Neutrophil diversity is associated with T-cell immunity and clinical relevance in patients with thyroid cancer.

Neutrophil heterogeneity is involved in autoimmune diseases, sepsis, and several cancers. However, the link between neutrophil heterogeneity and T-cell immunity in thyroid cancer is incompletely understood. We investigated the circulating neutrophil heterogeneity in 3 undifferentiated thyroid cancer (UTC), 14 differentiated thyroid cancer (DTC) (4 Stage IV, 10 Stage I-II), and healthy controls (n = 10) by transcriptomic data and cytometry. Participants with UTC had a significantly higher proportion of immature high-density neutrophils (HDN) and lower proportion of mature HDN in peripheral blood compared to DTC. The proportion of circulating PD-L1+ immature neutrophils were significantly increased in advanced cancer patients. Unsupervised analysis of transcriptomics data from circulating HDN revealed downregulation of innate immune response and T-cell receptor signaling pathway in cancer patients. Moreover, UTC patients revealed the upregulation of glycolytic process and glutamate receptor signaling pathway. Comparative analysis across tumor types and stages revealed the downregulation of various T-cell-related pathways, such as T-cell receptor signaling pathway and T-cell proliferation in advanced cancer patients. Moreover, the proportions of CD8+ and CD4+ T effector memory CD45RA+ (TEMRA) cells from peripheral blood were significantly decreased in UTC patients compared to DTC patients. Finally, we demonstrated that proportions of tumor-infiltrated neutrophils were increased and related with poor prognosis in advanced thyroid cancer using data from our RNA-seq and TCGA (The Cancer Genome Atlas) data. In conclusion, observed prevalence of circulating immature high-density neutrophils and their immunosuppressive features in undifferentiated thyroid cancers underscore the importance of understanding neutrophil dynamics in the context of tumor progression in thyroid cancer.

Cathepsin C regulates tumor progression via the Yes-associated protein signaling pathway in non-small cell lung cancer.

Cathepsin C (CTSC), also known as dipeptidyl peptidase I, is a cathepsin with lysosomal exocysteine protease activity and a central coordinator for the activation of neutrophil-derived serine proteases in the lysosomes of neutrophils. Although the role of CTSC in various cancers, including liver and breast cancers, has recently been reported, its role in non-small cell lung cancer (NSCLC) is largely unknown. This study aimed to investigate the functional role of CTSC in NSCLC and the molecular mechanisms underlying CTSC involvement in disease progression. CTSC overexpression markedly enhanced the growth, motility, and invasiveness of NSCLC cells in vitro and in vivo. CTSC knockdown using shRNA in NSCLC cells reversed the migratory and invasive behavior of NSCLC cells. CTSC also induced epithelial-mesenchymal transition through the Yes-associated protein signaling pathway. In addition, our analyses of clinical samples confirmed that high CTSC expression was associated with lymph node metastasis and recurrence in lung adenocarcinoma. In conclusion, CTSC plays an important role in the progression of NSCLC. Thus, targeting CTSC may be a promising treatment option for patients with NSCLC.

Prediction of lung cancer using novel biomarkers based on microbiome profiling of bronchoalveolar lavage fluid.

There is an unmet need for biomarkers for the diagnosis of lung cancer and decision criteria for lung biopsy. We comparatively investigated the lung microbiomes of patients with lung cancer and benign lung diseases. Patients who underwent bronchoscopy at Chungnam National University Hospital between June 2021 and June 2022 were enrolled. Bronchoalveolar lavage fluid (BALF) was collected from 24 patients each with lung cancer and benign lung diseases. The samples were analyzed using 16S rRNA-based metagenomic sequencing. We found that alpha diversity and the beta diversity distribution (P = 0.001) differed significantly between patients with benign lung diseases and those with lung cancer. Firmicutes was the most abundant phylum in patients with lung cancer (33.39% ± 17.439), whereas Bacteroidota was the most abundant phylum in patients with benign lung disease (31.132% ± 22.505), respectively. In differential abundance analysis, the most differentially abundant microbiota taxon was unclassified_SAR202_clade, belonging to the phylum Chloroflexi. The established prediction model distinguished patients with benign lung disease from those with lung cancer with a high accuracy (micro area under the curve [AUC] = 0.98 and macro AUC = 0.99). The BALF microbiome may be a novel biomarker for the detection of lung cancer.

Plasma GDF15 levels associated with circulating immune cells predict the efficacy of PD-1/PD-L1 inhibitor treatment and prognosis in patients with advanced non-small cell lung cancer.

