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Abstract Background In the collagen-induced arthritis (CIA) mouse model, inflammation readouts are usually quantified using operator-dependent clinical scoring systems, and no systematic relationship with functional deficits has been detected. In this study, we extensively quantified sensory and motor deficits in CIA mice during natural disease progression and therapeutic treatment. Then, we used these data to build a scale to predict functional deficits on the basis of the classical clinical score. Methods Using the CIA mouse model, we longitudinally screened multiple approaches to assess locomotion (open field test, Catwalk™), sensitivity (Von Frey, Hargreaves, static weight-bearing tests), and inflammation (skin temperature), and identified the most accurate tests to correlate sensory and motor deficits with disease severity, measured by clinical score. We then used these tests to characterize functional deficits in control (naïve and mice injected with complete Freund’s adjuvant) and CIA mice, either untreated or treated with methotrexate to prevent functional deficits. By mathematical approaches, we finally investigated the relationship between functional deficits and clinical score. Results We found that the functional disability scores obtained with the open field, Catwalk™, Hargreaves, and skin temperature tests significantly correlated with the clinical score in CIA mice, either untreated or treated with methotrexate. Mathematical correlation showed that motor deficits, robustly characterized by two different tests, were twice more responsive than thermal sensitivity deficits. Conclusion We propose the arthritis sensory and motor (ArthriSM) scale as a new theranostic tool to predict motor and sensory deficit based on the clinical score, in the experimental mouse model of CIA. This ArthriSM scale may facilitate the transfer of knowledge between preclinical and clinical studies.

Despite their distinct etiology, several lines of evidence suggest that innate immunity plays a pivotal role in both juvenile idiopathic arthritis (JIA) and septic arthritis (SA) pathophysiology. Indeed, monocytes and dendritic cells (DC) are involved in the first line of defense against pathogens and play a critical role in initiating and orchestrating the immune response. The aim of this study was to compare the number and phenotype of monocytes and DCs in peripheral blood (PB) and synovial fluid (SF) from patients with JIA and SA to identify specific cell subsets and activation markers associated with pathophysiological mechanisms and that could be used as biomarkers to discriminate both diseases. The proportion of intermediate and non-classical monocytes in the SF and PB, respectively, were significantly higher in JIA than in SA patients. In contrast the proportion of classical monocytes and their absolute numbers were higher in the SF from SA compared with JIA patients. Higher expression of CD64 on non-classical monocyte was observed in PB from SA compared with JIA patients. In SF, higher expression of CD64 on classical and intermediate monocyte as well as higher CD163 expression on intermediate monocytes was observed in SA compared with JIA patients. Moreover, whereas the number of conventional (cDC), plasmacytoid (pDC) and inflammatory (infDC) DCs was comparable between groups in PB, the number of CD141+ cDCs and CD123+ pDCs in the SF was significantly higher in JIA than in SA patients. CD14+ infDCs represented the major DC subset in the SF of both groups with potent activation assessed by high expression of HLA-DR and CD86 and significant up-regulation of HLA-DR expression in SA compared with JIA patients. Finally, higher activation of SF DC subsets was monitored in SA compared with JIA with significant up-regulation of CD86 and PDL2 expression on several DC subsets. Our results show the differential accumulation and activation of innate immune cells between septic and inflammatory arthritis. They strongly indicate that the relative high numbers of CD141+ cDC and CD123+ pDCs in SF are specific for JIA while the over-activation of DC and monocyte subsets is specific for SA.

