Current Landscape of Immune Checkpoint Inhibitors for Metastatic Urothelial Carcinoma: Is There a Role for Additional T-Cell Blockade?

Urothelial carcinoma (UC) is the most common form of bladder cancer (BC) and is the variant with the most immunogenic response. This makes urothelial carcinoma an ideal candidate for immunotherapy with immune checkpoint inhibitors. Key immune checkpoint proteins PD-1 and CTLA-4 are frequently expressed on T-cells in urothelial carcinoma. The blockade of this immune checkpoint can lead to the reactivation of lymphocytes and augment the anti-tumor immune response. The only immune checkpoint inhibitors that are FDA-approved for metastatic urothelial carcinoma target the programmed death-1 receptor and its ligand (PD-1/PD-L1) axis. However, the overall response rate and progression-free survival rates of these agents are limited in this patient population. Therefore, there is a need to find further immune-bolstering treatment combinations that may positively impact survival for patients with advanced UC. In this review, the current immune checkpoint inhibition treatment landscape is explored with an emphasis on combination therapy in the form of PD-1/PD-L1 with CTLA-4 blockade. The investigation of the current literature on immune checkpoint inhibition found that preclinical data show a decrease in tumor volumes and size when PD-1/PD-L1 is blocked, and similar results were observed with CTLA-4 blockade. However, there are limited investigations evaluating the combination of CTLA-4 and PD-1/PD-L1 blockade. We anticipate this review to provide a foundation for a deeper experimental investigation into combination immune checkpoint inhibition therapy in metastatic urothelial carcinoma.

Unbiased high-dimensional flow cytometry identified NK and DC immune cell signature in Luminal A-type and triple negative breast cancer

Breast cancer is the most common malignancy in women worldwide and a highly heterogeneous disease. Four different subtypes are described that differ in the expression of hormone receptors as well as the growth factor receptor HER2. Treatment modalities and survival rate depend on the subtype of breast cancer. However, it is still not clear which patients benefit from immunotherapeutic approaches such as checkpoint blockade. Thus, we aimed to decipher the immune cell signature of the different breast cancer subtypes based on high-dimensional flow cytometry followed by unbiased approaches. Here, we show that the frequency of NK cells is reduced in Luminal A and B as well as triple negative breast cancer and that the phenotype of residual NK cells is changed toward regulatory CD11b-CD16- NK cells. Further, we found higher frequencies of PD-1+ CD4+ and CD8+ T cells in triple negative breast cancer. Moreover, while Luminal A-type breast cancer was enriched for CD14+ cDC2 (named type 3 DC (DC3)), CD14- cDC2 (named DC2) were more frequent in triple negative breast cancer. In contrast, HER2-enriched breast cancer did not show major alterations in the composition of the immune cell compartment in the tumor microenvironment. These findings suggest that patients with Luminal A- and B-type as well as triple negative breast cancer might benefit from immunotherapeutic approaches targeting NK cells.

FLT3L-dependent dendritic cells control tumor immunity by modulating Treg and NK cell homeostasis

FLT3-L-dependent classical dendritic cells (cDCs) recruit anti-tumor and tumor-protecting lymphocytes. We evaluate cancer growth in mice with low, normal, or high levels of cDCs. Paradoxically, both low or high numbers of cDCs improve survival in mice with melanoma. In low cDC context, tumors are restrained by the adaptive immune system through influx of effector T cells and depletion of Tregs and NK cells. High cDC numbers favor the innate anti-tumor response, with massive recruitment of activated NK cells, despite high Treg infiltration. Anti CTLA-4 but not anti PD-1 therapy synergizes with FLT3-L therapy in the cDCHi but not in the cDCLo context. A combination of cDC boost and Treg depletion dramatically improves survival of tumor-bearing mice. Transcriptomic data confirm the paradoxical effect of cDC levels on survival in several human tumor types. cDCHi-TregLo state in such patients predicts best survival. Modulating cDC numbers via FLT3 signaling may have therapeutic potential in human cancer.

The inter-link of ageing, cancer and immunity: findings from real-world retrospective study

BACKGROUND

Although the concept of declined immune function associated with cancer has been accepted extensively, real-world clinical studies focusing on analysis of the peripheral blood immune changes underlying ageing, immunity and cancer are scarce.

METHODS

In this case-control study, we retrospectively analysed 1375 cancer patients and enrolled 275 age and gender matched healthy individuals. Flow cytometry was conducted to assess the immune changes. Further analysis was examined by SPSS 17.0 and GraphPad Prism 9 software.

RESULTS

Cancer patients showed obviously decreased CD3+ T, CD3+CD4+ Th, CD3+CD8+ CTL, CD19+ B, CD16+CD56+ NK cell counts and lower percentage of PD-1 (programmed cell death protein-1, PD-1) positive cells than healthy control (P < 0.0001). For cancer patients, the reference range of circulating percentage of PD-1+CD45+ cells, PD-1+CD3+ T cells, PD-1+CD3+CD4+ Th cells and PD-1+CD3+CD8+ CTL (Cytotoxic T Lymphocyte, CTL) were 11.2% (95% CI 10.8%-11.6%), 15.5% (95% CI 14.7%-16.0%), 15.4% (95% CI 14.9%-16.0%) and 14.5% (95% CI 14.0%-15.5%), respectively. Moreover, the reduction of CD3+ T, CD3+CD4+ Th, CD3+CD8+ CTL, CD19+ B cell counts accompanied with age and stage advancing (P < 0.05). CD16+CD56+ NK cells decreased with stage, but elevated in aged and male cancer patients (P < 0.05). Additionally, the percentage of PD-1 positive cells varied across cancer types, raised with age and stage. Head and neck, pancreatic, gynaecological and lung demonstrated a higher level of the percentage of PD-1 positive cells than melanoma, prostate, and breast cancer (P < 0.05).

CONCLUSIONS

This study provides the reference range of the percentage of PD-1 positive cells on peripheral blood, confirms the decreased immune cells and a series of immune changes accompanying with cancer, expands our real world evidence to better understand the interactions of ageing, cancer and immunity. Moreover, the circulating percentage of PD-1 positive cells shows similar tumor type distribution with tumor mutational burden (TMB), supports that it maybe a potential predictive biomarker for immune checkpoint inhibitor therapy.

Implications of Senescent T Cells for Cancer Immunotherapy

T-cell senescence is thought to result from the age-related loss of the ability to mount effective responses to pathogens and tumor cells. In addition to aging, T-cell senescence is caused by repeated antigenic stimulation and chronic inflammation. Moreover, we demonstrated that T-cell senescence was induced by treatment with DNA-damaging chemotherapeutic agents. The characteristics of therapy-induced senescent T (TIS-T) cells and general senescent T cells are largely similar. Senescent T cells demonstrate an increase in the senescence-associated beta-galactosidase-positive population, cell cycle arrest, secretion of senescence-associated secretory phenotypic factors, and metabolic reprogramming. Furthermore, senescent T cells downregulate the expression of the co-stimulatory molecules CD27 and CD28 and upregulate natural killer cell-related molecules. Moreover, TIS-T cells showed increased PD-1 expression. However, the loss of proliferative capacity and decreased expression of co-stimulatory molecules associated with T-cell senescence cause a decrease in T-cell immunocompetence. In this review, we discuss the characteristics of senescent T-cells, including therapy-induced senescent T cells.

Unveiling immune checkpoint regulation: exploring the power of in vivo CRISPR screenings in cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionized cancer immunotherapy by reinvigorating antitumor immune responses, but their efficacy remains limited in most patients. To address this challenge and optimize Immune check inhibitor treatment, understanding the underlying molecular intricacies involved is crucial. The emergence of CRISPR-Cas9 technology has empowered researchers to precisely investigate gene function and has introduced transformative shifts in identifying key genes for various physiological and pathological processes. CRISPR screenings, particularly in vivo CRISPR screenings, have become invaluable tools in deciphering molecular networks and signaling pathways governing suppressive immune checkpoint molecules. In this review, we provide a comprehensive overview of in vivo CRISPR screenings in cancer immunotherapy, exploring how this cutting-edge technology has unraveled potential novel therapeutic targets and combination strategies. We delve into the latest findings and advancements, shedding light on immune checkpoint regulation and offering exciting prospects for the development of innovative and effective treatments for cancer patients.

Large-scale manufacturing of base-edited chimeric antigen receptor T cells

Base editing is a revolutionary gene-editing technique enabling the introduction of point mutations into the genome without generating detrimental DNA double-stranded breaks. Base-editing enzymes are commonly delivered in the form of modified linear messenger RNA (mRNA) that is costly to produce. Here, we address this problem by developing a simple protocol for manufacturing base-edited cells using circular RNA (circRNA), which is less expensive to synthesize. Compared with linear mRNA, higher editing efficiencies were achieved with circRNA, enabling an 8-fold reduction in the amount of RNA required. We used this protocol to manufacture a clinical dose (1 × 108 cells) of base-edited chimeric antigen receptor (CAR) T cells lacking expression of the inhibitory receptor, PD-1. Editing efficiencies of up to 86% were obtained using 0.25 μg circRNA/1 × 106 cells. Increased editing efficiencies with circRNA were attributed to more efficient translation. These results suggest that circRNA, which is less expensive to produce than linear mRNA, is a viable option for reducing the cost of manufacturing base-edited cells at scale.

