Biology subjects

Griffin, A.

Publications and source records attributed to Griffin, A..

13 recordsLinked to original sources

bioRxiv2026

Systemic and tumor intrinsic expansion of FCRL5 expressing B cells associates with poor response to Bacillus Calmette-Guerin immunotherapy in patients with non-muscle invasive bladder cancer

The majority of patients treated with Bacillus Calmette-Guerin (BCG) immunotherapy, for non-muscle invasive bladder cancer (NMIBC), experience early recurrence due to pre-existing mucosal immune dysfunction. Since B cell are mucosal immune sentinels, we characterized the systemic and local B cell responses in 45 patients with NMIBC. Expansion of circulating atypical B cells (ABCs) following repeated BCG instillation, expanded IgG autoantibody repertoire, progressive IgG reactivity against BCG antigens, and higher tumor IgG deposition, were features of patients who recurred early. Integrated spatial immunophenotyping and single cell spatial transcriptomic analysis of corresponding tumors revealed increased ABCs within tertiary lymphoid structures, and co-localization with PD-1 B cells, regulatory T cells, and CD163 macrophages. Independent validation in two patient cohorts (total n = 409), revealed a significant association between high expression of the ABC specific, FCRL5, and poor outcomes. Our study identifies ABCs as key mediators of poor response to BCG in patients with high-risk NMIBC.

cancer biology↗

bioRxiv2026

Low-dose VSV-EBOV vaccination provides rapid protection from lethal Ebola virus challenge

In the decade since the West African Ebola virus (EBOV) epidemic, several medical countermeasures against this often-fatal hemorrhagic disease have been approved by regulatory authorities for human use. This includes monoclonal antibody-based therapies and vaccines which have been stockpiled in limited quantities. One of the vaccines is based on vesicular stomatitis virus (VSV) expressing the EBOV glycoprotein (GP) as the immunogen. The vaccine is stockpiled in limited quantity for emergency use. A single high dose has been shown to rapidly protect humans within 10 days. We developed an updated version of this vaccine expressing the GP from the 2015 EBOV-Makona isolate. Here, we wanted to determine the protective efficacy within 10 days of a single moderate dose (10-fold and 1,000-fold dilution) of the updated vaccine in nonhuman primates (NHPs). As a comparator we included a 1000-fold dilution dose group of the approved vaccine expressing the EBOV-Kikwit GP. While we achieved uniform protection with the approved vaccine at the moderate dose, only 50% of the NHPs receiving the same dose of the updated vaccine expressing the EBOV-Makona GP were protected. This study highlights the importance of evaluating VSV-based vaccine stocks expressing different filovirus GPs in preclinical models prior to progression with clinical development. Our study also highlights that rapid vaccination with reduced doses still leads to protection but at the cost of "sterile" immunity raising concerns regarding EBOV persistence and potential downstream transmission. Therefore, lower vaccine doses should only be considered in cases of severe vaccine shortage.

microbiology↗

bioRxiv2025

Haploinsufficiency of KPNA7 causes otosclerosis, likely due to the release of import inhibition of PTHrP and the reactivation of chondrogenesis in the globuli interossei

Otosclerosis is a genetic bone disorder restricted to the otic capsule and a common cause of conductive hearing loss with both familial and sporadic cases. To date, 14 genomic loci (OTSC) and four underlying OTSC genes (MEPE, SERPINF1, FOXL1, SMARCA4) have been identified in autosomal dominant families. A combined genetic/genomics approach on five affected siblings of Northern European ancestry from the island of Newfoundland, Canada identified a premature stop mutation in Karyopherin subunit 7 (KPNA7, c.49C>T, p.R17X). KPNA7 maps to OTSC2 (7q22.1) and encodes the newest of the seven-member importin- family of nuclear transporters and plays a critical role in early embryonic cleavage events and zygotic genome activation. Previous studies reveal that recessive KPNA7 variants cause skeletal abnormalities, including scoliosis and ocular hypertelorism in two sisters with Partial Corpus Callosum Agenesis-Cerebellar Vermis Hypoplasia With Posterior Fosa Cysts Syndrome and more recently, have been implicated in preimplantation embryo arrest (PREMBA) (OMIM 614107). Interestingly, KPNA7 is also a maternal factor with an exclusively embryonic role and likely inhibits non-classical NLS transport of PTHrP, a known activator of chondrogenesis. We propose that KPNA7 haploinsufficiency causes a failure in nuclear transport inhibition of PTHrP in the quiescent embryonic cells of the globuli interossei in the otic capsule and re-activates chondrogenesis. The KPNA7 discovery provides new insights into the pathogenesis of otosclerosis and potential for targeted therapies. Author SummaryOtosclerosis is a distinctly human genetic bone disorder of the otic capsule and a major cause of progressive hearing loss in young adults, particularly in females. Even though otosclerosis has been recognized as a distinct entity for a long time, both its pathogenesis and restriction to the otic capsule remains a mystery. Here, we use a combined genetic/genomics approach to identify a premature stop mutation in five affected siblings of Northern European ancestry from the island of Newfoundland, Canada. KPNA7 encodes the newest of the seven-member importin- family of nuclear transporters and plays a critical role in early embryonic cleavage events and zygotic genome activation. Based on the unique features of the otic capsule, we hypothesize that the premature stop mutation in KPNA7 leads to haploinsufficiency causing a failure in nuclear transport inhibition of PTHrP and reactivates chondrogenesis in the otherwise quiescent embryonic cells within the otic capsule. The KPNA7 discovery provides new insights into the pathogenesis of otosclerosis and potential for targeted therapies.

