Intermediate monocytes contribute to pathologic immune response in Leishmania braziliensis infections.

Abstract

Ulcer development in patients with cutaneous leishmaniasis (CL) caused by Leishmania braziliensis is associated with high levels of tumor necrosis factor (TNF). We found that early after infection, before ulcer development, the frequency of CD16(+) (both intermediate [CD14(+)CD16(+)] and nonclassical [CD14(dim)CD16(+)]) monocytes was increased in the peripheral blood of patients with L. braziliensis, compared with uninfected controls. These results suggest that CD16(+) monocytes might promote disease. Also, we found that intermediate monocytes expressed CCR2 and that increased levels of CCL2 protein were present in lesions from patients, suggesting that intermediate monocytes are more likely than nonclassical monocytes to migrate to the lesion site. Finally, we found that the intermediate monocytes produced TNF. Our results show that intermediate monocytes are increased in frequency soon after infection; express CCR2, which would promote their migration into the lesions; and, owing to their production of TNF, can enhance the inflammatory response.

• Authors: Sara Passos, Lucas P Carvalho, Rúbia S Costa, Taís M Campos, Fernanda O Novais, Andréa Magalhães, Paulo R L Machado, Daniel Beiting, David Mosser, Edgar M Carvalho, Phillip Scott
• Journal: The Journal of infectious diseases (J Infect Dis) Vol. 211 Issue 2 Pg. 274-82 (Jan 15 2015) ISSN: 1537-6613 [Electronic] United States
• PMID: 25139016 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: [email protected].

Chemical References

• CCL2 protein, human
• CCR2 protein, human
• Chemokine CCL2
• FCGR3B protein, human
• GPI-Linked Proteins
• Receptors, CCR2
• Receptors, IgG
• TNF protein, human
• Tumor Necrosis Factor-alpha

Topics

• Adolescent
• Adult
• Chemokine CCL2 (metabolism)
• Female
• GPI-Linked Proteins (analysis)
• Humans
• Leishmania braziliensis (immunology)
• Leishmaniasis, Cutaneous (immunology, pathology)
• Male
• Middle Aged
• Monocytes (chemistry, immunology)
• Receptors, CCR2 (analysis)
• Receptors, IgG (analysis)
• Tumor Necrosis Factor-alpha (metabolism)
• Ulcer (immunology, pathology)
• Young Adult