bioRxiv Science⌕ Search

Biology subjects

Goff, K.

Publications and source records attributed to Goff, K..

7 recordsLinked to original sources

Passive infusion of an S2-Stem broadly neutralizing antibody protects against SARS-CoV-2 infection and lower airway inflammation in rhesus macaques

The continued evolution of SARS-CoV-2 variants capable of subverting vaccine and infection-induced immunity suggests the advantage of a broadly protective vaccine against betacoronaviruses ({beta}-CoVs). Recent studies have isolated monoclonal antibodies (mAbs) from SARS-CoV-2 recovered-vaccinated donors capable of neutralizing many variants of SARS-CoV-2 and other {beta}-CoVs. Many of these mAbs target the conserved S2 stem region of the SARS-CoV-2 spike protein, rather the receptor binding domain contained within S1 primarily targeted by current SARS-CoV-2 vaccines. One of these S2-directed mAbs, CC40.8, has demonstrated protective efficacy in small animal models against SARS-CoV-2 challenge. As the next step in the pre-clinical testing of S2-directed antibodies as a strategy to protect from SARS-CoV-2 infection, we evaluated the in vivo efficacy of CC40.8 in a clinically relevant non-human primate model by conducting passive antibody transfer to rhesus macaques (RM) followed by SARS-CoV-2 challenge. CC40.8 mAb was intravenously infused at 10mg/kg, 1mg/kg, or 0.1 mg/kg into groups (n=6) of RM, alongside one group that received a control antibody (PGT121). Viral loads in the lower airway were significantly reduced in animals receiving higher doses of CC40.8. We observed a significant reduction in inflammatory cytokines and macrophages within the lower airway of animals infused with 10mg/kg and 1mg/kg doses of CC40.8. Viral genome sequencing demonstrated a lack of escape mutations in the CC40.8 epitope. Collectively, these data demonstrate the protective efficiency of broadly neutralizing S2-targeting antibodies against SARS-CoV-2 infection within the lower airway while providing critical preclinical work necessary for the development of pan-{beta}-CoV vaccines. AUTHOR SUMMARYIn this study, we explore the development of a broadly protective vaccine against betacoronaviruses ({beta}-CoVs), including SARS-CoV-2. We focused on monoclonal antibodies (mAbs) from individuals who recovered-vaccinated donors capable of neutralizing many variants of SARS-CoV-2 and other {beta}-CoVs. Unlike current vaccines that target the S1 region of the virus, these mAbs target a highly conserved S2 region of the spike protein. One antibody, CC40.8, showed promising results in small animal models. To further test its effectiveness, we infused CC40.8 into rhesus macaques at different doses and then challenged them with SARS-CoV-2. We found that higher doses of CC40.8 significantly reduced viral loads and inflammation in the lower airway. Additionally, there were no escape mutations in the targeted region, suggesting that the virus could not easily evade the antibody. Our findings highlight the potential of S2-targeting antibodies to protect against SARS-CoV-2 and support the development of vaccines that can broadly protect against various {beta}-CoVs. Conflicting InterestsRA, TFR, and DRB are listed as inventors on pending patent applications describing the SARS-CoV-2 and HCoV-HKU1 S cross-reactive antibodies. DRB and RA are listed as inventors on a pending patent application describing the S2 stem epitope immunogens identified in this study. DRB is a consultant for IAVI. All other authors declare that they have no competing interests. ONE SENTENCE SUMMARYPan-beta-coronavirus neutralizing mAb CC40.8 reduces SARS-CoV-2 viral loads and inflammation within the lower airway of infected rhesus macaques and provides pre-clinical support for S2-directed immunization strategies.

immunology↗

Construction of whole cell bacterial biosensors as an alternative environmental monitoring technology to detect naphthenic acids in oil sands process-affected water.

