Background
We previously showed that supernatants of
Lactobacillus
biofilms induced an anti-inflammatory response by affecting the secretion of macrophage-derived cytokines, which was abrogated upon ...immunodepletion of the stress protein GroEL.
Methods
We purified GroEL from
L. reuteri
and analysed its anti-inflammatory properties in vitro in human macrophages isolated from buffy coats, ex vivo in explants from human biopsies and in vivo in a mouse model of DSS induced intestinal inflammation. As a control, we used GroEL purified (LPS-free) from
E. coli
.
Results
We found that
L. reuteri
GroEL (but not
E. coli
GroEL) inhibited pro-inflammatory M1-like macrophages markers, and favored M2-like markers. Consequently,
L. reuteri
GroEL inhibited pro-inflammatory cytokines (TNFα, IL-1β, IFNγ) while favouring an anti-inflammatory secretome. In colon tissues from human biopsies,
L. reuteri
GroEL was also able to decrease markers of inflammation and apoptosis (caspase 3) induced by LPS. In mice, we found that rectal administration of
L. reuteri
GroEL (but not
E. coli
GroEL) inhibited all signs of haemorrhagic colitis induced by DSS including intestinal mucosa degradation, rectal bleeding and weight loss. It also decreased intestinal production of inflammatory cytokines (such as IFNγ) while increasing anti-inflammatory IL-10 and IL-13. These effects were suppressed when animals were immunodepleted in macrophages. From a mechanistic point of view, the effect of
L. reuteri
GroEL seemed to involve TLR4, since it was lost in TRL4
−/−
mice, and the activation of a non-canonical TLR4 pathway.
Conclusions
L. reuteri
GroEL, by affecting macrophage inflammatory features, deserves to be explored as an alternative to probiotics.
Pro-survival stress-inducible chaperone HSP110 is the only HSP for which a mutation has been found in a cancer. Multicenter clinical studies demonstrated a direct association between HSP110 ...inactivating mutation presence and excellent prognosis in colorectal cancer patients. Here, we have combined crystallographic studies on human HSP110 and in silico modeling to identify HSP110 inhibitors that could be used in colorectal cancer therapy. Two molecules (foldamers 33 and 52), binding to the same cleft of HSP110 nucleotide-binding domain, were selected from a chemical library (by co-immunoprecipitation, AlphaScreening, Interference-Biolayer, Duo-link). These molecules block HSP110 chaperone anti-aggregation activity and HSP110 association to its client protein STAT3, thereby inhibiting STAT3 phosphorylation and colorectal cancer cell growth. These effects were strongly decreased in HSP110 knockdown cells. Foldamer's 33 ability to inhibit tumor growth was confirmed in two colorectal cancer animal models. Although tumor cell death (apoptosis) was noted after treatment of the animals with foldamer 33, no apparent toxicity was observed, notably in epithelial cells from intestinal crypts. Taken together, we identified the first HSP110 inhibitor, a possible drug-candidate for colorectal cancer patients whose unfavorable outcome is associated to HSP110.
APO2L/TRAIL (TNF-related apoptosis-inducing ligand) induces death of tumor cells through two agonist receptors, TRAIL-R1 and TRAIL-R2. We demonstrate here that N-linked glycosylation (N-glyc) plays ...also an important regulatory role for TRAIL-R1-mediated and mouse TRAIL receptor (mTRAIL-R)-mediated apoptosis, but not for TRAIL-R2, which is devoid of N-glycans. Cells expressing N-glyc-defective mutants of TRAIL-R1 and mouse TRAIL-R were less sensitive to TRAIL than their wild-type counterparts. Defective apoptotic signaling by N-glyc-deficient TRAIL receptors was associated with lower TRAIL receptor aggregation and reduced DISC formation, but not with reduced TRAIL-binding affinity. Our results also indicate that TRAIL receptor N-glyc impacts immune evasion strategies. The cytomegalovirus (CMV) UL141 protein, which restricts cell-surface expression of human TRAIL death receptors, binds with significant higher affinity TRAIL-R1 lacking N-glyc, suggesting that this sugar modification may have evolved as a counterstrategy to prevent receptor inhibition by UL141. Altogether our findings demonstrate that N-glyc of TRAIL-R1 promotes TRAIL signaling and restricts virus-mediated inhibition.
