B lymphocytes and macrophages release cell membrane deposited C3-fragments on exosomes with T cell response-enhancing capacity☆

Papp, Krisztián; Végh, Péter; Prechl, József; Kerekes, Krisztina; Kovács, János; Csikós, György; Bajtay, Zsuzsa; Erdei, Anna

doi:10.1016/j.molimm.2007.11.021

Cited by 42 publications

(46 citation statements)

References 43 publications

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“…4,7 Additionally, C3b deposition on exosomes enhances antigen presentation and splenic uptake. 10,39 There is 1 description of the rat-restricted Galectin 5 mediating the binding of erythrocyte exosomes to macrophages, 40 but to our knowledge, ours is the first report of a macrophage-specific exosome receptor expressed in lymphoid tissue.…”

Section: Discussionmentioning

confidence: 86%

“…Removal of exosomes by complement-mediated destruction and uptake by phagocytes, 10,39 or uptake by fenestrated endothelium in the liver sieve, 41 may mask the contribution of a selectively expressed receptor present only in a subpopulation of LN and splenic macrophages. In contrast to our findings, liposomes displaying highaffinity glycan ligands for CD169 exhibited delayed clearance from circulation in CD169 2/2 mice.…”

Section: Discussionmentioning

confidence: 99%

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CD169 mediates the capture of exosomes in spleen and lymph node

Saunderson

Dunn

Crocker

et al. 2014

Blood

319

315

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Section: Discussionmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

CD169 mediates the capture of exosomes in spleen and lymph node

Saunderson

Dunn

Crocker

et al. 2014

Blood

319

315

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“…An alternative explanation, however, may be that these constituents are genuinely expressed by exosomes. If not directly loaded into/onto exosomes during manufacture, it may be possible that some proteins may be present at low levels at the outer surface of the cell and subsequently become taken up into the endosomal system and packaged into exosomes (50). In addition, a host of poorly understood cellular alterations occurring in cancer cells may modify trafficking of some proteins, resulting in inappropriate distributions, such as hnRNPK, which may become cytoplasmically rather than nuclearly located in certain cancers (51,52).…”

Section: Discussionmentioning

confidence: 99%

Proteomics Analysis of Bladder Cancer Exosomes

Welton

Khanna

Giles

et al. 2010

Molecular & Cellular Proteomics

348

343

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Exosomes are nanometer-sized vesicles, secreted by various cell types, present in biological fluids that are particularly rich in membrane proteins. Ex vivo analysis of exosomes may provide biomarker discovery platforms and form non-invasive tools for disease diagnosis and monitoring. These vesicles have never before been studied in the context of bladder cancer, a major malignancy of the urological tract. We present the first proteomics analysis of bladder cancer cell exosomes. Using ultracentrifugation on a sucrose cushion, exosomes were highly purified from cultured HT1376 bladder cancer cells and verified as low in contaminants by Western blotting and flow cytometry of exosome-coated beads. Solubilization in a buffer containing SDS and DTT was essential for achieving proteomics analysis using an LC-MALDI-TOF/TOF MS approach. We report 353 high quality identifications with 72 proteins not previously identified by other human exosome proteomics studies. Overrepresentation analysis to compare this data set with previous exosome proteomics studies (using the ExoCarta database) revealed that the proteome was consistent with that of various exosomes with particular overlap with exosomes of carcinoma origin. Interrogating the Gene Ontology database highlighted a strong association of this proteome with carcinoma of bladder and other sites. The data also highlighted how homology among human leukocyte antigen haplotypes may confound MASCOT designation of major histocompatability complex Class I nomenclature, requiring data from PCR-based human leukocyte antigen haplotyping to clarify anomalous identifications. Validation of 18 MS protein identifications (including basigin, galectin-3, trophoblast glycoprotein (5T4), and others) was performed by a combination of Western blotting, flotation on linear sucrose gradients, and flow cytometry, confirming their exosomal expression. Some were confirmed positive on urinary exosomes from a bladder cancer patient. In summary, the exosome proteomics data set presented is of unrivaled quality. The data will aid in the development of urine exosome-based clinical tools for monitoring disease and will inform follow-up studies into varied aspects of exosome manufacture and function. Molecular & Cellular Proteomics 9:1324 -1338, 2010.

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“…We were surprised in fact to find proteins identified by our LCMS proteomic analyses which are normally considered to be located in the nucleus and therefore not likely candidates for exosome cargo. Rather than assume that these proteins are contaminants of our exosome preparation we would rather tend to the idea that they might play a role in cell-cell communication via exosomal transfer (50). In keeping with this notion, it is thought that dysregulation of key biological mechanisms in cancer cells, such as those regulating protein synthesis and transportation, may result in altered distribution of proteins within and outside of defined intracellular compartments (51).…”

Section: Fig 2 Transmission Electron Microscopy (Tem)mentioning

confidence: 99%