Intercellular communication is an essential bedrock in the maintenance and development of multicellular organisms.
Conventional models of cellular exchange include transfer of secreted molecules and direct contact; only recently, exosomes have emerged as a new avenue for cell-to-cell communication.
Discovered nearly 30years ago, exosomes were initially considered little cellular garbage disposals acting to discard unwanted proteins and molecules, and research on exosome biology developed at an extremely slow pace; it is only in the past two decades or so that we have been able to unscramble some of the various biological roles of these nanovesicles.
The foundation for the hypothesis that exosomes could play a large and active role in intercellular communication came in 1996, when Graca Raposo published her discovery of exosomes, secreted by Epstein-Barr virus transformed B lymphocytes, able to induce antigen-specific MHC class II-restricted T cell responses. Interest in exosomes was boosted further by a publication in 1998 by Zitvogel’s team reporting that dendritic cell-derived exosomes could promote the induction of antitumor response in mice, prompting the first attempt for their clinical application. Over the past few years, however, considerable research really brings us closer to harnessing the potential of these tiny vesicles as both a diagnostic and therapeutic tool.
Secreted by multiple cell types and virtually found in all body fluids, exosomes are nano-sized, cell membrane surrounded structures harboring a broad range of biomolecules, including mRNAs, miRNAs, and proteins linked to cell type-associated functions. To understand the biological function of exosomes, a number of proteomic and transcriptomic profile studies has been performed. The huge amount of data obtained have allowed researchers to develop Exocarta.com, a free web-based and centralized repository of molecules that have been documented in exosomes, in order to facilitate novel biological insight. Exosomes were subsequently found to play important role in influencing physiological pathways in the recipient cells. (read more…)