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Efficient uptake of blood-borne BK and JC polyomavirus-like particles in endothelial cells of liver sinusoids and renal vasa recta.

Simon-Santamaria J, Rinaldo CH, Kardas P, Li R, Malovic I, Elvevold K, McCourt P, Smedsrød B, Hirsch HH, Sørensen KK - PLoS ONE (2014)

Bottom Line: Most VLP-positive vessels in renal medulla did not express PV-1/Meca 32, suggesting location to the non-fenestrated part of vasa recta.The endothelial cells of these vessels also efficiently endocytosed a scavenger receptor ligand, formaldehyde-denatured albumin, suggesting high endocytic activity compared to other renal endothelia.We conclude that LSECs very effectively cleared a large fraction of blood-borne BK- and JC-VLPs, indicating a central role of these cells in early removal of polyomavirus from the circulation.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biology, UiT - The Arctic University of Norway, Tromsø, Norway.

ABSTRACT
Liver sinusoidal endothelial cells (LSECs) are specialized scavenger cells that mediate high-capacity clearance of soluble waste macromolecules and colloid material, including blood-borne adenovirus. To explore if LSECs function as a sink for other viruses in blood, we studied the fate of virus-like particles (VLPs) of two ubiquitous human DNA viruses, BK and JC polyomavirus, in mice. Like complete virions, VLPs specifically bind to receptors and enter cells, but unlike complete virions, they cannot replicate. 125I-labeled VLPs were used to assess blood decay, organ-, and hepatocellular distribution of ligand, and non-labeled VLPs to examine cellular uptake by immunohisto- and -cytochemistry. BK- and JC-VLPs rapidly distributed to liver, with lesser uptake in kidney and spleen. Liver uptake was predominantly in LSECs. Blood half-life (∼1 min), and tissue distribution of JC-VLPs and two JC-VLP-mutants (L55F and S269F) that lack sialic acid binding affinity, were similar, indicating involvement of non-sialic acid receptors in cellular uptake. Liver uptake was not mediated by scavenger receptors. In spleen, the VLPs localized to the red pulp marginal zone reticuloendothelium, and in kidney to the endothelial lining of vasa recta segments, and the transitional epithelium of renal pelvis. Most VLP-positive vessels in renal medulla did not express PV-1/Meca 32, suggesting location to the non-fenestrated part of vasa recta. The endothelial cells of these vessels also efficiently endocytosed a scavenger receptor ligand, formaldehyde-denatured albumin, suggesting high endocytic activity compared to other renal endothelia. We conclude that LSECs very effectively cleared a large fraction of blood-borne BK- and JC-VLPs, indicating a central role of these cells in early removal of polyomavirus from the circulation. In addition, we report the novel finding that a subpopulation of endothelial cells in kidney, the main organ of polyomavirus persistence, showed selective and rapid uptake of VLPs, suggesting a role in viremic organ tropism.

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Blood clearance and organ distribution of mutant JC-VLPs.Mice were injected intravenously with 125I-JC-VLPL55F (n = 3, A–B), or 125I-JC-VLPS269F (n = 3, C–D), and blood samples taken at the indicated time points and analyzed for 125I-labeled degradation products and intact ligand [15]. Panels A and C show the decrease of intact ligand in blood as a function of time. Panels B and D show the increase in degradation products released into the blood with time. Different symbols refer to separate animals, and cpm to counts per minute. The slopes of the lines drawn in B and D represent the average release rate of degradation products in the 10–30 min period after ligand injection where this release followed approximate first order kinetics. E) Tissue distribution 60 min post injection. The animals in A–D were sacrificed after 60 min, and organs and tissues analyzed for radioactivity. Recovered radioactivity in all tissues at this time point was taken as 100%. Error bars represent SEM. GI tract, gastrointestinal tract (stomach and intestines including mesenterium); U bladder, urine bladder. F) Hepatocellular distribution (±SD) of 125I-labeled JC-VLP mutants 10 min after intravenous injection; liver tissue was dispersed by collagenase perfusion, and radioactivity was measured in hepatocyte and non-parenchymal cell (NPC) fractions, respectively. G) Cellular distribution of JC-VLPS269F (anti-VP1 staining) 15 min after VLP injection. Uptake of JC-VLPS269F (red fluorescence; arrowheads) is seen along the sinusoids (s).
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pone-0111762-g006: Blood clearance and organ distribution of mutant JC-VLPs.Mice were injected intravenously with 125I-JC-VLPL55F (n = 3, A–B), or 125I-JC-VLPS269F (n = 3, C–D), and blood samples taken at the indicated time points and analyzed for 125I-labeled degradation products and intact ligand [15]. Panels A and C show the decrease of intact ligand in blood as a function of time. Panels B and D show the increase in degradation products released into the blood with time. Different symbols refer to separate animals, and cpm to counts per minute. The slopes of the lines drawn in B and D represent the average release rate of degradation products in the 10–30 min period after ligand injection where this release followed approximate first order kinetics. E) Tissue distribution 60 min post injection. The animals in A–D were sacrificed after 60 min, and organs and tissues analyzed for radioactivity. Recovered radioactivity in all tissues at this time point was taken as 100%. Error bars represent SEM. GI tract, gastrointestinal tract (stomach and intestines including mesenterium); U bladder, urine bladder. F) Hepatocellular distribution (±SD) of 125I-labeled JC-VLP mutants 10 min after intravenous injection; liver tissue was dispersed by collagenase perfusion, and radioactivity was measured in hepatocyte and non-parenchymal cell (NPC) fractions, respectively. G) Cellular distribution of JC-VLPS269F (anti-VP1 staining) 15 min after VLP injection. Uptake of JC-VLPS269F (red fluorescence; arrowheads) is seen along the sinusoids (s).

