Gene-expression profiling of different arms of lymphatic vasculature identifies candidates for manipulation of cell traffic.
Afferent lymphatic vessels bring antigens and diverse populations of leukocytes to draining lymph nodes, whereas efferent lymphatics allow only lymphocytes and antigens to leave the nodes. Despite the fundamental importance of afferent vs. efferent lymphatics in immune response and cancer spread, the molecular characteristics of these different arms of the lymphatic vasculature are largely unknown. The objective of this work was to explore molecular differences behind the distinct functions of afferent and efferent lymphatic vessels, and find possible molecules mediating lymphocyte traffic. We used laser-capture microdissection and cell sorting to isolate lymphatic endothelial cells (LECs) from the subcapsular sinus (SS, afferent) and lymphatic sinus (LS, efferent) for transcriptional analyses. The results reveal marked differences between afferent and efferent LECs and identify molecules on lymphatic vessels. Further characterizations of Siglec-1 (CD169) and macrophage scavenger receptor 1 (MSR1/CD204), show that they are discriminatively expressed on lymphatic endothelium of the SS but not on lymphatic vasculature of the LS. In contrast, endomucin (EMCN) is present on the LS endothelium and not on lymphatic endothelium of the SS. Moreover, both murine and human MSR1 on lymphatic endothelium of the SS bind lymphocytes and in in vivo studies MSR1 regulates entrance of lymphocytes from the SS to the lymph node parenchyma. In conclusion, this paper reports surprisingly distinct molecular profiles for afferent and efferent lymphatics and a function for MSR1. These results may open avenues to explore some of the now-identified molecules as targets to manipulate the function of lymphatic vessels.
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland;
Imtiaz
I
Iftakhar-E-Khuda
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland;
Ruth
R
Fair-Mäkelä
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland;
Anu
A
Kukkonen-Macchi
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland; Department of Medical Biochemistry and Genetics, University of Turku, 20520 Turku, Finland;
Kati
K
Elima
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland;
Marika
M
Karikoski
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland;
Pia
P
Rantakari
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland; World Premier International Immunology Frontier Research Center, Osaka University, 565-0871 Osaka, Japan;
Masayuki
M
Miyasaka
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland; Department of Medical Microbiology and Immunology, University of Turku, 20520 Turku, Finland.
Marko
M
Salmi
MediCity Research Laboratory, University of Turku, 20520 Turku, Finland; Department of Medical Microbiology and Immunology, University of Turku, 20520 Turku, Finland sirpa.jalkanen@utu.fi.
Sirpa
S
Jalkanen
D000818:Animals; D002465:Cell Movement / Q000235:genetics; D004729:Endothelium, Lymphatic / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D007111:Immunity, Cellular / Q000235:genetics; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D042601:Lymphatic Vessels / Q000378:metabolism / Q000473:pathology; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D046228:Microarray Analysis / Q000379:methods; D009369:Neoplasms / Q000235:genetics* / Q000276:immunology; D009389:Neovascularization, Pathologic / Q000235:genetics*; D051117:Scavenger Receptors, Class A / Q000235:genetics*; D063267:Sialic Acid Binding Ig-like Lectin 1 / Q000235:genetics*; D012795:Sialoglycoproteins / Q000235:genetics*
C431275:EMCN protein, human; C495139:MSR1 protein, human; C571166:SIGLEC1 protein, human; D051117:Scavenger Receptors, Class A; D063267:Sialic Acid Binding Ig-like Lectin 1; D012795:Sialoglycoproteins
cell traffic; endothelium; lymphatics; lymphocytes