genetics↗

bioRxiv2025

Nerve injury promotes glial immune responses through a Draper/Ninjurin A pathway

Degenerating neurons elicit striking immune reactions from glial cells, including directed invasion of injury sites and engulfment of neuronal debris. While these conserved glial immune responses are neuroprotective, our mechanistic understanding of glial immunity in the damaged and diseased brain is still incomplete. Here, using an in vivo nerve injury assay in the adult Drosophila olfactory system, we characterize a novel role for the transmembrane adhesion molecule Ninjurin A (NijA). We show that NijA is transcriptionally upregulated in neuropil ensheathing glia, but not local astrocytes, within hours after olfactory nerve transection. In NijA mutants, glia fail to properly infiltrate areas that contain severed olfactory nerves, and degenerating axonal debris is not cleared from the CNS. One well-defined signaling cascade critical for ensheathing glial clearance of damaged olfactory axons is the conserved MEGF10/Draper pathway, which includes the engulfment receptor Draper, downstream transcriptional complex AP-1, and known gene target MMP-1. We show that injury-induced transcription of NijA in responding glia requires the Draper receptor but is independent of MMP-1, suggesting a parallel signaling cascade is activated downstream of Draper in responding glia. Our findings reveal an essential role for the glial adhesion factor NijA in morphological and phagocytic responses to CNS damage, highlighting this conserved molecule as a new potential glial therapeutic target for neurodegenerative conditions.

neuroscience↗

bioRxiv2024

Jamaican fruit bats (Artibeus jamaicensis) competence for Ebola virus but not Marburg virus is driven by intrinsic differences in viral entry and IFN-I signaling antagonism.

Ebola virus (EBOV) and Marburg virus (MARV) are zoonotic filoviruses that cause hemorrhagic fever in humans. Bat species in both Chiropteran suborders host filoviruses, suggesting that bats may have coevolved with this viral family. Correlative data implicate bats as natural EBOV hosts, but neither a full-length genome nor an EBOV isolate has been found in any bats sampled. Here, we modelled filovirus infection in the Jamaican fruit bat (JFB), Artibeus jamaicensis. Bats were inoculated with either EBOV or MARV through a combination of oral, intranasal, and subcutaneous routes. EBOV-infected bats supported systemic virus replication and shed infectious virus orally. In contrast, MARV replicated only transiently and was not shed. In vitro, JFB cells replicate EBOV more efficiently than MARV, and MARV infection induced innate antiviral responses that EBOV efficiently suppressed. Experiments using VSV pseudoparticles or replicating VSV expressing the EBOV or MARV glycoprotein demonstrated an advantage for EBOV entry and replication early, respectively, in JFB cells. Overall, this study describes filovirus species-specific phenotypes for both JFB and their cells.

immunology↗

bioRxiv2023

Prenatal inflammation reprograms hyperactive ILC2s that promote allergic lung inflammation and airway dysfunction

Allergic asthma is a chronic respiratory disease that initiates in early life, but causal mechanisms are poorly understood. Here we examined how prenatal inflammation shapes allergic asthma susceptibility by reprogramming lung immunity from early development. Induction of Type I interferon-mediated inflammation during development provoked expansion and hyperactivation of group 2 innate lymphoid cells (ILC2s) seeding the developing lung. Hyperactivated ILC2s produced increased IL-5 and IL-13, and were associated with acute Th2 bias, eosinophilia, and decreased Tregs in the lung. The hyperactive ILC2 phenotype was recapitulated by adoptive transfer of a fetal liver precursor following exposure to prenatal inflammation, indicative of developmental programming. Programming of ILC2 function and subsequent lung immune remodeling by prenatal inflammation led to airway dysfunction at baseline and in response to papain, indicating increased asthma susceptibility. Our data provide a link by which developmental programming of progenitors by early-life inflammation drives lung immune remodeling and asthma susceptibility through hyperactivation of lung-resident ILC2s. One Sentence SummaryPrenatal inflammation programs asthma susceptibility by inducing the production of hyperactivated ILC2s in the developing lung.

