C-Reactive Protein Promotes the Expansion of Myeloid Derived Cells With Suppressor Functions

C-reactive protein: structure, function, regulation, and role in clinical diseases

C-reactive protein (CRP) is a plasma protein that is evolutionarily conserved, found in both vertebrates and many invertebrates. It is a member of the pentraxin superfamily, characterized by its pentameric structure and calcium-dependent binding to ligands like phosphocholine (PC). In humans and various other species, the plasma concentration of this protein is markedly elevated during inflammatory conditions, establishing it as a prototypical acute phase protein that plays a role in innate immune responses. This feature can also be used clinically to evaluate the severity of inflammation in the organism. Human CRP (huCRP) can exhibit contrasting biological functions due to conformational transitions, while CRP in various species retains conserved protective functions in vivo. The focus of this review will be on the structural traits of CRP, the regulation of its expression, activate complement, and its function in related diseases in vivo.

Prognostic significance of C-reactive protein in unresectable hepatocellular carcinoma treated with atezolizumab and bevacizumab

AIM

C-reactive protein (CRP) is both an inflammatory and prognostic marker in various cancers. This study aimed to elucidate the characteristics of CRP and the prognostic factors in patients who were administered with atezolizumab plus bevacizumab (ATZ + BEV) for unresectable hepatocellular carcinoma (HCC).

METHODS

A total of 213 patients who received ATZ + BEV for HCC from November 2020 to March 2023 at 15 hospitals were enrolled in this retrospective study. The prognosis was analyzed by subdividing the patients based on baseline characteristics, radiologic response, and treatment lines. Accuracy of survival prediction was assessed using CRP, alpha fetoprotein (AFP), C-reactive protein and alpha fetoprotein in immunotherapy (CRAFITY), and Glasgow Prognostic Score.

RESULTS

Compared with patients with baseline CRP <1 mg/dL, those with baseline CRP ≥1 mg/dL (n = 45) had a significantly higher baseline albumin-bilirubin score and AFP levels, significantly lower disease control rate (62.2%), and significantly shorter median overall survival (hazards ratios 2.292; 95% confidence interval 1.313-5.107; log-rank test, p < 0.001). Multivariate analysis identified CRP ≥1 mg/dL, AFP ≥100 ng/mL, and modified albumin-bilirubin grade as the significant prognostic factors. The baseline CRP, AFP, CRAFITY, and Glasgow Prognostic Score demonstrated higher discrimination for 1-year survival prediction after first-line ATZ + BEV administration, compared with beyond second line, with area under the receiver operating characteristic curves of 0.759, 0.761, 0.805, and 0.717, respectively.

CONCLUSIONS

CRP was a significant biomarker in patients treated with ATZ + BEV for HCC. Elevated CRP levels may indicate aggressive cancer progression and potential resistance to ATZ + BEV therapy.

Immature neutrophils in cord blood exert increased expression of genes associated with antimicrobial function

Introduction

The immune systems of both the mother and the newborn face significant challenges during birth. Proper immune regulation after birth is essential for the survival of neonates. Numerous studies have demonstrated that the neonatal immune system is relatively immature, particularly in its adaptive arm, placing the primary responsibility for immune surveillance on innate immunity.

Methods

Given the significant role of neutrophils in protecting the neonate after birth, we conducted a study investigating the properties of neutrophils in newborn cord blood using various methodological approaches.

Results

Our findings demonstrate the presence of immature low-density neutrophils in the cord blood, which are likely responsible for the observed elevated expression of genes coding for proteins essential to antimicrobial response, including myeloperoxidase, neutrophils elastase, and defensins.

Discussion

We propose that these cells function normally and support the protection of newborns early after birth. Furthermore, our results suggest that the mode of delivery might significantly influence the programming of neutrophil function. The presented findings emphasize the importance of distinct neutrophil subpopulations in neonatal immunity and their potential impact on early postnatal health.

Neutrophilic Myeloid-Derived Suppressor Cells and Severity in SARS-CoV-2 Infection

BACKGROUND

While we strive to live with SARS-CoV-2, defining the immune response that leads to recovery rather than severe disease remains highly important. COVID-19 has been associated with inflammation and a profoundly suppressed immune response.

OBJECTIVE

To study myeloid-derived suppressor cells (MDSCs), which are potent immunosuppressive cells, in SARS-CoV-2 infection.

RESULTS

Patients with severe and critical COVID-19 showed higher frequencies of neutrophilic (PMN)-MDSCs than patients with moderate illness and control individuals (P = .005). Severe disease in individuals older and younger than 60 years was associated with distinct PMN-MDSC frequencies, being predominantly higher in patients of 60 years of age and younger (P = .004). However, both age groups showed comparable inflammatory markers. In our analysis for the prediction of poor outcome during hospitalization, MDSCs were not associated with increased risk of death. Still, patients older than 60 years of age (odds ratio [OR] = 5.625; P = .02) with preexisting medical conditions (OR = 2.818; P = .003) showed more severe disease and worse outcome. Among the immunological parameters, increased C-reactive protein (OR = 1.015; P = .04) and lymphopenia (OR = 5.958; P = .04) strongly identified patients with poor prognosis.