PURPOSE: Although increased plasma growth differentiation factor-15 (GDF15) levels have been reported in patients with various cancers, the predictive role of PD-1/PD-L1 inhibitors in advanced cancers remains unknown. This study aimed to investigate GDF15 levels as a predictive marker in advanced non-small cell lung cancer (NSCLC) treated with PD-1/PD-L1 inhibitors and analyze their association with immune cell populations. METHODS: This study included 87 patients with advanced NSCLC receiving anti-PD-1/PD-L1 inhibitors between March 2018 and May 2020. Blood samples were obtained immediately before and months after PD-1/PD-L1 inhibitor administration. RESULTS: The objective response rate (ORR) was significantly higher in the low GDF15 than in the high GDF15 group (39.2% vs. 15.3%, P = 0.013). The median progression-free survival (PFS) was significantly longer in the low GDF15 than in the high GDF15 group (13.2 [95% CI 7.6-18.9] vs. 7.2 [95% CI 4.8-9.6] months, P = 0.048). Moreover, plasma GDF15 levels negatively correlated with PD-1+/CD8+ T cells (r = - 0.399, P = 0.003) and positively with PD-1+/Treg cells (r = 0.507, P < 0.001) and PD-1+Treg/CD4+ T cells (r = 0.439, P < 0.001). The ORR was significantly higher in the group with decreased GDF15 from baseline than in the increased GDF15 group (37.2% vs. 10.0%, P = 0.026). The median PFS was significantly longer in the decreased GDF15 group (14.8 [95% CI 10.4-19.2] vs. 5.9 [95% CI 2.8-9.0] months, P = 0.002). Plasma GDF15 levels were associated with PD-1+CD8+ T cells and PD-1+ Treg cells. CONCLUSION: Plasma GDF15 could be a potential biomarker for predicting the efficacy and survival benefit of immunotherapy in advanced NSCLC.

The rest period between chemotherapy and immunotherapy influences the efficacy of immune checkpoint inhibitors in lung cancer.

BACKGROUND: The use of immune checkpoint inhibitors (ICIs) as first-line treatment rather than as second-line treatment makes a big difference in the drug efficacy and progression-free survival. However, the mechanism for this is still not clear. This study aimed to analyze the effects of the rest period between chemotherapy and immunotherapy on the efficacy of ICIs. METHODS: This study included 100 patients with advanced NSCLC treated with PD-1/PD-L1 inhibitors at Chungnam National University Hospital (CNUH) between May 2016 and August 2019. The rest period was defined from the last dose of cytotoxic chemotherapy to the first dose of ICIs. We retrospectively reviewed patients' clinical data and blood test records and analyzed lymphocyte subsets using flow cytometry. RESULTS: The median rest period was 64 days. The long rest period group (≥36 days) showed significantly higher clinical benefits than the short rest period group (<36 days) (69.4% vs. 39.5%, p = 0.003). White blood cell (WBC) count, absolute neutrophil count (ANC), absolute lymphocyte count (ALC), and neutrophil-lymphocyte ratio (NLR) just before chemotherapy were not different between the two groups. However, the blood test after chemotherapy immediately before immunotherapy showed significantly higher ANC and NLR in the short rest period group than in the long rest period group. The frequency of the Th1 subset and PD-1 + CD8+ T cells were significantly higher in the long rest period group than in the short rest period group. CONCLUSION: Time interval from chemotherapy to immunotherapy may affect immune cell status and efficacy of ICIs.

Circulating regulatory T cells predict efficacy and atypical responses in lung cancer patients treated with PD-1/PD-L1 inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have become the standard of care for a variety of cancers, including non-small cell lung cancer (NSCLC). In this study, we investigated the frequency of pseudoprogression and hyperprogression in lung cancer patients treated with ICIs in the real world and aimed to discover a novel candidate marker to distinguish pseudoprogression from hyperprogression soon after ICI treatment. METHODS: This study included 74 patients with advanced NSCLC who were treated with PD-1/PD-L1 inhibitors at Chungnam National University Hospital (CNUH) between January 2018 and August 2020. Chest X-rays were examined on day 7 after the first ICI dose to identify changes in the primary mass, and the response was assessed by computed tomography (CT). We evaluated circulating regulatory T (Treg) cells using flow cytometry and correlated the findings with clinical outcomes. RESULTS: The incidence of pseudoprogression was 13.5%, and that of hyperprogression was 8.1%. On day 7 after initiation of treatment, the frequency of CD4+CD25+CD127loFoxP3+ Treg cells was significantly decreased compared with baseline (P = 0.038) in patients who experienced pseudoprogression and significantly increased compared with baseline (P = 0.024) in patients who experienced hyperprogression. In the responder group, the frequencies of CD4+CD25+CD127loFoxP3+ Treg cells and PD-1+CD4+CD25+CD127loFoxP3+ Treg cells were significantly decreased 7 days after commencement of treatment compared with baseline (P = 0.034 and P < 0.001, respectively). CONCLUSION: Circulating Treg cells represent a promising potential dynamic biomarker to predict efficacy and differentiate atypical responses, including pseudoprogression and hyperprogression, after immunotherapy in patients with NSCLC.

Clinical Significance of Composition Changes in T-cell Subpopulations After Chemotherapy in Patients With Gastric Cancer.

