239 research outputs found

    Determinants of anti-PD-1 response and resistance in clear cell renal cell carcinoma

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    ADAPTeR is a prospective, phase II study of nivolumab (anti-PD-1) in 15 treatment-naive patients (115 multiregion tumor samples) with metastatic clear cell renal cell carcinoma (ccRCC) aiming to understand the mechanism underpinning therapeutic response. Genomic analyses show no correlation between tumor molecular features and response, whereas ccRCC-specific human endogenous retrovirus expression indirectly correlates with clinical response. T cell receptor (TCR) analysis reveals a significantly higher number of expanded TCR clones pre-treatment in responders suggesting pre-existing immunity. Maintenance of highly similar clusters of TCRs post-treatment predict response, suggesting ongoing antigen engagement and survival of families of T cells likely recognizing the same antigens. In responders, nivolumab-bound CD8+ T cells are expanded and express GZMK/B. Our data suggest nivolumab drives both maintenance and replacement of previously expanded T cell clones, but only maintenance correlates with response. We hypothesize that maintenance and boosting of a pre-existing response is a key element of anti-PD-1 mode of action

    Gait in Parkinson’s disease: a visuo-cognitive challenge

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    Vision and cognition have both been related to gait impairment in Parkinson’s disease (PD) through separate strands of research. The cumulative and interactive effect of both (which we term visuo-cognition) has not been previously investigated and little is known about the influence of cognition on vision with respect to gait. Understanding the role of vision, cognition and visuo-cognition in gait in PD is critical for data interpretation and to infer and test underlying mechanisms. The purpose of this comprehensive narrative review was to examine the interdependent and interactive role of cognition and vision in gait in PD and older adults. Evidence from a broad range of research disciplines was reviewed and summarised. A key finding was that attention appears to play a pivotal role in mediating gait, cognition and vision, and should be considered emphatically in future research in this field

    The Formyl Peptide Receptor 2 Regulates Microglial Phenotype Through Immunometabolism: Implications for Alzheimer’s Disease

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    Microglia are key players in the pathology of Alzheimer’s disease (AD), driving chronic inflammation, oxidative stress, and the altered metabolism seen in the brains of patients. With clinical trials continuing to fail, new approaches towards drug development are critical. Strategies to reduce microglial activation may therefore be a viable therapeutic approach to tackling AD. Formyl peptide receptor 2 (Fpr2), which drives peripheral inflammatory resolution, is expressed in microglia. However, its functional role in neuroinflammation is unclear. This thesis provides evidence to support the peripheral findings of Fpr2 stimulation, wherein it may also hold promise for exploitation as a therapeutic for neurodegenerative disorders, including AD. We also highlight novel findings surrounding the modulation of both oxidative stress and microglial metabolism associated with Fpr2 activation. Under inflammatory conditions, we report that selective agonists for Fpr2 modulate the microglial inflammatory response, actively shifting from a pro-inflammatory to a pro-resolving phenotype, emphasised by the reduction of pro-inflammatory cytokines and concomitant increases in both pro-resolving cytokines and phagocytosis. Metabolic shifting away from glycolysis was also observed for pro-resolving microglia. Moreover, we describe for the first time that Fpr2 completely reverses reactive oxygen species (ROS) production from the mitochondria and NADPH oxidase enzymes following an inflammatory stimulus. We also highlight that the toxic oligomeric amyloid (oAβ) facilitates microglial ROS production and subsequent metabolic changes without triggering an inflammatory response. oAβ facilitated NADPH oxidase activation, which in turn resulted in the activation of glucose 6-phosphate dehydrogenase (G6PD), the rate limiting step for the pentose phosphate pathway. This metabolic pathway is responsible for producing NADPH, which in turn NADPH oxidases exploit for further ROS production. These changes resulted in noticeable reductions in both microglial glycolysis and oxidative phosphorylation. We present data underlining that Fpr2/3 stimulation reverses oAβ-induced ROS production, with a resultant reduction in G6PD activity and the return of homeostatic glycolysis. These oAβ-induced microglial changes triggered the apoptosis of SH-SY5Y cells in co-culture with BV-2 microglia. However, supporting our interest in Fpr2/3 for therapeutic approaches to neurodegenerative diseases, post-treatment with a select agonist for the receptor successfully prevented apoptosis of these neuronal like SH-SY5Y cells. This original data unveils novel functions of Fpr2/3 in the central nervous system (CNS), supplementing the well-established pro-resolving functions the receptor facilitates within the periphery. The combination of pro-resolving, anti-oxidative, immunometabolic and anti-apoptotic functions of Fpr2/3 support the exploitation of this receptor for therapeutic research into multiple different CNS disorders, including AD

