Argiope bruennichi (Scopoli, 1772) sur l'île de Bagaud (Parc national de Port-Cros, Var, France) (Arachnida, Araneae, Araneidae)

International audienc

MicroRNA-29b Modulates Innate and Antigen-Specific Immune Responses in Mouse Models of Autoimmunity

International audienceIn addition to important regulatory roles in gene expression through RNA interference, it has recently been shown that microRNAs display immune stimulatory effects through direct interaction with receptors of innate immunity of the Toll-like receptor family, aggravating neuronal damage and tumour growth. Yet no evidence exists on consequences of microRNA immune stimulatory actions in the context of an autoimmune disease. Using microRNA analogues, we here show that pancreatic beta cell-derived microRNA sequences induce pro-inflammatory (TNFa, IFNa, IL-12, IL-6) or suppressive (IL-10) cytokine secretion by primary mouse dendritic cells in a sequence-dependent manner. For miR-29b, immune stimulation in RAW264.7 macrophages involved the endosomal Toll-like receptor-7, independently of the canonical RNA interference pathway. In vivo, the systemic delivery of miR-29b activates CD11b+B2202 myeloid and CD11b-B220+ plasmacytoid dendritic cells and induces IFNa, TNFa and IL-6 production in the serum of recipient mice. Strikingly, in a murine model of adoptive transfer of autoimmune diabetes, miR-29b reduces the cytolytic activity of transferred effector CD8+ T-cells, insulitis and disease incidence in a single standalone intervention. Endogenous miR-29b, spontaneously released from beta- cells within exosomes, stimulates TNFa secretion from spleen cells isolated from diabetes-prone NOD mice in vitro. Hence, microRNA sequences modulate innate and ongoing adaptive immune responses raising the question of their potential role in the breakdown of tolerance and opening up new applications for microRNA-based immune therapy

Le Parc Naturel Régional du Queyras vu par ses résidents permanents et secondaires

Cette note de synthèse présente les résultats de l'enquête par questionnaire réalisée auprès des résidents du périmètre du PNRQ (433 résidents permanents et 172 résidents secondaires). L'objectif est de proposer un éclairage sur leurs ressentis et leurs attentes concernant le PNRQ et son territoire

Radio- immunothérapie alpha : Principes et intérêts en immunité antitumorale

International audience> La radioimmunothérapie alpha (RITα) est une thérapie anticancéreuse vectorisée utilisant généralement un anticorps monoclonal spécifique d'un antigène tumoral couplé à un émetteur de particules α. Les émetteurs α représentent un outil idéal pour éradiquer les tumeurs disséminées ou les métastases. De récentes données démontrent que les rayonnements ionisants, en plus de leur cytotoxicité directe, peuvent aussi induire une immunité antitumorale efficace. Les effets biologiques de l'irradiation pourraient donc être utilisés pour potentialiser la réponse à différents types d'immunothérapie, et ainsi ouvrir la voie au développement de nouvelles thérapies combinant RITα et immunothérapies. < radionucléide. Le choix du radionu-cléide repose sur des considérations pratiques (le coût, la disponibilité, le type de techniques de radiomar-quage et la facilité d'utilisation), le type d'émission du radioélément, le transfert d'énergie linéique (TEL : quantité d'énergie transférée au milieu par la particule incidente, par unité de longueur de la trajectoire en keV 1 /µm) et la demi-vie physique du radioisotope (durée nécessaire pour que la moitié des noyaux radioactifs d'une source se soient désintégrés) [2]. Cette dernière doit être, autant que possible, en adéquation avec la pharmacocinétique du vecteur utilisé, afin de délivrer la plus grande dose possible de radioactivité à la tumeur après l'injection. Une demi-vie trop courte entraînera un nombre élevé de désintégrations avant d'atteindre la cible. À l'inverse, une demi-vie trop longue engendrera un grand nombre de désintégrations du radionucléide pendant la phase d'éli-mination du vecteur, rendant le radioimmunoconjugué plus toxique. La demi-vie doit également être compatible avec les applications cliniques et la prise en charge du patient. Ainsi, le temps nécessaire au transfert du radionucléide du site de production jusqu'à l'hôpital, 1 1 keV (kiloélectronvolts) = 10 3 eV ; 1 MeV (megaélectonvolts) = 10 6 eV

Single-dose anti-CD138 radioimmunotherapy: bismuth-213 is more efficient than lutetium-177 for treatment of multiple myeloma in a preclinical model

