Transcriptome profiling of the rice blast fungus during invasive plant infection and in vitro stresses

<p>Abstract</p> <p>Background</p> <p>Rice blast is the most threatening disease to cultivated rice. <it>Magnaporthe oryzae</it>, its causal agent, is likely to encounter environmental challenges during invasive growth in its host plants that require shifts in gene expression to establish a compatible interaction. Here, we tested the hypothesis that gene expression patterns during <it>in planta </it>invasive growth are similar to <it>in vitro </it>stress conditions, such as nutrient limitation, temperature up shift and oxidative stress, and determined which condition most closely mimicked that of <it>in planta </it>invasive growth. Gene expression data were collected from these <it>in vitro </it>experiments and compared to fungal gene expression during the invasive growth phase at 72 hours post-inoculation in compatible interactions on two grass hosts, rice and barley.</p> <p>Results</p> <p>We identified 4,973 genes that were differentially expressed in at least one of the <it>in planta </it>and <it>in vitro </it>stress conditions when compared to fungal mycelia grown in complete medium, which was used as reference. From those genes, 1,909 showed similar expression patterns between at least one of the <it>in vitro </it>stresses and rice and/or barley. Hierarchical clustering of these 1,909 genes showed three major clusters in which <it>in planta </it>conditions closely grouped with the nutrient starvation conditions. Out of these 1,909 genes, 55 genes and 129 genes were induced and repressed in all treatments, respectively. Functional categorization of the 55 induced genes revealed that most were either related to carbon metabolism, membrane proteins, or were involved in oxidoreduction reactions. The 129 repressed genes showed putative roles in vesicle trafficking, signal transduction, nitrogen metabolism, or molecular transport.</p> <p>Conclusions</p> <p>These findings suggest that <it>M. oryzae </it>is likely primarily coping with nutrient-limited environments at the invasive growth stage 72 hours post-inoculation, and not with oxidative or temperature stresses.</p

Inhibition of PbGP43 expression may suggest that gp43 is a virulence factor in Paracoccidioides brasiliensis

ABSTARCT: Glycoprotein gp43 is an immunodominant diagnostic antigen for paracoccidioidomycosis caused by Paracoccidioides brasiliensis. It is abundantly secreted in isolates such as Pb339. It is structurally related to beta-1,3-exoglucanases, however inactive. Its function in fungal biology is unknown, but it elicits humoral, innate and protective cellular immune responses; it binds to extracellular matrix-associated proteins. In this study we applied an antisense RNA (aRNA) technology and Agrobacterium tumefaciens-mediated transformation to generate mitotically stable PbGP43 mutants (PbGP43 aRNA) derived from wild type Pb339 to study its role in P. brasiliensis biology and during infection. Control PbEV was transformed with empty vector. Growth curve, cell vitality and morphology of PbGP43 aRNA mutants were indistinguishable from those of controls. PbGP43 expression was reduced 80-85% in mutants 1 and 2, as determined by real time PCR, correlating with a massive decrease in gp43 expression. This was shown by immunoblotting of culture supernatants revealed with anti-gp43 mouse monoclonal and rabbit polyclonal antibodies, and also by affinity-ligand assays of extracellular molecules with laminin and fibronectin. In vitro, there was significantly increased TNF-α production and reduced yeast recovery when PbGP43 aRNA1 was exposed to IFN-γ-stimulated macrophages, suggesting reduced binding/uptake and/or increased killing. In vivo, fungal burden in lungs of BALB/c mice infected with silenced mutant was negligible and associated with decreased lung ΙΛ-10 and IL-6. Therefore, our results correlated low gp43 expression with lower pathogenicity in mice, but that will be definitely proven when PbGP43 knockouts become available.

Antibody Evasion by a Gammaherpesvirus O-Glycan Shield

All gammaherpesviruses encode a major glycoprotein homologous to the Epstein-Barr virus gp350. These glycoproteins are often involved in cell binding, and some provide neutralization targets. However, the capacity of gammaherpesviruses for long-term transmission from immune hosts implies that in vivo neutralization is incomplete. In this study, we used Bovine Herpesvirus 4 (BoHV-4) to determine how its gp350 homolog - gp180 - contributes to virus replication and neutralization. A lack of gp180 had no impact on the establishment and maintenance of BoHV-4 latency, but markedly sensitized virions to neutralization by immune sera. Antibody had greater access to gB, gH and gL on gp180-deficient virions, including neutralization epitopes. Gp180 appears to be highly O-glycosylated, and removing O-linked glycans from virions also sensitized them to neutralization. It therefore appeared that gp180 provides part of a glycan shield for otherwise vulnerable viral epitopes. Interestingly, this O-glycan shield could be exploited for neutralization by lectins and carbohydrate-specific antibody. The conservation of O-glycosylation sites in all gp350 homologs suggests that this is a general evasion mechanism that may also provide a therapeutic target

Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age

The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research

Blue nevus of the uterine cervix.

