UNASSIGNED: Therapeutic antibodies have become a major strategy to treat oncologic diseases. For chronic lymphocytic leukemia, antibodies against CD20 are used to target and elicit cytotoxic responses against malignant B cells. However, efficacy is often compromised due to a suppressive microenvironment that interferes with cellular immune responses. To overcome this suppression, agonists of pattern recognition receptors have been studied which promote direct cytotoxicity or elicit anti-tumoral immune responses. NOD2 is an intracellular pattern recognition receptor that participates in the detection of peptidoglycan, a key component of bacterial cell walls. This detection then mediates the activation of multiple signaling pathways in myeloid cells. Although several NOD2 agonists are being used worldwide, the potential benefit of these agents in the context of antibody therapy has not been explored.
UNASSIGNED: Primary cells from healthy-donor volunteers (PBMCs, monocytes) or CLL patients (monocytes) were treated with versus without the NOD2 agonist L18-MDP, then antibody-mediated responses were assessed. In vivo, the Eµ-TCL1 mouse model of CLL was used to test the effects of L18-MDP treatment alone and in combination with anti-CD20 antibody.
UNASSIGNED: Treatment of peripheral blood mononuclear cells with L18-MDP led to activation of monocytes from both healthy donors and CLL patients. In addition, there was an upregulation of activating FcγR in monocytes and a subsequent increase in antibody-mediated phagocytosis. This effect required the NF-κB and p38 signaling pathways. Treatment with L18-MDP plus anti-CD20 antibody in the Eµ-TCL model of CLL led to a significant reduction of CLL load, as well as to phenotypic changes in splenic monocytes and macrophages.
UNASSIGNED: Taken together, these results suggest that NOD2 agonists help overturn the suppression of myeloid cells, and may improve the efficacy of antibody therapy for CLL.

Henipaviruses are enveloped single-stranded, negative-sense RNA viruses of the paramyxovirus family. Two henipaviruses, Nipah virus and Hendra virus, cause a systemic respiratory and/or neurological disease in humans and ten additional species of mammals, with a high fatality rate. Because of their highly pathogenic nature, Nipah virus and Hendra virus are categorized as BSL-4 pathogens, which limits the number and scope of translational research studies on these important human pathogens. To begin to address this limitation, we are developing a BSL-2 model of authentic henipavirus infection in mice, using the non-pathogenic henipavirus, Cedar virus. Notably, wild-type mice are highly resistant to Hendra virus and Nipah virus infection. However, previous work has shown that mice lacking expression of the type I interferon receptor (IFNAR-KO mice) are susceptible to both viruses. Here, we show that luciferase-expressing recombinant Cedar virus (rCedV-luc) is also able to replicate and establish a transient infection in IFNAR-KO mice, but not in wild-type mice. Using longitudinal bioluminescence imaging (BLI) of luciferase expression, we detected rCedV-luc replication as early as 10 h post-infection. Viral replication peaks between days 1 and 3 post-infection, and declines to levels undetectable by BLI by 7 days post-infection. Immunohistochemistry is consistent with viral infection and replication in endothelial cells and other non-immune cell types within tissue parenchyma. Serology analyses demonstrate significant IgG responses to the Cedar virus surface glycoprotein with potent neutralizing activity in IFNAR-KO mice, whereas antibody responses in wild-type animals were non-significant. Overall, these data suggest that rCedV-luc infection of IFNAR-KO mice represents a viable platform for the study of in vivo henipavirus replication, anti-henipavirus host responses and henipavirus-directed therapeutics.

Traumatic brain injury (TBI) survivors often suffer from agitated behaviors and will most likely receive pharmacological treatments. Choosing an optimal and safe treatment that will not interfere with neurological recovery remains controversial. By interfering with dopaminergic circuits, antipsychotics may impede processes important to cognitive recovery. Despite their frequent use, there have been no large randomized controlled studies of antipsychotics for the management of agitated behaviors during the acute TBI recovery period. We conducted a systematic review and meta-analysis of pre-clinical studies evaluating the effects of antipsychotics post-TBI on both cognitive and motor recovery. MEDLINE and Embase databases were searched up to August 2, 2023. Pre-clinical studies evaluating the effects of antipsychotics on cognitive and motor functions post-TBI were considered. Risk of bias was evaluated with the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool. We identified 15 studies including a total of 1188 rodents, mostly conducted in male Sprague-Dawley rats using cortical impact injury. The analysis revealed no consistent effect of haloperidol on motor functions, but risperidone was associated with a significant impairment in motor function on day 5 post-injury (7.05 sec; 95% confidence interval [CI]: 1.47, 12.62; I2 = 92%). Other atypical antipsychotics did not result in impaired motor function. When evaluating cognitive function, haloperidol- (23.00 sec; 95% CI: 17.42-28.59; I2 = 7%) and risperidone-treated rats (24.27 sec; 95% CI: 16.18-32.36; I2 = 0%) were consistently impaired when compared to controls. In studies evaluating atypical antipsychotics, no impairments were observed. Clinicians should avoid the regular use of haloperidol and risperidone, and future human studies should be conducted with atypical antipsychotics.

