Fluids and barriers of the CNS
Errede, M;Annese, T;Petrosino, V;Longo, G;Girolamo, F;de Trizio, I;d'Amati, A;Uccelli, A;Kerlero de Rosbo, N;Virgintino, D;
PMID: 36042496 | DOI: 10.1186/s12987-022-00365-5
In myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), several areas of demyelination are detectable in mouse cerebral cortex, where neuroinflammation events are associated with scarce inflammatory infiltrates and blood-brain barrier (BBB) impairment. In this condition, the administration of mesenchymal stem cells (MSCs) controls neuroinflammation, attenuating astrogliosis and promoting the acquisition of stem cell traits by astrocytes. To contribute to the understanding of the mechanisms involved in the pathogenesis of EAE in gray matter and in the reverting effects of MSC treatment, the neocortex of EAE-affected mice was investigated by analyzing the cellular source(s) of chemokine CCL2, a molecule involved in immune cell recruitment and BBB-microvessel leakage.The study was carried out by immunohistochemistry (IHC) and dual RNAscope IHC/in situ hybridization methods, using astrocyte, NG2-glia, macrophage/microglia, and microglia elective markers combined with CCL2.The results showed that in EAE-affected mice, hypertrophic microglia are the primary source of CCL2, surround the cortex neurons and the damaged BBB microvessels. In EAE-affected mice treated with MSCs, microgliosis appeared diminished very soon (6 h) after treatment, an observation that was long-lasting (tested after 10 days). This was associated with a reduced CCL2 expression and with apparently preserved/restored BBB features. In conclusion, the hallmark of EAE in the mouse neocortex is a condition of microgliosis characterized by high levels of CCL2 expression.This finding supports relevant pathogenetic and clinical aspects of the human disease, while the demonstrated early control of neuroinflammation and BBB permeability exerted by treatment with MSCs may have important therapeutic implications.
Kersten K, Coffelt SB, Hoogstraat M, Verstegen NJM, Vrijland K, Ciampricotti M, Doornebal CW, Hau CS, Wellenstein MD, Salvagno C, Doshi P, Lips EH, Wessels LFH, de Visser KE.
PMID: - | DOI: 10.1080/2162402X.2017.1334744
Patients with primary solid malignancies frequently exhibit signs of systemic inflammation. Notably, elevated levels of neutrophils and their associated soluble mediators are regularly observed in cancer patients, and correlate with reduced survival and increased metastasis formation. Recently, we demonstrated a mechanistic link between mammary tumor-induced IL17-producing γδ T cells, systemic expansion of immunosuppressive neutrophils and metastasis formation in a genetically engineered mouse model for invasive breast cancer. How tumors orchestrate this systemic inflammatory cascade to facilitate dissemination remains unclear. Here we show that activation of this cascade relies on CCL2-mediated induction of IL1β in tumor-associated macrophages. In line with these findings, expression of CCL2 positively correlates with IL1Β and macrophage markers in human breast tumors. We demonstrate that blockade of CCL2 in mammary tumor-bearing mice results in reduced IL17 production by γδ T cells, decreased neutrophil expansion and enhanced CD8+ T cell activity. These results highlight a new role for CCL2 in facilitating the breast cancer-induced pro-metastatic systemic inflammatory γδ T cell – IL17 – neutrophil axis.
