CXCL10 production by human monocytes in response to Leishmania braziliensis infection.
Leishmania (subgenus Viannia) braziliensis is the causative agent of mucocutaneous leishmaniasis (ML) in South America, and ML is characterized by excessive T- and B-cell responses to the parasite. We speculate that the unbalanced production of inflammatory mediators in response to L. braziliensis infection contributes to cell recruitment and disease severity. To test this hypothesis, we first examined the response of peripheral blood mononuclear cells (PBMCs) from healthy volunteers to L. braziliensis infection. We observed that while L. braziliensis infection induced the production of chemokine (C-X-C motif) ligand 10 (CXCL10) and interleukin-10 (IL-10) in human PBMCs and macrophages (MPhis), enhanced expression of CXCL10 and its receptor, chemokine CXC receptor (CXCR3), was predominantly detected in CD14(+) monocytes. The chemoattractant factors secreted by L. braziliensis-infected cells were highly efficient in recruiting uninfected PBMCs (predominantly CD14(+) cells) through Transwell membranes. Serum samples from American tegumentary leishmaniasis (ATL) patients (especially the ML cases) had significantly higher levels of CXCL10, CCL4, and soluble tumor necrosis factor (TNF) receptor II (sTNFRII) than did those of control subjects. Our results suggest that, following L. braziliensis infection, the production of multiple inflammatory mediators by the host may contribute to disease severity by increasing cellular recruitment.
Vargas-Inchaustegui
Diego A
DA
Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA.
Hogg
Alison E
AE
Tulliano
Gianfranco
G
Llanos-Cuentas
Alejandro
A
Arevalo
Jorge
J
Endsley
Janice J
JJ
Soong
Lynn
L
D000818:Animals; D002478:Cells, Cultured; D054357:Chemokine CXCL10 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D007892:Leishmania braziliensis / Q000502:physiology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism* / Q000469:parasitology*; D054367:Receptors, CXCR3 / Q000235:genetics / Q000378:metabolism
C114753:CXCL10 protein, human; C515187:CXCR3 protein, human; D054357:Chemokine CXCL10; D054367:Receptors, CXCR3