CONCLUSION

PMN-MDSCs are associated with disease severity in COVID-19; however, MDSC levels do not predict increased risk of death during hospitalization.

Transversal psoas muscle thickness measurement is associated with response and survival in patients with HCC undergoing immunotherapy

BACKGROUND

Sarcopenia is a common problem in patients with HCC. We aimed to evaluate the prognostic and predictive value of baseline transversal psoas muscle thickness (TPMT) measurement in patients with HCC undergoing immunotherapy.

METHODS

HCC patients treated with programmed death ligand 1-based therapies between June 2016 and October 2022 at the Vienna General Hospital (n = 80) and the Hôpital Beaujon Clichy (n = 96) were included and followed until April 2023. TPMT at the level of the third lumbar vertebra was measured independently by 2 radiologists to evaluate interreader reliability. TPMT <12 mm/m in men and <8 mm/m in women indicated sarcopenia.

RESULTS

Overall, 176 patients (age: 66.3±11.7 y; male: n=143, 81%, Barcelona-Clinic Liver Cancer C: n=121, 69%) were included, of which 131 (74%) exhibited cirrhosis. Interreader agreement for the diagnosis of sarcopenia based on TPMT was 92.6%, and Cohen κ showed a "strong agreement" [κ = 0.84 (95% CI: 0.75-0.92)]. Sarcopenia, present in 58 patients (33%), was associated with shorter median overall survival [7.2 (95% CI: 5.0-9.5) vs. 22.6 (95% CI: 16.4-28.8 months); p < 0.001] and median progression-free survival [3.4 (95% CI: 0.2-6.8) vs. 7.9 (95% CI: 5.8-9.9 months), p = 0.001], and an independent predictor of overall [adjusted HR: 1.63 (95% CI: 1.07-2.48)] and progression-free mortality [adjusted HR: 1.54 (95% CI: 1.06-2.23)] in multivariable analyses. The objective response rate [evaluable in 162 subjects (92.0%)] per modified Response Evaluation Criteria In Solid Tumors (mRECIST) in patients with and without sarcopenia was 22% and 39%, respectively (p = 0.029). Survival and radiological responses were worse in patients with sarcopenia and systemic inflammation [median overall survival: 6.1 (95% CI: 3.6-8.6) mo; median progression-free survival: 2.8 (95% CI: 2.1-3.4) mo; objective response rate=16%; disease control rate=39%].

CONCLUSIONS

Evaluation of sarcopenia using TPMT measurement is reliable and identifies HCC patients with a dismal prognosis and response to immunotherapy.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

The distribution of myeloid-derived suppressor cells subsets and up-regulation of programmed death-1/PD-L1 axis in peripheral blood of adult CAP patients

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) have been reported to expand and have a potent ability in the expansion of regulatory T cells in malignant and infectious disease. The current study was performed to investigate the role of MDSCs and possible immune mechanisms in dampening immune responses of community acquired pneumonia (CAP).

METHODS

This was a single-center cross-sectional study. The distribution of MDSCs subsets, the PD-1/PD-L1(L2) level of MDSCs subsets and Tregs in the peripheral blood of adult CAP patients and healthy control were measured by flow cytometry analysis.

RESULTS

Peripheral blood mononuclear cells (PBMCs) from 63 adult CAP patients contained an elevated frequency of both G-MDSC (4.92±0.30 vs 2.25±0.21,p<0.0001) and M-MDSC (19.40±1.30 vs 9.64±0.57,p<0.001) compared to healthy controls. Treg in the peripheral blood of CAP patients exhibited increased expression of PD-1 and CTLA-4, accompanied by no difference of their frequency. Moreover, up-regulated expression of PD-L1 on MDSC subsets in the peripheral blood of CAP patients was also revealed. Of note, the frequency of circulating MDSCs subset displayed a positive correlation with neutrophil count percentage in blood in CAP patients.

CONCLUSIONS

In summary, the significant expansion of circulating MDSCs subsets and the up-regulated expression of PD-1/PD-L1 level in CAP patients may suggest the possible involvement of PD-1/PD-L1axis in MDSCs mediated immune regulation on Treg at least partially in CAP patients.

