Low immunogenicity of LNP allows repeated administrations of CRISPR-Cas9 mRNA into skeletal muscle in mice

Genome editing therapy for Duchenne muscular dystrophy (DMD) holds great promise, however, one major obstacle is delivery of the CRISPR-Cas9/sgRNA system to skeletal muscle tissues. In general, AAV vectors are used for in vivo delivery, but AAV injections cannot be repeated because of neutralization antibodies. Here we report a chemically defined lipid nanoparticle (LNP) system which is able to deliver Cas9 mRNA and sgRNA into skeletal muscle by repeated intramuscular injections. Although the expressions of Cas9 protein and sgRNA were transient, our LNP system could induce stable genomic exon skipping and restore dystrophin protein in a DMD mouse model that harbors a humanized exon sequence. Furthermore, administration of our LNP via limb perfusion method enables to target multiple muscle groups. The repeated administration and low immunogenicity of our LNP system are promising features for a delivery vehicle of CRISPR-Cas9 to treat skeletal muscle disorders.

Comprehensive assessment of multiple tryptophan metabolites as potential biomarkers for immune checkpoint inhibitors in patients with non-small cell lung cancer

Purpose

Tryptophan metabolites have immunomodulatory functions, suggesting possible roles in cancer immunity.

Methods

Plasma tryptophan metabolites were measured using liquid chromatography/mass spectrometry before immune checkpoint inhibitors (ICIs) in patients with non-small cell lung cancer (NSCLC).

Results

The 19 patients with NSCLC had significantly lower levels of tryptophan (p = 0.002) and xanthurenic acid (p = 0.032), and a significantly higher level of 3-hydroxyanthranilic acid (3-HAA) (p = 0.028) compared with the 10 healthy volunteers. The patients achieving objective responses had significantly lower levels of 3-HAA than those who did not (p = 0.045). Receiver operating characteristic analyses determined that the cutoff value of 3-HAA for objective response was 35.4 pmol/mL (sensitivity: 87.5% and specificity: 83.3%). The patients with 3-HAA < 35.4 pmol/mL had significantly longer median progression-free survival (7.0 months) than those without (1.6 months, p = 0.022).

Conclusions

Tryptophan metabolites may have a potential for predicting the efficacy of ICIs.

Registration number

University Hospital Medical Information Network Clinical Trial Registry 000026140.

Electronic supplementary material

The online version of this article (10.1007/s12094-020-02421-8) contains supplementary material, which is available to authorized users.

Extracellular nanovesicles for packaging of CRISPR-Cas9 protein and sgRNA to induce therapeutic exon skipping

Prolonged expression of the CRISPR-Cas9 nuclease and gRNA from viral vectors may cause off-target mutagenesis and immunogenicity. Thus, a transient delivery system is needed for therapeutic genome editing applications. Here, we develop an extracellular nanovesicle-based ribonucleoprotein delivery system named NanoMEDIC by utilizing two distinct homing mechanisms. Chemical induced dimerization recruits Cas9 protein into extracellular nanovesicles, and then a viral RNA packaging signal and two self-cleaving riboswitches tether and release sgRNA into nanovesicles. We demonstrate efficient genome editing in various hard-to-transfect cell types, including human induced pluripotent stem (iPS) cells, neurons, and myoblasts. NanoMEDIC also achieves over 90% exon skipping efficiencies in skeletal muscle cells derived from Duchenne muscular dystrophy (DMD) patient iPS cells. Finally, single intramuscular injection of NanoMEDIC induces permanent genomic exon skipping in a luciferase reporter mouse and in mdx mice, indicating its utility for in vivo genome editing therapy of DMD and beyond.

Type-1 polarised dendritic cells are a potent immunogen against Mycobacterium tuberculosis

OBJECTIVE

Application of immunotherapy using dendritic cells (DCs) is considered an effective treatment strategy against persistent Mycobacterium tuberculosis infection. With the goal of developing improved therapeutic vaccination strategies for patients with tuberculosis (TB), we tested the ability of ex vivo-generated DCs to induce an effective TB antigen-specific type-1 immune response.

METHODS

Monocyte-derived DCs from TB patients were induced to mature using a 'standard' cytokine cocktail (interleukin [IL] 1β, tumour necrosis factor alpha [TNF-α], IL-6 and prostaglandin E2) or a type 1-polarised DC (DC1) cocktail (IL-1β, TNF-α, interferon [IFN] α, IFN-γ and polyinosinic:polycytidylic acid), and were loaded with the established TB antigen 6-kDa early secretory antigenic target protein (ESAT-6).

