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Phosphatidylserine exposure on the surface of L eishmania amazonensis amastigotes modulates in vivo infection and dendritic cell function
Author(s) -
Wanderley J. L. M.,
Thorpe P. E.,
Barcinski M. A.,
Soong L.
Publication year - 2013
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1111/pim.12019
Subject(s) - amastigote , biology , leishmania , immune system , phosphatidylserine , leishmania mexicana , immunology , microbiology and biotechnology , antigen presentation , macrophage , dendritic cell , antigen , in vivo , cutaneous leishmaniasis , immunosuppression , t cell , in vitro , parasite hosting , leishmaniasis , phospholipid , biochemistry , genetics , membrane , world wide web , computer science
Summary Leishmania amazonensis parasites can cause diverse forms of leishmaniasis in humans and persistent lesions in most inbred strains of mice. In both cases, the infection is characterized by a marked immunosuppression of the host. We previously showed that amastigote forms of the parasite make use of surface‐exposed phosphatidylserine ( PS ) molecules to infect host cells and promote alternative macrophage activation, leading to uncontrolled intracellular proliferation of the parasites. In this study, we demonstrated that treatment of infected mice with a PS ‐targeting monoclonal antibody ameliorated parasite loads and lesion development, which correlated with increased proliferative responses by lymphocytes. In addition, we observed an enhanced dendritic cell ( DC ) activation and antigen presentation in vitro . Our data imply that the recognition of PS exposed on the surface of amastigotes plays a role in down‐modulating DC functions, in a matter similar to that of apoptotic cell clearance. This study provides new information regarding the mechanism of immune suppression in Leishmania infection.