Extracellular vesicles remodel tumor environment for cancer immunotherapy

Tumor immunotherapy has transformed neoplastic disease management, yet low response rates and immune complications persist as major challenges. Extracellular vesicles including exosomes have emerged as therapeutic agents actively involved in a diverse range of pathological conditions. Mounting evidence suggests that alterations in the quantity and composition of extracellular vesicles (EVs) contribute to the remodeling of the immune-suppressive tumor microenvironment (TME), thereby influencing the efficacy of immunotherapy. This revelation has sparked clinical interest in utilizing EVs for immune sensitization. In this perspective article, we present a comprehensive overview of the origins, generation, and interplay among various components of EVs within the TME. Furthermore, we discuss the pivotal role of EVs in reshaping the TME during tumorigenesis and their specific cargo, such as PD-1 and non-coding RNA, which influence the phenotypes of critical immune cells within the TME. Additionally, we summarize the applications of EVs in different anti-tumor therapies, the latest advancements in engineering EVs for cancer immunotherapy, and the challenges encountered in clinical translation. In light of these findings, we advocate for a broader understanding of the impact of EVs on the TME, as this will unveil overlooked therapeutic vulnerabilities and potentially enhance the efficacy of existing cancer immunotherapies.

A follow-up study: 6-year cART-free virologic control of rhesus macaques after PD-1-based DNA vaccination against pathogenic SHIVSF162P3CN challenge

IMPORTANCE

Efficient strategies for HIV-1 cART-free virologic control are critical for ending the AIDS pandemic. The essential role of effector-memory CD8+ T cells in controlling viremia and eliminating virus-infected cells has made them a promising target for vaccine development. It has been previously reported that PD-1-based DNA vaccination was effective in inducing polyfunctional effector-memory CD8+ T cells for AIDS virus control for 2 years in rhesus monkeys. This follow-up study extends the findings and shows that a viremia-free period of over 6 years was detected in two monkeys immunized with PD-1-based DNA vaccine against pathogenic SHIVSF162P3CN infection in the absence of antiretroviral therapy. Long-term vaccine-induced memory T cell responses were detected. Our results warrant the clinical trials of PD-1-based DNA vaccines for achieving HIV-1 cART-free virologic control used either alone or in combination with other biomedical interventions.

Checkpoint Immunotherapy in Pediatric Oncology: Will We Say Checkmate Soon?

Immune checkpoint inhibitors (ICIs) are a relatively new class of immunotherapy which bolsters the host immune system by "turning off the brakes" of effector cells (e.g., CTLA-4, PD-1, PD-L1). Although their success in treating adult malignancy is well documented, their utility in pediatric cancer has not yet been shown to be as fruitful. We review ICIs, their use in pediatric malignancies, and active pediatric clinical trials, exemplifying some of adult efforts that could be related to pediatric future trials and complications of ICI therapy. Through our review, we propose the consideration of ICI as standard therapy in lymphoma and various solid tumor types, especially in relapsed or refractory (R/R) disease. However, further studies are needed to demonstrate ICI effectiveness in pediatric leukemia.

New Immunological Markers in Chromoblastomycosis-The Importance of PD-1 and PD-L1 Molecules in Human Infection

The pathogenesis of chromoblastomycosis (CBM) is associated with Th2 and/or T regulatory immune responses, while resistance is associated with a Th1 response. However, even in the presence of IFN-γ, fungi persist in the lesions, and the reason for this persistence is unknown. To clarify the factors associated with pathogenesis, this study aimed to determine the polarization of the cellular immune response and the densities of cells that express markers of exhaustion in the skin of CBM patients. In the skin of patients with CBM, a moderate inflammatory infiltrate was observed, characterized primarily by the occurrence of histiocytes. Analysis of fungal density allowed us to divide patients into groups that exhibited low and high fungal densities; however, the intensity of the inflammatory response was not related to mycotic loads. Furthermore, patients with CBM exhibited a significant increase in the number of CD4+ and CD8+ cells associated with a high density of IL-10-, IL-17-, and IFN-γ-producing cells, indicating the presence of a chronic and mixed cellular immune response, which was also independent of fungal load. A significant increase in the number of PD-1+ and PD-L1+ cells was observed, which may be associated with the maintenance of the fungus in the skin and the progression of the disease.

A real-world study on the safety profile of extended-interval dosing of immune checkpoint inhibitors for melanoma: a single-center analysis in Japan

Background

Anti-programmed death-1 (PD-1) antibodies are the mainstay for the treatment of unresectable or high-risk melanoma. However, real-world data on the safety profile of their extended-interval doses (EDs) are limited, particularly in Asian patients with melanoma.

Materials and methods

In this single-center retrospective study, we analyzed the risks of immune-related adverse events (irAEs) among 71 Japanese patients (36 males; mean age, 65.0 years) who received anti-PD-1 monotherapy for melanoma at our institute. Patients who were administered ipilimumab prior to anti-PD-1 monotherapy were excluded. Patients were divided into three groups: canonical-interval dose (CD) group (n = 50, body weight-based dosing or 240 mg Q2W for nivolumab and body weight-based dosing or 200 mg Q3W for pembrolizumab), ED group (n = 14, 480 mg Q4W for nivolumab and 400 mg Q6W for pembrolizumab), and dose-switch (DS) group (n = 7, upfront CD followed by ED).

Results

The CD group received nivolumab more frequently in the metastatic setting. There were no significant differences in baseline characteristics among the three groups, including in sex, age, primary tumor site, tumor subtype, and follow-up period. irAEs occurred in 36.6% (26 patients) of all patients (32.0% of the CD group, 35.7% of the ED group, and 71.4% of the DS group), while severe (grade ≥ 3) irAEs occurred in only two patients, both of whom were in the CD group. Most of the irAEs occurred during the first 6 months of anti-PD-1 therapy and, interestingly, all of the irAEs in the DS group occurred before the switch (during the CD). There was no significant difference among the three groups in the probability of irAE estimated by the Kaplan-Meier method.

Conclusion

These findings may highlight the safety of ED of anti-PD-1 monotherapy in the treatment of Asian patients with melanoma.

Mechanisms of the PD-1/PD-L1 pathway in itch: From acute itch model establishment to the role in chronic itch in mouse

Programmed cell death receptor/ligand 1 (PD-1/PD-L1) blockade therapy for various cancers induces itch. However, few studies have evaluated the mechanism underlying PD-1/PD-L1 inhibitor-induced itch. This study aimed to establish and evaluate a mouse model of acute itch induced by PD-1/PD-L1 inhibitors and to explore the role of the PD-1/PD-L1 pathway in chronic itch. The intradermal injection of the PD-1/PD-L1 small molecule inhibitors, or anti-PD-1/PD-L1 antibodies in the nape of the neck in the mice elicited intense spontaneous scratches. The model was evaluated using pharmacological methods. The number of scratches was reduced by naloxone but not by antihistamines or the transient receptor potential (TRP) channel inhibitor. Moreover, the PD-1 receptor was detected in the spinal cord of the mouse models of chronic itch that exhibited acetone, diethyl ether, and water (AEW)-induced dry skin, imiquimod-induced psoriasis, and 1-fluoro-2,4-dinitrobenzene (DNFB)-induced allergic contact dermatitis. Intrathecal PD-L1 (1 μg, 4 times a week for 1 week) suppressed the activation of the microglia in the spinal dorsal horn to relieve the chronic itch that was elicited by imiquimod-induced psoriasis and DNFB-induced allergic contact dermatitis. Although the activation of the microglia in the spinal dorsal horn was not detected in the AEW-treated mice, intrathecal PD-L1 still reduced the number of scratches that were elicited by AEW. Our findings suggest that histamine receptor inhibitors or TRP channel inhibitors have limited effects on PD-1/PD-L1 inhibitor-induced itch and that spinal PD-1 is important for the spinal activation of the microglia, which may underlie chronic itch.