A case of blue naevus of the endocervix is reported with immunohistochemical and ultrastructural findings. The dendritic melanin-containing cells are analogous to the blue naevi cells of the skin. Electron microscopy showed melanosomes in dendritic cells but no cells with melanin-producing Schwann cells features were observed. Histogenetic hypotheses are discussed

Tricholemmal carcinoma: a study of seven cases.

Seven cases of tricholemmal carcinoma (TLC), a rarely recognized cutaneous adnexal neoplasm of external hair sheath origin, are described. Most occurred on sun-exposed skin; five involved the head and neck, one the right leg, and one the right thigh. TLC had a generally short history and all were treated by local excision. The lesions had an exophytic (3 cases) or polypoid (4 cases) gross appearance. Histologically, TLC exhibited a sharply circumscribed, lobular epithelial proliferation in continuity with the epidermis. A cytologic hallmark of these tumors was the presence of large cells with PAS-reactive, diastase-sensitive, clear or pale eosinophilic cytoplasm. High mitotic rate was a constant feature. Four tumors were infiltrative, with pushing borders, whereas three were intraepithelial. One case showed acantholysis. Immunocytochemistry revealed positivity for prekeratin and negativity for CEA and EMA, supporting the trichogenic origin of these tumors. Ultrastructural examination gave clear indication of epithelial origin for the cells but did not verify hair follicular differentiation. Despite locally aggressive growth, the clinical course of TLC appeared indolent. Moreover, there are no cases with metastases reported in the literature

Assessment and optimization of Theileria parva sporozoite full-length p67 antigen expression in mammalian cells

Delivery of various forms of recombinant Theileria parva sporozoite antigen (p67) has been shown to elicit antibody responses in cattle capable of providing protection against East Coast fever, the clinical disease caused by T. parva. Previous formulations of full-length and shorter recombinant versions of p67 derived from bacteria, insect, and mammalian cell systems are expressed in non-native and highly unstable forms. The stable expression of full-length recombinant p67 in mammalian cells has never been described and has remained especially elusive. In this study, p67 was expressed in human-derived cells as a full-length, membrane-linked protein and as a secreted form by omission of the putative transmembrane domain. The recombinant protein expressed in this system yielded primarily two products based on Western immunoblot analysis, including one at the expected size of 67 kDa, and one with a higher than expected molecular weight. Through treatment with PNGase F, our data indicate that the larger product of this mammalian cell-expressed recombinant p67 cannot be attributed to glycosylation. By increasing the denaturing conditions, we determined that the larger sized mammalian cell-expressed recombinant p67 product is likely a dimeric aggregate of the protein. Both forms of this recombinant p67 reacted with a monoclonal antibody to the p67 molecule, which reacts with the native sporozoite. Additionally, through this work we developed multiple mammalian cell lines, including both human and bovine-derived cell lines, transduced by a lentiviral vector, that are constitutively able to express a stable, secreted form of p67 for use in immunization, diagnostics, or in vitro assays. The recombinant p67 developed in this system is immunogenic in goats and cattle based on ELISA and flow cytometric analysis. The development of a mammalian cell system that expresses full-length p67 in a stable form as described here is expected to optimize p67-based immunization.Fil: Tebaldi, Giulia. Università di Parma; ItaliaFil: Williams, Laura B.. Washington State University. Animal Disease Research Unit, Agricultural Research Service. United States Department of Agriculture and Department of Veterinary Microbiology & Pathology; Estados UnidosFil: Verna, Andrea Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Laboratorio de Biotecnología de la Reproduccion; Argentina. Università di Parma; ItaliaFil: Macchi, Francesca. Universita di Parma. Dipartimento Di Scienze Medico Veterinarie; ItaliaFil: Franceschi, Valentina. Universita di Parma. Dipartimento Di Scienze Medico Veterinarie; ItaliaFil: Fry, Lindsay M.. Washington State University. Animal Disease Research Unit, Agricultural Research Service. United States Department of Agriculture and Department of Veterinary Microbiology & Pathology; Estados UnidosFil: Knowles, Donald P.. Washington State University. Animal Disease Research Unit, Agricultural Research Service. United States Department of Agriculture and Department of Veterinary Microbiology & Pathology; Estados UnidosFil: Donofrio, Gaetano. Washington State University College of Veterinary Medicine. Paul G. Allen School for Global Animal Health; Estados Unido