Novel trehalose-based excipients for stabilizing nebulized anti-SARS-CoV-2 antibody

COVID-19 is caused by the infection of the lungs by SARS-CoV-2. Monoclonal antibodies, such as sotrovimab, showed great efficiency in neutralizing the virus before its internalization by lung epithelial cells. However, parenteral routes are still the preferred route of administration, even for local infections, which requires injection of high doses of antibody to reach efficacious concentrations in the lungs. Lung administration of antibodies would be more relevant requiring lower doses, thus reducing the costs and the side effects. But aerosolization of therapeutic proteins is very challenging, as the different processes available are harsh and trigger protein aggregation and conformational changes. This decreases the efficiency of the treatment, and can increase its immunogenicity. To address those issues, we developed a series of new excipients composed of a trehalose core, a succinyl side chain and a hydrophobic carbon chain (from 8 to 16 carbons). Succinylation increased the solubility of the excipients, allowing their use at relevant concentrations for protein stabilization. In particular, the excipient with 16 carbons (C₁₆TreSuc) used at 5.6 mM was able to preserve colloidal stability and antigen-binding ability of sotrovimab during the nebulization process. It could also be used as a cryoprotectant, allowing storage of sotrovimab in a lyophilized form during weeks. Finally, we demonstrated that C₁₆TreSuc could be used as an excipient to stabilize antibodies for the treatment against COVID-19, by in vitro and in vivo assays. The presence of C₁₆TreSuc during nebulization preserved the neutralization capacity of sotrovimab against SARS-CoV-2 in vitro; an increase of its efficacy was even observed, compared to the non-nebulized control. The in vivo study also showed the wide distribution of sotrovimab in mice lungs, after nebulization with 5.6 mM of excipient. This work brings a solution to stabilize therapeutic proteins during storage and nebulization, making pulmonary immunotherapy possible in the treatment of COVID-19 and other lung diseases.

Long-term impact of postnatal overfeeding on cardio-metabolism risk and on sensitivity to ischemia-reperfusion injury in vivo

Funding Acknowledgements

Type of funding sources: None.

Introduction

Nutritional disturbances during the postnatal period may be responsible for a predisposition, or "programming", to increased cardio-metabolic risk and to a progressive alteration of left ventricular contractility in adulthood. However, these data have mainly obtained in young male mice, but less is known for older animals.

Purpose

Our aim was to evaluate the impact of postnatal overfeeding (PNOF) on cardiac function, on cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo and on glucose metabolism in young (4 months), adult (6 months) and old (12 months) male mice.

Methods

PNOF was induced by the reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (OF) of 3 pups/mother. Echocardiography and blood sugar tests (glucose tolerance and insulin resistance) have been performed at all ages. An in vivo ischemia-reperfusion injury was induced by the ligation of the anterior interventricular artery for 45 minutes followed by 24 h of reperfusion. All experiments have been done on 4-, 6- and 12-months aged male mice.

Results

PNOF induced an early and permanent increase in body weight in OF group, independently of mice’s age (+23% at 24 days of life, +14% at 4 months, +23% at 6 and 12 months, compared to NF group). The echocardiographic measurements showed an alteration of contractile function from 6 months aged males and up to 12 months as evidenced by a decrease of the left ventricular ejection fraction (-11 % for OF males from 6 to 12 months, compared to NF groups). These cardiac alterations were associated with glucose metabolism imbalance: OF males presented glucose intolerance and insulin resistance from 4 to 12 months of age. To finish, PNOF induced a significant increase of infarct size at 4 months (+37%, p<0.01, n=8), 6 months (+32%, p<0.05, n=9) and 12 months (+38%, p<0,05, n=9) after cardiac surgery.

