%), CD10 (61.9%, 100%), Bcl-6 (42.86%, 100%), PD-1 (83.87%, 96.43%), and its Youden Index (0.84) was the highest. The areas under the curve (AUC) of CD10, Bcl-6, PD-1, and new mode to diagnosis AITL were 0.81, 0.71, 0.90, and 0.92, respectively, while the new mode had the highest AUC. The simultaneous proliferation of TFH/B/FDC cells outside the inherent lymphoid follicles can be used to assist in the diagnosis of AITL, and the simultaneous spatiotemporal proliferation of TFH/B/FDC cells is a specific immunomorphology of AITL.

Regulation of Treg cells by cytokine signaling and co-stimulatory molecules.

CD4+CD25+Foxp3+ regulatory T cells (Tregs), a vital component of the immune system, are responsible for maintaining immune homeostasis and preventing excessive immune responses. This review explores the signaling pathways of the cytokines that regulate Treg cells, including transforming growth factor beta (TGF-ß), interleukin (IL)-2, IL-10, and IL-35, which foster the differentiation and enhance the immunosuppressive capabilities of Tregs. It also examines how, conversely, signals mediated by IL-6 and tumor necrosis factor -alpha (TNF-α) can undermine Treg suppressive functions or even drive their reprogramming into effector T cells. The B7 family comprises indispensable co-stimulators for T cell activation. Among its members, this review focuses on the capacity of CTLA-4 and PD-1 to regulate the differentiation, function, and survival of Tregs. As Tregs play an essential role in maintaining immune homeostasis, their dysfunction contributes to the pathogenesis of autoimmune diseases. This review delves into the potential of employing Treg-based immunotherapy for the treatment of autoimmune diseases, transplant rejection, and cancer. By shedding light on these topics, this article aims to enhance our understanding of the regulation of Tregs by cytokines and their therapeutic potential for various pathological conditions.

GNUV201, a novel human/mouse cross-reactive and low pH-selective anti-PD-1 monoclonal antibody for cancer immunotherapy.

BACKGROUND: Several PD-1 antibodies approved as anti-cancer therapies work by blocking the interaction of PD-1 with its ligand PD-L1, thus restoring anti-cancer T cell activities. These PD-1 antibodies lack inter-species cross-reactivity, necessitating surrogate antibodies for preclinical studies, which may limit the predictability and translatability of the studies. RESULTS: To overcome this limitation, we have developed an inter-species cross-reactive PD-1 antibody, GNUV201, by utilizing an enhanced diversity mouse platform (SHINE MOUSE™). GNUV201 equally binds to human PD-1 and mouse PD-1, equally inhibits the binding of human PD-1/PD-L1 and mouse PD-1/PD-L1, and effectively suppresses tumor growth in syngeneic mouse models. The epitope of GNUV201 mapped to the "FG loop" of hPD-1, distinct from those of Keytruda® ("C'D loop") and Opdivo® (N-term). Notably, the structural feature where the protruding epitope loop fits into GNUV201's binding pocket supports the enhanced binding affinity due to slower dissociation (8.7 times slower than Keytruda®). Furthermore, GNUV201 shows a stronger binding affinity at pH 6.0 (5.6 times strong than at pH 7.4), which mimics the hypoxic and acidic tumor microenvironment (TME). This phenomenon is not observed with marketed antibodies (Keytruda®, Opdivo®), implying that GNUV201 achieves more selective binding to and better occupancy on PD-1 in the TME. CONCLUSIONS: In summary, GNUV201 exhibited enhanced affinity for PD-1 with slow dissociation and preferential binding in TME-mimicking low pH. Human/monkey/mouse inter-species cross-reactivity of GNUV201 could enable more predictable and translatable efficacy and toxicity preclinical studies. These results suggest that GNUV201 could be an ideal antibody candidate for anti-cancer drug development.