Develop a PD-1-blockade peptide to reinvigorate T-cell activity and inhibit tumor progress

Immune checkpoint inhibitors, particularly monoclonal antibodies blocking the programmed cell death 1 (PD-1)/programmed cell death ligand-1 (PD-L1) pathway, have been successfully utilized in the clinic. However, certain drawbacks associated with antibodies, such as high immunogenicity and poor tissue penetration, need to be addressed for their broader clinical application. Peptides, as low molecular weight alternatives, have garnered increasing interest in this field. In this study, we employed bacterial surface display technology to identify a PD-1-binding peptide, PBP. The PBP peptide exhibited moderate affinity for human PD-1 (hPD-1) and displayed cross-reactivity with mouse PD-1 (mPD-1). Molecular docking analysis revealed that the interaction residues of the PBP peptide with PD-1 played crucial roles in the formation of the PD-1/PD-L1 complex. A competing binding assay demonstrated that the peptide could interfere the interaction of PD-1 and PD-L1. Moreover, in vitro experiments showed that the PBP peptide could reinvigorate T cells inhibited by PD-L1. In an in vivo mouse model of CT26, the PBP peptide effectively suppressed tumor growth by enhancing T cell function. In conclusion, our results suggest that the PBP peptide exerts an anti-tumor effect by impeding the interplay between PD-1 and PD-L1, highlighting its potential as an alternative for tumor immunotherapy.

Modulation of miR-146b by N6-methyladenosine modification remodels tumor-associated macrophages and enhances anti-PD-1 therapy in colorectal cancer

PURPOSE

MicroRNA-146b (miR-146b) alleviates experimental colitis in mice by mediating macrophage polarization and the release of inflammatory factors. Our goals were to evaluate the antitumor efficacy of miR-146b in colorectal cancer (CRC) and to investigate the underlying mechanisms.

METHODS

We used murine models of CRC to evaluate whether miR-146b influenced the progression of tumors independent of tumor-associated macrophages (TAMs). RNA immunoprecipitation, N6-methyladenosine (m6A) RNA immunoprecipitation and in vitro pri-miRNA processing assays were conducted to examine whether m6A mediates the maturation of pri-miR-146b/miR-146b. In a series of in vitro and in vivo experiments, we further defined the molecular mechanisms of methyltransferase-like 3 (METTL3)/miR-146b-mediated antitumor immunity and its efficacy in combination with anti-PD-1 immunotherapy.

RESULTS

We found that miR-146b deletion supported tumor progression by increasing the number of alternatively activated (M2) TAMs. Mechanistically, the m6A-related "writer" protein METTL3 and "reader" protein HNRNPA2B1 controlled miR-146b maturation by regulating the m6A modification region of pri-miR-146b. Furthermore, miR-146b deletion promoted the polarization of M2-TAMs by enhancing phosphoinositide 3-kinase (PI3K)/AKT signaling, and this effect was mediated by the class IA PI3K catalytic subunit p110β, which reduced T cell infiltration, aggravated immunosuppression and ultimately promoted tumor progression. METTL3 knockdown or miR-146b deletion induced programmed death ligand 1 (PD-L1) production via the p110β/PI3K/AKT pathway in TAMs and consequently augmented the antitumor activity of anti-PD-1 immunotherapy.

CONCLUSIONS

The maturation of pri-miR-146b is m6A-dependent, and miR-146b deletion-mediated TAM differentiation promotes the development of CRC by activating the PI3K/AKT pathway, which induces upregulation of PD-L1 expression, inhibits T cell infiltration into the TME and enhances the antitumor activity of anti-PD-1 immunotherapy. The findings reveal that targeting miR-146b can serve as an adjuvant to anti-PD-1 immunotherapy.

The predictive and prognostic role of single nucleotide gene variants of PD-1 and PD-L1 in patients with advanced melanoma treated with PD-1 inhibitors

Background

Despite having revolutionized the treatment paradigm for advanced melanoma, not all patients benefit from immune checkpoint inhibitor therapy. To date, there are no predictive biomarkers for response or the occurrence of immune-related adverse events (irAEs) to programmed cell death protein 1 (PD-1) inhibitors. Our aim was to investigate the predictive and prognostic role of single nucleotide variants (SNVs) of genes involved in the PD-1 axis.

Methods

We analysed, in metastatic melanoma patients treated with nivolumab or pembrolizumab, five PD-1 SNVs, namely PD1.3 G>A (rs11568821), PD1.5 C>T (rs2227981), PD1.6 G>A (rs10204525), PD1.7 T>C(rs7421861), PD1.10 C>G (rs5582977) and three programmed death-ligand 1 (PD-L1) SNVs: +8293 C>A (rs2890658), PD-L1 C>T (rs2297136) and PD-L1 G>C (rs4143815). Association of SNV genotypic frequencies with best overall response to PD-1 inhibitors and development of irAEs were estimated through a modified Poisson regression. A Cox regression modelling approach was applied to evaluate the SNV association with OS.

Results

A total of 125 patients with advanced melanoma were included in the analysis. A reduction in irAEs risk was observed in patients carrying the PD-L1 +8293 C/A genotype compared with those carrying the C/C genotype (risk ratio = 0.45; 95% CL 0.22-0.93; P = 0.031). A trend for a reduction in irAEs was also observed with the PD1.5 T allele (risk ratio = 0.70, 95% confidence limits 0.48-1.01 versus C allele). None of the SNVs was associated with response to therapy. Finally, a survival benefit was observed in patients harbouring the PD1.7 C/C genotype (hazard ratio = 0.37; 95% confidence limits 0.14-0.96; P = 0.028) in the homozygous model.

Conclusions

Our study showed that PD-1.5 and PD-L1 +8293 SNVs may play a role as a predictive biomarker of development of irAEs to PD-1 inhibitors. PD1.7 SNV may also be associated with a reduction of the risk of death, although further translational research is needed to confirm these results.

ATOR-1017 (evunzekibart), an Fc-gamma receptor conditional 4-1BB agonist designed for optimal safety and efficacy, activates exhausted T cells in combination with anti-PD-1

BACKGROUND

4-1BB (CD137) is a co-stimulatory receptor highly expressed on tumor reactive effector T cells and NK cells, which upon stimulation prolongs persistence of tumor reactive effector T and NK cells within the tumor and induces long-lived memory T cells. 4-1BB agonistic antibodies have been shown to induce strong anti-tumor effects that synergize with immune checkpoint inhibitors. The first generation of 4-1BB agonists was, however, hampered by dose-limiting toxicities resulting in suboptimal dose levels or poor agonistic activity.

METHODS

ATOR-1017 (evunzekibart), a second-generation Fc-gamma receptor conditional 4-1BB agonist in IgG4 format, was designed to overcome the limitations of the first generation of 4-1BB agonists, providing strong agonistic effect while minimizing systemic immune activation and risk of hepatoxicity. The epitope of ATOR-1017 was determined by X-ray crystallography, and the functional activity was assessed in vitro and in vivo as monotherapy or in combination with anti-PD1.

RESULTS

ATOR-1017 binds to a unique epitope on 4-1BB enabling ATOR-1017 to activate T cells, including cells with an exhausted phenotype, and NK cells, in a cross-linking dependent, FcγR-conditional, manner. This translated into a tumor-directed and potent anti-tumor therapeutic effect in vivo, which was further enhanced with anti-PD-1 treatment.

CONCLUSIONS

These preclinical data demonstrate a strong safety profile of ATOR-1017, together with its potent therapeutic effect as monotherapy and in combination with anti-PD1, supporting further clinical development of ATOR-1017.

Mediastinal lymph node removal modulates natural killer cell exhaustion in patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death globally. In this study, the effect of complete removal of mediastinal lymph nodes by video-assisted mediastinoscopic lymphadenectomy (VAMLA) on natural killer (NK) cell phenotype and functions in patients with NSCLC was evaluated. The study included 21 NSCLC patients (cIA-IVA) undergoing VAMLA staging and 33 healthy controls. Mononuclear cells were isolated from peripheral blood of all participants and mediastinal lymph nodes of the patients. NK cells were analyzed by flow cytometry to define NK subsets, expressions of PD-1, CTLA-4, activating/inhibitory receptors, granzyme A, and CD107a. The plasma levels of soluble PD-1, PDL-1, and CTLA-4 were measured by ELISA. Mediastinal lymph nodes of NSCLC patients had increased ratios of exhausted NK cells, increased expression of PD-1 and IL-10, and impaired cytotoxicity. Mediastinal lymph nodes removal increased CD56dimCD16bright cytotoxic effector phenotype and reduced exhausted NK cells. PD-1+ NK cells were significantly more abundant in patients' blood, and VAMLA significantly reduced their ratio as well. The ratio of IL-10 secreting regulatory NK cells was also reduced after VAMLA. Blood NK cells had increased cytotoxic functions and spontaneous IFN-γ secretion, and these NK cell functions were also recovered by VAMLA. Mediastinal lymph node removal reversed NK cell exhaustion, reduced regulatory NK cells, and improved antitumoral functions of NK cells. Tumor-draining lymph nodes may contribute to tumor evasion from antitumoral immune responses. The role of their removal needs to be further studied both to better understand this mechanism and as a potential immunotherapeutic approach.