Conclusion

Nutritional programming through short-term PNOF induced an early alteration of glucose metabolism and was associated with a constant higher susceptibility to myocardial I-R injury in vivo. Moreover, mice which were submitted to PNOF developed altered cardiac contractility at 6 months and up to 12 months. The cellular and biochemical mechanism of these pathological modifications induced by PNOF need further exploration but could involve alterations in cardiomyocyte pathways, and/or modification of global inflammatory status.

Butyrate, a typical product of gut microbiome, affects function of the AhR gene, being a possible agent of crosstalk between gut microbiome and hepatic drug metabolism

Modulation of gut microbiome composition seems to be a promising therapeutic strategy for a wide range of pathological states. However, these microbiota-targeted interventions may affect production of microbial metabolites, circulating factors in the gut-liver axis influencing hepatic drug metabolism with possible clinical relevance. Butyrate, a short-chain fatty acid produced through microbial fermentation of dietary fibers in the colon, has well established anti-inflammatory role in the intestine, while the effect of butyrate on the liver is unknown. In this study, we have evaluated the effect of butyrate on hepatic AhR activity and AhR-regulated gene expression. We have showed that AhR and its target genes were upregulated by butyrate in dose dependent manner in HepG2-C3 as well as in primary human hepatocytes. The involvement of AhR has been proved using specific AhR antagonist and siRNA-mediated AhR silencing. Experiments with AhR reporter cells have shown that butyrate regulates the expression of AhR target genes by modulating the AhR activity. Our results suggest also epigenetic action by butyrate on AhR and its repressor (AHRR) presumably through mechanisms based on HDAC inhibition in the liver. Our results demonstrate that butyrate may influence the drug metabolizing ability of liver enzymes e.g. through the interaction with AhR dependent pathways.

Grey Matter changes in treatment-resistant depression during electroconvulsive therapy

INTRODUCTION

20-30% of depressed patients experience Treatment Resistant Depression (TRD). Electroconvulsive Therapy (ECT) remains the treatment of choice for TRD. However, the exact mechanism of ECT remains unclear. We aim to assess grey matter changes in patients with TRD undergoing bilateral ECT treatment at different points during and after treatment.

METHODS

Patients are recruited at the University Hospital of Toulouse. Eligibility criteria include a diagnosis of TRD and an age between 50 and 70 years old. Patients received clinical assessments (Hamilton Depression Rating Scale) and structural scans (MRI) at three points: baseline (within 48 h before the first ECT); V2 (after the first ECT considered effective); and V3 (within 1 week of completing ECT).

RESULTS

At baseline, controls had significantly higher cortical thickness than patients in the fusiform gyrus, the inferior, middle and superior temporal gyrus, the parahippocampal gyrus and the transverse temporal gyrus (respectively: t(35)=2.7, p = 0.02; t(35)=2.89, p = 0.017; t(35)=3.1, p = 0.015; t(35)=3.6, p = 0.009; t(35)=2.37, p = 0.031; t(35)=2.46, p = 0.03). This difference was no longer significant after ECT. We showed an increase in cortical thickness in superior temporal gyrus between (i) baseline and V3 (t(62)=-3.43 p = 0.009) and (ii) V2 and V3 (t(62)=-3.42 p = 0.009). We showed an increase in hippocampal volume between (i) baseline and V3 (t(62)=-5.23 p < 0.001) and (ii) V2 and V3 (t(62)=-5.3 p < 0.001).

CONCLUSION

We highlight that there are grey matter changes during ECT treatment in a population with TRD compared to a healthy control population. These changes seem to occur after several rounds of ECT.

P4613Long-term impact of postnatal nutritional programming on cardiac sensitivity to ischemia-reperfusion injury in vivo and on cardio-protective pathways in mice

Introduction

Nutritional disturbances during the postnatal period may be responsible for a predisposition, or “programming”, to increased cardio-metabolic risk and to a progressive alteration of left ventricular contractility in adulthood. This nutritional perinatal programming may also lead to an alteration of cellular pathways involved in cardiac protection, such as the specific RISK and SAFE pathways, highlighted during pre- and post-ischemic conditioning or those of sirtuins (SIRT), histone deacetylases involved in the regulation of essential biological process.

