Small Subunit Research Articles

Phylogeny of Geoglossomycetes with species diversity in China

ABSTRACT Geoglossomycetes is a class within the phylum Ascomycota that accommodates a single order and a single family, comprising nine genera. Geoglossomycetes is traditionally referred to as “earth tongues”. The class is characterised by tongue-shaped to clavate, stipitate, black ascomata covered with or without black setae, a swollen ascigerous portion, a cylindric stipe, filiform, septate paraphyses, cylindrical-clavate, 4–8-spored asci, and filiform or falciform, multi-septate, dark brown to hyaline ascospores. In this study, we examined 34 samples from four genera in China. Based on ecological comparisons, morphological studies, and phylogenetic analyses inferred from the combined internal transcribed spacer (ITS) regions and the large subunit of the ribosomal RNA gene (LSU), we introduce ten new species of Geoglossomycetes, and identify four known species. In addition, we summarise the sexual morph characters of all species within the two largest genera, Geoglossum and Trichoglossum.

Paraloratospora edkuensis sp. nov. (Ascomycota, Phaeosphaeriaceae) from the brackish Lake Edku, Egypt

Abstract In this study, we introduce a novel saprobic taxon Paraloratospora edkuensis, from a decaying stem of Phragmites australis collected at Lake Edku, El-Behera Governorate, Egypt. Multi-locus analyses of the combined ITS (internal transcribed spacers of rDNA), LSU (nuclear large subunit rDNA) and tef1-α (translation elongation factor) sequence data placed the new taxon within Paraloratospora as a phylogenetically distinct species in a clade containing two aquatic species P. fructigena and P. marina. The new species is characterized by having globose to subglobose, dark brown to black ascomata with a short neck, 4–8-spored, cylindrical to obclavate asci, and 3-septate, hyaline and fusiform ascospores. Paraloratospora edkuensis differs from P. fructigena and P. marina by having smaller ascomata with a single neck, asci with four or eight ascospores, different mycelial colony morphology, and nucleotide differences of 2.1–3 %, 0.6–1.4 %, and 1.3–6.9 % in the ITS, LSU and tef1-α genes, respectively.

New members of Alternaria (Pleosporales, Pleosporaceae) collected from Apiaceae in Algeria

Alternaria species have often been reported as plant pathogens and are commonly isolated from diseased plant hosts. During an investigation of this genus in Algeria, seven Embellisia-like isolates were collected from Apiaceae. Phylogenetic analysis using sequences at four loci, the internal transcribed spacer of the rDNA region (ITS), glyceraldehyde-3-phosphate dehydrogenase (gpd), translation elongation factor 1-alpha (tef1), and RNA polymerase second largest subunit (rpb2), revealed that these isolates grouped into three sections, namely Embellisia, Embellisioides, and Eureka. Four isolates had significant differences with their closest species and were determined to be new species, namely Alternaria longiformis and A. radicicolaspp. nov. The three other isolates of section Eureka were identified as A. eureka and A. hungarica, the latter species being described as a new record in Algeria. Detailed descriptions of new species are provided based on colony color, aspect, diameter, conidial size, septa, sporulation patterns and compared with other relevant Alternaria species within same sections. All these species were weakly pathogenic on carrot, coriander, and fennel under greenhouse experiments. Apiaceae may constitute a reservoir of Alternaria species that could represent potential pathogens for other plant families.

Detection of Leishmania donovani DNA from Oral Swab in Visceral Leishmaniasis

Visceral leishmaniasis (VL) is the most severe form of leishmaniasis and is fatal if left untreated in over 95% of cases. Leishmaniasis is one of the neglected tropical diseases that tend to thrive in developing regions of the world where inadequate access to healthcare makes it difficult for some people to even receive a diagnosis. This study examined the usefulness of oral swabs as specimens for VL diagnosis, by detecting Leishmania donovani DNA in oral swabs from both VL patients and L. donovani-infected mice. Eighty oral swab (OS) and blood buffy coat (BC) samples were collected from suspected VL cases in Bangladesh. These samples were evaluated using Leishmania kinetoplast minicircle DNA (kDNA) in real-time PCR, and the results showed that 62.5% (50/80) and 67.5% (54/80) of the cases tested positive for the BC specimen and OS, respectively. The OS positivity was statistically comparable to the BC. L. donovani DNA was also detected in an oral swab of all infected BALB/c mice by conventional PCR targeting the large subunit ribosomal RNA gene (LSUrRNA), while it was negative in uninfected mice. This study highlights the potential of practical methods for the molecular diagnosis of VL using oral swabs as a non-invasive, simple, and accurate approach.