RESULTS

Although DC1s from TB patients expressed the same levels of multiple co-stimulatory molecules (CD83, CD86, CD80 and CD40) as the standard DCs (sDCs), DC1s secreted substantially higher levels of IL-12p70. Furthermore, when DCs pulsed with or without ESAT-6 were cultured with lymphocytes from the same patients, DC1s induced much higher numbers of ESAT-6-specific IFN-γ-producing T-cells than sDCs, as manifested by their superior induction of natural killer cell activation and antigen-independent suppression of regulatory T-cells.

CONCLUSION

TB antigen-loaded DC1s are potent inducers of antigen-specific T-cells, which could be used to develop improved immunotherapies of TB.

Respiratory impedance is correlated with airway narrowing in asthma using three-dimensional computed tomography

BACKGROUND

Respiratory impedance comprises the resistance and reactance of the respiratory system and can provide detailed information on respiratory function. However, details of the relationship between impedance and morphological airway changes in asthma are unknown.

OBJECTIVE

We aimed to evaluate the correlation between imaging-based airway changes and respiratory impedance in patients with asthma.

METHODS

Respiratory impedance and spirometric data were evaluated in 72 patients with asthma and 29 reference subjects. We measured the intraluminal area (Ai) and wall thickness (WT) of third- to sixth-generation bronchi using three-dimensional computed tomographic analyses, and values were adjusted by body surface area (BSA, Ai/BSA, and WT/the square root (√) of BSA).

RESULTS

Asthma patients had significantly increased respiratory impedance, decreased Ai/BSA, and increased WT/√BSA, as was the case in those without airflow limitation as assessed by spirometry. Ai/BSA was inversely correlated with respiratory resistance at 5 Hz (R5) and 20 Hz (R20). R20 had a stronger correlation with Ai/BSA than did R5. Ai/BSA was positively correlated with forced expiratory volume in 1 second/forced vital capacity ratio, percentage predicted forced expiratory volume in 1 second, and percentage predicted mid-expiratory flow. WT/√BSA had no significant correlation with spirometry or respiratory impedance.

CONCLUSIONS & CLINICAL RELEVANCE

Respiratory resistance is associated with airway narrowing.

[Advances in genome editing technologies for treating muscular dystrophy.]

Recent advances in genome editing technologies have opened the possibility for treating genetic diseases, such as Duchenne muscular dystrophy(DMD), by correcting the causing gene mutations in dystrophin gene. In fact, there are several reports that demonstrated the restoration of the mutated dystrophin gene in DMD patient-derived iPS cell or functional recovery of forelimb grip strength in DMD model mice. For future clinical applications, there are several aspects that need to be taken into consideration:efficient delivery of the genome editing components, risk of off-target mutagenesis and immunogenicity against genome editing enzyme. In this review, we summarize the current status and future prospective of the research in applying genome editing technologies to DMD.

Safety and efficacy of nivolumab and standard chemotherapy drug combination in patients with advanced non-small-cell lung cancer: a four arms phase Ib study

In this phase Ib study, four combination therapies of nivolumab 10 mg/kg and standard chemotherapy (cisplatin/gemcitabine, cisplatin/pemetrexed, carboplatin/paclitaxel/bevacizumab, or docetaxel) showed acceptable toxicity profiles in patients with advanced non-small-cell lung cancer. Furthermore, these combination therapies presented encouraging antitumor activities.

Background

The human IgG4 monoclonal antibody nivolumab targets programmed cell death-1 (PD-1) and promotes antitumor response by blocking the interaction of PD-1 with its ligands. This single-center phase Ib study investigated the tolerability, safety, and pharmacokinetics of nivolumab combined with standard chemotherapy in patients with advanced non-small-cell lung cancer (NSCLC).

Patients and methods

Patients who had stage IIIB without indication for definitive radiotherapy, stage IV, or recurrent NSCLC were eligible. Regimens were nivolumab 10 mg/kg + gemcitabine/cisplatin (arm A), pemetrexed/cisplatin (arm B), paclitaxel/carboplatin/bevacizumab (arm C), or docetaxel (arm D). Regimens A, B, and D were repeated every 3 weeks for up to four cycles and regimen C was repeated for up to six cycles; nivolumab alone (arm A), with pemetrexed (arm B), bevacizumab (arm C), or docetaxel (arm D) was continued every 3 weeks as maintenance therapy until disease progression or unacceptable toxicity. Dose-limiting toxicity (DLT) was evaluated during the first treatment cycle.

