Differential immunological effects of silica nanoparticles on peripheral blood mononuclear cells of silicosis patients and controls

Silica-induced ROS in alveolar macrophages and its role on the formation of pulmonary fibrosis via polarizing macrophages into M2 phenotype: a review

Alveolar macrophages (AMs), the first line against the invasion of foreign invaders, play a predominant role in the pathogenesis of silicosis. Studies have shown that inhaled silica dust is recognized and engulfed by AMs, resulting in the production of large amounts of silica-induced reactive oxygen species (ROS), including particle-derived ROS and macrophage-derived ROS. These ROS change the microenvironment of the AMs where the macrophage phenotype is stimulated to swift from M0 to M1 and/or M2, and ultimately emerge as the M2 phenotype to trigger silicosis. This is a complex process accompanied by various molecular biological events. Unfortunately, the detailed processes and mechanisms have not been systematically described. In this review, we first systematically introduce the process of ROS induced by silica in AMs. Then, describe the role and molecular mechanism of M2-type macrophage polarization caused by silica-induced ROS. Finally, we review the mechanism of pulmonary fibrosis induced by M2 polarized AMs. We conclude that silica-induced ROS initiate the fibrotic process of silicosis by inducing macrophage into M2 phenotype, and that targeted intervention of silica-induced ROS in AMs can reprogram the macrophage polarization and ameliorate the pathogenesis of silicosis.

Role of physicochemical properties in silica nanoparticle-mediated immunostimulation

Immunostimulation caused by nanoparticles may be beneficial or adverse depending on their intended application. Activation of immune cells is beneficial for indications targeting the immune system for therapeutic purposes, such as tumor microenvironment reprogramming, immunotherapy, and vaccines. When it is unwanted, however, immunostimulation may lead to excessive inflammation, cytokine storm, and hypersensitivity reactions. The increasing use of silica nanoparticles (SiNPs) for the delivery of drugs, imaging agents, and antigens warrants preclinical studies aimed at understanding carrier-mediated effects on the number, activation status, and function of immune cell subsets. Herein, we present an in vitro study utilizing primary human peripheral blood mononuclear cells (PBMC) to investigate the proinflammatory properties of four types of SiNPs varying in size and porosity. Cytokine analysis was performed in resting and LPS-primed PBMC cultures to understand the ability of silica nanoparticles to induce de novo and exaggerate preexisting inflammation, respectively. Changes in the number and activation status of lymphoid and myeloid cells were studied by flow cytometry to gain further insight into SiNP-mediated immunostimulation. Nonporous SiNPs were found to be more proinflammatory than mesoporous SiNPs, and larger-sized particles induced greater cytokine response. LPS-primed PBMC resulted in increased susceptibility to SiNPs. Immunophenotyping analysis of SiNP-treated PBMC resulted in T and B lymphocyte, natural killer cell, and dendritic cell activation. Additionally, a loss of regulatory T cells and an increase in γδ TCR T cell population were observed with all particles. These findings have implications for the utility of SiNPs for the delivery of drugs and imaging agents.

Inflammatory biomarkers in workers exposed to silica dust: integrative review

Introduction

Silicosis is a severe, progressive, fibrosing lung disease caused by the inhalation of free crystalline silica dust; it is the most prevalent pneumoconiosis worldwide. It is associated with a chronic inflammatory process triggered by silica particles in the pulmonary alveoli. Alveolar macrophages play a key role in the pathogenesis of silicosis, with additional contributions from polymorphonuclear cells, epithelial cells, and the release of inflammatory mediators.

Objectives

To compile updated information on key inflammatory biomarkers in workers exposed to silica.

Methods

Integrative review to discuss the state of the art regarding major biomarkers used in the early diagnosis and search for treatments for workers exposed to silica. The SciELO and PubMed databases were searched for articles published from 2012 to 2022.

Results

The search strategy retrieved 111 articles, of which 29 were duplicates across the two databases. Of the 82 remaining articles, 67 were excluded after screening of abstracts (review articles, articles on polymorphisms/genetics, and animal studies). Fifteen articles were read in full; of these, two were eliminated as they did not meet the inclusion criteria. Of the 13 articles retained for analysis, 12 were cross-sectional and only 1 was a prospective observational study.

Conclusions

This integrative review identified the importance of cytokines in silica-related illness. This can help encourage future research and guide the development of new therapies and interventions for silicosis.

