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Release of Small RNA-containing Exosome-like Vesicles from the Human Filarial Parasite Brugia malayi.

Zamanian M, Fraser LM, Agbedanu PN, Harischandra H, Moorhead AR, Day TA, Bartholomay LC, Kimber MJ - PLoS Negl Trop Dis (2015)

Bottom Line: Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes.The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced.Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America; Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America.

ABSTRACT
Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes. The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced. Manipulation of this interface to the detriment of the parasite is a promising potential avenue to develop disease therapies but is prevented by our very limited understanding of the host-parasite relationship. Exosomes are bioactive small vesicles (30-120 nm) secreted by a wide range of cell types and involved in a wide range of physiological processes. Here, we report the identification and partial characterization of exosome-like vesicles (ELVs) released from the infective L3 stage of the human filarial parasite Brugia malayi. Exosome-like vesicles were isolated from parasites in culture media and electron microscopy and nanoparticle tracking analysis were used to confirm that vesicles produced by juvenile B. malayi are exosome-like based on size and morphology. We show that loss of parasite viability correlates with a time-dependent decay in vesicle size specificity and rate of release. The protein cargo of these vesicles is shown to include common exosomal protein markers and putative effector proteins. These Brugia-derived vesicles contain small RNA species that include microRNAs with host homology, suggesting a potential role in host manipulation. Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1. To our knowledge, this is the first report of exosome-like vesicle release by a human parasitic nematode and our data suggest a novel mechanism by which human parasitic nematodes may actively direct the host responses to infection. Further interrogation of the makeup and function of these bioactive vesicles could seed new therapeutic strategies and unearth stage-specific diagnostic biomarkers.

No MeSH data available.


Related in: MedlinePlus

Brugia malayi ELV miRNA sequence homology to nematode and mammalian host miRNAs.miRNAs from B. malayi, A. suum, C. elegans, H. sapiens, and M. musculus were grouped by seed site sequence identity (nucleotides 2–8) for multiple sequence alignments. Alignments are shown for bma-let-7, bma-miR-9 and bma-miR-993. bma-let-7 is shown as an example of a Brugia ELV miRNA that exhibits both seed site and full length sequence conservation extending to other parasitic and free-living nematodes, as well as to mammalian host species. bma-miR-9 and bma-miR-993 are presented as examples where conserved parasite miRNAs have clear host homologs, yet lack one-to-one C. elegans orthologs. The complete set of alignments can be found in S1 Fig.
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pntd.0004069.g006: Brugia malayi ELV miRNA sequence homology to nematode and mammalian host miRNAs.miRNAs from B. malayi, A. suum, C. elegans, H. sapiens, and M. musculus were grouped by seed site sequence identity (nucleotides 2–8) for multiple sequence alignments. Alignments are shown for bma-let-7, bma-miR-9 and bma-miR-993. bma-let-7 is shown as an example of a Brugia ELV miRNA that exhibits both seed site and full length sequence conservation extending to other parasitic and free-living nematodes, as well as to mammalian host species. bma-miR-9 and bma-miR-993 are presented as examples where conserved parasite miRNAs have clear host homologs, yet lack one-to-one C. elegans orthologs. The complete set of alignments can be found in S1 Fig.

Mentions: Bma-let-7 is significantly enriched in L3 ELVs as compared to L3 tissue, where it does not appear among the 20 most abundant miRNAs. Bma-let-7, along with four other B. malayi mature miRNAs found in ELVs (bma-miR-1, bma-miR-9, bma-miR-92, and bma-miR-100b), share perfect sequence identity with host (Homo sapiens) mature miRNAs, as shown in Fig 5B. Additionally, bma-miR-34 shares near perfect sequence identity with its H. sapiens homolog. 11 B. malayi miRNAs also share common seed sites with H. sapiens miRNAs (Fig 5C). Brugia ELV miRNA sequences were more broadly clustered by putative seed site and aligned to miRNAs from the soil-transmitted parasitic nematode Ascaris suum, the free living model nematode Caenorhabditis elegans, and mammalian host species H. sapiens and Mus musculus (Fig 6 and S1 Fig). In all cases, Brugia ELV miRNAs that share common seed sites with host miRNAs have one-to-one A. suum orthologs. In some cases, parasite miRNAs are better conserved in mammalian hosts than in C. elegans (e.g., bma-miR-9, bma-miR-993, and bma-miR-100b/c).


