A team of international scientists led by Dr. Martin Olivier from the Research Institute of the McGill University Health Centre (RI-MUHC) has discovered an important mechanism underlying the pathogenicity of leishmaniasis, a deadly parasitic disease caused by protozoans of the Leishmania genus that are transmitted by to humans by sandfly bites. The disease affects over 12 million people worldwide, and more than 1.3 million new cases are reported every year. In the new study, published online on October 22, 2015 in an open-access article in Cell Reports, the researchers describe how sub-cellular vesicles known as exosomes, boost the process by which the Leishmania parasite infects humans and other mammals. These findings could lead to the development of new potential vaccine targets and diagnostic tools for leishmaniasis and other parasitic diseases. The article is titled “Exosome Secretion by the Parasitic Protozoan Leishmania within the Sand Fly Midgut.” “Our study reports the first observation that a pathogen within its insect vector can release extracellular vesicles or exosomes that are an integral part of the parasite's infectious life cycle,'' states the study's lead author Dr. Olivier, a researcher from the Infectious Diseases and Immunity in Global Health Program of the RI-MUHC and a full Professor of Medicine at McGill University. "This means that any bacteria and parasites transmitted via insect blood meals could use a similar strategy to extend their successful infection.'' Exosomes are small, cell-derived vesicles that are present in all biological fluids, including blood, urine, saliva, etc. Exosomes have been the focus of numerous studies, particularly due to their apparent involvement in communication between cells, especially immune and tumor cells.Login Or Register To Read Full Story