Objectives: Radioimmunotherapy (RIT) has emerged as a potential treatment option for multiple myeloma (MM). In humans, a dosimetry study recently showed the relevance of RIT using an antibody targeting the CD138 antigen. The therapeutic efficacy of RIT using an anti-CD138 antibody coupled to 213Bi, an α-emitter, was also demonstrated in a preclinical MM model. Since then, RIT with β-emitters has shown efficacy in treating hematologic cancer. In this paper, we investigate the therapeutic efficacy of RIT in the 5T33 murine MM model using a new anti-CD138 monoclonal antibody labeled either with 213Bi for α-RIT or 177Lu for β-RIT. Methods: A new monoclonal anti-CD138 antibody, 9E7.4, was generated by immunizing a rat with a murine CD138-derived peptide. Antibody specificity was validated by flow cytometry, biodistribution, and α-RIT studies. Then, a β-RIT dose-escalation assay with the 177Lu-radiolabeled 9E7.4 mAb was performed in KalwRij C57/BL6 mice 10 days after i.v. engraftment with 5T33 MM cells. Animal survival and toxicological parameters were assessed to define the optimal activity. Results: α-RIT performed with 3.7 MBq of 213Bi-labeled 9E7.4 anti-CD138 mAb increased median survival to 80 days compared to 37 days for the untreated control and effected cure in 45% of animals. β-RIT performed with 18.5 MBq of 177Lu-labeled 9E7.4 mAb was well tolerated and significantly increased mouse survival (54 vs. 37 days in the control group); however, no mice were cured with this treatment. Conclusion: This study revealed the advantages of α-RIT in the treatment of MM in a preclinical model where β-RIT shows almost no efficacy.JRC.E.5-Nuclear chemistr

Single-Dose Anti-CD138 Radioimmunotherapy: Bismuth-213 is More Efficient than Lutetium-177 for Treatment of Multiple Myeloma in a Preclinical Model

International audienceOBJECTIVES: Radioimmunotherapy (RIT) has emerged as a potential treatment option for multiple myeloma (MM). In humans, a dosimetry study recently showed the relevance of RIT using an antibody targeting the CD138 antigen. The therapeutic efficacy of RIT using an anti-CD138 antibody coupled to (213)Bi, an α-emitter, was also demonstrated in a preclinical MM model. Since then, RIT with β-emitters has shown efficacy in treating hematologic cancer. In this paper, we investigate the therapeutic efficacy of RIT in the 5T33 murine MM model using a new anti-CD138 monoclonal antibody labeled either with (213)Bi for α-RIT or (177)Lu for β-RIT.METHODS: A new monoclonal anti-CD138 antibody, 9E7.4, was generated by immunizing a rat with a murine CD138-derived peptide. Antibody specificity was validated by flow cytometry, biodistribution, and α-RIT studies. Then, a β-RIT dose-escalation assay with the (177)Lu-radiolabeled 9E7.4 mAb was performed in KalwRij C57/BL6 mice 10 days after i.v. engraftment with 5T33 MM cells. Animal survival and toxicological parameters were assessed to define the optimal activity.RESULTS: α-RIT performed with 3.7 MBq of (213)Bi-labeled 9E7.4 anti-CD138 mAb increased median survival to 80 days compared to 37 days for the untreated control and effected cure in 45% of animals. β-RIT performed with 18.5 MBq of (177)Lu-labeled 9E7.4 mAb was well tolerated and significantly increased mouse survival (54 vs. 37 days in the control group); however, no mice were cured with this treatment.CONCLUSION: This study revealed the advantages of α-RIT in the treatment of MM in a preclinical model where β-RIT shows almost no efficacy

Cytokine profile in BALB/c mice serum after intravenous miRNA delivery.

<p>Cytokine content in serum from BALB/c mice was analysed by a BD Cytometric Bead Array two and seven hours following intravenous injection of miR29b, the immune-silent miR-127 or positive (R848) or negative (HBS) controls. Results are presented as mean concentration (pg/ml) ± SEM from two experiments (n = 4 total mice); nd: not detected.</p><p>Cytokine profile in BALB/c mice serum after intravenous miRNA delivery.</p

Splenic mDC and pDC activation by miR-29b <i>in vivo</i>.