CBX4 promotes antitumor immunity by suppressing Pdcd1 expression in T cells

E3 SUMO-protein ligase CBX4 (CBX4), a key component of polycomb-repressive complexes 1 (PRC1), has been reported to regulate a variety of genes implicated in tumor growth, metastasis, and angiogenesis. However, its role in T-cell-mediated antitumor immunity remains elusive. To shed light on this issue, we generated mice with T-cell-specific deletion of Cbx4. Tumor growth was increased in the knockout mice. Additionally, their tumor-infiltrating lymphocytes exhibited impaired tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) production, with an elevated programmed cell death protein 1 (PD-1) level. In fact, dysregulated Pdcd1 expression was observed in all major subsets of peripheral T cells from the knockout mice, which was accompanied by a functional defect in response to T-cell receptor (TCR) stimulation. In support of a direct link between CBX4 and PD-1, Cbx4 overexpression resulted in the downregulation of Pdcd1 expression. Epigenetic analyses indicated that Cbx4 deficiency leads to diminished accumulation of inhibitory histone modifications at conserved region (CR)-C and CR-B sites of the Pdcd1 promoter, namely mono-ubiquitinated histone H2A at lysine 119 (H2AK119ub1) and trimethylated histone H3 at lysine 27 (H3K27me3). Moreover, inhibition of either the E3 ligase activity of polycomb-repressive complexes 1 (PRC1) or the methyltransferase activity of polycomb-repressive complexes 2 (PRC2) restores Pdcd1 expression in Cbx4-transfected cells. Cumulatively, this study reveals a novel function of CBX4 in the regulation of T-cell function and expands our understanding of the epigenetic control of Pdcd1 expression.

PD-1 and PD-L1: architects of immune symphony and immunotherapy breakthroughs in cancer treatment

PD-1 (Programmed Cell Death Protein-1) and PD-L1 (Programmed Cell Death Ligand-1) play a crucial role in regulating the immune system and preventing autoimmunity. Cancer cells can manipulate this system, allowing them to escape immune detection and promote tumor growth. Therapies targeting the PD-1/PD-L1 pathway have transformed cancer treatment and have demonstrated significant effectiveness against various cancer types. This study delves into the structure and signaling dynamics of PD-1 and its ligands PD-L1/PD-L2, the diverse PD-1/PD-L1 inhibitors and their efficacy, and the resistance observed in some patients. Furthermore, this study explored the challenges associated with the PD-1/PD-L1 inhibitor treatment approach. Recent advancements in the combination of immunotherapy with chemotherapy, radiation, and surgical procedures to enhance patient outcomes have also been highlighted. Overall, this study offers an in-depth overview of the significance of PD-1/PD-L1 in cancer immunotherapy and its future implications in oncology.

Inhibitory checkpoint molecule mRNA expression in canine soft tissue sarcoma

Canine soft tissue sarcomas (STS) are common neoplasms and considered immune deserts. Tumour infiltrating lymphocytes are sparse in STS and, when present, tend to organize around blood vessels or at the periphery of the neoplasm. This pattern is associated with an immunosuppressive tumour microenvironment linked to overexpression of molecules of the PD-axis. PD-1, PD-L1 and PD-L2 expression correlates with malignancy and poor prognosis in other neoplasms in humans and dogs, but little is known about their role in canine STS, their relationship to tumour grade, and how different therapies affect expression. The objective of this study was to evaluate the expression of checkpoint molecules across STS tumour grades and after tumour ablation treatment. Gene expression analysis was performed by reverse-transcriptase real-time quantitative PCR in soft tissue sarcomas that underwent histotripsy and from histologic specimens of STS from the Virginia Tech Animal Laboratory Services archives. The expression of PD-1, PD-L1 and PD-L2 was detected in untreated STS tissue representing grades 1, 2, and 3. Numerically decreased expression of all markers was observed in tissue sampled from the treatment interface relative to untreated areas of the tumour. The relatively lower expression of these checkpoint molecules at the periphery of the treated area may be related to liquefactive necrosis induced by the histotripsy treatment, and would potentially allow TILs to infiltrate the tumour. Relative increases of these checkpoint molecules in tumours of a higher grade and alongside immune cell infiltration are consistent with previous reports that associate their expression with malignancy.

Microbial metabolite butyrate promotes anti-PD-1 antitumor efficacy by modulating T cell receptor signaling of cytotoxic CD8 T cell

Recent studies have demonstrated that the antitumor immunity of immune cells can be modulated by gut microbiota and their metabolites. However, the underlying mechanisms remain unclear. Here, we showed that the serum butyric acid level is positively correlated with the expression of programmed cell death-1 (PD-1) on circulating CD8+ and Vγ9 Vδ2 (Vδ2+) T cells in patients with non-small cell lung cancer (NSCLC). Responder NSCLC patients exhibited higher levels of serum acetic acid, propionic acid, and butyric acid than non-responders. Depletion of the gut microbiota reduces butyrate levels in both feces and serum in tumor-bearing mice. Mechanistically, butyrate increased histone 3 lysine 27 acetylation (H3K27ac) at the promoter region of Pdcd1 and Cd28 in human CD8+ T cells, thereby promoting the expression of PD-1/CD28 and enhancing the efficacy of anti-PD-1 therapy. Butyrate supplementation promotes the expression of antitumor cytokines in cytotoxic CD8+ T cells by modulating the T-cell receptor (TCR) signaling pathway. Collectively, our findings reveal that the metabolite butyrate of the gut microbiota facilitates the efficacy of anti-PD-1 immunotherapy by modulating TCR signaling of cytotoxic CD8 T cells, and is a highly promising therapeutic biomarker for enhancing antitumor immunity.

Functional enhancement of mesothelin-targeted TRuC-T cells by a PD1-CD28 chimeric switch receptor

T cells expressing a mesothelin (MSLN)-specific T cell receptor fusion construct (TRuC®), called TC-210, have demonstrated robust antitumor activity in preclinical models of mesothelioma, ovarian cancer, and lung cancer. However, they are susceptible to suppression by the programmed cell death protein 1 (PD-1)/programmed cell death protein ligand 1 (PD-L1) axis and lack intrinsic costimulatory signaling elements. To enhance the function of anti-MSLN TRuC-T cells, chimeric switch receptors (CSRs) have been designed to co-opt the immunosuppressive PD-1/PD-L1 axis and to deliver a CD28-mediated costimulatory signal. Here, we report that coexpression of the PD1-CD28 CSR in TRuC-T cells enhanced T cell receptor signaling, increased proinflammatory effector cytokines, decreased anti-inflammatory cytokines, and sustained effector function in the presence of PD-L1 when compared with TC-210. Anti-MSLN TRuC-T cells engineered to coexpress PD1-CD28 CSRs comprising the ectodomain of PD-1 and the intracellular domain of CD28 linked by the transmembrane domain of PD-1 were selected for integration into an anti-MSLN TRuC-T cell therapy product called TC-510. In vitro, TC-510 showed significant improvements in persistence and resistance to exhaustion upon chronic stimulation by tumor cells expressing MSLN and PD-L1 when compared with TC-210. In vivo, TC-510 showed a superior ability to provide durable protection following tumor rechallenge, versus TC-210. These data demonstrate that integration of a PD1-CD28 CSR into TRuC-T cells improves effector function, resistance to exhaustion, and prolongs persistence. Based on these findings, TC-510 is currently being evaluated in patients with MSLN-expressing solid tumors.

SHP2 potentiates anti-PD-1 effectiveness through intervening cell pyroptosis resistance in triple-negative breast cancer

Triple negative breast cancer (TNBC) presents a formidable challenge due to the lack of effective treatment modalities. Immunotherapy stands as a promising therapeutic approach; however, the emergence of drug resistance mechanisms within tumor cells, particularly those targeting apoptosis and pyroptosis, has hampered its clinical efficacy. SHP2 is intricately involved in diverse physiological processes, including immune cell proliferation, infiltration, and tumor progression. Nevertheless, the precise contribution of SHP2 to tumor cell pyroptosis resistance remains inadequately understood. Herein, we demonstrate that SHP2 inhibition hampers the proliferative, migratory, and invasive capabilities of TNBC, accompanied by noticeable alterations in cellular membrane architecture. Mechanistically, we provide evidence that SHP2 depletion triggers the activation of Caspase-1 and GSDMD, resulting in GSDMD-dependent release of LDH, IL-1β, and IL-18. Furthermore, computational analyses and co-localization investigations substantiate the hypothesis that SHP2 may hinder pyroptosis through direct binding to JNK, thereby impeding JNK phosphorylation. Our cellular experiments further corroborate these findings by demonstrating that JNK inhibition rescues pyroptosis induced by SHP2 knockdown. Strikingly, in vivo experiments validate the suppressive impact of SHP2 knockdown on tumor progression via enhanced JNK phosphorylation. Additionally, SHP2 knockdown augments tumor sensitivity to anti-PD-1 therapy, thus reinforcing the pro-pyroptotic effects and inhibiting tumor growth. In summary, our findings elucidate the mechanism by which SHP2 governs TNBC pyroptosis, underscoring the potential of SHP2 inhibition to suppress cell pyroptosis resistance and its utility as an adjunctive agent for tumor immunotherapy.