Glutamine Deficiency Promotes Immune and Endothelial Cell Dysfunction in COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has caused the death of almost 7 million people worldwide. While vaccinations and new antiviral drugs have greatly reduced the number of COVID-19 cases, there remains a need for additional therapeutic strategies to combat this deadly disease. Accumulating clinical data have discovered a deficiency of circulating glutamine in patients with COVID-19 that associates with disease severity. Glutamine is a semi-essential amino acid that is metabolized to a plethora of metabolites that serve as central modulators of immune and endothelial cell function. A majority of glutamine is metabolized to glutamate and ammonia by the mitochondrial enzyme glutaminase (GLS). Notably, GLS activity is upregulated in COVID-19, favoring the catabolism of glutamine. This disturbance in glutamine metabolism may provoke immune and endothelial cell dysfunction that contributes to the development of severe infection, inflammation, oxidative stress, vasospasm, and coagulopathy, which leads to vascular occlusion, multi-organ failure, and death. Strategies that restore the plasma concentration of glutamine, its metabolites, and/or its downstream effectors, in conjunction with antiviral drugs, represent a promising therapeutic approach that may restore immune and endothelial cell function and prevent the development of occlusive vascular disease in patients stricken with COVID-19.

Combining Cryo-Thermal Therapy with Anti-IL-6 Treatment Promoted the Maturation of MDSCs to Induce Long-Term Survival in a Mouse Model of Breast Cancer

Immunosuppression plays a significant role in tumor recurrence and metastasis, ultimately causing poor survival outcomes. Overcoming immunosuppression and stimulating durable antitumor immunity are essential for tumor treatment. In our previous study, a novel cryo-thermal therapy involving liquid nitrogen freezing and radiofrequency heating could reduce the proportion of Myeloid-derived suppressor cells (MDSCs), but the remaining MDSCs produced IL-6 by the NF-κB pathway, resulting in an impaired therapeutic effect. Therefore, here we combined cryo-thermal therapy with anti-IL-6 treatment to target the MDSC-dominant immunosuppressive environment, thereby optimizing the efficacy of cryo-thermal therapy. We found that combinational treatment significantly increased the long-term survival rate of breast cancer-bearing mice. Mechanistic investigation revealed that combination therapy was capable of reducing the proportion of MDSCs in the spleen and blood while promoting their maturation, which resulted in increased Th1-dominant CD4⁺ T-cell differentiation and enhancement of CD8⁺ T-mediated tumor killing. In addition, CD4⁺ Th1 cells promoted mature MDSCs to produce IL-7 through IFN-γ, indirectly contributing to the maintenance of Th1-dominant antitumor immunity in a positive feedback loop. Our work suggests an attractive immunotherapeutic strategy targeting the MDSC-dominant immunosuppressive environment, which would offer exciting opportunities for highly immunosuppressive and unresectable tumors in the clinic.

Regulation of the Innate Immune System as a Therapeutic Approach to Supporting Respiratory Function in ALS

Amyotrophic lateral sclerosis (ALS) is a clinical diagnosis used to define a neurodegenerative process that involves progressive loss of voluntary muscle function and leads to death within 2–5 years after diagnosis, in most cases because of respiratory function failure. Respiratory vital capacity (VC) measurements are reproducible and strong predictors of survival. To understand the role of the innate immune response in progressive VC loss we evaluated ALS clinical trial and biomarker results from a 6-month phase 2 study of NP001, a regulator of innate immune function. All ALS baseline values were similar between treated and controls except for those > 65 years old who were excluded from analysis. Treated patients with plasma CRP ≥ 1.13 mg/L (high CRP) showed a 64% slower rate of VC decline compared with placebo and those with plasma CRP < 1.13 mg/L (low CRP) who showed no response. High CRP patients showed no age associated loss of VC whereas low CRP patients showed an age dependent loss of VC function. Plasma levels of serum amyloid A (SAA) were similarly elevated in high CRP patients consistent with ongoing innate immune activation. Plasma TGFB1 in high CRP treated patients was 95% higher than placebo at 6-months, confirming the activation and release of this anti-inflammatory factor by the innate immune alpha 2 macroglobulin (A2M) system. This report is the first to link a biomarker confirmed regulation of the innate immune system with a therapeutic approach for controlling VC loss in ALS patients.

Distinct phenotype of neutrophil, monocyte, and eosinophil populations indicates altered myelopoiesis in a subset of patients with multiple myeloma