Nuclear ANLN regulates transcription initiation related Pol II clustering and target gene expression

Anillin (ANLN), a mitotic protein that regulates contractile ring assembly, has been reported as an oncoprotein. However, the function of ANLN in cancer cells, especially in the nucleus, has not been fully understood. Here, we report a role of nuclear ANLN in gene transcriptional regulation. We find that nuclear ANLN directly interacts with the RNA polymerase II (Pol II) large subunit to form transcriptional condensates. ANLN enhances initiated Pol II clustering and promotes Pol II CTD phase separation. Short-term depletion of ANLN alters the chromatin binding and enhancer-mediated transcriptional activity of Pol II. The target genes of ANLN-Pol II axis are involved in oxidoreductase activity, Wnt signaling and cell differentiation. THZ1, a super-enhancer inhibitor, specifically inhibits ANLN-Pol II clustering, target gene expression and esophageal squamous cell carcinoma (ESCC) cell proliferation. Our results reveal the function of nuclear ANLN in transcriptional regulation, providing a theoretical basis for ESCC treatment.

Dissecting the Affinity of Neighboring Malvaceae Genera; Brachychiton and Sterculia Through Morphological, Anatomical, and Molecular Approaches

Morphological, anatomical, and molecular information facilitates the identification and inference of the relatedness of plant species. In this study, the macromorphological, micromorphological, and anatomical characteristics of nine species from the Brachychiton and Sterculia genera belonging to the Malvaceae family were examined by light and a scanning electron microscope. The study recorded 66 macromorphological, micromorphological, and anatomical characteristics, thus revealing important variations between the studied species in leaf morphology and anatomy. This included variations in leaf complexity, leaf arrangement (phyllotaxy), epidermal cell walls, and their sculpture, as well as in the types of glandular and non-glandular trichomes. The studied species were mostly conserved in shedding patterns, being evergreen only in one out of nine studied species. Similarly, eight species were petiolate. Conversely, leaf arrangement and leaf complexity characteristics were highly divergent among the studied species, though only one species, Sterculia foetida, had compound leaves. The differences in the studied features and the chloroplast genes MaturaseK (MatK) and ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcl) were exploited to deduce the relationship between the studied species. While the morphological and anatomical features demonstrated a close relationship between the studied intrageneric species, the DNA barcoding analysis proved very efficient in distinguishing the two neighboring genera. Collectively, the different clustering analyses suggest a close relatedness between Brachychiton acerifolius and B. australis, while only DNA-based clustering demonstrates cladistic monophyly of the Sterculia species. This study, therefore, provides a detailed description of various morphological and anatomical features important for the systematic studies within the Malvaceae family and highlights the value of incorporating morphological, anatomical, and molecular approaches for inferring the evolutionary relationship between closely related plant species.

Neuronal cell type specific roles for Nprl2 in neurodevelopmental disorder-relevant behaviors.

Loss of function in the subunits of the GTPase-activating protein (GAP) activity toward Rags-1 (GATOR1) complex, an amino-acid sensitive negative regulator of the mechanistic target of rapamycin complex 1 (mTORC1), is implicated in both genetic familial epilepsies and Neurodevelopmental Disorders (NDDs) (Baldassari et al., 2018). Previous studies have found seizure phenotypes and increased activity resulting from conditional deletion of GATOR1 function from forebrain excitatory neurons (Yuskaitis et al., 2018; Dentel et al., 2022); however, studies focused on understanding mechanisms contributing to NDD-relevant behaviors are lacking, especially studies understanding the contributions of GATOR1's critical GAP catalytic subunit, nitrogen permease regulator like-2 (Nprl2). Given the clinical phenotypes observed in patients with Nprl2 mutations, in this study, we sought to investigate the neuronal cell type contributions of Nprl2 to NDD behaviors. We conditionally deleted Nprl2 broadly in most neurons (Synapsin1cre), in inhibitory neurons only (Vgatcre), and in Purkinje cells within the cerebellum (L7cre). Broad neuronal deletion of Nprl2 resulted in seizures, social and learning deficits, and hyperactivity. In contrast, deleting Nprl2 from inhibitory neurons led to increased motor learning, hyperactive behavior, in addition to social and learning deficits. Lastly, Purkinje cell (PC) loss of Nprl2 also led to learning and social deficits but did not affect locomotor activity. These phenotypes enhance understanding of the spectrum of disease found in human populations with GATOR1 loss of function and highlight the significance of distinct cellular populations to NDD-related behaviors. SIGNIFICANCE STATEMENT: We aim to elucidate the neuronal-specific contributions of nitrogen permease regulator like-2 (Nprl2) to its neurodevelopmental disorder (NDD)-relevant phenotypes. We conditionally deleted Nprl2 broadly in neurons (Syn1cre), in inhibitory neurons (Vgatcre), and in cerebellar Purkinje cells (L7cre). We identify seizures only in the Syn1cre conditional mutant (cKO); hyperactivity, learning difficulties, social deficits, and impulsivity in the Syn1cre and Vgatcre cKOs; and social deficits, and fear learning deficits in L7cre cKOs. To our knowledge, we are the first to describe the behavioral contributions of Nprl2's function across multiple cell types. Our findings highlight both critical roles for Nprl2 in learning and behavior and also distinct contributions of select neuronal populations to these NDD-relevant behaviors.