Association of CD8 + T cells expressing nivolumab-free PD-1 with clinical status in a patient with relapsed refractory classical Hodgkin lymphoma

A 37-year-old man with refractory classical Hodgkin lymphoma (cHL) underwent PD-1 blockade therapy with nivolumab, which resulted in a partial response. However, treatment was discontinued due to immune-related adverse events (irAEs), including myasthenia gravis and myositis. Retreatment with nivolumab resulted in a complete metabolic response and hepatic irAE. Subsequently, nivolumab was administered at extended dosing intervals. Intermittent infusion of ten doses of nivolumab for a total dose of 2400 mg/body helped control the relapsed/refractory cHL over three years. During nivolumab treatment, disease progression and emergence of irAEs were associated with the proportion of CD8 + T cells expressing nivolumab-free PD-1 relative to the total number of CD8 + T cells. The findings in this nivolumab-sensitive patient highlight the clinical utility of monitoring immune cells expressing nivolumab-free PD-1 in patients with cHL who have been treated with nivolumab and have experienced irAEs.

Immune checkpoint inhibitors in bone metastasis: Clinical challenges, toxicities, and mechanisms

Immune checkpoint inhibitors (ICIs) have revolutionized the field of anti-cancer therapy over the last decade; they provide durable clinical responses against tumors by inhibiting immune checkpoint proteins that canonically regulate the T cell-mediated immune response. Despite their success in many primary tumors and soft tissue metastases, ICIs function poorly in patients with bone metastases, and these patients do not have the same survival benefit as patients with the same primary tumor type (e.g., non-small cell lung cancer [NSCLC], urothelial, renal cell carcinoma [RCC], etc.) that has not metastasized to the bone. Additionally, immune-related adverse events including rheumatologic and musculoskeletal toxicities, bone loss, and increased fracture risk develop after treatment with ICIs. There are few preclinical studies that investigate the interplay of the immune system in bone metastases; however, the current literature suggests a role for CD8+ T cells and myeloid cell subsets in bone homeostasis. As such, this review focuses on findings from the clinical and pre-clinical studies that have investigated immune checkpoint blockade in the bone metastatic setting and highlights the need for more comprehensive investigations into the relationship between immune cell subsets, ICIs, and the bone-tumor microenvironment.

Epigenome-Driven Strategies for Personalized Cancer Immunotherapy

Fighting cancer remains one of the greatest challenges for science in the 21st century. Advances in immunotherapy against different types of cancer have greatly contributed to the treatment, remission, and cure of patients. In this context, knowledge of epigenetic phenomena, their relationship with tumor cells and how the immune system can be epigenetically modulated represent some of the greatest advances in the development of anticancer therapies. Epigenetics is a rapidly growing field that studies how environmental factors can affect gene expression without altering DNA sequence. Epigenomic changes include DNA methylation, histone modifications, and non-coding RNA regulation, which impact cellular function. Epigenetics has shown promise in developing cancer therapies, such as immunotherapy, which aims to stimulate the immune system to attack cancer cells. For example, PD-1 and PD-L1 are biomarkers that regulate the immune response to cancer cells and recent studies have shown that epigenetic modifications can affect their expression, potentially influencing the efficacy of immunotherapy. New therapies targeting epigenetic modifications, such as histone deacetylases and DNA methyltransferases, are being developed for cancer treatment, and some have shown promise in preclinical studies and clinical trials. With growing understanding of epigenetic regulation, we can expect more personalized and effective cancer immunotherapies in the future. This review highlights key advances in the use of epigenetic and epigenomic tools and modern immuno-oncology strategies to treat several types of tumors.

PD-L1 and PD-1 expression in pediatric post-transplant Burkitt lymphoma and other monomorphic post-transplant lymphoproliferative disorders

BACKGROUND

Post-transplant lymphoproliferative disorders (PTLD) develop as a consequence of immune suppression. Programmed death protein 1 (PD-1), a regulator of host immune activation, binds to programmed death-ligand 1 (PD-L1) to suppress the T-cell immune response. PD-1/PD-L1 pathway may play a role in PTLD. The objective was to describe intratumoral expression of PD-L1 and PD-1 in pediatric monomorphic PTLD, and assess if density of these cells is associated with progression-free survival (PFS) and overall survival (OS).

PROCEDURE

Clinical variables and outcome data were collected on B-cell monomorphic PTLD treated in Toronto, Canada between 2000 and 2017. Diagnostic area from tumor tissue was identified to count CD3-positive or PD-1-positive cells and CD3-negative lymphoma B cells or PD-L1-positive cells. CD3+ , PD-1+ , and PD-L1+ cell densities were compared between cases of PTLD. OS and PFS were analyzed.

RESULTS

We identified 25 cases of B-cell monomorphic PTLD; majority Burkitt lymphoma (32%) and diffuse large B-cell lymphoma (56%). All cases had CD3+ cells infiltrating the tumor, and median percentage of CD3+ cells was 14% (interquartile range: 6.2%-25%). Twelve cases (48%) had PD-1+ cell infiltrating (range: 1%-83%) and 13 cases (52%) had no PD-1+ cells infiltrating. Sixteen cases (64%) had PD-L1+ cells present; however, there was no PD-L1 expression on any Burkitt lymphoma tissue. When comparing PD-1 and PD-L1 expression, there was no difference in OS or PFS.

CONCLUSION

Intratumoral presence of PD-1+ and PD-L1+ cells varied in pediatric patients with monomorphic PTLD; however, no relationship to OS and PFS was identified.

PD-1 and PD-L1 inhibitors in cold colorectal cancer: challenges and strategies

Colorectal cancer (CRC) is the second most common cause of cancer mortality, with mismatch repair proficient (pMMR) and/or microsatellite stable (MSS) CRC making up more than 80% of metastatic CRC. Programmed death-ligand 1 (PD-L1) and programmed death 1 (PD-1) immune checkpoint inhibitors (ICIs) are approved as monotherapy in many cancers including a subset of advanced or metastatic colorectal cancer (CRC) with deficiency in mismatch repair (dMMR) and/or high microsatellite instability (MSI-H). However, proficient mismatch repair and microsatellite stable (pMMR/MSS) cold CRCs have not shown clinical response to ICIs alone. To potentiate the anti-tumor response of PD-L1/PD-1 inhibitors in patients with MSS cold cancer, combination strategies currently being investigated include dual ICI, and PD-L1/PD-1 inhibitors in combination with chemotherapy, radiotherapy, vascular endothelial growth factor (VEGF) /VEGF receptor (VEGFR) inhibitors, mitogen-activated protein kinase (MEK) inhibitors, and signal transducer and activation of transcription 3 (STAT3) inhibitors. This paper will review the mechanisms of PD-1/PD-L1 ICI resistance in pMMR/MSS CRC and potential combination strategies to overcome this resistance, summarize the published clinical experience with different combination therapies, and make recommendations for future avenues of research.

The prognostic significance of tumor-immune microenvironment in ascites of patients with high-grade serous carcinoma

BACKGROUND

High-grade serous carcinoma (HGSC) is often associated with ascites at presentation. Our objective was to quantify immune cells (ICs) in ascites prior to any treatment was given and evaluate their impact on progression-free survival (PFS) and overall survival (OS).

PATIENTS AND METHODS

Forty-seven patients with primary HGSC and ascites were included. Flow-cytometric analysis was performed to detect percentages of CD3+ T cells (CD4+, CD8+, Tregs, and NKT cells), B cells, NK cells (CD56brightCD16- and CD56dimCD16+ subsets), macrophages and dendritic cells (DCs). Furthermore, CD103 expression was analyzed on T cells and their subsets, while PD-1 and PD-L1 expression on all ICs. Cut-off of low and high percentages of ICs was determined by the median of variables, and correlation with PFS and OS was calculated.

RESULTS

CD3+ cells were the predominant ICs (median 51%), while the presence of other ICs was much lower (median ≤10%). CD103+ expression was mostly present on CD8+, and not CD4+ cells. PD-1 was mainly expressed on CD3+ T cells (median 20%), lower expression was observed on other ICs (median ≤10%). PD-L1 expression was not detected. High percentages of CD103+CD3+ T cells, PD-1+ Tregs, CD56brightCD16- NK cells, and DCs correlated with prolonged PFS and OS, while high percentages of CD8+ cells, macrophages, and PD-1+CD56brightCD16- NK cells, along with low percentages of CD4+ cells, correlated with better OS only. DCs were the only independent prognostic marker among all ICs.

CONCLUSIONS

Our results highlight the potential of ascites tumor-immune microenvironment to provide additional prognostic information for HGSC patients. However, a larger patient cohort and longer follow-up are needed to confirm our findings.