Results

As of March 2014, six patients were enrolled in each arm. The combination of nivolumab 10 mg/kg and chemotherapy was well tolerated. DLT was observed in only one patient in arm A (alanine aminotransferase increased). Select adverse events (those with a potential immunologic cause) of any grade were observed in six, four, six, and five patients in arms A, B, C, and D, respectively. Three, three, six, and one patient achieved partial response while median progression-free survival was 6.28, 9.63 months, not reached, and 3.15 months in arms A, B, C, and D, respectively.

Conclusions

Combination of nivolumab 10 mg/kg and chemotherapy showed an acceptable toxicity profile and encouraging antitumor activity in patients with advanced NSCLC.

Clinical trials number

Japanese Pharmaceutical Information Center Clinical Trials Information (JapicCTI)-132071.

Inositol Hexakisphosphate Kinase 3 Regulates Metabolism and Lifespan in Mice

Inositol hexakisphosphate kinase 3 (IP6K3) generates inositol pyrophosphates, which regulate diverse cellular functions. However, little is known about its own physiological role. Here, we show the roles of IP6K3 in metabolic regulation. We detected high levels of both mouse and human IP6K3 mRNA in myotubes and muscle tissues. In human myotubes, IP6K3 was upregulated by dexamethasone treatment, which is known to inhibit glucose metabolism. Furthermore, Ip6k3 expression was elevated under diabetic, fasting, and disuse conditions in mouse skeletal muscles. Ip6k3(-/-) mice demonstrated lower blood glucose, reduced circulating insulin, deceased fat mass, lower body weight, increased plasma lactate, enhanced glucose tolerance, lower glucose during an insulin tolerance test, and reduced muscle Pdk4 expression under normal diet conditions. Notably, Ip6k3 deletion extended animal lifespan with concomitant reduced phosphorylation of S6 ribosomal protein in the heart. In contrast, Ip6k3(-/-) mice showed unchanged skeletal muscle mass and no resistance to the effects of high fat diet. The current observations suggest novel roles of IP6K3 in cellular regulation, which impact metabolic control and lifespan.

Involvement of neuropeptide Y in hyperphagia in human growth hormone transgenic rats

We have previously produced human growth hormone (hGH) transgenic (TG) rats that show low circulating levels of both hGH and endogenous rat GH. Although body length of the TG rats is normal, they develop hyperphagia and severe obesity. The present study was undertaken to elucidate the causes of hyperphagia in the TG rats by focusing on temporal changes in plasma ghrelin levels and hypothalamic neuropeptide Y (NPY) contents. In both wild-type (WT) and TG rats, the highest value of plasma ghrelin levels was observed just before the dark phase, and thereafter plasma ghrelin levels were maintained higher in the TG than WT rats. Although NPY contents also showed the peak level just before the dark phase in both the arcuate (ARC) and paraventricular nuclei (PVN) of the hypothalamus, the values in the ARC, but not the PVN, of the TG rats was always lower than those of the WT rats, suggesting increased transport of NPY from the ARC to PVN in the TG rats. In addition, treatment with antagonists for Y1 and Y5 receptors for NPY reduced food intake much more effectively in the TG than WT rats. Intermittent treatment with recombinant hGH for a week significantly decreased food consumption, adipose tissue weight and plasma triglyceride concentrations in the TG rats. These results suggest that, in the TG rats, insufficiency in circulating GH stimulates the ghrelin-NPY system with a resultant increase in food intake.

Analyses of hind leg skeletons in human growth hormone transgenic rats

Growth hormone (GH) is essential in the development and growth of the skeleton and for the maintenance of bone mass and density, and its secretion is known to decline with aging. We have previously produced transgenic rats with low circulating GH that represent several age-associated phenotypes such as obesity, insulin-resistance and leptin-resistance. In the present study, the cross-sectional area, bone mineral density, and strength indexes of the hind leg skeletons of the transgenic rats were examined by an X-ray computed tomography scanning. The mean cross-sectional area of the transgenic rats showed no increase after 2 months old up to 8 months old and the strength indexes were significantly lower than their non-transgenic siblings at all ages examined. The trabecular bone mineral density in the transgenic rats drastically decreased at 8 months old, while the cortical bone mineral density was comparable to the non-transgenic rats, suggesting the onset of osteoporosis at this period. The results obtained in this study indicate that the transgenic rats could be useful model to gain insight into the complex mechanism leading to osteoporosis with aging.

