Safety and efficacy of first-in-man intrathecal injection of human astrocytes (AstroRx®) in ALS patients: phase I/IIa clinical trial results.

BACKGROUND: Malfunction of astrocytes is implicated as one of the pathological factors of ALS. Thus, intrathecal injection of healthy astrocytes in ALS can potentially compensate for the diseased astrocytes. AstroRx® is an allogeneic cell-based product, composed of healthy and functional human astrocytes derived from embryonic stem cells. AstroRx® was shown to clear excessive glutamate, reduce oxidative stress, secrete various neuroprotective factors, and act as an immunomodulator. Intrathecal injection of AstroRx® to animal models of ALS slowed disease progression and extended survival. Here we report the result of a first-in-human clinical study evaluating intrathecal injection of AstroRx® in ALS patients. METHODS: We conducted a phase I/IIa, open-label, dose-escalating clinical trial to evaluate the safety, tolerability, and therapeutic effects of intrathecal injection of AstroRx® in patients with ALS. Five patients were injected intrathecally with a single dose of 100 × 106 AstroRx® cells and 5 patients with 250 × 106 cells (low and high dose, respectively). Safety and efficacy assessments were recorded for 3 months pre-treatment (run-in period) and 12 months post-treatment (follow-up period). RESULTS: A single administration of AstroRx® at either low or high doses was safe and well tolerated. No adverse events (AEs) related to AstroRx® itself were reported. Transient AEs related to the Intrathecal (IT) procedure were all mild to moderate. The study demonstrated a clinically meaningful effect that was maintained over the first 3 months after treatment, as measured by the pre-post slope change in ALSFRS-R. In the 100 × 106 AstroRx® arm, the ALSFRS-R rate of deterioration was attenuated from - 0.88/month pre-treatment to - 0.30/month in the first 3 months post-treatment (p = 0.039). In the 250 × 106 AstroRx® arm, the ALSFRS-R slope decreased from - 1.43/month to - 0.78/month (p = 0.0023). The effect was even more profound in a rapid progressor subgroup of 5 patients. No statistically significant change was measured in muscle strength using hand-held dynamometry and slow vital capacity continued to deteriorate during the study. CONCLUSIONS: Overall, these findings suggest that a single IT administration of AstroRx® to ALS patients at a dose of 100 × 106 or 250 × 106 cells is safe. A signal of beneficial clinical effect was observed for the first 3 months following cell injection. These results support further investigation of repeated intrathecal administrations of AstroRx®, e.g., every 3 months. TRIAL REGISTRATION: NCT03482050.

Astrocytes Downregulate Inflammation in Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome: Applicability to COVID-19.

Background: An acute respiratory distress syndrome (ARDS) is caused by the increased amounts of pro-inflammatory cytokines and neutrophil-mediated tissue injury. To date, there is no effective treatment for the ARDS available, while the need for one is growing due to the most severe complications of the current coronavirus disease-2019 (COVID-19) pandemic. The human astrocytes (AstroRx) have shown immunomodulatory properties in the central nervous system (CNS). This study aimed to evaluate the capacity of astrocytes to decrease lung inflammation and to be applied as a treatment therapy in ARDS. Methods: First, we assessed the ability of clinical-grade AstroRx to suppress T-cell proliferation in a mixed lymphocyte reaction test. Next, we tested the therapeutical potential of AstroRx cells in a lipopolysaccharide (LPS)-based ARDS mouse model by injecting AstroRx intravenously (i.v). We determined the degree of lung injury by using a severity scoring scale of 0-2, based on the American Thoracic Society. The scoring measured the presence of neutrophils, fibrin deposits, and the thickening of alveolar walls. The state of inflammation was further assessed by quantifying the immune-cell infiltration to the bronchoalveolar lavage fluid (BALF) and by the presence of proinflammatory cytokines and chemokines in the BALF and serum. Results: We detected that AstroRx cells were capable to suppress T-cell proliferation in vitro after exposure to the mitogen concanavalin A (ConA). In vivo, AstroRx cells were able to lower the degree of lung injury in LPS-treated animals compared with the sham injected animals (P = 0.039). In this study, 30% of AstroRx treated mice showed no lung lesions (responder mice), these mice presented a steady number of eosinophils, T cells, and neutrophils comparable with the level of naïve control mice. The inflammatory cytokines and chemokines, such as TNFα, IL1b, IL-6, and CXCL1, were also kept in check in responder AstroRx-treated mice and were not upregulated as in the sham-injected mice (P < 0.05). As a result, the LPS-treated ARDS mice had a higher survival rate when they were treated with AstroRx. Conclusions: Our results demonstrate that the immunosuppressive activity of AstroRx cells support the application of AstroRx cells as a cell therapy treatment for ARDS. The immunoregulatory activity may also be a part of the mechanism of action of AstroRx reported in the amyotrophic lateral sclerosis (ALS) neurodegenerative disease.