Novel Amazonian Ceratomyxa species (Cnidaria: Myxozoa) with amoeboid plasmodial motility.

Myxosporeans are a diverse group of cnidarian endoparasites of aquatic animals, with more than 2600 described species. The genus Ceratomyxa includes some 270 species that are mostly coelozoic and infect the gall bladders of mainly marine fish. During our survey in Tapajós River in the Brazilian Amazon, two Ceratomyxa species were discovered in the gallbladders of the anostomid fishes Schyzodon fasciatus and Schyzodon vittatus. Based on myxospore morphology and sequencing of small subunit ribosomal DNA, we propose that these are novel Ceratomyxa species. Ceratomyxa deformis n. sp. from S. fasciatus and Ceratomyxa anomala n. sp. from S. vittatus are similar in morphology, with mature myxospores slightly arcuate with rounded ends. Plasmodia are elongated, and can move by expanding and contracting the cytoplasm. This amoeboid-like motility is heretofore unreported in freshwater South American Ceratomyxa species. Ultrastructural analyses showed the plasmodial organization of both species comprised a cytoplasmic region harboring organelles and sporogonic stages and an internal large vacuole. Phylogenetic analysis corroborates monophyletic grouping of freshwater Ceratomyxa species from South America. Ceratomyxa deformis n. sp. and C. anomala n. sp., which are the first Ceratomyxa species described in anostomid fishes, grouped as sister taxa to C. gracillima and C. mandi, which infect bile in pimelodid fishes from the Amazon region.

Redescription and phylogeny of the little-known type species Rhinakis faurei Deroux, 1994 (Alveolata, Ciliophora, Nassophorea).

Ciliates of the class Nassophorea Small & Lynn, 1981, inhabit a wide range of aquatic environments and serve as a trophic link in microbial food webs. However, their diversity remains underestimated. In the present study, the morphology and molecular phylogeny of Rhinakis faurei Deroux, 1994, an insufficiently known nassulid ciliate, were investigated using an integrative taxonomic approach. The studied population was collected from a freshwater pond in Qingdao, China. Details of the live morphology and ciliature of R. faurei are documented for the first time, and an improved species diagnosis is provided. Phylogenetic analyses of the small subunit ribosomal RNA gene sequence revealed that R. faurei clusters within the family Nassulidae de Fromentel, 1874. However, evolutionary interrelationships within the Nassulidae remain obscure owing to under-sampling, the lack of sequence data for most nominal species, and low nodal support or unstable gene tree topologies.

Deletion of Flv3A facilitates long-term H2 photoproduction in diazotrophic Anabaena sp. PCC 7120.

Molecular hydrogen (H2) is a promising energy carrier, and its production by photosynthetic microorganisms holds substantial potential for advancing renewable energy generation. The nitrogenase-mediated H2 production using heterocyst-forming cyanobacteria represents a promising approach, as the process utilizes light energy and photosynthetic reductants while being naturally protected from O2-rich environments by its restriction to microoxic heterocyst cells. We investigated the impact of deleting the vegetative cell-specific flavodiiron protein, Flv3A, on the long-term H2 photoproduction of the model heterocyst-forming cyanobacterium Anabaena sp. PCC 7120. The H2 photoproduction response was evaluated under varying atmospheric conditions, with or without N2 and O2, and compared to the ∆hupL mutant, which is deficient in the large subunit of uptake hydrogenase, and the ∆hupL/flv3A double mutant. Unlike the ΔhupL mutant, H2 photoproduction in Δflv3A is not enhanced by increased nitrogenase activity or high accumulation of sugars in cells. Our results suggest that the absence of the vegetative cell-localized Flv3A positively affects H2 photoproduction in heterocysts by simultaneously downregulating hupL expression and enhancing the O2 tolerance of nitrogenase via a yet unexplored mechanism. These findings advance our understanding of nitrogenase-driven H2 production and provide a new strategy to address key limitations in long-term photobiological H2 production.