[Multiple pulmonary arteriovenous malformations associated with hereditary hemorrhagic telangiectasia]

A 61-year old asymptomatic woman was admitted to our hospital for the examination of an abnormal shadow in the left lower lung lobe in 1978. Enhanced chest computed tomograms and pulmonary arteriograms revealed a pulmonary arteriovenous malformation (PAVM) composed of feeding artery and draining vein. The patient had suffered brain abscesses 3 times because of paradoxical emboli from PAVMs. A diagnosis of hereditary hemorrhagic telangiectasia (HHT) was made according to the criteria. The patient died of septic shock due to urinary tract infection by Candida albicans. We reviewed cases of PAVMs associated with HHT in the Japanese literature. In Japan, 126 HHT families and 144 HHT patients have been reported to date. PAVMs occur in approximately one-third of HHT patients in Japan. Twenty-four out of 45 patients (44.4%) had multiple PAVMs. We also discussed the diagnosis, complications, and treatment of PAVM-associated HHT.

A novel point mutation affecting the tyrosine kinase domain of the TRKA gene in a family with congenital insensitivity to pain with anhidrosis

A nerve growth factor receptor encoded by the TRKA gene plays an important part in the formation of autonomic neurons and small sensory neurons in dorsal root ganglia and in signal transduction through its intracytoplasmic tyrosine kinase domain. Recently, three mutations in the tyrosine kinase domain of TRKA have been reported in patients with congenital insensitivity to pain with anhidrosis, which is an autosomal recessive disorder characterized by recurrent fever due to absence of sweating, no reaction to noxious stimuli, self-mutilating behavior, and mental retardation. We examined the TRKA gene in five generations of a large Japanese family with many consanguineous marriages who live in a small remote island of the southern part of Japan. We found a novel point mutation at nucleotide 1825 (A-->G transition) resulting in Met-581-Val in the tyrosine kinase domain. Two of the three affected patients were homozygous for this mutation; however, the third affected patient was heterozygous. Further analysis revealed that the third patient was a compound heterozygote with the Met-581-Val mutation in one allele and with a single base C deletion mutation at nucleotide 1726 in exon 14 in the other allele, resulting in a frameshift and premature termination codon.

Development of Ladder Climbing Robot LCR-1

A new mobile robot has been developed, which is capable of ascending and descending vertical ladders such as those used in nuclear power plants and other facilities. The Ladder Climbing Robot releases personnel from dangerous and laborious work at high elevations. The body of the robot has four grippers which grip each rung of the ladder as it ascends or descends. Each gripper is able to move up, down, forward or backward, and has two kinds of sensors to detect a rung: one photoelectric-switch and one limit-switch. The robot can operate automatically or be remote controlled. Three of the grippers are continuously in contact with the ladder rungs to prevent falling. As a result of experiment, it has been confirmed that in trials the prototype model LCR-1 with a built-in microcomputer can ascend and descend an actual vertical ladder automatically.

Responsiveness of the ductus arteriosus to prostaglandin E1 assessed by combined cross sectional and pulsed Doppler echocardiography

Cross sectional echocardiography combined with Doppler echocardiography was used to record either ductal morphology or the flow profile within the ductus arteriosus before and after infusion of prostaglandin E1 in 25 newborn infants with cyanotic and acyanotic congenital heart disease with ductus dependent blood flow. The ultrasound results were compared with changes in arterial oxygen tension and the overall clinical response to prostaglandin E1 seen during the same period in 24 of the 25 patients in whom the degree of ductal narrowing could be determined with the ultrasound method. At the time of the study, the ductus was widely patent or slightly narrowed in 12 patients and was closed in two patients. These patients did not respond to prostaglandin E1. There was prominent localised narrowing of the ductus in seven patients and generalised narrowing in three. After the infusion of prostaglandin E1 there was no ductal narrowing in these patients, except for one patient who had slight residual localised narrowing. There was also a considerable change in the ductal flow profiles in each patient. In these 10 patients infusion of prostaglandin E1 resulted in an increase in arterial oxygen tension, clinical improvement, or both. The present study indicates that prostaglandin E1 is effective in patients with prominent narrowing of the ductus but is not in patients in whom the ductus is widely patent or closed. Cross sectional echocardiography combined with Doppler echocardiography was useful for predicting the responsiveness of the ductus arteriosus to the infusion.