Purpose

Our aim was to evaluate in mice the impact of postnatal overfeeding (PNOF) on cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo and on the myocardial expression of genes involved in heart protection against ischemia.

Methods

PNOF was induced by the reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (OF) of 3 pups/mother. In vivo ischemia-reperfusion injury was induced by the ligation of the anterior interventricular artery for 45 minutes followed by 24 h of reperfusion in hearts from 6-months aged mice. The gene expressions of proteins of interest composing the cardioprotective pathways (RISK pathway: Akt, ERK; SAFE pathway: JAK/STAT3; Sirtuins: SIRT1) were measured by RT-qPCR in mice aged 4 and 6 months.

Results

PNOF induced in OF group an early and permanent increase in body weight (+23%, p<0.01, n=11) and a significant increase of infarct size (+32%, p<0.05, n=11) at 6 months. Hearts OF mice aged 4 months showed a decreased expression of cardioprotective pathways, represented by a reduction in the gene expression of ERK1, Akt, PI3K, STAT3 and SIRT1. At 6 months, the expression of cardioprotective pathways was also reduced in OF group, with the diminution of the gene expression of STAT3, Akt and Erk1.

Conclusion

Nutritional programming through short-term PNOF induced a long-lasting decrease in the expression of signaling pathways involved in cardiac cellular protection, which could explain why 6-months old mice show increased susceptibility to myocardial I-R injury in vivo. The mechanism of these alterations needs further exploration, but could involve alterations in cardiomyocyte's balance between apoptotic and regenerative pathways, and epigenetic modifications.

Acknowledgement/Funding

French Fundation

Transient postnatal over nutrition induces long-term alterations in cardiac NLRP3-inflammasome pathway

BACKGROUND AND AIMS

The prevalence of obesity is increasing worldwide at an alarming rate. Altered early nutrition, in particular postnatal overfeeding (PNOF), is a risk factor for impaired cardiac function in adulthood. In the understanding of the initiation or progression of heart diseases, NLRP3 inflammasome and non-coding RNAs have been proposed as key players. In this context, the aim of this study was to decipher the role of NLRP3 inflammasome and its post transcriptional control by micro-RNAs in the regulation of cardiac metabolic function induced by PNOF in mice.

METHODS AND RESULTS

Based on a model of mice exposed to PNOF through litter size reduction, we observed increased cardiac protein expression levels of NLRP3 and ETS-1 associated with alterations in insulin signaling. Additionally, miR-193b levels were down-regulated in the adult hearts of overfed animals. In a cardiomyocyte cell line, transfection with miR-193b induced down-regulation of ETS-1 and NLRP3 and improved insulin signaling.

CONCLUSIONS

These findings suggest that the miR-193b could be involved in cardiac phenotypic changes observed in adulthood induced by PNOF likely through the regulation of ETS-1 and NLRP3 expression, and through this of insulin signaling.

Suppressive therapy using azithromycin in 2 rare cases of recurrent staphylococcal infections

Recurrent staphylococcal skin and soft tissue infections may recur despite decontamination and multiple courses of antibiotic therapy and may dramatically impair the patient's quality of life. We report successful use of long-term azithromycin prophylaxis in a recurrent laryngitis and a scalp folliculitis due to methicillin-susceptible Staphylococcus aureus.

Infections associated with monoclonal antibody and fusion protein therapy in humans

Monoclonal antibodies (mAbs), especially those that interact with immune or hematologic leukocyte membrane targets, have changed the outcome of numerous diseases. However, mAbs can block or reduce immune cells and cytokines, and can lead to increased risk of infection. Some of these risks are predictable and can be explained by their mechanisms of action. Others have been observed only after the mAbs were licensed and used extensively in patients. In this review, we focus on infectious complications that occur upon treatment with mAbs or Fc-containing fusion proteins targeting leukocyte membrane proteins, including CD52, CD20, tumor necrosis factor, VLA4, CD11a and CTLA4. We report their known infectious risks and the recommendations for their use. Although most of these drugs are clinically safe when the indications are respected, we emphasize the need for regular updating of pharmacovigilance data.