An analysis of sintilimab combined with ruxolitinib as compassionate therapy for 12 adults with EBV-associated hemophagocytic lymphohistiocytosis

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is a severe hyperinflammatory illness that affects adults and is caused by an EBV infection. Without allogeneic hematopoietic stem cell transplantation (allo-HSCT), the overall survival of adult patients with EBV-HLH is unsatisfactory, necessitating the development of innovative therapeutic approaches. The clinical records of twelve EBV-HLH patients who received sintilimab therapy combined with ruxolitinib on a compassionate basis at the First Affiliated Hospital of Soochow University were retrospectively examined in this investigation. All the patients responded without fever, but three patients relapsed within a week. Among the nine patients achieving complete response (CR), 55.6% (5/9) maintained CR for >4.5 months, and 33.3% (3/9) relapsed following CR. Neither patients with no response (NR) nor relapsed patients were fit for allo-HSCT, and all died soon after discharge. Six patients had clinical CR with a median follow-up of 5 (4.4-14.7) months. There were no documented severe negative effects. Additional information on this innovative treatment for adult EBV-HLH is provided in our report.

Inducing the Abscopal Effect in Liver Cancer Treatment: The Impact of Microwave Ablation Power Levels and PD-1 Antibody Therapy

Microwave ablation (MWA) is an effective treatment for liver cancer (LC), but its impact on distant tumors remains to be fully elucidated. This study investigated the abscopal effects triggered by MWA treatment of LC, at different power levels and with or without combined immune checkpoint inhibition (ICI). We established a mouse model with bilateral subcutaneous LC and applied MWA of varied power levels to ablate the right-sided tumor, with or without immunotherapy. Left-sided tumor growth was monitored to assess the abscopal effect. Immune cell infiltration and distant tumor neovascularization were quantified via immunohistochemistry, revealing insights into the tumor microenvironment and neovascularization status. Th1- and Th2-type cytokine concentrations in peripheral blood were measured using ELISA to evaluate systemic immunological changes. It was found that MWA alone, especially at lower power, promoted distant tumor growth. On the contrary, combining high-power MWA with anti-programmed death (PD)-1 therapy promoted CD8+ T-cell infiltration, reduced regulatory T-cell infiltration, upregulated a Th1-type cytokine (TNF-α) in peripheral blood, and inhibited distant tumor growth. In summary, combining high-power MWA with ICI significantly enhances systemic antitumor immune responses and activates the abscopal effect, offering a facile and robust strategy for improving treatment outcomes.

Efficacy and safety of PD-1 inhibitors in recurrent or metastatic nasopharyngeal carcinoma patients after failure of platinum-containing regimens: a systematic review and meta-analysis

OBJECTIVE

There is a lack of standard salvage treatment options for recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) that has failed platinum-containing regimens. Breakthroughs in immunotherapy have opened up new options for these patients. However, the efficacy and safety of immunotherapy have not been clarified. This study aimed to summarize and assess the efficacy and safety of PD-1 inhibitors in patients with RM-NPC who failed platinum-containing chemotherapy.

METHODS

Up to August 25, 2022, clinical trials of PD-1 inhibitors in RM-NPC patients who failed platinum-containing regimens were searched in the PubMed, Embase, Cochrane, and Web of Science databases. Retrieval subject terms included "nasopharyngeal carcinoma", "metastatic", "recurrence", "PD-1", and "PD-L1". The clinical trials eligible for inclusion were systematically reviewed and meta-analyzed.

RESULTS

A total of 9 studies including 842 patients with RM-NPC were included in this meta-analysis. The results showed that PD-1 inhibitors had promising efficacy in patients with RM-NPC who failed platinum-containing regimens: objective response rate (ORR) was 24% (95% confidence interval [CI] 21-26%), disease control rate (DCR) was 52% (95% CI 45-58%), 1-year progression-free survival (PFS) rate was 25% (95% CI 18-32%), and 1-year overall survival (OS) rate was 53% (95% CI 37-68%). In terms of treatment-related adverse events (AEs), the incidence of grade ≥ 3 treatment-related AEs was 19% (95% CI 13-24%). In addition, we found that PD-1 inhibitors were more effective in patients with PD-L1 positive than in patients with PD-L1 negative nasopharyngeal carcinoma who had failed platinum-containing regimens (ORR 31% (95%CI 26-35%) vs. 21% (95% CI 17-25%)).

CONCLUSION

PD-1 inhibitors may provide a survival benefit for patients with RM-NPC who have failed platinum-containing regimens and have the advantage of a good safety profile, making them a promising treatment option.

Immune checkpoints in rheumatoid arthritis: progress and promise

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune inflammatory conditions, and while the mechanisms driving pathogenesis are yet to be completely elucidated, self-reactive T cells and immune checkpoint pathways have a clear role. In this review, we provide an overview of the importance of checkpoint pathways in the T cell response and describe the involvement of these in RA development and progression. We discuss the relationship between immune checkpoint therapy in cancer and autoimmune adverse events, draw parallels with the involvement of immune checkpoints in RA pathobiology, summarise emerging research into some of the lesser-known pathways, and the potential of targeting checkpoint-related pathways in future treatment approaches to RA management.

The Effect of Oxaliplatin on the Immunogenic Cell Death and Cell Apoptosis of Human Merkel Cell Cancerous Tumor

Oxaliplatin, as previously studied in the paper, is a derivative of Cisplatin that is effective in treating the Lewis Lung Carcinoma (LLC)4. As it can actively induce immunogenic cell death of the cancer cells, and result in apoptosis, which increases the therapeutic efficacy in the LLC cancer treatment.4 Merkel cell caner is a type of skin cancer that is rare but highly aggressive, with high metastasizing and reoccurring rate. In this study, we aim the determine the potential of Oxaliplatin to induce apoptosis and ICD in cancerous Merkel cell line MCC1, in associate with the PD-1 inhibitor Nivolumab. The cancer cells will be treated with Oxaliplatin at concentrations 1 mM, 10 mM, or 100 mM. Avelumab and PBS will be used as the positive and negative control, respectively. The treated cells will be measured by checking for tumor size change in confocal microscopy and MTT assay, measuring the ICD using flow cytometry analysis of CRT expression, and conducting Western Blot for Cytokeratin 20 expression. The results of the study will provide insights on the potential of Oxaliplatin as a treatment of Merkel Cell Cancer in the future.

Efficacy of PD-1 checkpoint inhibitor therapy in melanoma and beyond: are peripheral T cell phenotypes the key?

Immunotherapy treatment strategies have proven effective in a limited portion of patients, where identifying responders from non-responders to treatment remains a challenge. While some indications can be drawn from invasive biopsies, we need more accessible methods for predicting response and better correlates of response prior to starting therapy. Recent work has identified differences in immune composition at baseline in peripheral blood from melanoma patients responding to PD-1 blockade treatment. Through flow cytometric analysis of T cell receptors, phenotypical features of CD8+ and CD4+ T cells and Tregs could allow for the stratification of treatment response. Analysing T cells within peripheral blood could potentially allow for the stratification of PD-1 treatment response prior to therapy in different cancer settings.

A phase 1a/1b first-in-human study (COMPASSION-01) evaluating cadonilimab in patients with advanced solid tumors

Simultaneous inhibition of programmed cell death protein-1 (PD-1) and cytotoxic T lymphocyte-associated protein-4 (CTLA-4) with bispecific antibodies may improve efficacy over single-agent treatment while limiting toxicity. Cadonilimab is a humanized, bispecific antibody targeting PD-1 and CTLA-4. This is a phase 1 study of cadonilimab including dose escalation (n = 39) and dose expansion (n = 80). One dose-limiting toxicity event is observed, with the maximum tolerated dose not reached. 6 mg/kg cadonilimab once every 2 weeks is established as the recommended dose for future studies. The most common treatment-related adverse event is infusion-related reaction (18.5%), mostly grade 1/2 in severity. The incidences of any grade and grade ≥3 immune-related adverse events are 44.5% and 6.7%, respectively. The confirmed overall response rate is 13.4%, and the median duration of response is 12.9 months. Cadonilimab is well tolerated and showed promising efficacy in patients with advanced solid tumors. This study is registered with ClinicalTrials.gov: NCT03261011.