Hematologic malignancies, including multiple myeloma (MM), promote systemic immune dysregulation resulting in an alteration and increased plasticity of myeloid cell subsets. To determine the heterogeneity of the myeloid cell compartment in the peripheral blood of patients with MM, we performed a detailed investigation of the phenotype and function of myeloid subpopulations. We report that a subset of MM patients exhibits a specific myeloid cell phenotype indicative of altered myelopoiesis characterized by significant changes in the properties of circulating granulocytic, monocytic, and eosinophilic populations. The subset, referred to as MM2, is defined by a markedly elevated level of CD64 (FcγRI) on the surface of circulating neutrophils. Compared to healthy controls or MM1 patients displaying intermediate levels of CD64, neutrophils from MM2 patients exhibit a less differentiated phenotype, low levels of CD10 and CXC chemokine receptor 2 (CXCR2), increased capacity for the production of mitochondrial reactive oxygen species, and an expansion of CD16^neg immature neutrophil subset. Classical and patrolling monocytes from MM2 patients express elevated levels of CD64 and activation markers. MM2 eosinophils display lower levels of C-C Chemokine receptor 3 (CCR3), Toll-like receptor 4 (TLR4, CD284), and tissue factor (TF, CD142). The MM2 (CD64^high) phenotype is independent of age, race, sex, and treatment type. Characteristic features of the MM2 (CD64^high) phenotype are associated with myeloma-defining events including elevated involved/uninvolved immunoglobulin free light chain (FLC) ratio at diagnosis. Detailed characterization of the altered myeloid phenotype in multiple myeloma will likely facilitate the identification of patients with an increased risk of disease progression and open new avenues for the rational design of novel therapeutic approaches.

Prognostic impact of C-reactive protein and alpha-fetoprotein in immunotherapy score in hepatocellular carcinoma patients treated with atezolizumab plus bevacizumab: a multicenter retrospective study

AIM

This study aimed to investigate the utility of C-reactive protein (CRP) and alpha-fetoprotein (AFP) in immunotherapy (CRAFITY) score in hepatocellular carcinoma (HCC) patients receiving atezolizumab and bevacizumab (Atez/Bev).

METHODS

This retrospective cohort study included a total of 297 patients receiving Atez/Bev from September 2020 to November 2021 at 21 different institutions and hospital groups in Japan. Patients with AFP ≥ 100 ng/mL and those with CRP ≥ 1 mg/dL were assigned a CRAFITY score of 1 point.

RESULTS

The patients were assigned CRAFITY scores of 0 points (n = 147 [49.5%]), 1 point (n = 111 [37.4%]), and 2 points (n = 39 [13.1%]). AFP ≥ 100 ng/mL and CRP ≥ 1.0 mg/dL were significantly associated with progression-free survival (PFS) and overall survival (OS). The median PFS in the CRAFITY score 0, 1, and 2 groups was 11.8 months (95% confidence interval [CI] 6.4-not applicable [NA]), 6.5 months (95% CI 4.6-8.0), and 3.2 months (95% CI 1.9-5.0), respectively (p < 0.001). The median OS in patients with CRAFITY score 0, 1 and 2 was not reached, 14.3 months (95% CI 10.5-NA), and 11.6 months (95% CI 4.9-NA), respectively. The percentage of patients with grade ≥ 3 liver injury, any grade of decreased appetite, any grade of proteinuria, any grade of fever, and any grade of fatigue was lowest in patients with a CRAFITY score of 0, followed by patients with CRAFITY scores of 1 and 2.

CONCLUSIONS

The CRAFITY score is simple and could be useful for predicting therapeutic outcomes and treatment-related adverse events.

Current Understanding and Future Perspectives on Hyperprogressive Disease Highlight the Tumor Microenvironment

Cancer immunotherapy with immune checkpoint inhibitors has revolutionized traditional cancer therapy. Although many patients have achieved long-term survival benefits from immune checkpoint inhibitors treatment, there are still some patients who develop rapid tumor progression after immunotherapy, known as hyperprogressive disease. Here we summarize current knowledge on hyperprogressive disease after immune checkpoint inhibitors treatment to promote more thorough understanding of the disease. This review focuses on multiple aspects of hyperprogressive disease, especially the tumor microenvironment, with the hope that more reliable biomarkers and therapeutics could be established for hyperprogressive disease in the future. This article is protected by copyright. All rights reserved.

Prognosis of patients with hepatocellular carcinoma treated with immunotherapy - development and validation of the CRAFITY score

BACKGROUND & AIMS

Immunotherapy with atezolizumab plus bevacizumab represents the new standard of care in systemic front-line treatment of hepatocellular carcinoma (HCC). However, biomarkers that predict treatment success and survival remain an unmet need.

METHODS

Patients with HCC put on PD-(L)1-based immunotherapy were included in a training set (n = 190; 6 European centers) and a validation set (n = 102; 8 European centers). We investigated the prognostic value of baseline variables on overall survival using a Cox model in the training set and developed the easily applicable CRAFITY (CRP and AFP in ImmunoTherapY) score. The score was validated in the independent, external cohort, and evaluated in a cohort of patients treated with sorafenib (n = 204).