BACKGROUND/AIM: New therapeutic agents and prognostic biomarkers for gastric cancer are needed. We analyzed the composition of peripheral blood T-cell subpopulations in response to chemotherapy in patients with gastric cancer. PATIENTS AND METHODS: Peripheral blood samples were collected from patients diagnosed with gastric cancer before and after chemotherapy (FOLFOX; oxaliplatin, 5-fluorouracil, and leucovorin). Peripheral blood mononuclear cells were isolated. Patients were divided into responder (n=5) and non-responder groups (n=2) based on their chemotherapy outcomes. RESULTS: Non-responders showed lower numbers of CD4+/total cells and CD8+/total cells after chemotherapy compared to the responder group, but the difference was not significant (p=0.905, p=0.095). Naïve T, central memory T, effector memory T and effector T-cell counts differed in both groups after chemotherapy. CONCLUSION: Changes in peripheral T-cell subpopulations after chemotherapy were confirmed in patients with gastric cancer, which may be a prognostic predictor and development of therapeutic agents.

Peripheral Blood from Rheumatoid Arthritis Patients Shows Decreased Treg CD25 Expression and Reduced Frequency of Effector Treg Subpopulation.

Rheumatoid arthritis (RA) is a common autoimmune disease characterized by immune cell infiltration of the synovium, leading to the loss of cartilage, bone, and joint function. Although regulatory T (Treg) cells are thought to modulate the initiation and progression of RA, a consensus has yet to be reached regarding the function and composition of Treg cells in RA patients. To address these discrepancies, we analyzed not only the total Treg frequency but also that of Treg subpopulations in the peripheral blood of RA patients and healthy controls by flow cytometry. We found that the total Treg population was not significantly different between RA and control subjects. However, the effector Treg cell subgroup, defined as CD45RA-CD25hi, showed markedly decreased frequency in RA patients. In addition, the total Treg population from RA patients showed a significant decline in the expression of CD25. Both the naïve and effector Treg subgroups also showed marked reduction of CD25 expression in RA patients compared to controls. These data suggest that the decreased frequency of effector Treg cells and overall reduction of CD25 expression in Treg cells in the peripheral blood may be evidence of altered Treg homeostasis associated with RA pathogenesis.

Carrot Pomace Polysaccharide (CPP) Improves Influenza Vaccine Efficacy in Immunosuppressed Mice via Dendritic Cell Activation.

Despite the advancements in vaccination research and practices, influenza viruses remain a global health concern. Inducing a robust immune response by vaccination is especially challenging in the elderly, the immunocompromised, and persons with chronic illnesses. Polysaccharides derived from food may act as a safe and readily accessible means to boost the immune system during vaccination. In this study, we investigated whether crude polysaccharides derived from carrot pomace (CPP) could stimulate innate immune cell function and promote influenza vaccine immunogenicity. In bone marrow-derived dendritic cells (BMDCs), CPP increased the fraction of CD11c+MHCII+ cells and the expression of co-stimulatory molecules CD40 and CD80, indicative of enhanced maturation and activation. Functionally, CPP-treated BMDCs promoted inflammatory cytokine production in splenic lymphocytes. In a mouse model of immunosuppression induced by cyclophosphamide, animals given CPP before and after an influenza vaccine challenge showed increased frequencies of dendritic cells and natural killer cells in the spleen, in addition to the recovery of vaccine-specific antibody titers. Moreover, innate myeloid cells in CPP-fed mice showed evidence of phenotypic modification via markedly enhanced interleukin(IL)-12 and interferon(IFN)-γ production in response to lipopolysaccharide(LPS) stimulation ex vivo. Our findings suggest that the administration of carrot pomace polysaccharides can significantly enhance the efficacy of influenza vaccination.

Baseline Serum Interleukin-6 Levels Predict the Response of Patients with Advanced Non-small Cell Lung Cancer to PD-1/PD-L1 Inhibitors.

Although various studies on predictive markers in the use of PD-1/PD-L1 inhibitors are in progress, only PD-L1 expression levels in tumor tissues are currently used. In the present study, we investigated whether baseline serum levels of IL-6 can predict the treatment response of patients with advanced non-small cell lung cancer (NSCLC) treated with PD-1/PD-L1 inhibitors. In our cohort of 125 NSCLC patients, the objective response rate (ORR) and disease control rate (DCR) were significantly higher in those with low IL-6 (<13.1 pg/ml) than those with high IL-6 (ORR 33.9% vs. 11.1%, p=0.003; DCR 80.6% vs. 34.9%, p<0.001). The median progression-free survival was 6.3 months (95% confidence interval [CI], 3.9-8.7) in the low IL-6 group, significantly longer than in the high IL-6 group (1.9 months, 95% CI, 1.6-2.2, p<0.001). The median overall survival in the low IL-6 group was significantly longer than in the high IL-6 group (not reached vs. 7.4 months, 95% CI, 4.8-10.0). Thus, baseline serum IL-6 levels could be a potential biomarker for predicting the efficacy and survival benefit of PD-1/PD-L1 inhibitors in NSCLC.

The Role of PI3K/AKT Pathway and NADPH Oxidase 4 in Host ROS Manipulation by Toxoplasma gondii.

Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H2O2-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.