Dataset Information

Proteomic analysis of soluble and surface-enriched proteins from Acanthamoeba castellanii trophozoites

ABSTRACT: Acanthamoeba castellanii is a free-living organism widely distributed in the environment that may cause disease. This protozoan exists in two forms, an infective trophozoite and a dormant cyst. The trophozoites are able to cause keratitis and granulomatous amoebic encephalitis in humans. Keratitis is an acute, sight threatening infection of cornea with potential to cause permanent blindness without prompt treatment. However, the lack of suspicion and the low awareness about these amoebae besides of the absence of commercially available immunodiagnostic tests may delay an accurate diagnosis. The identification of proteins with potential for use in immunodiagnosis may improve the parasite detection more quickly and specifically. The amoeba adhesion to the host cell is the primary step for infection but there is no full understanding of A. castellanii proteins relevant for host invasion or infection. In this study, an assessment of soluble and surface-enriched protein fractions expressed by A. castellanii trophozoites, based on complementary LC-MS/MS approach using peptides from SDS-PAGE excised bands, was performed. Our proteomic analysis allowed identification of a total of 503 proteins, of which 308 proteins were exclusively identified in the soluble fraction, 119 in surface-enriched fraction and 76 in both. In silico analysis of functional classification revealed several proteins involved in many biological mechanisms in A. castellanii, including pathogen survival and infection of mammalian hosts.

ORGANISM(S): Cellular Organisms

SUBMITTER: Vinicius José Maschio

PROVIDER: PXD010448 | JPOST Repository | Wed Jul 17 00:00:00 BST 2019

REPOSITORIES: jPOST

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	~~Lnb16~Usuarios~nanoESI.PRO~Data~11maio_Vinicius_UFRGS_2_S_10.raw	Raw
	~~Lnb16~Usuarios~nanoESI.PRO~Data~11maio_Vinicius_UFRGS_2_S_10_2.raw	Raw
	~~Lnb16~Usuarios~nanoESI.PRO~Data~11maio_Vinicius_UFRGS_2_S_11.raw	Raw
	~~Lnb16~Usuarios~nanoESI.PRO~Data~11maio_Vinicius_UFRGS_2_S_11_2.raw	Raw
	~~Lnb16~Usuarios~nanoESI.PRO~Data~11maio_Vinicius_UFRGS_2_S_2.raw	Raw

Items per page:

1 - 5 of 20

Similar Datasets

Project description:Toxoplasma gondii is an obligate intracellular parasite which can cause toxoplasmosis. Surface and secreted proteins of T. gondii play important roles in infection and immunity, and also are antigen targets in immunological diagnosis and vaccine development. However, it is difficult to investigate identities and antigenicities of surface and secreted proteins due to limitation of surface protein extraction methods. In this study, a total of 785 potential surface and secreted proteins of T. gondii RH tachyzoites were identified using a method combination of biotin labeling, avidin chromatography isolation, and high flux proteomics (LC-MS/MS). Among the highly-expressed 65 proteins, 43 proteins (66%) were originally annotated as surface or secreted proteins in the released T. gondii genomes, which proved the method combination to be a credible strategy. Furthermore, the transcriptomic responses and cytokine secretions induced by the isolated proteins, the live T. gondii RH tachyzoites infection, and the live pathogenic E. coli infection, in the human peripheral blood monocyte THP-1 cell lines, were comparatively analyzed to reveal antigenicities and immunobiological properties of T. gondii surface and secreted proteins. The transciptomic profiles induced by the isolated proteins were similar to those induced by the live bacterium infection, but were different from those induced by the live parasite infection. Contrary to the low cytokine secretion induced by the live parasite infection, the isolated proteins induced significant cytokine and chemokines secretion. Especially, the secretions of several chemokines induced by the isolated proteins were even higher than those induced by the live bacterium infection. These data suggested that T. gondii surface and secreted proteins were effective antigens, while the live parasite could evade the host innate immunity. This study comprehensively revealed the identities and antigenicities of T. gondii surface and secreted proteins, which laid foundation for further screening new T. gondii antigens, developing immunological diagnosis methods, and studying host immune response to T. gondii infection.

Project description:Virus infection may shut off host protein synthesis in order to achieve the replicative advantage over host cells. It is well known that human pathogenic viruses, particularly the picornaviruses, can block host protein synthesis by cleavage or inhibition of eukaryotic initiation factors (eIFs). In this study we found a novel mechanism that microRNA (miRNA) is involved in viral pathogenesis. Infection of enteroviruses can disturb the expression of host miRNAs, in which miR-141 is up-regulated and inhibits host protein synthesis by post-transcriptional repression of the target gene eIF4E, a key element for cap-dependent translation of host proteins. Knockdown of miR-141 by a specific siRNA, antagomiR-141, could restore host eIF4E expression, delay the occurrence of cytopathic effect (CPE), and impair virus propagation. We demonstrated that EV71 infection could increase early growth response 1 (EGR1) expression which induced miR-141 causing the eIF4E suppression; while silencing of EGR1 attenuated virus production. Our results suggest that enterovirus infection causes the EGR1-mediated upregulation of host miR-141, further lead to the translational switch from cap-dependent to cap-independent protein synthesis in the host cells, an environmental beneficial for viral propagation. This novel mechanism may highlight a new approach for future development of antiviral therapy. Enteroviruses in the Picornaviridae family are important human pathogens which can cause fatal diseases, including cardiopulmonary failure, aseptic meningitis, paralysis, myocarditis, and encephalomyelitis. Virus infection may induce shutoff of host protein synthesis, particularly in picornavirus, whose protein translation is cap-independent. It is known that poliovirus 2A protease cleaves eIF4G, a scaffold component of mammalian cell translational complex, leading to the shut down of host protein synthesis. Nevertheless, the cleavage of eIF4G may not be sufficient for the complete shutoff of host protein synthesis. Previous studies showed that cleavage of polyA-binding protein (PABP) by viral protease 3C and dephosphorylation of the translational repressor, eIF4E binding protein 1 (4E-BP1), also contribute to this process. The cap-binding protein, eIF4E, is the most crucial factor in determining whether cap-dependent or -independent translation takes place. The mechanism by which viral infection modulates host cell protein synthesis through interfering eIF4E expression is not yet known. miRNAs are a newly discovered class of small non-protein-coding RNAs that may act via endogenous RNA interference. Our understanding of its role in the dynamic interplay between virus and host components is quite limited. Since both virus infection and miRNAs could hinder cellular protein synthesis, whether miRNAs are involved during virus infection in shutting off host protein synthesis is still unknown. To address this issue, we analyze the altered gene and microRNA expression after EV71 infection. ***This submission represents the mRNA expression component of the study only***

Dataset Information

Proteomic analysis of soluble and surface-enriched proteins from Acanthamoeba castellanii trophozoites

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets