title: Permissive and protective roles for neutrophils in leishmaniasis.
abstract: Leishmania parasites are the causative agents of leishmaniasis, a neglected tropical disease that causes substantial morbidity and considerable mortality in many developing areas of the world. Recent estimates suggest that roughly 10 million people suffer from cutaneous leishmaniasis (CL), and approximately 76,000 are afflicted with visceral leishmaniasis (VL), which is universally fatal without treatment. Efforts to develop therapeutics and vaccines have been greatly hampered by an incomplete understanding of the parasite's biology and a lack of clear protective correlates that must be met in order to achieve immunity. Although parasites grow and divide preferentially in macrophages, a number of other cell types interact with and internalize Leishmania parasites, including monocytes, dendritic cells and neutrophils. Neutrophils appear to be especially important shortly after parasites are introduced into the skin, and may serve a dual protective and permissive role during the establishment of infection. Curiously, neutrophil recruitment to the site of infection appears to continue into the chronic phase of disease, which may persist for many years. The immunological impact of these cells during chronic leishmaniasis is unclear at this time. In this review we discuss the ways in which neutrophils have been observed to prevent and promote the establishment of infection, examine the role of anti-neutrophil antibodies in mouse models of leishmaniasis and consider recent findings that neutrophils may play a previously unrecognized role in influencing chronic parasite persistence.
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases, MD-PhD Combined Degree Program.|Department of Microbiology and Immunology.
authors.forename: E D
authors.initials: ED
authors.lastname: Carlsen
authors.affiliation: Department of Microbiology and Immunology.
authors.forename: Y
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Pathology.
authors.forename: T R
authors.initials: TR
authors.lastname: Shelite
authors.affiliation: Department of Pathology.
authors.forename: D H
authors.initials: DH
authors.lastname: Walker
authors.affiliation: Department of Microbiology and Immunology.|Department of Pathology.|Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: P C
authors.initials: PC
authors.lastname: Melby
authors.affiliation: Department of Microbiology and Immunology.|Department of Pathology.
authors.forename: L
authors.initials: L
authors.lastname: Soong
mesh_terms: D000818:Animals; D006790:Host-Parasite Interactions / Q000276:immunology; D006801:Humans; D007891:Leishmania / Q000276:immunology* / Q000502:physiology; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000469:parasitology; D007898:Leishmaniasis, Visceral / Q000276:immunology* / Q000469:parasitology; D008264:Macrophages / Q000276:immunology / Q000469:parasitology; D051379:Mice; D020556:Neutrophil Infiltration / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology* / Q000469:parasitology
keywords: Leishmania, monoclonal antibody; mouse model; neutrophil