Analysis of Immune Cell Subsets in Peripheral Blood from Patients with Engineered Stone Silica-Induced Lung Inflammation

Silicosis caused by engineered stone (ES-silicosis) is an emerging worldwide issue characterized by inflammation and fibrosis in the lungs. To our knowledge, only a few reports have investigated leukocyte/lymphocyte subsets in ES-silicosis patients. The present study was designed to explore the proportions of the main lymphocyte subsets in ES-silicosis patients stratified into two groups, one with simple silicosis (SS) and the other with a more advanced state of the disease, defined as progressive massive fibrosis (PMF). The proportions of B (memory and plasmablasts) cells, T (helper, cytotoxic, regulatory) cells, and natural killer (NK) (regulatory and cytotoxic) cells were investigated by multiparameter flow cytometry in 91 ES-silicosis patients (53 SS patients and 38 PMF patients) and 22 healthy controls (HC). Although the total number of leukocytes did not differ between the groups studied, lymphopenia was observed in patients compared to healthy controls. Compared with those in healthy controls, the proportions of memory B cells, naïve helper T cells, and the CD4+/CD8+ T cells' ratio in the peripheral blood of patients with silicosis were significantly decreased, while the percentages of plasma cells, memory helper T cells, and regulatory T cells were significantly increased. For the NK cell subsets, no significant differences were found between the groups studied. These results revealed altered cellular immune processes in the peripheral blood of patients with ES-silicosis and provided further insight into silicosis pathogenesis.

Silica nanoparticles alleviate the immunosuppression, oxidative stress, biochemical, behavioral, and histopathological alterations induced by Aeromonas veronii infection in African catfish (Clarias gariepinus)

In the aquaculture industry, silica nanoparticles (SiNPs) have great significance, mainly for confronting diseases. Therefore, the present study aims to assess the antibacterial efficiency of SiNPs as a versatile trial against Aeromonas veronii infection in African catfish (Clarias gariepinus). Further, we investigated the influence of SiNPs in palliating the immune-antioxidant stress biochemical, ethological, and histopathological alterations induced by A. veronii. The experiment was conducted for 10 days, and about 120 fish were distributed into four groups at random, with 30 fish each. The first group is a control that was neither exposed to infection nor SiNPs. The second group (SiNPs) was vulnerable to SiNPs at a concentration of 20 mg/L in water. The third group was experimentally infected with A. veronii at a concentration of 1.5 × 107 CFU/mL. The fourth group (A. veronii + SiNPs) was exposed to SiNPs and infected with A. veronii. Results outlined that A. veronii infection induced behavioral alterations and suppression of immune-antioxidant responses that appeared as a clear decline in protein profile indices, complement 3, lysozyme activity, glutathione peroxidase, and total antioxidant capacity. The kidney and liver function biomarkers (creatinine, urea, alkaline phosphatase, and alanine aminotransferase) and lipid peroxide (malondialdehyde) were substantially increased in the A. veronii group, with marked histopathological changes and immunohistochemical alterations in these tissues. Interestingly, the exposure to SiNPs resulted in a clear improvement in all measured biomarkers and a noticeable regeneration of the histopathological changes. Overall, it will establish that SiNPs are a new, successful tool for opposing immunological, antioxidant, physiological, and histopathological alterations induced by A. veronii infection.

Macrophages reprogramming improves immunotherapy of IL-33 in peritoneal metastasis of gastric cancer

Peritoneal metastasis (PM) has a suppressive tumor immune microenvironment (TIME) that limits the effects of immunotherapy. This study aimed to investigate the immunomodulatory effects of intraperitoneal administration of IL-33, a cytokine that is reported to potentiate antitumor immunity and inhibit metastasis. We found survival was significantly prolonged in patients with high IL-33 mRNA expression. In immunocompetent mice, intraperitoneal administration of IL-33 could induce a celiac inflammatory environment, activate immunologic effector cells, and reverse the immunosuppressive tumor microenvironment, which effectively delayed tumor progression and PM of gastric cancer. Mechanistically, IL-33 could induce M2 polarization by activating p38-GATA-binding protein 3 signaling. IL-33 combined with anti-CSF1R or p38 inhibitor to regulate tumor-associated macrophages (TAMs) had a synergistic antitumor effect. Inducing a local inflammatory milieu by IL-33 administration provided a novel approach for treating peritoneal metastasis, which, when combined with TAM reprogramming to reshape TIME, can achieve better treatment efficacy.