After extraction of bitumen from oil sands deposits, the oil sand process-affected water (OSPW) is stored in tailings ponds. Naphthenic acids in tailings ponds have been identified as the primary contributor to toxicity to aquatic life. As an alternative to other analytical methods, here we identify bacterial genes induced after growth in naphthenic acids and use synthetic biology approaches to construct a panel of candidate biosensors for NA detection in water. The main promoters of interest were the atuAR promoters from a naphthenic acid degradation operon and upstream TetR regulator, the marR operon which includes a MarR regulator and downstream naphthenic acid resistance genes, and a hypothetical gene with a possible role in fatty acid biology. Promoters were printed and cloned as transcriptional lux reporter plasmids that were introduced into a tailings pond-derived Pseudomonas species. All candidate biosensor strains were tested for transcriptional responses to naphthenic acid mixtures and individual compounds. The three priority promoters respond in a dose-dependent manner, which allows semi-quantitative measurements, to simple, acyclic and complex NA mixtures, and each promoter has unique NA specificities. The limits of NA detection from the various NA mixtures ranged between 1.5 - 15 mg/L. The atuA and marR promoters also detected NA in small volumes of OSPW samples and were induced by extracts of the panel of OSPW samples. While biosensors have been constructed for other hydrocarbons, here we describe a biosensor approach that could be employed in environmental monitoring of naphthenic acids in oil sands mining wastewater.

microbiology↗

The Impact of SIV-Induced Immunodeficiency on Clinical Manifestation, Immune Response, and Viral Dynamics in SARS-CoV-2 Coinfection

Persistent and uncontrolled SARS-CoV-2 replication in immunocompromised individuals has been observed and may be a contributing source of novel viral variants that continue to drive the pandemic. Importantly, the effects of immunodeficiency associated with chronic HIV infection on COVID-19 disease and viral persistence have not been directly addressed in a controlled setting. Here we conducted a pilot study wherein two pigtail macaques (PTM) chronically infected with SIVmac239 were exposed to SARS-CoV-2 and monitored for six weeks for clinical disease, viral replication, and viral evolution, and compared to our previously published cohort of SIV-naive PTM infected with SARS-CoV-2. At the time of SARS-CoV-2 infection, one PTM had minimal to no detectable CD4+ T cells in gut, blood, or bronchoalveolar lavage (BAL), while the other PTM harbored a small population of CD4+ T cells in all compartments. Clinical signs were not observed in either PTM; however, the more immunocompromised PTM exhibited a progressive increase in pulmonary infiltrating monocytes throughout SARS-CoV-2 infection. Single-cell RNA sequencing (scRNAseq) of the infiltrating monocytes revealed a less activated/inert phenotype. Neither SIV-infected PTM mounted detectable anti-SARS-CoV-2 T cell responses in blood or BAL, nor anti-SARS-CoV-2 neutralizing antibodies. Interestingly, despite the diminished cellular and humoral immune responses, SARS-CoV-2 viral kinetics and evolution were indistinguishable from SIV-naive PTM in all sampled mucosal sites (nasal, oral, and rectal), with clearance of virus by 3-4 weeks post infection. SIV-induced immunodeficiency significantly impacted immune responses to SARS-CoV-2 but did not alter disease progression, viral kinetics or evolution in the PTM model. SIV-induced immunodeficiency alone may not be sufficient to drive the emergence of novel viral variants.

immunology↗

Myeloid cell-driven nonregenerative pulmonary scarring is conserved in multiple nonhuman primate species regardless of SARS-CoV-2 infection modality

The novel coronavirus SARS-CoV-2 has caused a worldwide pandemic resulting in widespread efforts in development of animal models that recapitulate human disease for evaluation of medical countermeasures, and to dissect COVID-19 immunopathogenesis. We tested whether route of experimental infection substantially changes COVID-19 disease characteristics in two species (Macaca mulatta; rhesus macaques; RM, Chlorocebus atheiops; African green monkeys; AGM) of nonhuman primates. Species-specific cohorts of RM and AGM Rhesus macaques (Macaca mulatta, RMs) and African green monkeys (Chlorocebus aethiops, AGMs) were experimentally infected with homologous SARS-CoV-2 by either direct mucosal instillation or small particle aerosol in route-discrete subcohorts. Both species demonstrated equivalent infection initially by either exposure route although the magnitude and duration of viral loading was greater in AGMs than that of the RM. Clinical onset was nearly immediate (+1dpi) in mucosally-exposed cohorts whereas aerosol-infected animals began to show signs +7dpi. Myeloid cell responses indicative of the development of pulmonary scarring and extended lack of regenerative capacity in the pulmonary compartment was a conserved pathologic response in both species by either exposure modality. This pathological commonality may be useful in future anti-fibrosis therapeutic evaluations and expands our understanding of how SARS-CoV-2 infection leads to ARDS and functional lung damage.