RESULTS

Baseline serum alpha-fetoprotein ≥100 ng/ml (hazard ratio [HR] 1.7; p = 0.007) and C-reactive protein ≥1 mg/dl (HR, 1.7; p = 0.007) were identified as independent prognostic factors in multivariable analysis and were used to develop the CRAFITY score. Patients who fulfilled no criterion (0 points; CRAFITY-low) had the longest median overall survival (27.6 (95% CI 19.5-35.8) months), followed by those fulfilling 1 criterion (1 point; CRAFITY-intermediate; 11.3 (95% CI 8.0-14.6) months), and patients meeting both criteria (2 points; CRAFITY-high; 6.4 (95% CI 4.8-8.1) months; p <0.001). Additionally, best radiological response (complete response/partial response/stable disease/progressive disease) was significantly better in patients with lower CRAFITY score (CRAFITY-low: 9%/20%/52%/20% vs. CRAFITY-intermediate: 3%/25%/36%/36% vs. CRAFITY-high: 2%/15%/22%/61%; p = 0.003). These results were confirmed in the independent validation set and in different subgroups, including Child-Pugh A and B, performance status 0 and ≥1, and first-line and later lines. In the sorafenib cohort, CRAFITY was associated with survival, but not radiological response.

CONCLUSIONS

The CRAFITY score is associated with survival and radiological response in patients receiving PD-(L)1 immunotherapy. The score may help with patient counseling but requires prospective validation.

LAY SUMMARY

The immunotherapy-based regimen of atezolizumab plus bevacizumab represents the new standard of care in systemic first-line therapy of hepatocellular carcinoma (HCC). Biomarkers to predict treatment outcome are an unmet need in patients undergoing immunotherapy for HCC. We developed and externally validated a score that predicts outcome in patients with HCC undergoing immunotherapy with immune checkpoint blockers.

Comorbidity-associated glutamine deficiency is a predisposition to severe COVID-19

SARS-CoV-2 vaccinations have greatly reduced COVID-19 cases, but we must continue to develop our understanding of the nature of the disease and its effects on human immunity. Previously, we suggested that a dysregulated STAT3 pathway following SARS-Co-2 infection ultimately leads to PAI-1 activation and cascades of pathologies. The major COVID-19-associated metabolic risks (old age, hypertension, cardiovascular diseases, diabetes, and obesity) share high PAI-1 levels and could predispose certain groups to severe COVID-19 complications. In this review article, we describe the common metabolic profile that is shared between all of these high-risk groups and COVID-19. This profile not only involves high levels of PAI-1 and STAT3 as previously described, but also includes low levels of glutamine and NAD+, coupled with overproduction of hyaluronan (HA). SARS-CoV-2 infection exacerbates this metabolic imbalance and predisposes these patients to the severe pathophysiologies of COVID-19, including the involvement of NETs (neutrophil extracellular traps) and HA overproduction in the lung. While hyperinflammation due to proinflammatory cytokine overproduction has been frequently documented, it is recently recognized that the immune response is markedly suppressed in some cases by the expansion and activity of MDSCs (myeloid-derived suppressor cells) and FoxP3+ Tregs (regulatory T cells). The metabolomics profiles of severe COVID-19 patients and patients with advanced cancer are similar, and in high-risk patients, SARS-CoV-2 infection leads to aberrant STAT3 activation, which promotes a cancer-like metabolism. We propose that glutamine deficiency and overproduced HA is the central metabolic characteristic of COVID-19 and its high-risk groups. We suggest the usage of glutamine supplementation and the repurposing of cancer drugs to prevent the development of severe COVID-19 pneumonia.

Correlation of myeloid-derived suppressor cells with C-reactive protein, ferritin and lactate dehydrogenase levels in patients with severe COVID-19

The novel coronavirus disease 2019 (COVID‐19) remains a global health emergency, and understanding the interactions between the virus and host immune responses is crucial to preventing its lethal effects. The expansion of myeloid‐derived suppressor cells (MDSCs) in COVID‐19, thereby suppressing immune responses, has been described as responsible for the severity of the disease, but the correlation between MDSC subsets and COVID‐19 severity remains elusive. Therefore, we classified patients according to clinical and laboratory findings—aiming to investigate the relationship between MDSC subsets and laboratory findings such as high C‐reactive protein, ferritin and lactate dehydrogenase levels, which indicate the severity of the disease. Forty‐one patients with COVID‐19 (26 mild and 15 severe; mean age of 49.7 ± 15 years) and 26 healthy controls were included in this study. MDSCs were grouped into two major subsets—polymorphonuclear MDSCs (PMN‐MDSCs) and monocytic MDSCs—by flow cytometric immunophenotyping, and PMN‐MDSCs were defined as mature and immature, according to CD16 expressions, for the first time in COVID‐19. Total MDSCs, PMN‐MDSCs, mature PMN‐MDSCs and monocytic MDSCs were significantly higher in patients with COVID‐19 compared with the healthy controls (P < .05). Only PMN‐MDSCs and their immature PMN‐MDSC subsets were higher in the severe subgroup than in the mild subgroup. In addition, a significant correlation was found between C‐reactive protein, ferritin and lactate dehydrogenase levels and MDSCs in patients with COVID‐19. These findings suggest that MDSCs play a role in the pathogenesis of COVID‐19, while PMN‐MDSCs, especially immature PMN‐MDSCs, are associated with the severity of the disease.