Release of Small RNA-containing Exosome-like Vesicles from the Human Filarial Parasite Brugia malayi.

Zamanian M, Fraser LM, Agbedanu PN, Harischandra H, Moorhead AR, Day TA, Bartholomay LC, Kimber MJ - PLoS Negl Trop Dis (2015)

Brugia malayi ELV miRNA sequence homology to nematode and mammalian host miRNAs.miRNAs from B. malayi, A. suum, C. elegans, H. sapiens, and M. musculus were grouped by seed site sequence identity (nucleotides 2–8) for multiple sequence alignments. Alignments are shown for bma-let-7, bma-miR-9 and bma-miR-993. bma-let-7 is shown as an example of a Brugia ELV miRNA that exhibits both seed site and full length sequence conservation extending to other parasitic and free-living nematodes, as well as to mammalian host species. bma-miR-9 and bma-miR-993 are presented as examples where conserved parasite miRNAs have clear host homologs, yet lack one-to-one C. elegans orthologs. The complete set of alignments can be found in S1 Fig.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581865&req=5

pntd.0004069.g006: Brugia malayi ELV miRNA sequence homology to nematode and mammalian host miRNAs.miRNAs from B. malayi, A. suum, C. elegans, H. sapiens, and M. musculus were grouped by seed site sequence identity (nucleotides 2–8) for multiple sequence alignments. Alignments are shown for bma-let-7, bma-miR-9 and bma-miR-993. bma-let-7 is shown as an example of a Brugia ELV miRNA that exhibits both seed site and full length sequence conservation extending to other parasitic and free-living nematodes, as well as to mammalian host species. bma-miR-9 and bma-miR-993 are presented as examples where conserved parasite miRNAs have clear host homologs, yet lack one-to-one C. elegans orthologs. The complete set of alignments can be found in S1 Fig.
Mentions: Bma-let-7 is significantly enriched in L3 ELVs as compared to L3 tissue, where it does not appear among the 20 most abundant miRNAs. Bma-let-7, along with four other B. malayi mature miRNAs found in ELVs (bma-miR-1, bma-miR-9, bma-miR-92, and bma-miR-100b), share perfect sequence identity with host (Homo sapiens) mature miRNAs, as shown in Fig 5B. Additionally, bma-miR-34 shares near perfect sequence identity with its H. sapiens homolog. 11 B. malayi miRNAs also share common seed sites with H. sapiens miRNAs (Fig 5C). Brugia ELV miRNA sequences were more broadly clustered by putative seed site and aligned to miRNAs from the soil-transmitted parasitic nematode Ascaris suum, the free living model nematode Caenorhabditis elegans, and mammalian host species H. sapiens and Mus musculus (Fig 6 and S1 Fig). In all cases, Brugia ELV miRNAs that share common seed sites with host miRNAs have one-to-one A. suum orthologs. In some cases, parasite miRNAs are better conserved in mammalian hosts than in C. elegans (e.g., bma-miR-9, bma-miR-993, and bma-miR-100b/c).

Bottom Line: Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes.The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced.Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America; Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America.

ABSTRACT
Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes. The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced. Manipulation of this interface to the detriment of the parasite is a promising potential avenue to develop disease therapies but is prevented by our very limited understanding of the host-parasite relationship. Exosomes are bioactive small vesicles (30-120 nm) secreted by a wide range of cell types and involved in a wide range of physiological processes. Here, we report the identification and partial characterization of exosome-like vesicles (ELVs) released from the infective L3 stage of the human filarial parasite Brugia malayi. Exosome-like vesicles were isolated from parasites in culture media and electron microscopy and nanoparticle tracking analysis were used to confirm that vesicles produced by juvenile B. malayi are exosome-like based on size and morphology. We show that loss of parasite viability correlates with a time-dependent decay in vesicle size specificity and rate of release. The protein cargo of these vesicles is shown to include common exosomal protein markers and putative effector proteins. These Brugia-derived vesicles contain small RNA species that include microRNAs with host homology, suggesting a potential role in host manipulation. Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1. To our knowledge, this is the first report of exosome-like vesicle release by a human parasitic nematode and our data suggest a novel mechanism by which human parasitic nematodes may actively direct the host responses to infection. Further interrogation of the makeup and function of these bioactive vesicles could seed new therapeutic strategies and unearth stage-specific diagnostic biomarkers.

No MeSH data available.


Related in: MedlinePlus