Translatomic analysis of regenerating and degenerating spinal motor neurons in injury and ALS
Shadrach, J;Stansberry, W;Milen, A;Ives, R;Fogarty, E;Antonellis, A;Pierchala, B;
| DOI: 10.1016/j.isci.2021.102700
The neuromuscular junction is a synapse critical for muscle strength and coordinated motor function. Unlike CNS injuries, motor neurons mount robust regenerative responses after peripheral nerve injuries. Conversely, motor neurons selectively degenerate in diseases such as amyotrophic lateral sclerosis (ALS). To assess how these insults affect motor neurons in vivo, we performed ribosomal profiling of mouse motor neurons. Motor neuron-specific transcripts were isolated from spinal cords following sciatic nerve crush, a model of acute injury and regeneration, and in the SOD1G93A ALS model. Of the 267 transcripts upregulated after nerve crush, 38% were also upregulated in SOD1G93A motor neurons. However, most upregulated genes in injured and ALS motor neurons were context specific. Some of the most significantly upregulated transcripts in both paradigms were chemokines such as Ccl2 and Ccl7, suggesting an important role for neuroimmune modulation. Collectively these data will aid in defining pro-regenerative and pro-degenerative mechanisms in motor neurons.
Xue T, Wang WG, Zhou XY, Li XQ.
PMID: - | DOI: 10.1016/j.pathol.2018.08.011
Summary Programmed cell death ligand 1 (PD-L1) is upregulated in various types of haematological malignancies and is associated with immunosuppression. This study aimed to investigate the expression pattern of PD-L1 in Epstein–Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL). We retrospectively analysed clinicopathological characteristics in 30 cases of EBV-positive DLBCL and immunohistochemically evaluated the level of membrane bound PD-L1 protein. Twenty-eight cases expressed PD-L1 protein 15 of which showed an intense positive staining. In addition, we investigated the relationships between PD-L1 protein and PD-L1 mRNA and MYC, respectively. The expression level of PD-L1 protein was not fully parallel with PD-L1 mRNA, and no significant correlation was observed between PD-L1 protein and MYC. Notably, PD-L1 mRNA was at a low dosage, which indicated that there might be other mechanisms inducing the overexpression of membrane bound PD-L1 protein apart from genetic alterations. Furthermore, the low expression level of MYC may not interfere with the PD-L1 protein expression in EBV-positive DLBCL. In conclusion, overexpression of PD-L1 protein can be observed in EBV-positive DLBCL, and the level was non-parallel with both PD-L1 mRNA and MYC. Moreover, we emphasise that immunohistochemistry is a clinically reasonable method for screening formalin fixed, paraffin embedded (FFPE) tumour samples in this entity.
Journal of immunology (Baltimore, Md. : 1950)
Manivasagam, S;Williams, JL;Vollmer, LL;Bollman, B;Bartleson, JM;Ai, S;Wu, GF;Klein, RS;
PMID: 35181638 | DOI: 10.4049/jimmunol.2101041
Type III IFNs (IFNLs) are newly discovered cytokines, acting at epithelial and other barriers, that exert immunomodulatory functions in addition to their primary roles in antiviral defense. In this study, we define a role for IFNLs in maintaining autoreactive T cell effector function and limiting recovery in a murine model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis. Genetic or Ab-based neutralization of the IFNL receptor (IFNLR) resulted in lack of disease maintenance during experimental autoimmune encephalomyelitis, with loss of CNS Th1 effector responses and limited axonal injury. Phenotypic effects of IFNLR signaling were traced to increased APC function, with associated increase in T cell production of IFN-γ and GM-CSF. Consistent with this, IFNL levels within lesions of CNS tissues derived from patients with MS were elevated compared with MS normal-appearing white matter. Furthermore, expression of IFNLR was selectively elevated in MS active lesions compared with inactive lesions or normal-appearing white matter. These findings suggest IFNL signaling as a potential therapeutic target to prevent chronic autoimmune neuroinflammation.
Guo L, Li W, Zhu X, Ling Y, Qiu T, Dong L, Fang Y, Yang H, Ying J.
PMID: 27390646 | DOI: 10.1186/s40064-016-2513-x
Abstract
PURPOSE:
To estimate the therapeutic potential of PD-L1 inhibition in breast cancer, we evaluated the prevalence and significance of PD-L1 protein expression with a validated antibody and CD274 gene alternation in a large cohort of triple negative breast cancer (TNBC) and correlated with clinicopathological data and patients overall survival.