SIRP-alpha-IL-6 axis induces immunosuppressive macrophages in non-small-cell lung cancer

Signal regulatory protein-alpha (SIRPα) and IL-6 participate in the induction of tumor immune suppressive environment and facilitate tumor growth. In this study, we found that SIRPα was significantly elevated in macrophages of non-small cell lung cancer (NSCLC) tissues, which was positively correlated to the expression of CD163, PD-1, IL-6, and lung cancer progression. SIRPα in peripheral blood mononuclear cells (PBMCs) of NSCLC patients was also associated with CD163, PD-1, and plasma IL-6. Blockade of SIRPα signaling in SIRPα ± and SIRPα-/- mice attenuated lung cancer growth and reduced IL-6 expression in LLC cells-transplanted murine lung cancer model. Co-targeting SIRPα and IL-6 additively suppressed the expression of IL-6 and activation of STAT3, accompanied with a reduced population of pro-tumorigenic CD206+ M2 subtype of macrophages, PD-1+ tumor-associated macrophages (TAMs), and PD-1+CD8+ T cells in tumor tissues of anti-IL-6 antibody (aIL-6)-treated mice deficient in SIRPα. Further in vitro studies showed that blockade of SIRPα signaling by anti-SIRPα effectively improved phagocytosis of human PBMCs. IL-6 treatment improved polarization of M2 subtypes and the expression of PD-1 in bone marrow-derived macrophages (BMDMs); whereas both aIL-6 and STAT3 inhibitor C188-9 suppressed the expression of PD-1 and SIRPα in BMDMs. M2 cell-biased polarization was also reduced in aIL-6 or C188-9 treated BMDMs. Thereby, SIRPα and IL-6 form a positive feedback loop and regulate each other through STAT3 signaling in macrophages. The increased SIRPα/IL-6 axis may promote immune suppressive environment and lung cancer growth, which may be a potential target for clinical treatment.

Characteristics of the immune microenvironment associated with RRM2 expression and its application to PD-L1/PD-1 inhibitors in lung adenocarcinoma

Recent studies have indicated that RRM2 plays a crucial part in the tumor immune microenvironment. According to the expression of RRM2, we evaluated immune cell infiltration, immunotherapy biomarkers, and the expression of immune checkpoint molecules in four lung adenocarcinoma (LUAD) datasets. We employed the Tumor Immune Dysfunction and Exclusion (TIDE) and CIBERSORTx algorithms to examine the patterns of immune cell distribution and evaluate the responses to anti-programmed death protein-1/programmed death ligand-1 (PD-1/PD-L1) therapy in three publicly available LUAD datasets. These findings were corroborated using a validation group comprising patients who received treatment with PD-1/PD-L1 inhibitors. Additionally, we conducted experiments using LUAD cell lines to investigate how RRM2 affects the expression of PD-L1. In comparison to the low RRM2 group, the high RRM2 group exhibited a high interferon gamma signature, high T-cell-inflamed signature, high CD274 expression, high CD8+ T cell levels, low cancer-associated fibroblasts, and low M2 macrophages, according to TIDE analysis in the three LUAD datasets. Analysis of the three LUAD datasets using CIBERSORTx confirmed a positive correlation between RRM2 and CD8+ T cells, and this finding was validated by immunohistochemistry in a separate validation set. In the three LUAD datasets without PD-1/PD-L1 inhibitor treatment, higher RRM2 expression was associated with a poorer prognosis. However, in the LUAD dataset treated with PD-1/PD-L1 inhibitors, higher RRM2 expression was associated with better prognosis. In the three datasets, the high-RRM2 group exhibited higher expression of inhibitory immune checkpoint molecules. In a LUAD cell line study, we discovered that RRM2 regulates PD-L1 expression through the ANXA1/AKT pathway. The expression of RRM2 shows promise as a predictive biomarker for PD-1/PD-L1 inhibitors in LUAD patients, and it may represent a new target to overcome resistance to PD-L1/PD-1 therapies.

A bedside to bench study of anti-PD-1, anti-CD40, and anti-CSF1R indicates that more is not necessarily better

BACKGROUND

Stimulating inflammatory tumor associated macrophages can overcome resistance to PD-(L)1 blockade. We previously conducted a phase I trial of cabiralizumab (anti-CSF1R), sotigalimab (CD40-agonist) and nivolumab. Our current purpose was to study the activity and cellular effects of this three-drug regimen in anti-PD-1-resistant melanoma.

METHODS

We employed a Simon's two-stage design and analyzed circulating immune cells from patients treated with this regimen for treatment-related changes. We assessed various dose levels of anti-CSF1R in murine melanoma models and studied the cellular and molecular effects.

RESULTS

Thirteen patients were enrolled in the first stage. We observed one (7.7%) confirmed and one (7.7%) unconfirmed partial response, 5 patients had stable disease (38.5%) and 6 disease progression (42.6%). We elected not to proceed to the second stage. CyTOF analysis revealed a reduction in non-classical monocytes. Patients with prolonged stable disease or partial response who remained on study for longer had increased markers of antigen presentation after treatment compared to patients whose disease progressed rapidly. In a murine model, higher anti-CSF1R doses resulted in increased tumor growth and worse survival. Using single-cell RNA-sequencing, we identified a suppressive monocyte/macrophage population in murine tumors exposed to higher doses.

CONCLUSIONS

Higher anti-CSF1R doses are inferior to lower doses in a preclinical model, inducing a suppressive macrophage population, and potentially explaining the disappointing results observed in patients. While it is impossible to directly infer human doses from murine studies, careful intra-species evaluation can provide important insight. Cabiralizumab dose optimization is necessary for this patient population with limited treatment options.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03502330.

IGF2 Peptide-Based LYTACs for Targeted Degradation of Extracellular and Transmembrane Proteins

Lysosome-targeting chimeras (LYTACs) have recently been developed to facilitate the lysosomal degradation of specific extracellular and transmembrane molecular targets. However, the LYTAC particles described to date are based on glycopeptide conjugates, which are difficult to prepare and produce on a large scale. Here, we report on the development of pure protein LYTACs based on the non-glycosylated IGF2 peptides, which can be readily produced in virtually any facility capable of monoclonal antibody production. These chimeras utilize the IGF2R/CI-M6PR pathway for lysosomal shuttling and, in our illustrative example, target programmed death ligand 1 (PD-L1), eliciting physiological effects analogous to immune checkpoint blockade. Results from in vitro assays significantly exceed the effects of anti-PD-L1 antibodies alone.

T Lymphocyte Characteristic Changes Under Serum Cytokine Deviations and Prognostic Factors of COVID-19 in Pregnant Women

Physiological changes during pregnancy make the individuals more susceptible to severe respiratory diseases. Hence, pregnant women with coronavirus disease 2019 (COVID-19) are likely at a higher risk. We investigated the effects of COVID-19 on T cell response and serum cytokine profile in pregnant patients. Peripheral blood mononuclear cells (PBMCs) of women with COVID-19 were collected during the first trimester of pregnancy, and the percentage of total lymphocytes, as well as CD4 + and CD8 + T cells, was assessed using flow cytometry. The expression of the programmed death-1 (PD-1) marker for exhausted T cells was evaluated. Additionally, the serum samples were provided to evaluate the levels of antiviral and proinflammatory cytokines, as well as laboratory serological tests. Pregnant women with COVID-19 presented lymphopenia with diminished CD4 + and CD8 + T cells. Besides, high expression levels of the PD-1 gene and protein were observed on PBMCs and T cells, respectively, when compared with normal pregnant individuals. Moreover, serum levels of TNF-α, IL-6, IL-1β, and IL-2 receptor were notably enhanced, while IFN-I α/β values were significantly decreased in the patients when compared with controls. Furthermore, hyperlipidemia, hyperglycemia, and hypertension were directly correlated with the disease although serum albumin and vitamin D3 levels adversely affected the viral infection. Our study showed extreme lymphopenia and poor T cell response while elevated values of serum inflammatory cytokines in infected pregnant women. Moreover, a hypertension background or metabolic changes, including hyperlipidemia, hyperglycemia, and vitamin D3 or albumin deficiency, might be promising prognostic factors in pregnant women with COVID-19.

Safety and Efficacy Analysis of PD-1 Inhibitors in Combination with Gemcitabine Plus Nab-Paclitaxel for Advanced Pancreatic Cancer: A Real-World, Single-Center Study

Background

Pancreatic cancer is a deadly disease with a low five years survival rate, and chemotherapy remains the standard treatment for advanced cases. However, the efficacy of chemotherapy alone is limited, and there is a need for new treatment options. Recently, immune checkpoint inhibitors (ICIs), particularly programmed death-1 (PD-1) inhibitors, have shown promising results in various cancers, including pancreatic cancer. In this study, we explore the safety and efficacy of PD-1 inhibitors in combination with chemotherapy for advanced pancreatic cancer.

Materials and Methods

A retrospective analysis was conducted on clinical data from 27 patients with advanced pancreatic cancer who were administered a combination of anti-PD-1 antibody and gemcitabine plus nab-paclitaxel (GnP) regimen. The study evaluated the safety of the treatment as well as the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS).

Results

In this study, treatment with a combination of anti-PD-1 antibody and GnP regimen for pancreatic cancer resulted in partial response (PR) for 10 out of 27 (37.04%) patients, stable disease (SD) for 10 (37.04%) patients, and progressive disease (PD) for 7 (25.92%) patients. The study found that the median OS (mOS) for these patients was 16.4 months [standard error (SE) = 1.117, 95% confidence interval (CI) 14.211-18.589], while the median PFS (mPFS) was 6.4 months (SE = 1.217, 95% CI 3.981-8.752). Subgroup analysis revealed that pancreatic cancer patients' Eastern Cooperative Oncology Group (ECOG) performance status (PS) (0 vs 1) and treatment cycles (≤6 cycles vs >6 cycles) significantly affected OS and PFS. Patients experienced mostly grade 1-2 adverse events (AEs), which were relieved through clinical treatment.