Bicarbonate use reduces the photorespiration in Ottelia alismoides adapting to the CO2-fluctuated aquatic systems.

Underwater CO2 concentration fluctuates extremely in natural water bodies. Under low CO2, the unique CO2 concentrating mechanism in aquatic plants, bicarbonate use, can suppress photorespiration. However, it remains unknown (1) to what extent bicarbonate use reduces photorespiration, (2) how exactly photorespiration varies between bicarbonate-users and CO2-obligate users under CO2-fluctuated environments, and (3) what are differences in Rubisco characteristics between these two types of aquatic plants. In the present study, the bicarbonate user Ottelia alismoides and its phylogenetically close CO2-obligate user Blyxa japonica were chosen to answer these questions. The results showed that bicarbonate use saved ~13% carbon loss under low CO2 via decreasing photorespiration in O. alismoides. Through bicarbonate use, the photorespiration of O. alismoides was kept stable both under high and low underwater CO2 concentrations, while the photorespiration significantly increased in the CO2-obligate user B. japonica under low CO2. However, B. japonica showed a significantly higher photosynthesis rate than O. alsimoides when CO2 was sufficient. These differences could be related to the kinetic characteristics of Rubisco showing a higher carboxylation turnover rate (Kcat) in B. japonica, and the similar affinity to CO2 (Kc) and specificity factor (Sc/o) in these two species that might be determined by the variation of six amino acid residuals in Rubisco large subunit sequences, especially the site 281 (A vs. S) and 282 (H vs. F). All these differences in photorespiration and kinetic characteristics of Rubisco could explain the distribution patterns of bicarbonate users and CO2-obligate users in the field.

Binding of Selected Ligands to Human Protein Disulfide Isomerase and Microsomal Triglyceride Transfer Protein Complex and the Associated Conformational Changes: A Computational Molecular Modelling Study.

Human protein disulfide isomerase (PDI) is a multifunctional protein, and also serves as the β subunit of the human microsomal triglyceride transfer protein (MTP) complex, a lipid transfer machinery. Dysfunction of the MTP complex is associated with certain disease conditions such as abetalipoproteinemia and cardiovascular diseases. It is known that the functions of PDI or the MTP complex can be regulated by the binding of a small-molecule ligand to either of these two proteins. In the present study, the conformational changes of the MTP complex upon the binding of three selected small-molecule ligands (17β-estradiol, lomitapide and a phospholipid) are investigated based on the available biochemical and structural information by using the protein-ligand docking method and molecular dynamics (MD) simulation. The ligand-binding sites, the binding poses and binding strengths, the key binding site residues, and the ligand binding-induced conformational changes in the MTP complex are analyzed based on the MD trajectories. The open-to-closed or closed-to-open transitions of PDI is found to occur in both reduced and oxidized states of PDI and also independent of the presence or absence of small-molecule ligands. It is predicted that lomitapide and 1,2-diacyl-sn-glycero-3-phosphocholine (a phospholipid) can bind inside the lipid-binding pocket in the MTP complex with high affinities, whereas 17β-estradiol interacts with the lipid-binding pocket in addition to its binding to the interface region of the MTP complex. Additionally, lomitapide can bind to the b' domain of PDI as reported earlier for E2. Key residues for the ligand-binding interactions are identified in this study. It will be of interest to further explore whether the binding of small molecules can facilitate the conformational transitions of PDI in the future. The molecular and structural insights gained from the present work are of value for understanding some of the important biological functions of PDI and the MTP complex.

Evaluating passive immunity in piglets from sows vaccinated with a PEDV S protein subunit vaccine

Evaluating passive immunity in piglets from sows vaccinated with a PEDV S protein subunit vaccine

Molecular phylogeny and morphology reveal a new wood-inhabiting fungus, Hyphoderma cinereofuscum (Polyporales, Basidiomycota), from southwest China

Hyphoderma is one of the important representative groups of wood-inhabiting fungi. These fungi secrete various enzymes capable of degrading cellulose, hemicellulose, and lignin into simple inorganic substances. The taxa within the genus cause a white rot of wood, play a key role in the carbon cycle and are the most efficient wood decomposers in the forest ecosystem. This study proposes a new wood-inhabiting fungal taxon, Hyphoderma cinereofuscum, based on morphological features and molecular evidence. It is characterized by the white hymenial surface, a monomitic hyphal system, generative hyphae with simple-septa, colorless, thin-walled, the presence of the tubular and capitate cystidia, and cylindrical basidiospores 9–11.5 × 4.5–5 µm. The phylogenetic tree inferred from a combination of the internal transcribed spacer regions (ITS) and the large subunit nuclear ribosomal RNA gene (nLSU) revealed that Hyphoderma cinereofuscum nested in the Hyphoderma clade and is closely related to H. marginatum. A full description, illustrations and phylogenetic analysis results of the new species are provided.