METHODS:
Immunohistochemistry and in situ mRNA hybridization was used to detect PD-L1 protein and mRNA expression in tumor tissues from 183 TNBC patients respectively. Fluorescence in situ hybridization analysis was performed on PD-L1 strong expression samples to assess copy number on chromosome 9p24.1 of CD274 gene.
RESULTS:
Expression of PD-L1 by immune cells was observed in 4.9 % of TNBC, while expression by tumor cells accounted for 8.7 %. There was a high concordance in PD-L1 protein expression and PDL1 mRNA expression. Samples with PD-L1 strong expression were found to have a CD274 gene copy number gain. PD-L1 expression was correlated with higher tumor grade, but was independent of menopausal status, lymph nodes metastasis, histological subtype and tumor size. In addition, we used precise stratification of PD-L1 expression on tumor or immune cells of certain breast cancer subtype and suggested that patients with PD-L1 expression in basal-like tumors by immune cells or with CD274 gene copy number gain had a longer disease-specific overall survival.
CONCLUSIONS:
Our findings may promote the more precise analysis of PD-L1 expression in breast cancer and aid the selection of patients who may benefit from immune therapy.
Licenziato, L;Minoli, L;Ala, U;Marconato, L;Fanelli, A;Giannuzzi, D;De Maria, R;Iussich, S;Orlando, G;Bertoni, F;Aresu, L;
PMID: 36951124 | DOI: 10.1177/03009858231162209
Canine diffuse large B-cell lymphoma (cDLBCL) is characterized by high mortality and clinical heterogeneity. Although chemo-immunotherapy improves outcome, treatment response remains mainly unpredictable. To identify a set of immune-related genes aberrantly regulated and impacting the prognosis, we explored the immune landscape of cDLBCL by NanoString. The immune gene expression profile of 48 fully clinically characterized cDLBCLs treated with chemo-immunotherapy was analyzed with the NanoString nCounter Canine IO Panel using RNA extracted from tumor tissue paraffin blocks. A Cox proportional-hazards model was used to design a prognostic gene signature. The Cox model identified a 6-gene signature (IL2RB, BCL6, TXK, C2, CDKN2B, ITK) strongly associated with lymphoma-specific survival, from which a risk score was calculated. Dogs were assigned to high-risk or low-risk groups according to the median score. Thirty-nine genes were differentially expressed between the 2 groups. Gene set analysis highlighted an upregulation of genes involved in complement activation, cytotoxicity, and antigen processing in low-risk dogs compared with high-risk dogs, whereas genes associated with cell cycle were downregulated in dogs with a lower risk. In line with these results, cell type profiling suggested the abundance of natural killer and CD8+ cells in low-risk dogs compared with high-risk dogs. Furthermore, the prognostic power of the risk score was validated in an independent cohort of cDLBCL. In conclusion, the 6-gene-derived risk score represents a robust biomarker in predicting the prognosis in cDLBCL. Moreover, our results suggest that enhanced tumor antigen recognition and cytotoxic activity are crucial in achieving a more effective response to chemo-immunotherapy.
Filley A, Henriquez M, Bhowmik T, Tewari BN, Rao X, Wan J, Miller MA, Liu Y, Bentley RT, Dey M.