The Crosstalk Between Cancer Cells and Neutrophils Enhances Hepatocellular Carcinoma Metastasis via Neutrophil Extracellular Traps-Associated Cathepsin G Component: A Potential Therapeutic Target

Background

Emerging evidences have highlighted the roles of neutrophils, as the major host microenvironment component, in the development of hepatocellular carcinoma (HCC). Neutrophils extracellular traps (NETs) produced in the infection can strengthen the behavior of cancer metastasis. Here, we investigated the roles of NETs in HCC metastasis and further explore the underlying mechanism of how NETs interact with cancer.

Methods

The neutrophils were isolated from whole blood of HCC patients and used to evaluate the formation of NETs. NET markers were detected in tissue samples, plasma and cell climbing slice. Mouse models were used to evaluate the roles of NETs in HCC metastasis in vivo, and the corresponding mechanisms were explored using in vivo and in vitro assays.

Results

An increase in the release of NETs in patients with HCC, particularly those with portal vein tumor thrombosis (PVTT). The presence of NETs in HCC tumor tissues closely correlated with a poor prognosis. Functionally, the invasion ability of HCC cells was enhanced by co-culture with HCC neutrophils, through NETs formation, while the neutrophils from a healthy donor (HD) exhibited the inhibition of the invasion ability. Furthermore, we observed an enhanced ability of forming NETs in neutrophils from HCC patients in vitro, especially patients with PVTT or extra-hepatic metastasis. An in-vivo animal study demonstrated that neutrophils of HCC facilitated the metastatic behavior towards the lung. The further mechanistic investigation unveiled that HCC cells-derived cytokine IL-8 triggered NETs formation in an NADPH oxidase-dependent manner, and NETs-associated cathepsin G (cG) promoted HCC metastasis in vitro as well as vivo. Clinically, the expression of the cG protein in tumor tissues displayed a close correlation with the disease prognosis of HCC patients.

Conclusion

Our findings implicated that the induction of NETs by HCC cells is a critical metastasis-supporting cancer–host interaction and that NETs may serve as an immune-based potential therapeutic target against HCC progression.

Serum levels of inflammatory markers CRP, ESR and albumin in relation to survival for patients with hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma is associated with several chronic inflammatory conditions. It is increasingly understood that the inflammation may be part of the carcinogenic process and prognostically important.

OBJECTIVE

To evaluate the serum levels of three inflammation markers in relation to survival in HCC patients.

METHODS

We retrospectively examined the serum levels of CRP, albumin and ESR, both singly and in combination, in relation to patient survival.

RESULTS

Survival worsened with increase in CRP or ESR or decrease in albumin levels. Combinations of CRP plus albumin or CRP plus ESR were associated with an even greater range of survival (3-fold), together with significant differences in maximum tumor diameter (PVT) and percent of patients with portal vein thrombosis (PVT). The triplet of CRP plus albumin plus ESR was associated with a sevenfold difference in survival, comparing low vs high parameter levels. These significant differences were found in patients with small or large tumors.

CONCLUSIONS

Combinations of CRP with albumin or ESR or all three parameters together significantly related to differences in survival and to differences in MTD and percent PVT, in patients with both small and large size HCCs.

Therapeutic Lowering of C-Reactive Protein

In the blood of healthy individuals C-reactive protein (CRP) is typically quite scarce, whereas its blood concentration can rise robustly and rapidly in response to tissue damage and inflammation associated with trauma and infectious and non-infectious diseases. Consequently, CRP plasma or serum levels are routinely monitored in inpatients to gauge the severity of their initial illness and injury and their subsequent response to therapy and return to health. Its clinical utility as a faithful barometer of inflammation notwithstanding, it is often wrongly concluded that the biological actions of CRP (whatever they may be) are manifested only when blood CRP is elevated. In fact over the last decades, studies done in humans and animals (e.g. human CRP transgenic and CRP knockout mice) have shown that CRP is an important mediator of biological activities even in the absence of significant blood elevation, i.e. even at baseline levels. In this review we briefly recap the history of CRP, including a description of its discovery, early clinical use, and biosynthesis at baseline and during the acute phase response. Next we overview evidence that we and others have generated using animal models of arthritis, neointimal hyperplasia, and acute kidney injury that baseline CRP exerts important biological effects. In closing we discuss the possibility that therapeutic lowering of baseline CRP might be a useful way to treat certain diseases, including cancer.

Targeting Myeloid-Derived Suppressor Cells for Premetastatic Niche Disruption After Tumor Resection

Surgical resection is a common therapeutic option for primary solid tumors. However, high cancer recurrence and metastatic rates after resection are the main cause of cancer related mortalities. This implies the existence of a “fertile soil” following surgery that facilitates colonization by circulating cancer cells. Myeloid-derived suppressor cells (MDSCs) are essential for premetastatic niche formation, and may persist in distant organs for up to 2 weeks after surgery. These postsurgical persistent lung MDSCs exhibit stronger immunosuppression compared with presurgical MDSCs, suggesting that surgery enhances MDSC function. Surgical stress and trauma trigger the secretion of systemic inflammatory cytokines, which enhance MDSC mobilization and proliferation. Additionally, damage associated molecular patterns (DAMPs) directly activate MDSCs through pattern recognition receptor-mediated signals. Surgery also increases vascular permeability, induces an increase in lysyl oxidase and extracellular matrix remodeling in lungs, that enhances MDSC mobilization. Postsurgical therapies that inhibit the induction of premetastatic niches by MDSCs promote the long-term survival of patients. Cyclooxygenase-2 inhibitors and β-blockade, or their combination, may minimize the impact of surgical stress on MDSCs. Anti-DAMPs and associated inflammatory signaling inhibitors also are potential therapies. Existing therapies under tumor-bearing conditions, such as MDSCs depletion with low-dose chemotherapy or tyrosine kinase inhibitors, MDSCs differentiation using all-trans retinoic acid, and STAT3 inhibition merit clinical evaluation during the perioperative period. In addition, combining low-dose epigenetic drugs with chemokine receptors, reversing immunosuppression through the Enhanced Recovery After Surgery protocol, repairing vascular leakage, or inhibiting extracellular matrix remodeling also may enhance the long-term survival of curative resection patients.

Income, inflammation and cancer mortality: a study of U.S. National Health and Nutrition Examination Survey mortality follow-up cohorts

Background

To estimate the relationship between inflammatory biomarkers and cancer mortality in a nationally representative sample of the U.S. population while controlling for education, occupation, and income.

Methods

Data were obtained from the U.S. National Health and Nutrition Examination Survey from 1988 to 1994 (N = 7817) and 1999–2002 (N = 2344). We fit Cox proportional hazard models to examine the relationship between C-reactive protein (CRP) and fibrinogen with cancer mortality.

Results

In the full Cox multivariate model, clinically raised CRP was associated with cancer mortality in NHANES 1988–1994 (> 0.99 mg/dL: 95%CI: 1.04–2.13). However, across two inflammatory biomarkers (CRP and Fibrinogen), two NHANES time periods (1998–1994 and 1999–2002) and three income levels (12 strata in total), Hazard ratio confidence intervals did not include the null only for one association: CRP and cancer mortality among low income participants from 1988 to 1994 (HR = 1.83, 95% CI: 1.10–3.04).

Conclusions

We find evidence that only in one unique stratum is earlier life CRP, and not fibrinogen, associated with prospective cancer mortality. After more complete control for socioeconomic confounding, CRP and fibrinogen do not predict cancer mortality in most subpopulations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-09923-8.

Expansion of Polymorphonuclear Myeloid-Derived Suppressor Cells in Patients With Gout

Gout is an inflammatory joint disease caused by monosodium urate (MSU) crystals; however, the mechanism underlying MSU-induced inflammation is unclear. Previous research has suggested that inflammation or cancer can drive the expansion of myeloid-derived suppressor cells (MDSCs). In this study, the role of MDSCs in MSU-induced gout inflammation was evaluated. A total of 28 patients with gout, and 20 healthy controls were recruited for the study. MDSCs, and their functions, were analyzed by flow cytometry and a T cell co-culture assay, respectively. We observed a higher frequency of PMN-MDSCs, and a stronger immunosuppressive function, in patients with gout compared to the controls. Moreover, circulating PMN-MDSCs were positively correlated with pathological indicators, including uric acid and C-reactive protein levels. We also demonstrated that MSU can induce significant PMN-MDSC expansion, using in vivo and in vitro experiments. Finally, MSU-induced PMN-MDSCs produced higher levels of IL-1β, which mediated gout inflammatory progression. Our results demonstrate that MSU modulates the expansion and suppressive function of PMN-MDSCs, providing insights into a novel mechanism underlying the pathogenesis of MSU-induced gout. Thus, MDSCs may be useful for the development of novel therapeutic strategies for the prevention and treatment of gout.

Obesity-Associated Myeloid-Derived Suppressor Cells Promote Apoptosis of Tumor-Infiltrating CD8 T Cells and Immunotherapy Resistance in Breast Cancer