microbiology↗

The pigtail macaque (Macaca nemestrina) model of COVID-19 reproduces diverse clinical outcomes and reveals new and complex signatures of disease

The novel coronavirus SARS-CoV-2, the causative agent of COVID-19 disease, has killed over four million people worldwide as of July 2021 with infections rising again due to the emergence of highly transmissible variants. Animal models that faithfully recapitulate human disease are critical for assessing SARS-CoV-2 viral and immune dynamics, for understanding mechanisms of disease, and for testing vaccines and therapeutics. Pigtail macaques (PTM, Macaca nemestrina) demonstrate a rapid and severe disease course when infected with simian immunodeficiency virus (SIV), including the development of severe cardiovascular symptoms that are pertinent to COVID-19 manifestations in humans. We thus proposed this species may likewise exhibit severe COVID-19 disease upon infection with SARS-CoV-2. Here, we extensively studied a cohort of SARS-CoV-2-infected PTM euthanized either 6- or 21-days after respiratory viral challenge. We show that PTM demonstrate largely mild-to-moderate COVID-19 disease. Pulmonary infiltrates were dominated by T cells, including CD4+ T cells that upregulate CD8 and express cytotoxic molecules, as well as virus-targeting T cells that were predominantly CD4+. We also noted increases in inflammatory and coagulation markers in blood, pulmonary pathologic lesions, and the development of neutralizing antibodies. Together, our data demonstrate that SARS-CoV-2 infection of PTM recapitulates important features of COVID-19 and reveals new immune and viral dynamics and thus may serve as a useful animal model for studying pathogenesis and testing vaccines and therapeutics.

immunology↗

Intra-host SARS-CoV-2 evolution in the gut of mucosally-infected Chlorocebus aethiops (African green monkeys)

In recent months, several SARS-CoV-2 variants have emerged that enhance transmissibility and escape host humoral immunity. Hence, the tracking of viral evolutionary trajectories is clearly of great importance. Little is known about SARS-CoV-2 evolution in nonhuman primate models used to test vaccines and therapies and to model human disease. Viral RNA was sequenced from rectal swabs from Chlorocebus aethiops (African green monkeys) after experimental respiratory SARS-CoV-2 infection. Two distinct patterns of viral evolution were identified that were shared between all collected samples. First, mutations in the furin cleavage site that were initially present in the virus as a consequence of VeroE6 cell culture adaptation were subsequently lost in virus recovered in rectal swabs, confirming the necessity of this motif for viral infection in vivo. Three amino acid changes were also identified; ORF 1a S2103F, and spike D215G and H655Y, that were detected in rectal swabs from all sampled animals. These findings are demonstrative of intra-host SARS-CoV-2 evolution unique to this nonhuman primate species and may identify a host-adapted variant of SARS-CoV-2 that would be useful in future development of primate disease models.

microbiology↗

Presynaptic development is controlled by the core active zone proteins CAST/ELKS

Many presynaptic active zone proteins have multiple regulatory roles that vary during distinct stages of neuronal circuit development. However, our understanding how presynaptic active zone proteins regulate synapse development during neuronal circuit maturation is in its early stages. Although CAST/ELKS are presynaptic active zone core proteins, their roles in synapse development in the mammalian central nervous system remain enigmatic. To unravel CAST/ELKS roles in glutamatergic synapse development, we analyzed how their loss during the early stages of circuit maturation impacted the calyx of Held presynaptic terminal development and function. We found a reduction in presynaptic surface area and volume, but an increase in active zone size. Additionally, we found a reduction in all presynaptic Cav2 channel subtype currents. Surprisingly, these changes did not impair synaptic transmission. We propose that CAST/ELKS are involved in pathways regulating presynaptic morphological properties and Cav2 channel subtype levels during early stages of neuronal circuit maturation.

neuroscience↗