L. amazonensis infection differentially affects migration of phagocyte populations from inflammatory site to the draining lymph node (102.27)

Abstract

Abstract Leishmania infection interferes with integrin function. In this work we use a model of chronic peritonitis to study the effect of L. amazonensis infection upon the ability of phagocytes populations to migrate from an inflammatory site to the draining lymph node (dLN). First we showed that macrophage recruitment into the peritoneum and migration to the dLN were both maximal 4 days after thioglycollate injection into the peritoneum. At this time point, cell tracking assays using cell transfer between MHC-mismatched mice showed that 1% of the leukocytes injected into the peritoneum migrated to the dLN after 24h. In the mice injected with cells cultivated with medium alone adoptive cells represented 14% of the peritoneal cells. Among these leukocytes 57% were macrophages, 2% were neutrophils and 35% were myeloid dendritic cells. In the LN, 22% of the migrating cells were macrophages, 4% were neutrophils and 25% were myeloid dendritic cells. In the mice injected with leukocytes co-cultivated with Leishmania adoptive cells represented 12% of the peritoneal cells. Among these cells 44% were macrophages, 1% were neutrophils and 46% were dendritic cells. In the LN 19% of the migrating cells were macrophages, 2% were neutrophils and 12% were myeloid dendritic cells. Our data show that: (1) A variety of phagocytes are able to migrate from the inflammatory site to the dLN. (2) Populations of Leishmania-infected dendritic cells appear to be retained in the peritoneum.