Nearly 70% of adults in the US are currently overweight or obese. Despite such high prevalence, the impact of obesity on antitumor immunity and immunotherapy outcomes remains incompletely understood, particularly in patients with breast cancer. Here, we addressed these gaps in knowledge using two murine models of breast cancer combined with diet-induced obesity. We report that obesity increases CXCL1 concentrations in the mammary tumor microenvironment, driving CXCR2-mediated chemotaxis and accumulation of granulocytic myeloid-derived suppressor cells (G-MDSCs) expressing Fas ligand (FasL). Obesity simultaneously promotes hyperactivation of CD8 tumor-infiltrating lymphocytes (TILs), as evidenced by increased expression of CD44, PD-1, Ki-67, IFNγ, and the death receptor Fas. Accordingly, G-MDSCs induce Fas/FasL-mediated apoptosis of CD8 T cells ex vivo and in vivo. These changes promote immunotherapy resistance in obese mice. Disruption of CXCR2-mediated G-MDSC chemotaxis in obese mice is sufficient to limit intratumoral G-MDSC accumulation and improve immunotherapy outcomes. The translational relevance of our findings is demonstrated by transcriptomic analyses of human breast tumor tissues, which reveal positive associations between CXCL1 expression and body mass index, poor survival, and a MDSC gene signature. Further, this MDSC gene signature is positively associated with FASLG expression. Thus, we have identified a pathway wherein obesity leads to increased intratumoral CXCL1 concentrations, which promotes CXCR2-mediated accumulation of FasL⁺ G-MDSCs, resulting in heightened CD8 TIL apoptosis and immunotherapy resistance. Disruption of this pathway may improve immunotherapy outcomes in patients with breast cancer and obesity.

Recent advances in myeloid-derived suppressor cell biology

In recent years, studying the role of myeloid-derived suppressor cells (MDSCs) in many pathological inflammatory conditions has become a very active research area. Although the role of MDSCs in cancer is relatively well established, their role in non-cancerous pathological conditions remains in its infancy resulting in much confusion. Our objectives in this review are to address some recent advances in MDSC research in order to minimize such confusion and to provide an insight into their function in the context of other diseases. The following topics will be specifically focused upon: (1) definition and characterization of MDSCs; (2) whether all MDSC populations consist of immature cells; (3) technical issues in MDSC isolation, estimation and characterization; (4) the origin of MDSCs and their anatomical distribution in health and disease; (5) mediators of MDSC expansion and accumulation; (6) factors that determine the expansion of one MDSC population over the other; (7) the Yin and Yang roles of MDSCs. Moreover, the functions of MDSCs will be addressed throughout the text.

Role of the Neutrophil in the Pathogenesis of Advanced Cancer and Impaired Responsiveness to Therapy

Notwithstanding the well-recognized involvement of chronic neutrophilic inflammation in the initiation phase of many types of epithelial cancers, a growing body of evidence has also implicated these cells in the pathogenesis of the later phases of cancer development, specifically progression and spread. In this setting, established tumors have a propensity to induce myelopoiesis and to recruit neutrophils to the tumor microenvironment (TME), where these cells undergo reprogramming and transitioning to myeloid-derived suppressor cells (MDSCs) with a pro-tumorigenic phenotype. In the TME, these MDSCs, via the production of a broad range of mediators, not only attenuate the anti-tumor activity of tumor-infiltrating lymphocytes, but also exclude these cells from the TME. Realization of the pro-tumorigenic activities of MDSCs of neutrophilic origin has resulted in the development of a range of adjunctive strategies targeting the recruitment of these cells and/or the harmful activities of their mediators of immunosuppression. Most of these are in the pre-clinical or very early clinical stages of evaluation. Notable exceptions, however, are several pharmacologic, allosteric inhibitors of neutrophil/MDSC CXCR1/2 receptors. These agents have entered late-stage clinical assessment as adjuncts to either chemotherapy or inhibitory immune checkpoint-targeted therapy in patients with various types of advanced malignancy. The current review updates the origins and identities of MDSCs of neutrophilic origin and their spectrum of immunosuppressive mediators, as well as current and pipeline MDSC-targeted strategies as potential adjuncts to cancer therapies. These sections are preceded by a consideration of the carcinogenic potential of neutrophils.

Overcoming immunotherapeutic resistance by targeting the cancer inflammation cycle

Inflammation is a hallmark of cancer and supports tumor growth, proliferation, and metastasis, but also inhibits T cell immunosurveillance and the efficacy of immunotherapy. The biology of cancer inflammation is defined by a cycle of distinct immunological steps that begins during disease conception with the release of inflammatory soluble factors. These factors communicate with host organs to trigger bone marrow mobilization of myeloid cells, trafficking of myeloid cells to the tumor, and differentiation of myeloid cells within the tumor bed. Tumor-infiltrating myeloid cells then orchestrate an immunosuppressive microenvironment and assist in sustaining a vicious cycle of inflammation that co-evolves with tumor cells. This Cancer-Inflammation Cycle acts as a rheostat or "inflammostat" that impinges upon T cell immunosurveillance and prevents the development of productive anti-tumor immunity. Here, we define the major nodes of the Cancer-Inflammation Cycle and describe their impact on T cell immunosurveillance in cancer. Additionally, we discuss emerging pre-clinical and clinical data suggesting that intervening upon the Cancer-Inflammation Cycle will be a necessary step for broadening the potential of immunotherapy in cancer.