Leishmania amazonensis: multiple receptor-ligand interactions are involved in amastigote infection of human dendritic cells.
In their mammalian hosts, Leishmania are obligate intracellular parasites that reside in macrophages and dendritic cells (DCs). In the present study, we have investigated in vitro the mechanisms of entry into human DCs of Leishmania amazonensis amastigotes isolated from lesions in nude mice (Am nude). The DC infection rate with Am nude was approximately 36%, while opsonization of Am nude with normal human serum and infected human serum increased the DC infection rates to 60% and 62%, respectively. Heat inactivation and depletion of antibodies in sera brought the DC infection rate down to 40%. The DC infection rate was inhibited after pre-treatment of Am nude with heparin. We were unable to implicate mannose-fucose receptors in the uptake of Am nude by DCs. Our data suggest that the ability of L. amazonensis amastigotes to infect human DCs involves the participation of at least three multiple receptor-ligand interactions, antibodies/FcR, complement components/CR and proteoglycans/heparin-binding protein.
Bosetto
Maira Cegatti
MC
Departamento de Parasitologia, Instituto de Biologia, Universidade Estadual de Campinas, Caixa Postal 6109, Cep 13083-970, Campinas, São Paulo, Brazil.
Giorgio
Selma
S
D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D003165:Complement System Proteins / Q000378:metabolism; D003713:Dendritic Cells / Q000469:parasitology*; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D037181:Lectins, C-Type / Q000378:metabolism*; D007894:Leishmania mexicana / Q000276:immunology / Q000502:physiology*; D008024:Ligands; D008351:Mannans / Q000378:metabolism*; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008819:Mice, Nude; D009895:Opsonin Proteins / Q000276:immunology; D011509:Proteoglycans / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011951:Receptors, Complement / Q000378:metabolism; D011961:Receptors, Fc / Q000378:metabolism*
D000913:Antibodies, Protozoan; D015815:Cell Adhesion Molecules; D003165:Complement System Proteins; D006497:Heparan Sulfate; D007106:Immune Sera; D037181:Lectins, C-Type; D008024:Ligands; D008351:Mannans; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009895:Opsonin Proteins; D011509:Proteoglycans; D011956:Receptors, Cell Surface; D011951:Receptors, Complement; D011961:Receptors, Fc; C074285:heparin-binding protein (Leishmania)