Immunotherapy, which is seen as a major tool for cancer treatment, requires, in some cases, the presence of several agents to maximize its effects. Adjuvants can enhance the effect of other agents. However, despite their long-time use, only a few adjuvants are licensed today, and their use in cancer treatment is rare. Azoximer bromide, marketed under the trade name Polyoxidonium® (PO), is a copolymer of N-oxidized 1,4-ethylenepiperazine and (N-carboxyethyl)-1,4-ethylene piperazinium bromide. It has been described as an immune adjuvant and immunomodulator that is clinically used with excellent tolerance. PO is used in the treatment and prophylaxis of diseases connected with damage to the immune system, and there is interest in testing it in antitumor therapy. We show here that PO treatment for 1 week induced positive pathological changes in 6 out of 20 patients with breast cancer, including complete response in a triple-negative patient. This correlated with an increased tumor CD4+ T-lymphocyte infiltration. The immune effects of PO are associated with myeloid cell activation, and little is known about the action of PO on lymphocyte lineages, such as natural killer (NK) and T cells. We reveal that PO increases T-cell proliferation in vitro without negative effects on any activation marker. PO does not affect dendritic cell (DC) viability and increases the expansion of immature DC (iDC) and mature DC (mDC) at 100 μg/ml, and it stimulates expression of several DC co-stimulatory molecules, inducing the proliferation of allogeneic T cells. In contrast, PO decreases DC viability when added at day 5 post-expansion. PO is not toxic for NK cells at doses up to 100 μM and does not affect their activation, maturation, and cytotoxicity but tends to increase degranulation. This could be beneficial against target cells that show low sensitivity to NK cells, e.g., solid tumor cells. Finally, we have found great variability in PO response between donors. In summary, our in vitro results show that PO increases the number of costimulatory molecules on DC that prime T cells, favoring the production of effector T cells. This may support the future clinical development of PO in cancer treatment.

IntroductionMost patients (>70%) experience acute neuropathic symptoms shortly after oxaliplatin infusions. These symptoms are not always resolved between infusions. Overall, 30%–50% of patients suffer from chronic oxaliplatin-induced peripheral neuropathy (OIPN). This cumulative and dose-dependent sensory neuropathy limits compliance or results in oxaliplatin-based chemotherapies to be substituted with less neurotoxic agents. These treatment changes impair clinical outcomes, and may be associated with comorbidities, such as distress, depression and anxiety. Currently, no drug used to prevent or treat OIPN is sufficiently effective to be used routinely in clinical practice. There is, thus, an unmet therapeutic need to reduce the intensity of and/or prevent OIPN. We hypothesised that riluzole would be an excellent candidate to address this public health issue. Riluzole is approved for treating amyotrophic lateral sclerosis. In animals, there is a beneficial effect on sensorimotor and pain disorders, as well as related comorbidities, after repeated administration of oxaliplatin. In humans, riluzole has shown neuroprotective, anxiolytic and antidepressive effects.Methods and analysisRILUZOX-01 trial was designed as a randomised, controlled, double-blind study to evaluate the efficacy of riluzole to prevent OIPN. Patients with colorectal cancer and initiating adjuvant oxaliplatin-based chemotherapy are eligible. Patients (n=210) will be randomly assigned to either riluzole or placebo, concomitantly with chemotherapy. The primary endpoint is the change in OIPN intensity, assessed by the sensory scale of the QLQ-CIPN20, after six 2-week cycles of chemotherapy. Secondary endpoints include incidence and severity of neuropathy, grade of sensory neuropathy, intensity and features of neuropathic pain, health-related quality of life, disease-free survival, overall survival and safety.Ethics and dessiminationThe study was approved by a French ethics committee (ref:39/18_1, ‘Comité de Protection des Personnes’ Ouest-IV, France) and plans to start enroling patients in September 2019. The trial is registered in EudraCT and clinicaltrials.gov.Trial registration numberN°2017-002320-25; NCT03722680

