Iron oxide nanoparticles (IONPs) have emerging anticancer applications via polarizing tumor-associated macrophages from tumor-promoting phenotype (M2) to tumor-suppressing phenotype (M1). However, ...the underlying mechanism and structure–function relationship remain unclear. We report magnetite IONPs are more effective compared to hematite in M1 polarization and tumor suppression. Moreover, magnetite IONPs specifically rely on interferon regulatory factor 5 signaling pathway for M1 polarization and down-regulate M2-assoicated arginase-1. This study provides new understandings and paves the way for designing advanced iron-based anticancer technologies.
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IJS, KILJ, NUK, PNG, UL, UM
IgG antibodies cause inflammation and organ damage in autoimmune diseases such as systemic lupus erythematosus (SLE). We investigated the metabolic profile of macrophages isolated from inflamed ...tissues in immune complex (IC)-associated diseases, including SLE and rheumatoid arthritis, and following IgG Fcγ receptor cross-linking. We found that human and mouse macrophages undergo a switch to glycolysis in response to IgG IC stimulation, mirroring macrophage metabolic changes in inflamed tissue in vivo. This metabolic reprogramming was required to generate a number of proinflammatory mediators, including IL-1β, and was dependent on mTOR and hypoxia-inducible factor (HIF)1α. Inhibition of glycolysis, or genetic depletion of HIF1α, attenuated IgG IC-induced activation of macrophages in vitro, including primary human kidney macrophages. In vivo, glycolysis inhibition led to a reduction in kidney macrophage IL-1β and reduced neutrophil recruitment in a murine model of antibody-mediated nephritis. Together, our data reveal the molecular mechanisms underpinning FcγR-mediated metabolic reprogramming in macrophages and suggest a therapeutic strategy for autoantibody-induced inflammation, including lupus nephritis.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Macrophages play a central role in intestinal immunity, but inappropriate macrophage activation is associated with inflammatory bowel disease (IBD). Here, we identify granulocyte-macrophage colony ...stimulating factor (GM-CSF) as a critical regulator of intestinal macrophage activation in patients with IBD and mice with dextran sodium sulfate (DSS)-induced colitis. We find that GM-CSF drives the maturation and polarization of inflammatory intestinal macrophages, promoting anti-microbial functions while suppressing wound-healing transcriptional programs. Group 3 innate lymphoid cells (ILC3s) are a major source of GM-CSF in intestinal inflammation, with a strong positive correlation observed between ILC or CSF2 transcripts and M1 macrophage signatures in IBD mucosal biopsies. Furthermore, GM-CSF-dependent macrophage polarization results in a positive feedback loop that augmented ILC3 activation and type 17 immunity. Together, our data reveal an important role for GM-CSF-mediated ILC-macrophage crosstalk in calibrating intestinal macrophage phenotype to enhance anti-bacterial responses, while inhibiting pro-repair functions associated with fibrosis and stricturing, with important clinical implications.
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•ILCs are a major source of GM-CSF, a critical regulator of gut inflammatory macrophages•GM-CSF promotes ILC-macrophage crosstalk and augments type 17 and barrier immunity•GM-CSF-induced macrophages are protective during infection but drive inflammatory colitis•GM-CSF suppresses wound-healing macrophage response associated with intestinal fibrosis
Castro-Dopico et al. identify GM-CSF as a major upstream regulator of intestinal inflammatory macrophages, with ILC-derived GM-CSF polarizing macrophages toward a glycolytic, anti-microbial phenotype while suppressing wound-healing, pro-fibrotic activity. GM-CSF initiates further ILC-macrophage crosstalk, amplifying ILC3 activation and type 17 immunity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Acute kidney injury (AKI) is a serious condition affecting one fifth of hospital inpatients. B lymphocytes have immunological functions beyond Ab production and may produce cytokines and chemokines ...that modulate inflammation. In this study, we investigated leukocyte responses in a mouse model of AKI and observed an increase in circulating and kidney B cells, particularly a B220
subset, following AKI. We found that B cells produce the chemokine CCL7, with the potential to facilitate neutrophil and monocyte recruitment to the injured kidney. Siglec-G-deficient mice, which have increased numbers of B220
innate B cells and a lower B cell activation threshold, had increased
transcripts, increased neutrophil and monocyte numbers in the kidney, and more severe AKI. CCL7 blockade in mice reduced myeloid cell infiltration into the kidney and ameliorated AKI. In two independent cohorts of human patients with AKI, we observed significantly higher
transcripts compared with controls, and in a third cohort, we observed an increase in urinary CCL7 levels in AKI, supporting the clinical importance of this pathway. Together, our data suggest that B cells contribute to early sterile inflammation in AKI via the production of leukocyte-recruiting chemokines.
