Serum cytokine profiles in healthy nonhuman primates are blunted by sedation and demonstrate sexual dimorphism as detected by a validated multiplex immunoassay

The exploration of neuroinflammatory mechanism by which CRHR2 deficiency induced anxiety disorder

Inflammation stimulates the hypothalamic-pituitary adrenal (HPA) axis and triggers glial neuroinflammatory phenotypes, which reduces monoamine neurotransmitters by activating indoleamine 2,3-dioxygenase enzyme. These changes can induce psychiatric diseases, including anxiety. Corticotropin releasing hormone receptor 2 (CRHR2) in the HPA axis is involved in the etiology of anxiety. Omega(n)-3 polyunsaturated fatty acids (PUFAs) can attenuate anxiety through anti-inflammation and HPA axis modulation. However, the underlying molecular mechanism by CRHR2 modulates anxiety and its correlation with neuroinflammation remain unclear. Here, we first constructed a crhr2 zebrafish mutant line, and evaluated anxiety-like behaviors, gene expression associated with the HPA axis, neuroinflammatory response, neurotransmitters, and PUFAs profile in crhr2+/+ and crhr2-/- zebrafish. The crhr2 deficiency decreased cortisol levels and up-regulated crhr1 and down-regulated crhb, crhbp, ucn3l and proopiomelanocortin a (pomc a) in zebrafish. Interestingly, a significant increase in the neuroinflammatory markers, translocator protein (TSPO) and the activation of microglia M1 phenotype (CD11b) were found in crhr2-/- zebrafish. As a consequence, the expression of granulocyte-macrophage colony-stimulating factor, pro-inflammatory cytokines vascular endothelial growth factor, and astrocyte A1 phenotype c3 were up-regulated. While microglia anti-inflammatory phenotype (CD206), central anti-inflammatory cytokine interleukin-4, arginase-1, and transforming growth factor-β were downregulated. In parallel, crhr2-deficient zebrafish showed an upregulation of vdac1 protein, a TSPO ligand, and its downstream caspase-3. Furthermore, 5-HT/5-HIAA ratio was decreased and n-3 PUFAs deficiency was identified in crhr2-/- zebrafish. In conclusion, anxiety-like behavior displayed by crhr2-deficient zebrafish may be caused by the HPA axis dysfunction and enhanced neuroinflammation, which resulted in n-3 PUFAs and monoamine neurotransmitter reductions.

Metagenomic next-generation sequencing for the identification of infections caused by Gram-negative pathogens and the prediction of antimicrobial resistance

OBJECTIVE

The aim of this study was to evaluate the efficacy of metagenomic next-generation sequencing (mNGS) for the identification of Gram-negative bacteria (GNB) infections and the prediction of antimicrobial resistance.

METHODS

A retrospective analysis was conducted on 182 patients with diagnosis of GNB infections who underwent mNGS and conventional microbiological tests (CMTs).

RESULTS

The detection rate of mNGS was 96.15%, higher than CMTs (45.05%) with a significant difference (χ 2 = 114.46, P < .01). The pathogen spectrum identified by mNGS was significantly wider than CMTs. Interestingly, the detection rate of mNGS was substantially higher than that of CMTs (70.33% vs 23.08%, P < .01) in patients with but not without antibiotic exposure. There was a significant positive correlation between mapped reads and pro-inflammatory cytokines (interleukin-6 and interleukin-8). However, mNGS failed to predict antimicrobial resistance in 5 of 12 patients compared to phenotype antimicrobial susceptibility testing results.

CONCLUSIONS

Metagenomic next-generation sequencing has a higher detection rate, a wider pathogen spectrum, and is less affected by prior antibiotic exposure than CMTs in identifying Gram-negative pathogens. The mapped reads may reflect a pro-inflammatory state in GNB-infected patients. Inferring actual resistance phenotypes from metagenomic data remains a great challenge.