Prolonged remission of advanced bronchoalveolar adenocarcinoma in a dog treated with autologous, tumour-derived chaperone-rich cell lysate (CRCL) vaccine.

PURPOSE: This paper presents the treatment of a 12-year-old female spayed Great Dane who presented with vestibular signs (ataxia, nystagmus, hind end collapse). Thoracic radiographs revealed a discrete pulmonary nodule in the right cranial lung lobe. Ultrasound-guided fine needle aspirate detected primary bronchoalveolar adenocarcinoma, verified via computed tomography, with a second smaller nodule discovered in the right cranial lung lobe. MATERIALS AND METHODS: A lateral thoracotomy with right cranial lung lobectomy was performed. Histopathological analysis of the nodules and an excised lymph node identified grade III bronchoalveolar adenocarcinoma with vascular infiltration and lymph node metastasis - a grim diagnosis with a reported median survival time of 6-27 days. A 10-g sample of the tumour was processed into a chaperone-rich cell lysate (CRCL) vaccine, which was administered weekly to the patient. Imiquimod - a Toll-like receptor 7 (TLR7) agonist - was applied topically for the first 12 treatments to stimulate local Langerhans cells. A single injection of bacillus Calmette-Guerin (BCG) was administered for additional immune stimulation at week 30 of treatment. RESULTS: The dog remained stable and in otherwise good health until diffuse relapse occurred 44 weeks after the initial treatment; following gastrointestinal bleeding, the dog was euthanised 50+ weeks post diagnosis. CONCLUSION: To the authors' knowledge, this is the first report of significantly prolonged survival following a diagnosis of grade III/stage III bronchoalveolar adenocarcinoma in a canine patient. This case report suggests that CRCL vaccine combined with topical imiquimod is a safe, effective treatment for canine tumours.

Proteomic analyses of different human tumour-derived chaperone-rich cell lysate (CRCL) anti-cancer vaccines reveal antigen content and strong similarities amongst the vaccines along with a basis for CRCL's unique structure: CRCL vaccine proteome leads to unique structure.

PURPOSE: The aim of this paper was to compare protein content of chaperone-rich cell lysate (CRCL) anti-cancer vaccines prepared from human tumours of different histological origins to evaluate the uniformity of their protein content. MATERIALS AND METHODS: Clinical grade CRCL was prepared under Good Manufacturing Practice (GMP) conditions from surgically resected human tumours (colorectal cancer, glioblastoma, non-small cell lung cancer, ovarian cancer). Protein samples were separated by SDS-PAGE and slices cut from gels for protease digestion followed by mass spectrometry analysis. Proteins were identified, and the content assessed by gene ontogeny/networking programmatic computation. CRCL preparations were also analysed by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). RESULTS: We identified between 200 and 550 proteins in the various CRCL preparations. Gene ontogeny analysis indicated that the vaccines showed clear relationships, despite different tumour origins. A total of 95 proteins were common to all the CRCLs. Networking analyses implicated heat shock proteins in antigen processing pathways, and showed connections to the cytoskeletal network. We found that CRCL vaccines showed a particulate structure by NTA, and TEM revealed an extended fence-like structural network in CRCL, with regions that were microns in size. CONCLUSIONS: We conclude that it is feasible to prepare and characterise CRCL from a variety of different tissue sources; a substantial portion of the protein content is identical among the different CRCLs, while the overall compositions also suggest high overlaps in functional categories. The protein content indicates the presence of antigens and implies a potential structure, which we believe may play a role in CRCL's ability to stimulate innate antigen presenting cell activation.

Targeting of prion-infected lymphoid cells to the central nervous system accelerates prion infection.