PMID: 29330750 | DOI: 10.1007/s11060-018-2753-4
Malignant glioma (MG), the most common primary brain tumor in adults, is extremely aggressive and uniformly fatal. Several treatment strategies have shown significant preclinical promise in murine models of glioma; however, none have produced meaningful clinicalresponses in human patients. We hypothesize that introduction of an additional preclinical animal model better approximating the complexity of human MG, particularly in interactions with host immune responses, will bridge the existing gap between these two stages of testing. Here, we characterize the immunologic landscape and gene expression profiles of spontaneous canine glioma and evaluate its potential for serving as such a translational model. RNA in situ hybridization, flowcytometry, and RNA sequencing were used to evaluate immune cell presence and gene expression in healthy and glioma-bearing canines. Similar to human MGs, canine gliomas demonstrated increased intratumoral immune cell infiltration (CD4+, CD8+ and CD4+Foxp3+ T cells). The peripheral blood of glioma-bearing dogs also contained a relatively greater proportion of CD4+Foxp3+ regulatory T cells and plasmacytoid dendritic cells. Tumors were strongly positive for PD-L1 expression and glioma-bearing animals also possessed a greater proportion of immune cells expressing the immune checkpoint receptors CTLA-4 and PD-1. Analysis of differentially expressed genes in our canine populations revealed several genetic changes paralleling those known to occur in human disease. Naturally occurring canine glioma has many characteristics closely resembling human disease, particularly with respect to genetic dysregulation and host immune responses to tumors, supporting its use as a translational model in the preclinical testing of prospective anti-glioma therapies proven successful in murine studies.
Brain, behavior, and immunity
Lehmann, ML;Samuels, JD;Kigar, SL;Poffenberger, CN;Lotstein, ML;Herkenham, M;
PMID: 35063606 | DOI: 10.1016/j.bbi.2022.01.011
Immune surveillance of the brain plays an important role in health and disease. Peripheral leukocytes patrol blood-brain barrier interfaces, and after injury, monocytes cross the cerebrovasculature and follow a pattern of pro- and anti-inflammatory activity leading to tissue repair. We have shown that chronic social defeat (CSD) causes scattered vasculature disruptions. Here, we assessed CCR2+ monocyte trafficking to the vascular injury sites in Ccr2wt/rfp reporter mice both during CSD and one week following CSD cessation. We found that CSD for 14 days induced microhemorrhages where plasma fibrinogen leaked into perivascular spaces, but it did not affect the distribution or density of CCR2rfp+ monocytes in the brain. However, after recovery from CSD, many vascularly adhered CCR2+ cells were detected, and gene expression of the CCR2 chemokine receptor ligands CCL7 and CCL12, but not CCL2, was elevated in endothelial cells. Adhered CCR2+ cells were mostly the non-classical, anti-inflammatory Ly6Clo type, and they phagocytosed fibrinogen in perivascular spaces. In CCR2-deficient Ccr2rfp/rfp mice, fibrinogen levels remained elevated in recovery. Fibrinogen infused intracerebroventricularly induced CCR2+ cells to adhere to the vasculature and phagocytose perivascular fibrinogen in Ccr2wt/rfp but not Ccr2rfp/rfp mice. Depletion of monocytes with clodronate liposomes during CSD recovery prevented fibrinogen clearance and blocked behavioral recovery. We hypothesize that peripheral CCR2+ monocytes are not elevated in the brain on day 14 at the end of CSD and do not contribute to its behavioral effects at that time, but in recovery following cessation of stress, they enter the brain and exert restorative functions mediating vascular repair and normalization of behavior.
Kazantseva M, Eiholzer RA, Mehta S, Taha A, Bowie S, Roth I, Zhou J, Joruiz SM, Royds JA, Hung NA, Slatter TL, Braithwaite AW.
PMID: 29888503 | DOI: 10.1002/path.5111
As tumour protein 53 (p53) isoforms have tumour promoting, migration and inflammatory properties, this study investigated whether p53 isoforms contributed to glioblastoma progression. The expression levels of full-length TP53α (TAp53α) and six TP53 isoforms were quantitated by RT-qPCR in 89 glioblastomas and correlated with TP53 mutation status, tumour-associated macrophage content and various immune cell markers. Elevated levels of Δ133p53β mRNA characterised glioblastomas with increased CD163-positive macrophages and wild-type TP53. In situ based analyses found Δ133p53β expression localised to malignant cells in areas with increased hypoxia, and in cells with the monocyte chemoattractant protein C-C motif chemokine ligand 2 (CCL2) expressed. Tumours with increased Δ133p53β had increased numbers of cell positive for macrophage colony stimulating factor 1 receptor (CSF1R) and programmed death ligand 1 (PDL1). In addition, cells expressing a murine 'mimic' of Δ133p53 (Δ122p53) were resistant to temozolomide treatment and oxidative stress. Our findings suggest elevated Δ133p53β is an alternative pathway to TP53 mutation in glioblastoma that aids tumour progression by promoting an immunosuppressive and chemoresistant environment. Adding Δ133p53β to a TP53 signature along with TP53 mutation status will better predict treatment resistance in glioblastoma.