    Determinants of anti-PD-1 response and resistance in clear cell renal cell carcinoma

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    Predicting Alcohol And Substance Abuse Treatment Outcomes Among Hispanic And African American Substance Abusers

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    Alcohol and drug use and abuse are significant concerns in the United States, yet few studies have investigated how cultural factors, such as acculturative type and acculturative stress, impact substance abuse treatment outcomes. In this study, African American (n = 171) and Hispanic (n = 101) substance abusers\u27 acculturative type and acculturative stress levels were compared to substance abuse treatment outcome. Although the results indicated that acculturative type did not predict substance abuse treatment outcome, a positive correlation between acculturative stress and alcohol and substance abuse problems emerged among the combined and Hispanic samples. In the combined and Hispanic groups, participants experiencing higher levels of acculturative stress demonstrated higher levels of substance use consequences at baseline. Additionally, Hispanic participants experiencing higher levels of pressure to acculturate related to difficulty in interpersonal interactions due to language or cultural barriers and encountering prejudice had higher levels of substance use consequences at the outcome of treatment. These findings suggest that cultural factors play a role in substance abuse treatment outcome. Recommendations on how substance abuse treatment facilities can respond to the unique needs of African American and Hispanic clients are provided

    Early immune pressure initiated by tissue-resident memory T cells sculpts tumor evolution in non-small cell lung cancer

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    Tissue-resident memory T (TRM) cells provide immune defense against local infection and can inhibit cancer progression. However, it is unclear to what extent chronic inflammation impacts TRM activation and whether TRM cells existing in tissues before tumor onset influence cancer evolution in humans. We performed deep profiling of healthy lungs and lung cancers in never-smokers (NSs) and ever-smokers (ESs), finding evidence of enhanced immunosurveillance by cells with a TRM-like phenotype in ES lungs. In preclinical models, tumor-specific or bystander TRM-like cells present prior to tumor onset boosted immune cell recruitment, causing tumor immune evasion through loss of MHC class I protein expression and resistance to immune checkpoint inhibitors. In humans, only tumors arising in ES patients underwent clonal immune evasion, unrelated to tobacco-associated mutagenic signatures or oncogenic drivers. These data demonstrate that enhanced TRM-like activity prior to tumor development shapes the evolution of tumor immunogenicity and can impact immunotherapy outcomes

    Monkey-based Research on Human Disease: The Implications of Genetic Differences

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    Assertions that the use of monkeys to investigate human diseases is valid scientifically are frequently based on a reported 90–93% genetic similarity between the species. Critical analyses of the relevance of monkey studies to human biology, however, indicate that this genetic similarity does not result in sufficient physiological similarity for monkeys to constitute good models for research, and that monkey data do not translate well to progress in clinical practice for humans. Salient examples include the failure of new drugs in clinical trials, the highly different infectivity and pathology of SIV/HIV, and poor extrapolation of research on Alzheimer’s disease, Parkinson’s disease and stroke. The major molecular differences underlying these inter-species phenotypic disparities have been revealed by comparative genomics and molecular biology — there are key differences in all aspects of gene expression and protein function, from chromosome and chromatin structure to post-translational modification. The collective effects of these differences are striking, extensive and widespread, and they show that the superficial similarity between human and monkey genetic sequences is of little benefit for biomedical research. The extrapolation of biomedical data from monkeys to humans is therefore highly unreliable, and the use of monkeys must be considered of questionable value, particularly given the breadth and potential of alternative methods of enquiry that are currently available to scientists

    The Hidden Role of Non-Canonical Amyloid beta Isoforms in Alzheimer's Disease

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    Recent advances have placed the pro-inflammatory activity of amyloid β (Aβ) on microglia cells as the focus of research on Alzheimer’s Disease (AD). Researchers are confronted with an astonishing spectrum of over 100 different Aβ variants with variable length and chemical modifications. With the exception of Aβ1-42 and Aβ1-40, the biological significance of most peptides for AD is as yet insufficiently understood. We therefore aim to provide a comprehensive overview of the contributions of these neglected Aβ variants to microglia activation. First, the impact of Aβ receptors, signaling cascades, scavenger mechanisms, and genetic variations on the physiological responses towards various Aβ species is described. Furthermore, we discuss the importance of different types of amyloid precursor protein processing for the generation of these Aβ variants in microglia, astrocytes, oligodendrocytes, and neurons, and highlight how alterations in secondary structures and oligomerization affect Aβ neurotoxicity. In sum, the data indicate that gene polymorphisms in Aβ-driven signaling pathways in combination with the production and activity of different Aβ variants might be crucial factors for the initiation and progression of different forms of AD. A deeper assessment of their interplay with glial cells may pave the way towards novel therapeutic strategies for individualized medicine
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