Lymphodepletion is currently used to enhance the efficacy of cytotoxic T lymphocyte adoptive transfer immunotherapy against cancer. This beneficial effect of conditioning regimens is due, at least in part, to promoting the breakdown of peripheral CD8+ T cell tolerance. Lymphodepletion by total body irradiation induces systemic translocation of commensal bacteria LPS from the gastrointestinal tract. Since LPS is a potent activator of the innate immune system, including antigen presenting dendritic cells, we hypothesized that LPS translocation could be required for the breakdown of peripheral tolerance observed in irradiated mice. To address this issue, we have treated irradiated mice with antibiotics in order to prevent LPS translocation and utilized them in T cell adoptive transfer experiments. Surprisingly, we found that despite of completely blocking LPS translocation into the bloodstream, antibiotic treatment did not prevent the breakdown of peripheral tolerance. Although irradiation induced the activation of cross-presenting CD8+ dendritic cells in the lymphoid tissue, LPS could not solely account for this effect. Activation of dendritic cells by mechanisms other than LPS translocation is sufficient to promote the differentiation of potentially autoreactive CD8+ T cells into effectors in irradiated mice. Our data indicate that LPS translocation is dispensable for the breakdown of CD8+ T cell tolerance in irradiated mice.

OBJECTIVE: Tumor necrosis factor alpha (TNFalpha) is among the most prominent cytokines in rheumatoid arthritis (RA) and is secreted mainly by macrophages. A direct method for restoring the immunologic balance in RA is use of small interfering RNA (siRNA) for silencing the TNFalpha transcript. The aim of this study was to determine the therapeutic effect of systemic administration of TNFalpha siRNA in an experimental model of RA, optimizing its delivery using new liposome formulations. METHODS: Murine macrophages were transfected with siRNA targeting TNFalpha, and expression was measured. The therapeutic effect in collagen-induced arthritis (CIA) was assessed after intravenous delivery of TNFalpha siRNA. Delivery was optimized using a carrier DNA for complexation with the cationic liposome RPR209120/DOPE. Levels of TNFalpha and other cytokines were measured in sera and joint tissue-conditioned media. Biodistribution was determined using a fluorescent siRNA. RESULTS: In vitro, TNFalpha siRNA efficiently and specifically modulated the expression of TNFalpha at both the messenger RNA and protein levels. In vivo, complete cure of CIA was observed when TNFalpha siRNA was administered weekly, complexed with the liposome and combined with carrier DNA. Inhibition (50-70%) of articular and systemic TNFalpha secretion was detected in the siRNA-injected groups, which correlated with a decrease in the levels of interleukin-6 and monocyte chemotactic protein 1. The main organs targeted by siRNA were the liver and spleen; the addition of liposome RPR209120 and carrier DNA significantly increased organ uptake. CONCLUSION: We demonstrated the efficiency of systemic delivery of siRNA designed to silence TNFalpha in CIA, using a liposome carrier system as a way to address the methodologic limitations in vivo. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Adult mesenchymal stem cells (MSCs) represent promising tools for therapeutic applications such as tissue engineering and cellular therapy. Recent data suggest that, due to their immunosuppressive nature, MSCs may be of interest to enhance allogeneic hematopoietic engraftment and prevent graft-versus-host disease. Using a murine model of rheumatoid arthritis (RA), this study investigated whether the immunosuppressive properties of MSCs could be of therapeutic value to inhibit reactive T cells in autoimmune diseases such as RA. METHODS: In mice with collagen-induced arthritis (CIA), we injected various doses of C3 MSCs at the time of immunization or booster injection, and subsequently evaluated the clinical and immunologic parameters. The immunosuppressive properties of MSCs were determined in vitro in mixed lymphocyte reactions with or without the addition of tumor necrosis factor alpha (TNFalpha). RESULTS: In the CIA model of arthritis, MSCs did not confer any benefit. Both the clinical and the immunologic findings suggested that MSCs were associated with accentuation of the Th1 response. Using luciferase-expressing MSCs, we were unable to detect labeled cells in the articular environment of the knee, suggesting that worsening of the symptoms was unlikely due to the homing of MSCs in the joints. Experiments in vitro showed that the addition of TNFalpha was sufficient to reverse the immunosuppressive effect of MSCs on T cell proliferation, and this observation was associated with an increase in interleukin-6 secretion. CONCLUSION: Our data suggest that environmental parameters, in particular those related to inflammation, may influence the immunosuppressive properties of MSCs. [ABSTRACT FROM AUTHOR]