[Therapeutic monoclonal antibodies: update on the risk of opportunistic infections]

The large experience accumulated with the therapeutic use of monoclonal antibodies has revealed undesirable effects, among which opportunistic infections when prescribed in inflammatory or hematological diseases. This deleterious effect is a direct consequence of the immunosuppression induced by these antibodies through the blockade of several key pathways involved in both innate and adaptative immune responses, including migration of effector cells, depletion of B or T lymphocytes, inhibition of key cell-cell interactions. Four antibodies are concerned, targeting CD52, CD20, TNF-a and VLA-4, and major risks include activation of latent tuberculosis, or of normally silent viruses. Precise evaluation of these risks and understanding of their mechanisms have now led to the improvement of clinical safety, based on the detection of patients at risk, weighting of the benefit/risk ratio, and a very rigorous detection of latent infections before the onset of treatment by monoclonal antibodies know to induce immunosuppression.

[Non-steroidal anti-inflammatory agents and diuretics: a combination with nephrotoxic risks]

We report the case of a reversible postoperative acute renal failure in a 55-year-old woman without preoperative risk factors who underwent a retinal surgery. The association of diuretics with nonsteroidal antiinflammatory drugs was probably responsible of an ischaemic acute tubular necrosis. Vitreoretinal surgery's postoperative period might be associated with a specific risk for the kidney because of an usual intensive diuretic prescription. Nonsteroidal antiinflammatory drugs should be avoided if possible in this indication.

Prospective evaluation of the protected specimen brush for the diagnosis of pulmonary infections in ventilated newborns

The precise diagnosis of lower respiratory tract infection in the critically ill newborn remains a difficult challenge. The bronchoscopic protected specimen brush (PSB) is a reliable method in intubated adults. Because the bronchoscopic procedure is not generally available for young children, Zucker proposed a blind technique for introducing the PSB into the distal airways. His results were promising but were not compared with any bacteriologic reference method. Therefore, we wanted to evaluate this technique in comparison with the open lung biopsy (OLB) when it could be ethically accomplished. Eleven PSB were collected simultaneously with an OLB. The sensitivity of the PSB procedure was 100%, its specificity 88%, its positive predictive value 66%, and its negative predictive value 100%. There were no complications secondary to the PSB procedure. In this short study, the PSB procedure using a blind technique is safe and feasible to obtain uncontaminated specimens in intubated and ventilated newborns, and is largely accurate in identifying the bacterial etiologic agent of lower respiratory tract infection.

[Posology of amikacin in newborn infants, adapted to the postconceptional age]

Two consecutive studies of amikacin plasma levels were performed in 63 and 64 neonates whose postconceptional age (PCA) ranged from 26 to 45 weeks. The first study, using a dose of 7.5 mg/kg every 12 hours, permitted to establish a dosage related to PCA. Half-life elimination of amikacin was strongly correlated with PCA (r = -0.42, p = 0.0009). The apparent volume of distribution was correlated with none of the variables studied. The mean volume of distribution was 640 +/- 190 ml/kg. From these data, the inferred dosage was 10 mg/kg, given at intervals of time predetermined as a function of PCA. A second prospective study proved the value of this PCA adapted dosage. The maximal concentrations obtained were higher (21.6 +/- 5.9 vs 18.5 +/- 4.6 micrograms/ml, p less than 0.001), the nadir concentrations were not significantly increased (5.7 +/- 3.1 vs 5.2 +/- 3.7 micrograms/ml, NS) and the number of nadir concentrations outside the desired interval of 2-8 micrograms/ml was smaller (p less than 0.01).