Editing Leishmania (section)

===Intracellular mechanism of infection===
In order to avoid destruction by the [[immune system]] and thrive, the ''Leishmania'' 'hides' inside its host's cells. This location enables it to avoid the action of the [[humoral immune response]] (because the pathogen is safely inside a cell and outside the open bloodstream), and furthermore it may prevent the immune system from destroying its host through nondanger surface signals which discourage [[apoptosis]]. The primary cell types ''Leishmania'' infiltrates are [[phagocytosis|phagocytotic]] cells such as [[neutrophils]] and [[macrophages]].<ref>{{cite journal|last=Vannier-Santos|first=MA|author2=Martiny A |author3=de Souza W.|title=Cell biology of Leishmania spp.: invading and evading.|journal=Current Pharmaceutical Design|date=August 2002|pages=297–318|pmid=11860368|volume=8|issue=4|doi=10.2174/1381612023396230}}</ref>

Usually, a phagocytotic immune cell like a macrophage will ingest a pathogen within an enclosed [[endosome]] and then fill this endosome with enzymes which digest the pathogen. However, in the case of ''Leishmania'', these enzymes have no effect, allowing the parasite to multiply rapidly. This uninhibited growth of parasites eventually overwhelms the host macrophage or other immune cell, causing it to die.<ref>{{cite journal|last=Paul|first=William E.|title=Infectious Diseases and the Immune System|journal=Scientific American|volume=269|issue=3|date=September 1993|pages=94–95|bibcode=1993SciAm.269c..90P|doi=10.1038/scientificamerican0993-90|pmid=8211095}}</ref>

Transmitted by the [[sandfly]], the [[protozoan]] [[parasitism|parasites]] of ''L. major'' may switch the strategy of the first immune defense from eating/inflammation/killing to eating/no inflammation/no killing of their host [[phagocyte]] and corrupt it for their own benefit.{{Citation needed|date=December 2008}} They use the willingly phagocytosing polymorphonuclear neutrophil granulocytes (PMNs) rigorously as a tricky hideout, where they [[cell growth|proliferate]] unrecognized from the immune system and enter the long-lived [[macrophages]] to establish a "hidden" [[infection]].{{Citation needed|date=December 2008}}