ONCOBREAST-TEST Is a Quick Diagnostic, Prognostic and Predictive Method of Response to Systemic Treatment

ONCOBREAST-TEST is a diagnostic and therapeutic procedure that is part of the comprehensive care of a patient with breast cancer.: Chemosensitivity of cancer cells was assessed using the MTT test, morphological assessment of cells, LDH activity in the culture medium, and flow cytometry technique (apoptosis, proliferation, CD24, CD44, GATA3, cytokeratin, Ki-67). Diagnostic tools included panels of simple tests which could be used to accurately predict the chemosensitivity of tumor cells previously isolated from a patient, even before actual chemotherapy. The proposed procedure allows for a simple (based on MTT results, cell morphology, LDH concentration), minimally invasive, quick, and accurate assessment of the sensitivity of breast cancer cells to the drugs used and, to select the most effective treatment plan as part of personalized therapy. In a patient with NOS G3, the most promising therapy will be docetaxel with cyclophosphamide and in the case of a patient with NOS G1, paclitaxel alone and in combination with trastuzumab. The implementation of such a procedure would undoubtedly increase the effectiveness of chemotherapy, reduce side effects by excluding drugs that are ineffective before using them, protect the patient's health, and shorten the treatment time, bringing economic and social benefits.

ZC3H4 governs epithelial cell migration through ROCK/p-PYK2/p-MLC2 pathway in silica-induced pulmonary fibrosis

BACKGROUND

Increased epithelial migration capacity is a key step accompanying epithelial-mesenchymal transition (EMT). Our lab has described that ZC3H4 mediated EMT in silicosis. Here, we aimed to explore the mechanisms of ZC3H4 by which to stimulate epithelial cell migration.

METHODS

Silicon dioxide (SiO2)-induced pulmonary fibrosis (PF) animal models were administered by intratracheal instillation in C57BL/6 J mice. Pathological analysis and 2D migration assay were established to uncover the pulmonary fibrotic lesions and epithelial cell migration, respectively. Inhibitors targeting ROCK/p-PYK2/p-MLC2 and CRISPR/Cas9 plasmids targeting ZC3H4 were administrated to explore the signaling pathways.

RESULTS

1) SiO2 upregulated epithelial migration in pulmonary fibrotic lesions. 2) ZC3H4 modulated SiO2-induced epithelial migration. 3) ZC3H4 governed epithelial migration through ROCK/p-PYK2/p-MLC2 signaling pathway.

CONCLUSIONS

ZC3H4 regulates epithelial migration through the ROCK/p-PYK2/p-MLC2 signaling pathway, providing the possibility that molecular drugs targeting ZC3H4-overexpression may exert effects on pulmonary fibrosis induced by silica.

Comparing [3H] thymidine LPT and CFSE assay to assess lymphocyte proliferation in beryllium-exposed sarcoidosis patients

The detection of antigen specific lymphocyte responses plays a vital role in the diagnosis of various diseases. Beryllium-specific [3H] thymidine lymphocyte proliferation test (LPT) is regarded as a gold standard in identifying chronic beryllium disease (CBD) cases. Alternatively, flow cytometric based carboxyfluorescein succinimidyl ester (CFSE) assay, has several benefits as opposed to LPT, since it further permits both phenotypical characterization and functional analysis of proliferating lymphocyte subsets. The suitability of both LPT and CFSE assay to therefore detect beryllium sensitivity in a group of Be-exposed sarcoidosis patients with suspected beryllium exposure, was evaluated in this study. The clinical relevance of the test responses, expressed as stimulation indices (SI), were additionally compared on a group and individual level. Agreement in clinical interpretation of the test responses between both methods was observed in 4 out of 5 recruited patients, when considering total lymphocyte population i.e., CD3+ and CD19+-cells combined, on day 7 and with CFSE-SI >1.5, when compared with LPT-SI >2.5. Variability in responses to beryllium was additionally evaluated in Be-exposed sarcoidosis patients and compared with healthy controls. To conclude, both LPT and CFSE assay are suitable assays to detect Be sensitivity in Be-exposed sarcoidosis patients. At the same time, flow cytometric based CFSE assay has the edge over LPT in identifying the relevant proliferating lymphocyte populations. As such, when comparing two or more methods, factors that contribute to assay variability such as timepoints, lymphocyte subsets and number of replicates should always be accounted for.