A new species of Hohenbuehelia in Nakhon Phanom, northeastern Thailand

Hohenbuehelia nakhonphanomensis, collected from wood in a tropical dry dipterocarp forest in Nakhon Phanom Province, northeastern Thailand, is described as a new species, based on its distinctive morphology and phylogeny. The fungus is characterized by a whitish dimidiate pileus, subglobose to obovoid basidiospores, and possession of small thick-walled cystidia without encrusted crystals that are embedded in the hymenium of a lamella beside the large crystal-encrusted projecting from the hymenium (metuloids), together with the Internal Transcribed Spacer (ITS), the Large subunit of the ribosomal DNA (LSU), and Elongation Factor 1-alpha (tef-1) sequences. Comparisons between this fungus to morphologically and phylogenetically related species are also discussed.

The chloroplast RNA–binding protein CP29A supports rbcL expression during cold acclimation

The chloroplast genome encodes key components of the photosynthetic light reaction machinery as well as the large subunit of the enzyme central for carbon fixation, Ribulose-1,5-bisphosphat-carboxylase/-oxygenase (RuBisCo). Its expression is predominantly regulated posttranscriptionally, with nuclear-encoded RNA-binding proteins (RBPs) playing a key role. Mutants of chloroplast gene expression factors often exhibit impaired chloroplast biogenesis, especially in cold conditions. Low temperatures pose a challenge for plants as this leads to electron imbalances and oxidative damage. A well-known response of plants to this problem is to increase the production of RuBisCo and other Calvin Cycle enzymes in the cold, but how this is achieved is unclear. The chloroplast RBP CP29A has been shown to be essential for cold resistance in growing leaf tissue of Arabidopsis thaliana. Here, we examined CP29A-RNA interaction sites at nucleotide resolution. We found that CP29A preferentially binds to the 5'-untranslated region of rbcL, downstream of the binding site of the pentatricopeptide repeat protein MATURATION OF RBCL 1 (MRL1). MRL1 is an RBP known to be necessary for the accumulation of rbcL. In Arabidopsis mutants lacking CP29A, we were unable to observe significant effects on rbcL, possibly due to CP29A's restricted role in a limited number of cells at the base of leaves. In contrast, CRISPR/Cas9-induced mutants of tobacco NtCP29A exhibit cold-dependent photosynthetic deficiencies throughout the entire leaf blade. This is associated with a parallel reduction in rbcL mRNA and RbcL protein accumulation. Our work indicates that a chloroplast RNA-binding protein contributes to cold acclimation of RbcL production.

P-601. Safety and Immunogenicity of a Respiratory Syncytial Virus and Human Metapneumovirus Virus-like Particle Protein Subunit Combination Vaccine in 60–85-Year-Old Adults: Interim Results from a Phase 2a Clinical Trial