Endogenous DNA damage can perturb transcription, triggering a multifaceted cellular response that repairs the damage, degrades RNA polymerase II and shuts down global transcription
. This response is ...absent in the human disease Cockayne syndrome, which is caused by loss of the Cockayne syndrome A (CSA) or CSB proteins
. However, the source of endogenous DNA damage and how this leads to the prominent degenerative features of this disease remain unknown. Here we find that endogenous formaldehyde impedes transcription, with marked physiological consequences. Mice deficient in formaldehyde clearance (Adh5
) and CSB (Csb
; Csb is also known as Ercc6) develop cachexia and neurodegeneration, and succumb to kidney failure, features that resemble human Cockayne syndrome. Using single-cell RNA sequencing, we find that formaldehyde-driven transcriptional stress stimulates the expression of the anorexiogenic peptide GDF15 by a subset of kidney proximal tubule cells. Blocking this response with an anti-GDF15 antibody alleviates cachexia in Adh5
Csb
mice. Therefore, CSB provides protection to the kidney and brain against DNA damage caused by endogenous formaldehyde, while also suppressing an anorexic endocrine signal. The activation of this signal might contribute to the cachexia observed in Cockayne syndrome as well as chemotherapy-induced anorectic weight loss. A plausible evolutionary purpose for such a response is to ensure aversion to genotoxins in food.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
B cells play a central role in humoral immunity but also have antibody-independent functions. Studies to date have focused on B cells in blood and secondary lymphoid organs but whether B cells reside ...in non-lymphoid organs (NLO) in homeostasis is unknown. Here we identify, using intravenous labeling and parabiosis, a bona-fide tissue-resident B cell population in lung, liver, kidney and urinary bladder, a substantial proportion of which are B-1a cells. Tissue-resident B cells are present in neonatal tissues and also in germ-free mice NLOs, albeit in lower numbers than in specific pathogen-free mice and following co-housing with 'pet-store' mice. They spatially co-localise with macrophages and regulate their polarization and function, promoting an anti-inflammatory phenotype, in-part via interleukin-10 production, with effects on bacterial clearance during urinary tract infection. Thus, our data reveal a critical role for tissue-resident B cells in determining the homeostatic 'inflammatory set-point' of myeloid cells, with important consequences for tissue immunity.
Improving the efficacy of immune checkpoint therapies will require a better understanding of how immune cells are recruited and sustained in tumors. Here, we used the photoconversion of the tumor ...immune cell compartment to identify newly entering lymphocytes, determine how they change over time, and investigate their egress from the tumor. Combining single-cell transcriptomics and flow cytometry, we found that while a diverse mix of CD8 T cell subsets enter the tumor, all CD8 T cells retained within this environment for more than 72 h developed an exhausted phenotype, revealing the rapid establishment of this program. Rather than forming tumor-resident populations, non-effector subsets, which express TCF-1 and include memory and stem-like cells, were continuously recruited into the tumor, but this recruitment was balanced by concurrent egress to the tumor-draining lymph node. Thus, the TCF-1+ CD8 T cell niche in tumors is highly dynamic, with the circulation of cells between the tumor and peripheral lymphoid tissue to bridge systemic and intratumoral responses.