<p>BALB/c mice were injected intravenously with miR-29b, miR-127, or siRNA9.1. Spleens were harvested eighteen hours after injection and CD40, CD86, and H-2Kd expression was evaluated by flow cytometry, on CD11c⁺CD11b⁺B220⁻ mDC (A) or CD11c^lowCD11b⁻B220⁺ pDC (B) subsets. Histogram plots show the results of CD40, CD86 and H-2K^d staining for one mouse out of two in one experiment representative of four independent experiments. Grey shading indicates isotypic controls. For each marker, graphs represent the relative fluorescence intensity (RFI) of individual mice in two independent experiments (n = 3 mice for miR-29b and siRNA9.1, n = 4 mice for miR-127), and are representative of two other independent experiments. *<i>P</i><0.05 (Mann-Whitney).</p

Systemic delivery of miR-29b protects against adoptive transfer of T1D <i>in vivo</i>.

<p>Ins-HA mice were treated intravenously with miR-29b, miR-127, HBS buffer or DOTAP alone, eighteen hours before receiving HA-specific CTLs from CL4-TCR mice. (A) Recipients were monitored for diabetes development for at least one month. The survival curves and table summarize the results of five independent experiments after transfer of 1 to 10×10⁵ cells, with miR-29b -injected mice as filled symbols, and HBS-injected mice as empty symbols. The table indicates, for each group, the percentage of final cumulative diabetes incidence and the number of diabetic mice among all mice in the group in brackets. A logrank test was performed for statistical significance of differences between Kaplan-Meier incidence curves. (B) Eighteen hours after miRNA injection, Ins-HA recipient mice received 5×10⁵ activated HA-specific CTLs, followed 48 h later by the intravenous administration of HA-pulsed «CFSE_high » and non-pulsed «CFSE_low » target cells mixed at a 1∶1 ratio. Splenocytes from recipient Ins-HA mice were analysed by flow cytometry, sixteen hours after target cell injection. The bar chart shows the compiled results of three independent experiments (n = 4–5 mice/group) as mean specific lysis ± SEM. *<i>P</i><0.05, **<i>P</i><0.01 (Mann-Whitney). (C–E) Eighteen hours after miRNA injection, Ins-HA were transferred with 8×10⁵ activated HA-specific Thy1.1⁺ CTLs from CL4-TCR⁺Thy1.1⁺ mice. Four days later, spleens (C) and PLNs (D) were harvested from Ins-HA recipient mice and analysed by flow cytometry. Compiled results of two independent experiments are presented as the percentage of Thy1.1⁺ cells in individual mice gated on the CD3⁺ CD8⁺ T-cell population (n = 3–5 mice), and were confirmed in a third experiment. *<i>P</i><0.05 (Mann-Whitney). (E) Histological analysis of insulitis of pancreata: 0 = islet free of mononuclear cell infiltration (unfilled bars); 1 = peri-insular infiltration involving <10% of the islet area (punctuated bars); 2 = infiltration involving between 10% and 50% of the islet area (hatched bars); 3 = infiltration involving >50% of the islet area (black bars). The stacked vertical bar graph indicates the percentage of islets in each category described above. Results are presented as the mean percentage of n = 5 mice for miR-29b, n = 3 for miR-127, and n = 4 mice in the HBS group from three independent experiments. For each pancreas, an average insulitis score was calculated by adding up the score of each islet and dividing it by the total number of islets counted. Results show the individual insulitis scores for each group of recipient mice. *<i>P</i><0.05 (Kruskal-Wallis).</p

Stimulation of immune cells with exosomes <i>in vitro</i>.

<p>(A–B, D) Cytokine concentration measured by cytometric bead analysis in supernatants from splenocytes of NOD mice at 48 h of culture (A) with 20 µg/ml of exosomes with n = 7 (NT) and n = 10 (EXO) samples per group from two independent experiments. <i>*P</i><0.05, <i>**P</i><0.01 and <i>***P</i><0.001 (Mann-Whitney) (B) after transfection with 750 nM of miR-29b or 2′-OMe-miR-29b. Data are representative of two independent experiments (n = 5–6 mice per group). <i>***P</i><0.001 (Kruskal Wallis) (C) TNFa concentration in supernatants of RAW264.7 macrophages stimulated for 48 h with various concentrations of MIN6 exosomes. Results from TNFa ELISA analysis are representative of four independent experiments (n = 12 to 15 wells per group). <i>**P</i><0.001 and <i>****P</i><0.0001(Kruskal-Wallis) (D) treatment with exosomes transfected with LNA-miR-29 family inhibitor or control (CT). Data were obtained from n = 7–8 replicates from two independent experiments. <i>**P</i><0.01 (Mann-Whitney). All bar graphs are presented as mean ± SEM. NT: no treatment.</p