Abstract Background Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) often cause serious lower respiratory tract infections in older adults. In this phase 2a trial, we evaluate the safety and immunogenicity of an RSV/hMPV virus-like particle (VLP) subunit combination vaccine, IVX-A12, ± adjuvant in 60–85-year-olds (NCT05903183). We present interim data to Day 180 post vaccination.Figure.Geometric mean titers (GMTs) against RSV-A, RSV-B, hMPV-A, and hMPV-B at baseline and Days 28 and 180 post vaccination Methods Participants were randomized 2:2:1 to receive a single dose of IVX-A12 containing 150µg RSV/150µg hMPV ± MF59® (CSL Seqirus) oil-in-water adjuvant, or placebo. Safety assessments included solicited and unsolicited adverse events (AEs), serious AEs (SAEs), AEs of special interest (AESIs), and medically attended AEs (MAAEs). Geometric mean titers (GMTs) of RSV and hMPV neutralizing antibodies are reported for Days 28 and 180. Results In total, 264 participants were included (IVX-A12 n=103; IVX-A12+MF59 n=108; placebo n=53), with a median age of 69.2 years (range 60–85) and 57.6% were female. Solicited and unsolicited AEs were mostly mild with no related SAEs, AESIs, or MAAEs. For IVX-A12, GMTs (international units/mL) against RSV-A and B were 2078 (95% CI: 1628, 2653) and 1507 (1180, 1926) at baseline, 12171 (9680, 15303) and 5533 (4360, 7020) at Day 28, and 7216 (5706, 9124) and 3277 (2627, 4089) at Day 180, respectively (Figure). For IVX-A12+MF59, GMTs were 2482 (2003, 3075) and 1465 (1175, 1827) at baseline, 12643 (9829, 16263) and 4536 (3623, 5680) at Day 28, and 7967 (6219, 10206) and 2836 (2281, 3526) at Day 180, respectively. For IVX-A12, GMTs (assay units/mL) against hMPV-A and B were 498 (412, 601) and 6322 (4841, 8255) at baseline, 1568 (95% CI 1242, 1980) and 15337 (12371, 19013) at Day 28, and 655 (550, 781) and 9795 (7788, 12319) at Day 180, respectively. For IVX-A12+MF59, GMTs were 615 (501, 754) and 6160 (4828, 7859) at baseline, 1527 (1250, 1864) and 16673 (14284, 19461) at Day 28, and 711 (614, 823) and 8938 (7128, 11209) at Day 180. Conclusion IVX-A12 containing 150µg RSV/150µg hMPV was well tolerated and immunogenic against RSV and hMPV to 6 months in older adults up to 85 years of age, regardless of adjuvant. These data support the ongoing clinical development of an unadjuvanted RSV/hMPV VLP combination vaccine. Disclosures Max Ciarlet, PhD, Icosavax/AstraZeneca: Employee of Icosavax, a member of the AstraZeneca Group, and may or may not hold stocks in AstraZeneca Elizabeth M Adams, MD, Icosavax/AstraZeneca: Employee of Icosavax, a member of the AstraZeneca Group, and may or may not hold stocks in AstraZeneca Nicholas Hourguettes, BA, Icosavax/AstraZeneca: Employee of Icosavax, a member of the AstraZeneca Group, and may or may not hold stocks in AstraZeneca Judy Wen, BA Econ, Icosavax/AstraZeneca: Employee of Icosavax, a member of the AstraZeneca Group, and may or may not hold stocks in AstraZeneca Wasima Rida, PhD, COH NCI grant for CMV vaccination of HCT-D: Grant/Research Support|Icosavax/AstraZeneca: Employee of Icosavax, a member of the AstraZeneca Group, and may or may not hold stocks in AstraZeneca Jennifer Price, BS, Icosavax/AstraZeneca: Employee of Icosavax, a member of the AstraZeneca Group, and may or may not hold stocks in AstraZeneca Lee-Jah Chang, MD, AstraZeneca: Employee of AstraZeneca Niranjan Kanesa-Thasan, MD, Icosavax/AstraZeneca: Previous employee of Icosavax, a member of the AstraZeneca Group

86. The Platform Trial In COVID-19 Priming and BOOsting (PICOBOO): the immunogenicity, reactogenicity, and safety of different COVID-19 vaccinations administered as a second booster (fourth dose) in AZD1222 primed individuals aged 50-< 70 years old