immunology↗

bioRxiv2023

Genomic epidemiology of European Aspergillus fumigatus causing COVID-19-associated pulmonary aspergillosis in Europe

The opportunistic fungus Aspergillus fumigatus has been found to cause coinfections in patients with severe SARS-CoV-2 virus infection, leading to COVID-19-associated pulmonary aspergillosis (CAPA). The CAPA all-cause mortality rate is approximately 50% and may be complicated by azole-resistance. Genomic epidemiology can help shed light on the genetics of A. fumigatus causing CAPA including the prevalence of alleles that are associated with azole-resistance. Here, a population genomic analysis of 21 CAPA isolates from four European countries is presented. The CAPA isolates were compared with A. fumigatus from a wider population of 167 non-CAPA clinical isolates and 73 environmental isolates. Bioinformatic analysis and antifungal susceptibility testing were performed to quantify resistance and identify possible genetically-encoded azole-resistant mechanisms. Phylogenetic analysis of the 21 CAPA isolates showed a lack of genetic distinction from the wider A. fumigatus population, with isolates distributed within two distinct clades (A and B), with the majority of the CAPA isolates in clade B (71.4%). The prevalence of phenotypic azole-resistance in CAPA was 14.3% (n=3/21); all three CAPA isolates contained a known resistance-associated cyp51A polymorphism. CAPA isolates are drawn from the wider A. fumigatus population rather than forming a unique genetic background showing that COVID-19 patients are susceptible to the entire A. fumigatus population. However, the relatively high prevalence of azole-resistance alleles that we document poses a threat to treatment success rates, warranting enhanced detection and surveillance of A. fumigatus genotypes in these patients. Furthermore, potential changes to antifungal first-line treatment guidelines may be needed to improve patient outcomes.

microbiology↗

bioRxiv2023

Gene conversion limits the cost of asexuality in immortal worms

Most multicellular organisms reproduce sexually despite the costs associated with sexuality. This has been explained as the result of selection favouring the ability to recombine the genome. The lack of recombination in asexual species constrains their adaptability and leads to the accumulation of deleterious mutations, ultimately increasing their risk of extinction. Nonetheless, successful asexual life histories persist among multicellular organisms, and explanatory mechanisms which may help limit the cost of asexuality remain enigmatic. In search of these mechanisms, we looked at that the molecular evolutionary changes in the sexual and obligately asexual strains of the planarian flatworm, Schmidtea mediterranea. We find that the accumulation of deleterious mutations in highly conserved genes is largely avoided in the asexual strain. We find evidence that this is achieved by somatic gene conversion in stem cells allowing for the restoration of beneficial alleles and purification of deleterious mutations. Taken together, our analysis identifies gene conversion as a mechanism which may contribute to the maintenance of asexuality in an obligately fissiparous metazoan.

evolutionary biology↗

bioRxiv2022

Molnupiravir (MK-4482) is efficacious against Omicron and other SARS-CoV-2 variants in the Syrian hamster COVID-19 model

The recent emergence of the SARS-CoV-2 Omicron variant of concern (VOC) containing a heavily mutated spike protein capable of escaping preexisting immunity, identifies a continued need for interventional measures. Molnupiravir (MK-4482), an orally administered nucleoside analog, has demonstrated efficacy against earlier SARS-CoV-2 lineages and was recently approved for SARS-CoV-2 infections in high-risk adults. Here we assessed the efficacy of MK-4482 against the earlier Alpha, Beta and Delta VOCs and Omicron in the Syrian hamster COVID-19 model. Omicron replication and associated lung disease in vehicle treated hamsters was reduced compared to the earlier VOCs. MK-4482 treatment inhibited virus replication in the lungs of Alpha, Beta and Delta VOC infected hamsters. Importantly, MK-4482 profoundly inhibited virus replication in the upper and lower respiratory tract of hamsters infected with the Omicron VOC. Consistent with its mutagenic mechanism, MK-4482 treatment had a more pronounced inhibitory effect on infectious virus titers compared to viral RNA genome load. Histopathologic analysis showed that MK-4482 treatment caused a concomitant reduction in the level of lung disease and viral antigen load in infected hamsters across all VOCs examined. Together, our data indicate the potential of MK-4482 as an effective antiviral against known SARS-CoV-2 VOCs, especially Omicron, and likely future SARS-CoV-2 variants. One Sentence SummaryMK-4482 inhibits replication of multiple SARS-CoV-2 variants of concern, including Omicron, in the Syrian hamster COVID-19 model

microbiology↗

bioRxiv2021

Serum from COVID-19 patients early in the pandemic shows limited evidence of cross-neutralization against variants of concern

