title: Deficiency of lymph node-resident dendritic cells (DCs) and dysregulation of DC chemoattractants in a malnourished mouse model of Leishmania donovani infection.
abstract: Malnutrition is thought to contribute to more than one-third of all childhood deaths via increased susceptibility to infection. Malnutrition is a significant risk factor for the development of visceral leishmaniasis, which results from skin inoculation of the intracellular protozoan Leishmania donovani. We previously established a murine model of childhood malnutrition and found that malnutrition decreased the lymph node barrier function and increased the early dissemination of L. donovani. In the present study, we found reduced numbers of resident dendritic cells (conventional and monocyte derived) but not migratory dermal dendritic cells in the skin-draining lymph nodes of L. donovani-infected malnourished mice. Expression of chemokines and their receptors involved in trafficking of dendritic cells and their progenitors to the lymph nodes was dysregulated. C-C chemokine receptor type 2 (CCR2) and its ligands (CCL2 and CCL7) were reduced in the lymph nodes of infected malnourished mice, as were CCR2-bearing monocytes/macrophages and monocyte-derived dendritic cells. However, CCR7 and its ligands (CCL19 and CCL21) were increased in the lymph node and CCR7 was increased in lymph node macrophages and dendritic cells. CCR2-deficient mice recapitulated the profound reduction in the number of resident (but not migratory dermal) dendritic cells in the lymph node but showed no alteration in the expression of CCL19 and CCL21. Collectively, these results suggest that the malnutrition-related reduction in the lymph node barrier to dissemination of L. donovani is related to insufficient numbers of lymph node-resident but not migratory dermal dendritic cells. This is likely driven by the altered activity of the CCR2 and CCR7 chemoattractant pathways.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA South Texas Veterans Health Care System, San Antonio, Texas, USA Department of Microbial Biotechnology, Genetic Engineering Division, National Research Center, Giza, Egypt.
authors.forename: Marwa K
authors.initials: MK
authors.lastname: Ibrahim
authors.affiliation: South Texas Veterans Health Care System, San Antonio, Texas, USA Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Barnes
authors.affiliation: Department of Internal Medicine and Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: E Yaneth
authors.initials: EY
authors.lastname: Osorio
authors.affiliation: South Texas Veterans Health Care System, San Antonio, Texas, USA Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Anstead
authors.affiliation: South Texas Veterans Health Care System, San Antonio, Texas, USA Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Fabio
authors.initials: F
authors.lastname: Jimenez
authors.affiliation: Department of Internal Medicine, University of Michigan, and the VA Ann Arbor Healthcare System, Ann Arbor, Michigan, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Osterholzer
authors.affiliation: Department of Internal Medicine and Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas, USA.
authors.forename: Bruno L
authors.initials: BL
authors.lastname: Travi
authors.affiliation: South Texas Veterans Health Care System, San Antonio, Texas, USA Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Seema S
authors.initials: SS
authors.lastname: Ahuja
authors.affiliation: Department of Internal Medicine and Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: A Clinton
authors.initials: AC
authors.lastname: White
authors.affiliation: Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Internal Medicine and Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas, USA Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, Texas, USA pcmelby@utmb.edu.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Melby
mesh_terms: D000818:Animals; D018925:Chemokines / Q000378:metabolism*; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D020869:Gene Expression Profiling; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000150:complications* / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology*; D008297:Male; D044342:Malnutrition / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D019707:Receptors, Chemokine / Q000096:biosynthesis
chemical_list: D018925:Chemokines; D019707:Receptors, Chemokine