Abstract Background PICOBOO is a randomised, adaptive trial evaluating the immunogenicity, reactogenicity, and safety of COVID-19 booster strategies. Here, we report data for second boosters among individuals aged 50-< 70 years old primed with AZD1222 (50-< 70y-AZD1222) until Day (D) 84. CONSORT diagram CONSORT diagram for participants recruited to the 50-<70y-AZD1222 stratum for second booster vaccines. Participants were excluded from subsequent analyses if they were infected with COVID-19 (C19 Infection) or had withdrawn. Participants that missed visits (Missed) were eligible to be included in subsequent analyses. Methods Immunocompetent adults who received any licensed first booster at least three months prior were eligible. Participants were randomly allocated to BNT162b2, mRNA-1273 or NVX-CoV2373 1:1:1. The log10 concentration of anti-spike IgG was summarised as the geometric mean concentration (GMC). Reactogenicity and safety outcomes were captured. Additional analyses were performed on a subset. ACTRN12622000238774. Baseline characteristics for study participants recruited to the 50-<70y-AZD1222 stratum for second booster vaccines summarised according to study arm. Baseline characteristics for study participants recruited to the 50-<70y-AZD1222 stratum for second booster vaccines summarised according to study arm. Results Between 29 Mar 2022 and 2 Aug 2023, 743 participants were recruited and had D28 samples; 155 belonged to the 50-< 70y-AZD1222 stratum. At D28, the mean adjusted GMCs (95% credible intervals) were 20 690 (17 555, 23 883), 23 867 (20 144, 27 604) and 8 654 (7 267, 9 962) U/mL following boosting with BNT162b2, mRNA-1273 and NVX-CoV2372, respectively. By D84, adjusted GMCs fell to 10 976 (8 826, 13 196), 15 779 (12 512, 19 070) and 6 559 (5 220, 7 937) U/mL in each group, respectively. At D28, mean adjusted neutralisation against Ancestral virus was 159, 213 and 75 IU/mL and 100, 156 and 72 IU/mL by D84 in each group. Limited neutralisation against Omicron subvariants BA.5 and XBB.1.5 was found following boosting with all vaccines. Severe reactogenicity events were few (< 4%). Further data will be available at the time of presentation. Posterior distributions of the anti-spike IgG adjusted GMC against Ancestral SARS-CoV-2 at D7, D28 and D84 for each study arm in participants recruited to the 50-<70y-AZD1222 stratum for second booster vaccines without COVID-19 infection after randomisation and before D28 (D7 for D7 distributions). Posterior distributions of the anti-spike IgG adjusted GMC against Ancestral SARS-CoV-2 at D7, D28 and D84 for each study arm in participants recruited to the 50-<70y-AZD1222 stratum for second booster vaccines without COVID-19 infection after randomisation and before D28 (D7 for D7 distributions). Conclusion These are the first randomised clinical trial data globally of the immunogenicity, reactogenicity and safety of second booster (fourth doses) of mRNA and protein subunit COVID-19 vaccines in adults previously primed with two doses of AZD1222. BNT162b2, mRNA-1273 and NVX-CoV2372 were well tolerated and boosted humoral immune responses. Higher binding and neutralising antibodies against Ancestral SARS-CoV-2 were observed following boosting with mRNA vaccines (BNT162b2 and mRNA-1273) compared to NVX-CoV2372 at all time points. Lower neutralising antibody responses were observed against Omicron subvariants BA.5 and XBB.1.5 following all vaccines until Day 84 highlighting the need for boosting with vaccines with greater specificity for Omicron subvariants. Posterior distributions of the adjusted geometric mean NF50 of Ancestral SARS-CoV-2 at D28 and D84 for each study arm in study participants recruited to the 50-<70y-AZD1222 stratum for second booster vaccines without COVID-19 infection after randomisation and before D28 in the immunological subset. Posterior distributions of the adjusted geometric mean NF50 of Ancestral SARS-CoV-2 at D28 and D84 for each study arm in study participants recruited to the 50-<70y-AZD1222 stratum for second booster vaccines without COVID-19 infection after randomisation and before D28 in the immunological subset. Disclosures Magdalena Plebanski, PhD, AstraZeneca: Grant/Research Support Helen Marshall, MD, ILiAD biotechnologies: Grant/Research Support Saul N. Faust, FRCPCH PhD, AstraZeneca: Grant/Research Support|BioNTech: Grant/Research Support|GSK: Grant/Research Support|Iliad Biotechnologies: Grant/Research Support|J&J: Grant/Research Support|J&J: Advisor, no personal payments (all honoraria paid to employing hospital)|Moderna: Grant/Research Support|Novavax: Advisor, no personal payments (all honoraria paid to employing hospital)|Pfizer: Advisor, no personal payments (all honoraria paid to employing hospital)|Sanofi: Grant/Research Support|Sanofi: Advisor, no personal payments (all honoraria paid to employing hospital)|Valneva: Grant/Research Support Peter Richmond, MBBS, ILiAD biotechnologies: Grant/Research Support

First Report of Agroathelia rolfsii Causing Southern Blight on Alpinia hainanensis in China.