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) results in a variety of clinical symptoms ranging from no or mild to severe disease. Currently, there are multiple postulated mechanisms that may push a moderate to severe disease into a critical state. Human serum contains abundant evidence of the immune status following infection. Cytokines, chemokines, and antibodies can be assayed to determine the extent to which a patient responded to a pathogen. We examined serum and plasma from a cohort of patients infected with SARS-CoV-2 early in the pandemic and compared them to negative-control sera. Cytokine and chemokine concentrations varied depending on the severity of infection, and antibody responses were significantly increased in severe cases compared to mild to moderate infections. Neutralization data revealed that patients with high titers against an early 2020 isolate had detectable but limited neutralizing antibodies against newly circulating SARS-CoV-2 variants of concern. This study highlights the potential of re-infection for recovered COVID-19 patients.

microbiology↗

bioRxiv2021

Phenotypic analysis of catastrophic childhood epilepsy genes: The Epilepsy Zebrafish Project

Genetic engineering techniques have contributed to the now widespread use of zebrafish to investigate gene function, but zebrafish-based human disease studies, and particularly for neurological disorders, are limited. Here we used CRISPR-Cas9 to generate 40 single-gene mutant zebrafish lines representing catastrophic childhood epilepsies. We evaluated larval phenotypes using electrophysiological, behavioral, neuro-anatomical, survival and pharmacological assays. Phenotypes with unprovoked electrographic seizure activity (i.e., epilepsy) were identified in zebrafish lines for 8 genes; ARX, EEF1A, GABRB3, GRIN1, PNPO, SCN1A, STRADA and STXBP1. A unifying epilepsy classification scheme was developed based on local field potential recordings and blinded scoring from ~3300 larvae. We also created an open-source database containing sequencing information, survival curves, behavioral profiles and representative electrophysiology data. We offer all zebrafish lines as a resource to the neuroscience community and envision them as a starting point for further functional analysis and/or identification of new therapies.

neuroscience↗

bioRxiv2020

Pancreatic Ductal Adenocarcinoma Comprises Coexisting Regulatory States with both Common and Distinct Dependencies

Despite extensive efforts, reproducible assessment of pancreatic ductal adenocarcinoma (PDA) heterogeneity and plasticity at the single cell level remains elusive. Systematic, network-based analysis of regulatory protein activity in single cells identified three PDA Developmental Lineages (PDLs), coexisting in virtually all tumors, whose transcriptional states are mechanistically driven by aberrant activation of Master Regulator (MR) proteins associated with gastrointestinal lineages (GLS state), morphogen and EMT pathways (MOS state), and acinar-to-ductal metaplasia (ALS state), respectively. Each PDL is further subdivided into sub-states characterized by low vs. high MAPK pathway activity. This taxonomy was remarkably conserved across multiple cohorts, cell lines, and PDX models, and harmonized with bulk profile analyses. Cross-state plasticity and MR essentiality was confirmed by barcode-based lineage tracing and CRISPR/Cas9 assays, respectively, while MR ectopic expression induced PDL transdifferentiation. Together these data provide a mechanistic foundation for PDA heterogeneity and a roadmap for targeting PDA cellular subtypes.

cancer biology↗

bioRxiv2019

Phenotype-based screening of synthetic cannabinoids in a Dravet Syndrome zebrafish model

Dravet syndrome (DS) is a catastrophic epilepsy of childhood, characterized by cognitive impairment, severe seizures and increased risk for sudden unexplained death in epilepsy (SUDEP). Although refractory to conventional antiepileptic drugs, emerging preclinical and clinical evidence suggests that modulation of the endocanniboid system could be therapeutic in these patients. Here we used a validated zebrafish model of DS, scn1lab homozygous mutants, to screen a commercially available library containing 370 synthetic cannabinoid (SC) compounds for compounds effective in reducing spontaneous seizures. Primary phenotype-based screening was performed using a locomotion-based assay in 96-well plates, and a secondary local field potential recording assay was then used to confirm suppression of electrographic epileptiform events. Identified SCs with anti-seizure activity, in both assays, included five SCs structurally classified as indole-based cannabinoids: JWH 018 N-(5-chloropentyl) analog, JWH 018 N-(2-methylbutyl) isomer, 5-fluoro PB-22 5-hydroxyisoquinoline isomer, 5-fluoro ADBICA, and AB-FUBINACA 3-fluorobenzyl isomer. Our approach demonstrates that two-stage phenotype-based screening in a zebrafish model of DS successfully identifies synthetic cannabinoids with anti-seizure activity, and supports further investigation of SCs for refractory epilepsies.

neuroscience↗