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Details	EV-TRACK ID	Experiment nr.	Species	Sample type	Separation protocol	First author	Year	EV-METRIC
	EV140024	1/1	Homo sapiens	NAY	(d)(U)C Filtration	de Carvalho JV	2014	44%
Study summary Full title Nef Neutralizes the Ability of Exosomes from CD4+ T Cells to Act as Decoys during HIV-1 Infection All authors de Carvalho JV, de Castro RO, da Silva EZ, Silveira PP, da Silva-Januário ME, Arruda E, Jamur MC, Oliver C, Aguiar RS, daSilva LL Journal PLoS One Abstract Nef is an HIV-1 accessory protein that promotes viral replication and pathogenesis. A key function o (show more...)Nef is an HIV-1 accessory protein that promotes viral replication and pathogenesis. A key function of Nef is to ensure sustained depletion of CD4 and MHC-I molecules in infected cells by inducing targeting of these proteins to multivesicular bodies (MVBs), and ultimately to lysosomes for degradation. Nef also affects cellular secretory routes promoting its own secretion via exosomes. To better understand the effects of Nef on the exocytic pathway, we investigated whether this viral factor modifies the composition of exosomes released by T lymphocytes. We showed that both CD4 and MHC-I molecules are secreted in exosomes from T cells and that the expression of Nef reduces the amount of these proteins in exosomes. To investigate the functional role for this novel activity of Nef, we performed in vitro HIV-1 infection assays in the presence of distinct populations of exosomes. We demonstrated that exosomes released by CD4+ T cells, but not CD4- T cells, efficiently inhibit HIV-1 infection in vitro. Because CD4 is the main receptor for HIV-1 infection, these results suggest that CD4 molecules displayed on the surface of exosomes can bind to envelope proteins of HIV-1 hindering virus interaction with target cells and infection. Importantly, CD4-depleted exosomes released by CD4+ T cells expressing Nef have a reduced capacity to inhibit HIV-1 infection in vitro. These results provide evidence that Nef promotes HIV-1 infection by reducing the expression of CD4 in exosomes from infected cells, besides the original role of Nef in reducing the CD4 levels at the cell surface. (hide) EV-METRIC 44% (84th percentile of all experiments on the same sample type) Reported Not reported Not applicable EV-enriched proteins Protein analysis: analysis of three or more EV-enriched proteins non EV-enriched protein Protein analysis: assessment of a non-EV-enriched protein qualitative and quantitative analysis Particle analysis: implementation of both qualitative and quantitative methods. For the quantitative method, the reporting of measured EV concentration is expected. electron microscopy images Particle analysis: inclusion of a widefield and close-up electron microscopy image density gradient Separation method: density gradient, at least as validation of results attributed to EVs EV density Separation method: reporting of obtained EV density ultracentrifugation specifics Separation method: reporting of g-forces, duration and rotor type of ultracentrifugation steps antibody specifics Protein analysis: antibody clone/reference number and dilution lysate preparation Protein analysis: lysis buffer composition Study data Sample type Cell culture supernatant Sample origin NAY Focus vesicles exosomes Separation protocol Separation protocol Gives a short, non-chronological overview of the different steps of the separation protocol. dUC = (Differential) (ultra)centrifugation DG = density gradient UF = ultrafiltration SEC = size-exclusion chromatography IAF = immuno-affinity capture (d)(U)C Filtration Protein markers EV: Alix/ CD63 non-EV: Cell organelle protein Proteomics no Show all info Study aim Function Sample Species Homo sapiens Sample Type Cell culture supernatant EV-harvesting Medium EV Depleted Separation Method (Differential) (ultra)centrifugation dUC: centrifugation steps Between 800 g and 10,000 g Between 100,000 g and 150,000 g Pelleting performed Yes Pelleting: time(min) 60 Filtration steps 0.22µm or 0.2µm Characterization: Protein analysis Western Blot Antibody details provided? No Detected EV-associated proteins Alix/ CD63 Detected contaminants Cell organelle protein Characterization: Particle analysis EM EM-type transmission EM/ scanning EM Image type Close-up, Wide-field Report size (nm) Not reported

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EV-TRACK ID	EV140024
species	Homo sapiens
sample type	Cell culture
cell type	NAY
condition	NAY
separation protocol	(d)(U)C Filtration
Exp. nr.	1
EV-METRIC %	44