Katsumada galangal seed (Alpinia hainanensis K. Schum) is an important member of the Zingiberaceae family, with both medicinal value and culinary applications (Park et al. 2020). In May 2023, a stem disease of Al. hainanensis was detected in a 100-acre plantation located in Danzhou City, Hainan Province in China, with an average incidence of 15% to 20%. The disease primarily targeted the basal stems, with the pathogen spreading by mycelia in the soil around the rhizome, and reaching neighboring plants. The infection caused the stem base to undergo necrosis, turning the tissue brown to black, and leading to a loosely attached epidermis. As the disease advanced, the necrosis progressed upward along the stem, resulting in curling of the leaves. A large number of white mycelia, as well as white immature sclerotia and brown mature sclerotia, were also observed on the surfaces of the leaves, stems and soil. The diameter of the mature sclerotia ranged from 0.7 to 1.6 mm (aver. ± SD = 1.2 ± 0.3 mm, n = 50). To identify the pathogen, eleven tissue samples were collected from symptomatic stems. The sclerotia on the surface of the tissue were sterilized with 75% (V/V) ethanol for 30 s, followed by three rinses with sterile water, and finally incubated on potato dextrose agar (PDA) at 28°C in darkness. Eleven isolates were obtained and subcultured at 28°C in darkness. After 48 hours, the colonies of these isolates had an average daily radial growth of 39.5 ± 0.4 mm (n = 11) and were white, featuring entire margins and abundant aerial mycelia. By the seventh day, spherical or oval white sclerotia began to form on the surface of their colonies. These sclerotia eventually turned brown, with a diameter ranging from 0.6 to 1.5 mm (aver. ± SD = 1.3 ± 0.3 mm, n = 50). The morphological characteristics of these isolates were similar to those of Agroathelia rolfsii (Sacc.) Redhead & Mullineux (basionym: Sclerotium rolfsii Sacc.; Amylocorticiaceae) (Redhead and Mullineux 2023). DNA of a representative isolate DZAS-01 was extracted for amplification of its internal transcribed spacer (ITS) rDNA region, the translation elongation factor 1-alpha (TEF1) gene and the large subunit (LSU) region using the primers ITS1/ITS4, EF1-983F/EF1-2218R and LROR/LR5, respectively (Moncalvo et al. 2000, Rehner and Buckley 2005, White et al. 1990). The three sequences have been deposited in GenBank (accession nos. PP659527 for ITS, 607 bp; PP976301 for TEF1, 1,040 bp; PP968104 for LSU, 876 bp). The BLASTn results showed that the similarity of the three sequences with the known sequences PP908473 (ITS), OL416131 (TEF1) and KY446370 (LSU) of Ag. rolfsii was 100%, 99.81% and 100%, respectively. Pathogenicity tests were conducted on ten potted, 6-week-old healthy Al. hainanensis plants. The stem bases of ten plants were wounded with sterile needles and divided into two groups with five plants in each group. Each plant in the first group was inoculated by placing three mature sclerotia of DZAS-01 near the wound (Urbina et al. 2024). Plants in the other group served as controls and were not inoculated. Ten plants were covered with plastic bags, placed at 25°C to 28°C with a 12-h/12-h light/dark cycle, and sprayed with sterile water daily. After seven days, all inoculated plants exhibited symptoms that were consistent with those in the field, while non-inoculated control plants remained symptom-free. This pathogenicity test was repeated three times with identical results. A fungus was re-isolated from symptomatic tissues of inoculated plants in each repeat trial and had identical morphological characteristics and ITS, TEF1 and LSU sequences to those of isolate DZAS-01. Ag. rolfsii can infect more than 500 species of cultivated and wild plants in tropical and subtropical regions (Daunde et al. 2020). To the best of our knowledge, this is the first report of Ag. rolfsii causing southern blight on Al. hainanensis in China. The results obtained from this study are going to provide guidance for preventing and treating this disease.

Morphology and multigene phylogeny revealed four new species of Geastrum (Geastrales, Basidiomycota) from China

In the present study, four new species, Geastrum artocarpicola, G. fibulatum, G. sinense and G. trachelium collected from China, are proposed based on a combination of morphological characteristics and molecular evidence. Geastrum artocarpicola is characterized by shallowly saccate to deep saccate exoperidium, bubble-shaped to flask shaped basidia, spherical basidiospores. G. fibulatum is characterized by shallowly saccate to deep saccate exoperidium, spherical basidiospores, generative hyphae with clamp connections in the mycelium layer. G. sinense has arched exoperidium, long stipe expanded basidiomata, and spherical basidiospores. G. trachelium has deep saccate exoperidium, flask-shaped basidia, and spherical basidiospores. Sequences of the internal transcribed spacers (ITS), large subunit (nrLSU), the largest subunit of ribosomal polymerase II (RPB1), and subunit 6 of ATP synthase (ATP6) of the nuclear ribosomal DNA (rDNA) markers of the studied samples were generated, and the phylogenetic analyses were performed with maximum likelihood, maximum parsimony and Bayesian inference methods. The results showed that our collection clustered within Geastrum but distinctly from the others. Full morphological descriptions, illustrations, and phylogenetic analyses results for the four new species are provided. In addition, G. sanglinense is treated as a synonym of beijingense.