A multicenter clinical study demonstrated the presence of a loss-of-function HSP110 mutation in about 15% of colorectal cancers, which resulted from an alternative splicing and was produced at the ...detriment of wild-type HSP110. Patients expressing low levels of wild-type HSP110 had excellent outcomes (i.e. response to an oxaliplatin-based chemotherapy). Here, we show in vitro, in vivo, and in patients' biopsies that HSP110 co-localizes with DNA damage (γ-H2AX). In colorectal cancer cells, HSP110 translocates into the nucleus upon treatment with genotoxic chemotherapy such as oxaliplatin. Furthermore, we show that HSP110 interacts with the Ku70/Ku80 heterodimer, an essential element of the non-homologous end joining (NHEJ) repair machinery. We also demonstrate by evaluating the resolved 53BP1 foci that depletion in HSP110 impairs repair steps of the NHEJ pathway, which is associated with an increase in DNA double-strand breaks and in the cells' sensitivity to oxaliplatin. HSP110-depleted cells sensitization to oxaliplatin-induced DNA damage is abolished upon re-expression of HSP110. Confirming a role for HSP110 in DNA non-homologous repair, SCR7 and NU7026, two inhibitors of the NHEJ pathway, circumvents HSP110-induced resistance to chemotherapy. In conclusion, HSP110 through its interaction with the Ku70/80 heterodimer may participate in DNA repair, thereby inducing a protection against genotoxic therapy.
β-thalassemia major (β-TM) is an inherited hemoglobinopathy caused by a quantitative defect in the synthesis of β-globin chains of hemoglobin, leading to the accumulation of free a-globin chains that ...aggregate and cause ineffective erythropoiesis. We have previously demonstrated that terminal erythroid maturation requires a transient activation of caspase-3 and that the chaperone Heat Shock Protein 70 (HSP70) accumulates in the nucleus to protect GATA-1 transcription factor from caspase-3 cleavage. This nuclear accumulation of HSP70 is inhibited in human β-TM erythroblasts due to HSP70 sequestration in the cytoplasm by free a-globin chains, resulting in maturation arrest and apoptosis. Likewise, terminal maturation can be restored by transduction of a nuclear-targeted HSP70 mutant. Here we demonstrate that in normal erythroid progenitors, HSP70 localization is regulated by the exportin-1 (XPO1), and that treatment of β-thalassemic erythroblasts with an XPO1 inhibitor increased the amount of nuclear HSP70, rescued GATA-1 expression and improved terminal differentiation, thus representing a new therapeutic option to ameliorate ineffective erythropoiesis of β-TM.
Radioimmunotherapy (RIT) is a cancer treatment that combines radiation therapy with tumor-directed monoclonal antibodies (Abs). Although RIT had been introduced for the treatment of CD20 positive ...non-Hodgkin lymphoma decades ago, it never found a broad clinical application. In recent years, researchers have developed theranostic agents based on Ab fragments or small Ab mimetics such as peptides, affibodies or single-chain Abs with improved tumor-targeting capacities. Theranostics combine diagnostic and therapeutic capabilities into a single pharmaceutical agent; this dual application can be easily achieved after conjugation to radionuclides. The past decade has seen a trend to increased specificity, fastened pharmacokinetics, and personalized medicine. In this review, we discuss the different strategies introduced for the noninvasive detection and treatment of hematological malignancies by radiopharmaceuticals. We also discuss the future applications of these radiotheranostic agents.
Cancer is the second leading cause of death globally. Early detection and disease management lead to a better survival rate. Consequently, discovery of novel methods in cancer early diagnosis is a ...field of active research. Minimally invasive liquid biopsies are generating growing interest. Circulating tumour cells (CTCs) have been identified in patients' blood; nevertheless, these cells are rare and heterogeneous. Exosomes are extracellular nanovesicles released into the extracellular environment via the endosomal vesicle pathway and found in different body fluids. Exosomes deliver bioactive cargo such as proteins, mRNA and miRNA to recipient cells in the tumour environment. We have recently shown that heat shock protein 70 (HSP70) is detected in the membrane of tumour-derived exosomes, in contrast to normal cells. One single cancer cell can release thousands of HSP70-exosomes, facilitating detection. The aim of the pilot study ExoDiag is to determine whether it is possible to detect and quantify HSP70-exosomes in blood in patients with solid cancers.
Bicentric pilot study that will include 60 adult patients with metastatic and non-metastatic solid tumours and 20 healthy volunteers. Exosomes will be isolated from blood and urine samples, and HSP70 concentration will be determined. Patients will be followed for 1 year. The study is sponsored by Georges-François Leclerc Centre and is currently ongoing.
We expect to demonstrate that HSP70-exosomes could be a powerful tool to diagnose cancer and to guide clinicians in therapeutic decision-making, improving patient's care.