A bioengineered artificial interstitium supports long-term islet xenograft survival in nonhuman primates without immunosuppression

Cell-based therapies hold promise for many chronic conditions; however, the continued need for immunosuppression along with challenges in replacing cells to improve durability or retrieving cells for safety are major obstacles. We subcutaneously implanted a device engineered to exploit the innate transcapillary hydrostatic and colloid osmotic pressure generating ultrafiltrate to mimic interstitium. Long-term stable accumulation of ultrafiltrate was achieved in both rodents and nonhuman primates (NHPs) that was chemically similar to serum and achieved capillary blood oxygen concentration. The majority of adult pig islet grafts transplanted in non-immunosuppressed NHPs resulted in xenograft survival >100 days. Stable cytokine levels, normal neutrophil to lymphocyte ratio, and a lack of immune cell infiltration demonstrated successful immunoprotection and averted typical systemic changes related to xenograft transplant, especially inflammation. This approach eliminates the need for immunosuppression and permits percutaneous access for loading, reloading, biopsy, and recovery to de-risk the use of "unlimited" xenogeneic cell sources to realize widespread clinical translation of cell-based therapies.

Precision-activated T-cell engagers targeting HER2 or EGFR and CD3 mitigate on-target, off-tumor toxicity for immunotherapy in solid tumors

To enhance the therapeutic index of T-cell engagers (TCEs), we engineered masked, precision-activated TCEs (XPAT proteins), targeting a tumor antigen (human epidermal growth factor receptor 2 (HER2) or epidermal growth factor receptor (EGFR)) and CD3. Unstructured XTEN polypeptide masks flank the N and C termini of the TCE and are designed to be released by proteases in the tumor microenvironment. In vitro, unmasked HER2-XPAT (uTCE) demonstrates potent cytotoxicity, with XTEN polypeptide masking providing up to 4-log-fold protection. In vivo, HER2-XPAT protein induces protease-dependent antitumor activity and is proteolytically stable in healthy tissues. In non-human primates, HER2-XPAT protein demonstrates a strong safety margin (>400-fold increase in tolerated maximum concentration versus uTCE). HER2-XPAT protein cleavage is low and similar in plasma samples from healthy and diseased humans and non-human primates, supporting translatability of stability to patients. EGFR-XPAT protein confirmed the utility of XPAT technology for tumor targets more widely expressed in healthy tissues.

A nonhuman primate model of vertical sleeve gastrectomy facilitates mechanistic and translational research in human obesity

The obesity epidemic significantly contributes to overall morbidity and mortality. Bariatric surgery is the gold standard treatment for obesity and metabolic dysfunction, yet the mechanisms by which it exerts metabolic benefit remain unclear. Here, we demonstrate a model of vertical sleeve gastrectomy (VSG) in nonhuman primates (NHP) that mimics the complexity and outcomes in humans. We also show that VSG confers weight loss and durable metabolic benefit, where equivalent caloric intake in shams resulted in significant weight gain following surgery. Furthermore, we show that VSG is associated with early, weight-independent increases in bile acids, short-chain fatty acids, and reduced visceral adipose tissue (VAT) inflammation with a polarization of VAT-resident immunocytes toward highly regulatory myeloid cells and Tregs. These data demonstrate that this strongly translational NHP model can be used to interrogate factors driving successful intervention to unravel the interplay between physiologic systems and improve therapies for obesity and metabolic syndrome.

Opportunities for Refinement of Non-Human Primate Vaccine Studies

Non-human primates (NHPs) are used extensively in the development of vaccines and therapeutics for human disease. High standards in the design, conduct, and reporting of NHP vaccine studies are crucial for maximizing their scientific value and translation, and for making efficient use of precious resources. A key aspect is consideration of the 3Rs principles of replacement, reduction, and refinement. Funders of NHP research are placing increasing emphasis on the 3Rs, helping to ensure such studies are legitimate, ethical, and high-quality. The UK's National Centre for the 3Rs (NC3Rs) and the Coalition for Epidemic Preparedness Innovations (CEPI) have collaborated on a range of initiatives to support vaccine developers to implement the 3Rs, including hosting an international workshop in 2019. The workshop identified opportunities to refine NHP vaccine studies to minimize harm and improve welfare, which can yield better quality, more reproducible data. Careful animal selection, social housing, extensive environmental enrichment, training for cooperation with husbandry and procedures, provision of supportive care, and implementation of early humane endpoints are features of contemporary good practice that should and can be adopted more widely. The requirement for high-level biocontainment for some pathogens imposes challenges to implementing refinement but these are not insurmountable.