BACKGROUND: Prions, composed of a misfolded protein designated PrP(Sc), are infectious agents causing fatal neurodegenerative diseases. We have shown previously that, following induction of experimental autoimmune encephalomyelitis, prion-infected mice succumb to disease significantly earlier than controls, concomitant with the deposition of PrP(Sc) aggregates in inflamed white matter areas. In the present work, we asked whether prion disease acceleration by experimental autoimmune encephalomyelitis results from infiltration of viable prion-infected immune cells into the central nervous system. METHODS: C57Bl/6 J mice underwent intraperitoneal inoculation with scrapie brain homogenates and were later induced with experimental autoimmune encephalomyelitis by inoculation of MOG(35-55) in complete Freund's adjuvant supplemented with pertussis toxin. Spleen and lymph node cells from the co-induced animals were reactivated and subsequently injected into naïve mice as viable cells or as cell homogenates. Control groups were infected with viable and homogenized scrapie immune cells only with complete Freund's adjuvant. Prion disease incubation times as well as levels and sites of PrP(Sc) deposition were next evaluated. RESULTS: We first show that acceleration of prion disease by experimental autoimmune encephalomyelitis requires the presence of high levels of spleen PrP(Sc). Next, we present evidence that mice infected with activated prion-experimental autoimmune encephalomyelitis viable cells succumb to prion disease considerably faster than do mice infected with equivalent cell extracts or other controls, concomitant with the deposition of PrP(Sc) aggregates in white matter areas in brains and spinal cords. CONCLUSIONS: Our results indicate that inflammatory targeting of viable prion-infected immune cells to the central nervous system accelerates prion disease propagation. We also show that in the absence of such targeting it is the load of PrP(Sc) in the inoculum that determines the infectivity titers for subsequent transmissions. Both of these conclusions have important clinical implications as related to the risk of prion disease contamination of blood products.

Chemically induced accumulation of GAGs delays PrP(Sc) clearance but prolongs prion disease incubation time.

Prion diseases are a group of fatal neurodegenerative diseases affecting humans and animals. The only identified component of the infectious prion is PrP(Sc), an aberrantly folded isoform of PrP(C). Glycosaminoglycans, which constitute the main receptor for prions on cells, play a complex role in the pathogenesis of prion diseases. For example, while agents inducing aberrant lysosomal accumulation of GAGs such as Tilorone and Quinacrine significantly reduced PrP(Sc) content in scrapie-infected cells, administration of Quinacrine to prion-infected subjects did not improve their clinical status. In this study, we investigated the association of PrP(Sc )with cells cultured with Tilorone. We found that while the initial incorporation of PrP(Sc) was similar in the treated and untreated cells, clearance of PrP(Sc) from the Tilorone-treated cells was significantly impaired. Interestingly, prolonged administration of Tilorone to mice prior to prion infection resulted in a significant delay in disease onset, concomitantly with in vivo accumulation of lysosomal GAGs. We hypothesize that GAGs may complex with newly incorporated PrP(Sc) in lysosomes and further stabilize the prion protein conformation. Over-stabilized PrP(Sc) molecules have been shown to comprise reduced converting activity.

Prion urine comprises a glycosaminoglycan-light chain IgG complex that can be stained by Congo red.

Light chain IgG, a known amyloidotic protein, is present in the urine of prion disease affected individuals in a protease resistant form. In addition, it was shown recently that prion urine samples comprise a significant excess of glycosaminoglycans. Since amyloidotic proteins and glycosaminoglycans are the major components of amyloid aggregates, a Congo red dot blot assay was developed for detection of Creutzfeldt-Jacob disease (CJD) in urine. This assay was also positive for about 10% of patients suffering from diseases such as Alzheimer disease, cerebrovascular attacks and multiple sclerosis, but negative for healthy controls. Both glycosaminoglycans and proteins such as light chain IgG were required for the binding of Congo red to the urine fractions, as shown by the fact that Proteinase K digestion of the samples either after guanidine or after choindrotinase abolished the Congo red signal from the CJD samples.

The metabolism of glycosaminoglycans is impaired in prion diseases.

It is well established that the conversion of PrP(C) to PrP(Sc) is the key event in prion disease biology. In addition, several lines of evidence suggest that glycosaminoglycans (GAGs) and in particular heparan sulfate (HS) may play a role in the PrP(C) to PrP(Sc) conversion process. It has been proposed that PrP(Sc) accumulation in prion diseases may induce aberrant activation of lysosomal activity, which has been shown to result in neurodegeneration in a number of diseases, especially lysosomal storage disorders. Among such diseases, only the ones resulting from defects in GAGs degradation are accompanied by secretion of large amounts of GAG metabolites in urine. In this work, we show that GAGs are secreted in the urine of prion-infected animals and humans, and surprisingly, also in the urine of mice ablated for the PrP gene. We hypothesize that both the presence of PrP(Sc) or the absence of PrP(C) may alter the metabolism of GAGs.