In December 2022 the US Food and Drug Administration (FDA) removed the requirement that drugs in development must undergo animal testing before clinical evaluation, a declaration that now demands the establishment and verification of ex vivo preclinical models that closely represent tumor complexity and that can predict therapeutic response. Fortunately, the emergence of patient-derived organoid (PDOs) culture has enabled the ex vivo mimicking of the pathophysiology of human tumors with the reassembly of tissue-specific features. These features include histopathological variability, molecular expression profiles, genetic and cellular heterogeneity of parental tissue, and furthermore growing evidence suggests the ability to predict patient therapeutic response. Concentrating on the highly lethal and heterogeneous gastrointestinal (GI) tumors, herein we present the state-of-the-art and the current methodology of PDOs. We highlight the potential additions, improvements and testing required to allow the ex vivo of study the tumor microenvironment, as well as offering commentary on the predictive value of clinical response to treatments such as chemotherapy and immunotherapy.

Treatment options for multidrug-resistant bacterial infections are limited and often ineffective. Fecal microbiota transplantation (FMT) has emerged as a promising therapy for intestinal multidrug-resistant bacterial decolonization. However, clinical results are discrepant. The aim of our pilot study was to evaluate the screening performance of a simple diagnostic tool to select fecal samples that will be effective in decolonizing the intestine. Fecal samples from 10 healthy subjects were selected. We developed an agar spot test to evaluate their antagonistic activity toward the growth of VanA Enterococcus faecium and OXA-48-producing Klebsiella pneumoniae, two of the most serious and urgent threats of antibiotic resistance. Most fecal samples were able to limit the growth of both bacteria in vitro but with large inter-individual variation. The samples with the highest and lowest antagonistic activity were used for FMT in a mouse model of intestinal colonization. FMT was not successful in reducing intestinal colonization with VanA Enterococcus faecium, whereas FMT performed with the fecal sample showing the highest activity on the agar spot test was able to significantly reduce the intestinal colonization of mice with Klebsiella pneumoniae OXA-48. The agar spot test could thus serve as a reliable screening tool to select stool samples with the best potential to eradicate/reduce multidrug-resistant bacteria carriage after FMT.

The eye is particularly suited to gene therapy due to its accessibility, immunoprivileged state and compartmentalised structure. Indeed, many clinical trials are underway for therapeutic gene strategies for inherited retinal degenerations (IRDs). However, as there are currently 281 genes associated with IRD, there is still a large unmet need for effective therapies for the majority of IRD-causing genes. In humans, RAB28 null and hypomorphic alleles cause autosomal recessive cone-rod dystrophy (arCORD). Previous work demonstrated that restoring wild type zebrafish Rab28 via germline transgenesis, specifically in cone photoreceptors, is sufficient to rescue the defects in outer segment phagocytosis (OSP) observed in zebrafish rab28-/- knockouts (KO). This rescue suggests that gene therapy for RAB28-associated CORD may be successful by RAB28 gene restoration to cones. It also inspired us to critically consider the scenarios in which zebrafish can provide informative preclinical data for development of gene therapies. Thus, this review focuses on RAB28 biology and disease, and delves into both the opportunities and limitations of using zebrafish as a model for both gene therapy development and as a diagnostic tool for patient variants of unknown significance (VUS).

Organ-on-chip systems are capable of replicating complex tissue structures and physiological phenomena. The fine control of biochemical and biomechanical cues within these microphysiological systems provides opportunities for cancer researchers to build complex models of the tumour microenvironment. Interest in applying organ chips to investigate mechanisms such as metastatsis and to test therapeutics has grown rapidly, and this review draws together the published research using these microfluidic platforms to study cancer. We focus on both in-house systems and commercial platforms being used in the UK for fundamental discovery science and therapeutics testing. We cover the wide variety of cancers being investigated, ranging from common carcinomas to rare sarcomas, as well as secondary cancers. We also cover the broad sweep of different matrix microenvironments, physiological mechanical stimuli and immunological effects being replicated in these models. We examine microfluidic models specifically, rather than organoids or complex tissue or cell co-cultures, which have been reviewed elsewhere. However, there is increasing interest in incorporating organoids, spheroids and other tissue cultures into microfluidic organ chips and this overlap is included. Our review includes a commentary on cancer organ-chip models being developed and used in the UK, including work conducted by members of the UK Organ-on-a-Chip Technologies Network. We conclude with a reflection on the likely future of this rapidly expanding field of oncological research.