ClinicalTrials.gov identifier NCT02662621. Registered 20 January 2016, https://clinicaltrials.gov/ct2/show/study/NCT02662621?term=NCT02662621&rank=1.
Escherichia coli is an important experimental, medical and industrial cell factory for recombinant protein production. The inducible lac promoter is one of the most commonly used promoters for ...heterologous protein expression in E. coli. Isopropyl-β-D-thiogalactoside (IPTG) is currently the most efficient molecular inducer for regulating this promoter's transcriptional activity. However, limitations have been observed in large-scale and microplate production, including toxicity, cost and culture monitoring. Here, we report the novel SILEX (Self-InducibLe Expression) system, which is a convenient, cost-effective alternative that does not require cell density monitoring or IPTG induction. We demonstrate the broad utility of the presented self-inducible method for a panel of diverse proteins produced in large amounts. The SILEX system is compatible with all classical culture media and growth temperatures and allows protein expression modulation. Importantly, the SILEX system is proven to be efficient for protein expression screening on a microplate scale.
Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterised by myofibroblast proliferation and abnormal extracellular matrix (ECM) accumulation in the lungs. Transforming-growth-factor ...(TGF)-β1 initiates key profibrotic signaling involving the SMADs pathway and the small heat shock protein αB-crystallin (HSPB5). TRIpartite Motif-containing 33 (TRIM33) has been reported to negatively regulate TGF-β/SMADs signaling but its role in fibrogenesis remains unknown.
To elucidate the role of TRIM33 in IPF.
TRIM33 expression was assessed in the lungs of IPF patients and rodent fibrosis models. Bone Marrow-derived Macrophages (BMDM), primary lung fibroblasts and 3D-lung tissue slices were isolated from
-floxed mice and cultured with TGF-β1 or bleomycin (BLM).
expression was then suppressed by adenovirus-Cre recombinase (AdCre). Pulmonary fibrosis was evaluated in hematopoietic-specific
knock-out (KO) mice and in
-floxed mice that received AdCre and BLM intratracheally.
TRIM33 was overexpressed in alveolar macrophages and fibroblasts in IPF patients and rodent fibrotic lungs.
inhibition in BMDM increased TGF-β1 secretion upon BLM treatment. Hematopoietic-specific
-KO sensitised mice to BLM-induced fibrosis. In primary lung fibroblasts and 3D-lung tissue slices,
-deficiency increased TGF-β1-downstream gene expression. In mice, AdCre-
inhibition worsened BLM-induced fibrosis.
, HSPB5 was able to bind directly to TRIM33, thereby diminishing its protein level and TRIM33/SMAD4 interaction.
Our results demonstrate a key role of TRIM33 as a negative regulator of lung fibrosis. Since TRIM33 directly associates with HSPB5 which impairs its activity, inhibitors of TRIM33/HSPB5 interaction may be of interest in the treatment of IPF.
Exosomes, via heat shock protein 70 (HSP70) expressed in their membrane, are able to interact with the toll-like receptor 2 (TLR2) on myeloid-derived suppressive cells (MDSCs), thereby activating ...them.
We analyzed exosomes from mouse (C57Bl/6) and breast, lung, and ovarian cancer patient samples and cultured cancer cells with different approaches, including nanoparticle tracking analysis, biolayer interferometry, FACS, and electron microscopy. Data were analyzed with the Student's t and Mann-Whitney tests. All statistical tests were two-sided.
We showed that the A8 peptide aptamer binds to the extracellular domain of membrane HSP70 and used the aptamer to capture HSP70 exosomes from cancer patient samples. The number of HSP70 exosomes was higher in cancer patients than in healthy donors (mean, ng/mL ± SD = 3.5 ± 1.7 vs 0.17 ± 0.11, respectively, P = .004). Accordingly, all cancer cell lines examined abundantly released HSP70 exosomes, whereas "normal" cells did not. HSP70 had higher affinity for A8 than for TLR2; thus, A8 blocked HSP70/TLR2 association and the ability of tumor-derived exosomes to activate MDSCs. Treatment of tumor-bearing C57Bl/6 mice with A8 induced a decrease in the number of MDSCs in the spleen and inhibited tumor progression (n = 6 mice per group). Chemotherapeutic agents such as cisplatin or 5FU increase the amount of HSP70 exosomes, favoring the activation of MDSCs and hampering the development of an antitumor immune response. In contrast, this MDSC activation was not observed if cisplatin or 5FU was combined with A8. As a result, the antitumor effect of the drugs was strongly potentiated.
A8 might be useful for quantifying tumor-derived exosomes and for cancer therapy through MDSC inhibition.
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