A Chemokine Regulatory Loop Induces Cholesterol Synthesis in Lung-Colonizing Triple-Negative Breast Cancer Cells to Fuel Metastatic Growth
Molecular therapy : the journal of the American Society of Gene Therapy
Han, B;Alonso-Valenteen, F;Wang, Z;Deng, N;Lee, TY;Gao, B;Zhang, Y;Xu, Y;Zhang, X;Billet, S;Fan, X;Shiao, S;Bhowmick, N;Medina-Kauwe, L;Giuliano, A;Cui, X;
PMID: 34274535 | DOI: 10.1016/j.ymthe.2021.07.003
Triple-negative breast cancer (TNBC) has a high propensity for organ-specific metastasis. However, the underlying mechanisms are not well understood. Here, we show that the primary TNBC tumor-derived C-X-C motif chemokines 1/2/8 (CXCL1/2/8) stimulate lung resident fibroblasts to produce C-C motif chemokines 2/7 (CCL2/7), which in turn activate cholesterol synthesis in lung-colonizing TNBC cells and induce angiogenesis at lung metastatic sites. Inhibiting cholesterol synthesis in lung-colonizing breast tumor cells by the pulmonary administration of simvastatin-carrying HER3-targeting nanoparticles reduces the angiogenesis and growth of lung metastases in a syngeneic TNBC mouse model. Our findings reveal a novel, chemokine-regulated mechanism for the cholesterol synthesis pathway and a critical role of metastatic site-specific cholesterol synthesis in the pulmonary tropism of TNBC metastasis. The study has implications for the unresolved epidemiological observation that the use of cholesterol-lowering drugs has no effect on breast cancer incidence but can unexpectedly reduce breast cancer mortality, suggesting interventions of cholesterol synthesis in lung metastases as an effective treatment to improve survival in TNBC patients.
Shi, Z;Yu, P;Lin, WJ;Chen, S;Hu, X;Chen, S;Cheng, J;Liu, Q;Yang, Y;Li, S;Zhang, Z;Xie, J;Jiang, J;He, B;Li, Y;Li, H;Xu, Y;Zeng, J;Huang, J;Mei, J;Cai, J;Chen, J;Wu, LJ;Ko, H;Tang, Y;
PMID: 36603584 | DOI: 10.1016/j.neuron.2022.12.009
The crosstalk between the nervous and immune systems has gained increasing attention for its emerging role in neurological diseases. Radiation-induced brain injury (RIBI) remains the most common medical complication of cranial radiotherapy, and its pathological mechanisms have yet to be elucidated. Here, using single-cell RNA and T cell receptor sequencing, we found infiltration and clonal expansion of CD8+ T lymphocytes in the lesioned brain tissues of RIBI patients. Furthermore, by strategies of genetic or pharmacologic interruption, we identified a chemotactic action of microglia-derived CCL2/CCL8 chemokines in mediating the infiltration of CCR2+/CCR5+ CD8+ T cells and tissue damage in RIBI mice. Such a chemotactic axis also participated in the progression of cerebral infarction in the mouse model of ischemic injury. Our findings therefore highlight the critical role of microglia in mediating the dysregulation of adaptive immune responses and reveal a potential therapeutic strategy for non-infectious brain diseases.