BACKGROUND: Thymic malignancies are a heterogeneous group of rare cancers for which systemic chemotherapy is the standard treatment in the setting of advanced, recurrent or refractory diseases. Both environmental and genetic risk factors have not been fully clarified and few target-specific drugs have been developed for thymic epithelial tumors. A major challenge in studying thymic epithelial tumors is the lack of preclinical models for translational studies.
METHODS: Starting from bioptic material of two consecutive recurrences of the same patient, we generated two patient-derived xenografts. The patient-derived xenografts models were characterized for histology by immunohistochemistry and mutations using next-generation sequencing. When compared to the original tumors resected from the patient, the two patient-derived xenografts had preserved morphology after the stain with hematoxylin and eosin, although there was a moderate degree of de-differentiation. From a molecular point of view, the two patient-derived xenografts maintained 74.3 and 61.8% of the mutations present in the human tumor of origin.
CONCLUSIONS: The newly generated patient-derived xenografts recapitulate both the molecular characteristics and the evolution of the thymoma it derives from well, allowing to address open questions for this rare cancer.

Spinal cord injury (SCI) frequently results in motor, sensory, and autonomic dysfunction for which there is currently no cure. Recent pre-clinical and clinical research has led to promising advances in treatment; however, therapeutics indicating promise in rodents have not translated successfully in human trials, likely due, in part, to gross anatomical and physiological differences between the species. Therefore, large animal models of SCI may facilitate the study of secondary injury processes that are influenced by scale, and may assist the translation of potential therapeutic interventions. The aim of this study was to characterize two severities of thoracic contusion SCI in female domestic pigs, measuring motor function and spinal cord lesion characteristics, over 2 weeks post-SCI. A custom-instrumented weight-drop injury device was used to release a 50 g impactor from 10 cm (n = 3) or 20 cm (n = 7) onto the exposed dura, to induce a contusion at the T10 thoracic spinal level. Hind limb motor function was assessed at 8 and 13 days post-SCI using a 10-point scale. Volume and extent of lesion-associated signal hyperintensity in T2-weighted magnetic resonance (MR) images were assessed at 3, 7, and 14 days post-injury. Animals were transcardially perfused at 14 days post-SCI and spinal cord tissue was harvested for histological analysis. Bowel function was retained in all animals and transient urinary retention occurred in one animal after catheter removal. All animals displayed hind limb motor deficits. Animals in the 10-cm group demonstrated some stepping and weight-bearing and scored a median 2-3 points higher on the 10-point motor function scale at 8 and 13 days post-SCI, than did the 20-cm group. Histological lesion volume was 20% greater, and 30% less white matter was spared, in the 20-cm group than in the 10-cm group. The MR signal hyperintensity in the 20-cm injury group had a median cranial-caudal extent approximately 1.5 times greater than the 10-cm injury group at all three time-points, and median volumes 1.8, 2.5, and 4.5 times greater at day 3, 7, and 14 post-injury, respectively. Regional differences in axonal injury were observed between groups, with amyloid precursor protein immunoreactivity greatest in the 20-cm group in spinal cord sections adjacent to the injury epicenter. This study demonstrated graded injuries in a domestic pig strain, with outcome measures comparable to miniature pig models of contusion SCI. The model provides a vehicle for the study of SCI and potential treatments, particularly where miniature pig strains are not available and/or where small animal models are not appropriate for the research question.

Chronic obstructive pulmonary disease (COPD) is a devastating disease commonly caused by cigarette smoke (CS) exposure that drives tissue injury by persistently recruiting myeloid cells into the lungs. A significant portion of COPD patients also present with overlapping asthma pathology including eosinophilic inflammation. The βc cytokine family includes granulocyte monocyte-colony-stimulating factor, IL-5 and IL-3 that signal through their common receptor subunit βc to promote the expansion and survival of multiple myeloid cells including monocytes/macrophages, neutrophils and eosinophils.
We have used our unique human βc receptor transgenic (hβc Tg) mouse strain that expresses human βc instead of mouse βc and βIL3 in an acute CS exposure model. Lung tissue injury was assessed by histology and measurement of albumin and lactate dehydrogenase levels in the bronchoalveolar lavage (BAL) fluid. Transgenic mice were treated with an antibody (CSL311) that inhibits human βc signalling.
hβc Tg mice responded to acute CS exposure by expanding blood myeloid cell numbers and recruiting monocyte-derived macrophages (cluster of differentiation 11b+ [CD11b+ ] interstitial and exudative macrophages [IM and ExM]), neutrophils and eosinophils into the lungs. This inflammatory response was associated with lung tissue injury and oedema. Importantly, CSL311 treatment in CS-exposed mice markedly reduced myeloid cell numbers in the blood and BAL compartment. Furthermore, CSL311 significantly reduced lung CD11b+ IM and ExM, neutrophils and eosinophils, and this decline was associated with a significant reduction in matrix metalloproteinase-12 (MMP-12) and IL-17A expression, tissue injury and oedema.
This study identifies CSL311 as a therapeutic antibody that potently inhibits immunopathology and lung injury caused by acute CS exposure.