Tumour dendritic cells (DCs) internalise antigen and upregulate CCR7, which directs their migration to tumour-draining lymph nodes (dLN). CCR7 expression is coupled to an activation programme ...enriched in regulatory molecule expression, including PD-L1. However, the spatio-temporal dynamics of CCR7
DCs in anti-tumour immune responses remain unclear. Here, we use photoconvertible mice to precisely track DC migration. We report that CCR7
DCs are the dominant DC population that migrate to the dLN, but a subset remains tumour-resident despite CCR7 expression. These tumour-retained CCR7
DCs are phenotypically and transcriptionally distinct from their dLN counterparts and heterogeneous. Moreover, they progressively downregulate the expression of antigen presentation and pro-inflammatory transcripts with more prolonged tumour dwell-time. Tumour-residing CCR7
DCs co-localise with PD-1
CD8
T cells in human and murine solid tumours, and following anti-PD-L1 treatment, upregulate stimulatory molecules including OX40L, thereby augmenting anti-tumour cytolytic activity. Altogether, these data uncover previously unappreciated heterogeneity in CCR7
DCs that may underpin a variable capacity to support intratumoural cytotoxic T cells.
Squamous cell carcinoma (SCC) is a common type of skin cancer that typically arises from premalignant precursor lesions named actinic keratoses (AK). Chronic inflammation is a well-known promoter of ...skin cancer progression. AK and SCC have been associated with an overabundance of the bacterium
(
). Certain secreted products from
are known to promote cutaneous pro-inflammatory responses; however, not all
strains produce these. As inflammation plays a key role in SCC development, we investigated the pro-inflammatory potential and toxin secretion profiles of skin-cancer associated
. Sterile culture supernatants ("secretomes") of
clinical strains isolated from AK and SCC were applied to human keratinocytes
Some
secretomes induced keratinocytes to overexpress inflammatory mediators that have been linked to skin carcinogenesis, including IL-6, IL-8, and TNFα. A large phenotypic variation between the tested clinical strains was observed. Strains that are highly pro-inflammatory
also caused more pronounced skin inflammation in mice. Proteomic characterization of
secretomes using mass spectrometry established that specific
enzymes and cytolytic toxins, including hemolysins, phenol-soluble modulins, and serine proteases, as well as currently uncharacterized proteins, correlate with the pro-inflammatory
phenotype. This study is the first to describe the toxin secretion profiles of AK and SCC-associated
, and their potential to induce a pro-inflammatory environment in the skin. Further studies are needed to establish whether these
products promote SCC development by mediating chronic inflammation.
Oral cavity Squamous Cell Carcinoma (OCSCC) is a common form of head and neck cancer throughout the developed and developing world. However, the etiology of OCSCC is still unclear. Here, we explored ...the extent to which tobacco use, Human Papillomavirus (HPV) infection and genetic and transcriptomic changes contributed to the oncogenesis of OCSCC. In a prospective observational study, we analysed fresh tissue biopsies from 45 OCSCC collected from 51 subjects presenting with OCSCC to the Brisbane Head and Neck Clinics between 2013 and 2015. Exploration of the genetic and transcriptomic landscape of the biopsies were performed using RNA sequencing (RNA-seq) and whole exome sequencing. HPV associated tumours were determined using p16 staining of histological sections and RNA sequencing. Patient demographics including tumor location within the oral cavity, and history of tobacco and alcohol use were correlated with genomic and transcriptomics analyses. About 4.5% of OCSCC were HPV associated. The most frequent mutations in the OCSCC samples were in the TP53 and CDKN2A genes, but no association of specific mutations with HPV or tobacco use was observed. Using weighted gene co-expression network analysis to explore the RNA-seq data, tumors from participants with a history of tobacco use showed a significant trend towards increased mammalian target of Rapamycin (mTOR) signaling and decreased mitochondrial respiration. In conclusion, HPV was shown to be an uncommon association with OCSCC and changes in TP53 transcriptional regulation, mTOR signaling and mitochondrial function were associated with a history of tobacco use. Larger data sets will be required to enable detection of differences which may help with development of personalized therapeutics in the future.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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