Conclusion

The combination of GnP with anti-PD-1 antibodies shows promise as a potential treatment option for advanced pancreatic cancer.

Neoadjuvant PD-1/PD-L1 combined with CTLA-4 inhibitors for solid malignancies: a systematic review and meta-analysis

BACKGROUND

The effectiveness and safety of neoadjuvant PD-1/PD-L1 inhibitors combined with CTLA-4 inhibitors is controversial. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of PD-1/PD-L1 inhibitors combined with CTLA-4 inhibitors as neoadjuvant therapy for malignant solid tumors.

METHODS

This study has been registered with the number CRD42023407275 on PROSPERO. Systematic searches were conducted in PubMed, Embase, Web of Science and Cochrane Library databases until March 17, 2023. In addition, manual searches were performed. The inclusion criteria encompassed randomized controlled trials (RCTs) that assessed the utilization of neoadjuvant PD-1/PD-L1 inhibitors combined with CTLA-4 inhibitors PD-1/PD-L1 inhibitors for patients with solid malignancies. The Cochrane Collaboration's tool for assessing risk of bias in randomized trials (ROB1) were used. Risk ratios (RRs), hazared ratios (HRs) and their respective 95% confidence intervals were calculated using Stata17.0 MP and Review Manager 5.4 software.

RESULTS

A total of 2780 records were identified, and ultimately 10 studies involving 273 patients were included. The meta-analysis showed that the addition of CTLA-4 inhibitors to PD-1/PD-L1 inhibitors did not demonstrate a significant effect on overall response rate, main pathological response, pathological complete response, surgical resection, radical resection, overall survival, progression-free survival, recurrence-free survival, grade 3-4 adverse events, all-cause mortality, and completed treatment (P > 0.05). However, further subgroup analysis indicated that the combination of PD-1 with CTLA-4 inhibitors significantly increased the occurrence of grade 3-4 adverse events in patients (P < 0.05).

CONCLUSIONS

As neoadjuvant therapy for malignant solid tumors, the addition of CTLA-4 inhibitors to PD-1/PD-L1 inhibitors does not appear to enhance efficacy.Moreover, there is a potential increase in the risk of grade 3-4 adverse events associated with this combination. However, it is important to note that the studies included in this analysis suffer from limitations such as small samples and single-center designs, which are inherent constrains with the available published literature. Further research involving large-sample and multicenter RCTs are warranted to obtain more reliable results.

Prior Anti-Angiogenic TKI-Based Treatment as Potential Predisposing Factor to Nivolumab-Mediated Recurrent Thyroid Disorder Adverse Events in mRCC Patients: A Case Series

Immune checkpoint inhibitors (ICIs) targeting programmed cell death 1 (PD-1) or its ligand 1 (PD-L1) have revolutionized the management of many types of solid tumors, including metastatic renal cell carcinoma (mRCC). Both sequential and combinatorial therapeutic strategies utilizing anti-PD-1 monoclonal antibodies (mAbs) and anti-angiogenic tyrosine kinase inhibitors (TKIs) have demonstrated to improve the survival of patients with mRCC as compared to standard therapies. On the other hand, both ICIs and TKIs are well known to potentially cause thyroid disorder adverse events (TDAEs). However, in the context of sequential therapeutic strategy, it is not clear whether prior anti-angiogenic TKI may increase the risk and/or the severity of ICI-related TDAEs. In this work, by describing and analyzing a case series of mRCC patients treated sequentially with prior TKIs and then with ICIs, we investigated the role of prior anti-angiogenic TKI-based treatment as a potential predisposing factor to anti-PD-1-mediated recurrent TDAEs, as well as its potential impact on the clinical characteristics of nivolumab-mediated recurrent TDAEs. Fifty mRCC patients were included in the analysis. TKI-mediated TDAEs were reported in ten out of fifty patients. TKI-mediated TDAEs were characterized by hypothyroidism in all ten patients. Specifically, 40%, 40% and 20% of patients presented grade 1, 2 and 3 hypothyroidisms, respectively. Following tumor progression and during anti-PD-1 nivolumab treatment, five out of ten patients developed anti-PD-1 nivolumab-mediated recurrent TDAEs. Anti-PD-1 nivolumab-mediated recurrent TDAEs were characterized by an early transient phase of thyrotoxicosis and a late phase of hypothyroidism in all five patients. The TDAEs were grade 1 and 2 in four and one patients, respectively. Prior anti-angiogenic TKI did not modify the clinical characteristics of nivolumab-mediated recurrent TDAEs. However, all five patients required an increased dosage of levothyroxine replacement therapy. In conclusion, our work suggests that prior anti-angiogenic TKI-based treatment significantly increases the risk of ICI-mediated recurrent TDAEs in patients with mRCC without modifying their clinical characteristics. The most relevant effect for these patients is the need to increase the dosage of lifelong levothyroxine replacement therapy.

Soluble immune checkpoints are elevated in patients with primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronically progressive liver disease mediated by an autoimmune response. The aetiology and pathogenesis of PBC are not fully understood and may be related to immune disorders caused by genetic factors and their interaction with environmental factors. Immune checkpoints play an important role in preventing the occurrence of autoimmunity. However, the level of immune checkpoints in PBC has not been reported. Here, we aimed to identify the serum levels of soluble checkpoints in patients with PBC.

METHODS

Soluble checkpoint levels were evaluated using enzyme-linked immunosorbent assay in 60 patients with PBC and 20 healthy controls (HCs). The expression of immune checkpoints was compared in liver biopsy tissue samples using immunohistochemistry. Receiver operating characteristic (ROC) curves and area under the curve (AUCs) were used to determine the diagnostic performance of soluble checkpoints and laboratory indexes between patients with PBC and HCs and patients with mild and advanced PBC. A logistic regression was performed for advanced PBC.

RESULTS

sCD134, sLAG-3, sPD-1, sPD-L1, and sTIM-3 levels were significantly increased in patients with PBC compared with those in healthy controls. Additionally, the levels of sCD134, sPD-1, sPD-L1, and sTIM-3 were positively associated with disease progression. Moreover, soluble checkpoints were correlated with immunoglobulin and liver functions. ROC analyses between patients with PBC and HCs showed that the AUCs of sOX40, sPD-1, and sPD-L1 were 0.967, 0.922, and 0.971, respectively. The optimal cut-off values of sOX40, sPD-1, and sPD-L1 for PBC diagnosis were 89.15, 213.4, and 68, respectively. ROC analyses between mild and advanced patients with PBC revealed that the AUCs of sOX40 and sTIM-3 were 0.767 and 0.765, respectively. The optimal cut-off values for predicting PBC stage ≥ III were 199.45 and 361.5, respectively. In univariate analysis, age, ALB, and sOX40 were associated with advanced PBC. Further, the expression of CD134 and TIM-3 was upregulated in the liver of patients with PBC.

CONCLUSIONS

Our study results indicate that the serum titer of soluble checkpoints is increased in Chinese patients with PBC.

Single-cell profiling reveals the heterogeneity of NK cells during anti-PD-1 therapy in non-small-cell lung cancer

BACKGROUND

The efficacy of immune checkpoint inhibitors remains limited in non-small cell lung cancer (NSCLC). Natural killer (NK) cells serve as the key element of innate immunity and play an important role in anti-tumor immunity, the impact of NK cells on efficacy of anti-PD-1 therapy in NSCLC is worth exploring.

METHODS

We analyzed single-cell transcriptome data derived from biopsies of NSCLC patients receiving anti-PD-1 treatment. Immune cell subtypes were identified and further cell-cell communication were analyzed and verified.

RESULTS

We observed totally 6 distinct NK cells clusters in NSCLC infiltrating immune cells. It's worth noting that enrichment of immature NK cells was found in responsive group. A series of marker genes of immature NK cells were associated with anti-PD-1 response and related to immune regulation processes such as antigen processing, Th1, Th17 cells activation. Moreover, effector CD8+ T cells were significantly enriched in responsive group and showed similar trajectories with immature NK cells. Cell-cell communication analysis showed that immature NK cells showed strong interactions with Th17 cells and effector CD8+ T cells. Furthermore, when validating the expression of immature NK cells marker genes, we found that CXCR4 was associated with enriched infiltration of CD8+ T cells.

CONCLUSIONS

In conclusion, immature NK cells may facilitate the efficacy of anti-PD-1 therapy by interacting with Th1 cells, Th17 cells and enhancing infiltration of effector CD8+ T cells. Our data suggested that NK cells could be a promising target to improve the prognosis of NSCLC patients.