Mentions: It is reported that BKV and JCV enter their natural host cells via carbohydrate receptors [55]. While BKV binds to alpha(2,3)-linked sialic acids on (for instance) gangliosides [56], JCV binds to alpha(2,6)-linked glycan lactoseries tetrasaccharide c (LSTc) [57]. To test whether blood clearance of JCV in mice is dependent on alpha(2,6)-linked sialic acids, we examined the elimination from blood of two JC-VLP variants occurring frequently in PML patients, namely JC-VLPL55F and JC-VLPS269F (Figure 6A–D, Table 2), which had been shown to no longer hemagglutinate red blood cells and to have lost their respective sialic acid receptor binding properties [58]. These VLPs were constructed from mutant forms of the JCV capsid protein VP1, in which one amino acid in the sialic acid binding loop of VP1 had been substituted. The data show that 125I-JC-VLPL55F and 125I-JC-VLPS269F were removed from the circulation in a similar manner as the JC-VLPs made from Mad-1 JC-VP1 (named here as JC-VLP) (Table 2). After 60 min nearly all 125I-JC-VLPL55F, and 80% of the 125I-JC-VLPS269F were eliminated from blood (Figure 6A, C). Similarly to the JC-VLPs, acid soluble 125I-degradation products appeared in the circulation already after 10 min (Figure 6B, D).


Efficient uptake of blood-borne BK and JC polyomavirus-like particles in endothelial cells of liver sinusoids and renal vasa recta.

Simon-Santamaria J, Rinaldo CH, Kardas P, Li R, Malovic I, Elvevold K, McCourt P, Smedsrød B, Hirsch HH, Sørensen KK - PLoS ONE (2014)

Blood clearance and organ distribution of mutant JC-VLPs.Mice were injected intravenously with 125I-JC-VLPL55F (n = 3, A–B), or 125I-JC-VLPS269F (n = 3, C–D), and blood samples taken at the indicated time points and analyzed for 125I-labeled degradation products and intact ligand [15]. Panels A and C show the decrease of intact ligand in blood as a function of time. Panels B and D show the increase in degradation products released into the blood with time. Different symbols refer to separate animals, and cpm to counts per minute. The slopes of the lines drawn in B and D represent the average release rate of degradation products in the 10–30 min period after ligand injection where this release followed approximate first order kinetics. E) Tissue distribution 60 min post injection. The animals in A–D were sacrificed after 60 min, and organs and tissues analyzed for radioactivity. Recovered radioactivity in all tissues at this time point was taken as 100%. Error bars represent SEM. GI tract, gastrointestinal tract (stomach and intestines including mesenterium); U bladder, urine bladder. F) Hepatocellular distribution (±SD) of 125I-labeled JC-VLP mutants 10 min after intravenous injection; liver tissue was dispersed by collagenase perfusion, and radioactivity was measured in hepatocyte and non-parenchymal cell (NPC) fractions, respectively. G) Cellular distribution of JC-VLPS269F (anti-VP1 staining) 15 min after VLP injection. Uptake of JC-VLPS269F (red fluorescence; arrowheads) is seen along the sinusoids (s).
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Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4222947&req=5

pone-0111762-g006: Blood clearance and organ distribution of mutant JC-VLPs.Mice were injected intravenously with 125I-JC-VLPL55F (n = 3, A–B), or 125I-JC-VLPS269F (n = 3, C–D), and blood samples taken at the indicated time points and analyzed for 125I-labeled degradation products and intact ligand [15]. Panels A and C show the decrease of intact ligand in blood as a function of time. Panels B and D show the increase in degradation products released into the blood with time. Different symbols refer to separate animals, and cpm to counts per minute. The slopes of the lines drawn in B and D represent the average release rate of degradation products in the 10–30 min period after ligand injection where this release followed approximate first order kinetics. E) Tissue distribution 60 min post injection. The animals in A–D were sacrificed after 60 min, and organs and tissues analyzed for radioactivity. Recovered radioactivity in all tissues at this time point was taken as 100%. Error bars represent SEM. GI tract, gastrointestinal tract (stomach and intestines including mesenterium); U bladder, urine bladder. F) Hepatocellular distribution (±SD) of 125I-labeled JC-VLP mutants 10 min after intravenous injection; liver tissue was dispersed by collagenase perfusion, and radioactivity was measured in hepatocyte and non-parenchymal cell (NPC) fractions, respectively. G) Cellular distribution of JC-VLPS269F (anti-VP1 staining) 15 min after VLP injection. Uptake of JC-VLPS269F (red fluorescence; arrowheads) is seen along the sinusoids (s).
Mentions: It is reported that BKV and JCV enter their natural host cells via carbohydrate receptors [55]. While BKV binds to alpha(2,3)-linked sialic acids on (for instance) gangliosides [56], JCV binds to alpha(2,6)-linked glycan lactoseries tetrasaccharide c (LSTc) [57]. To test whether blood clearance of JCV in mice is dependent on alpha(2,6)-linked sialic acids, we examined the elimination from blood of two JC-VLP variants occurring frequently in PML patients, namely JC-VLPL55F and JC-VLPS269F (Figure 6A–D, Table 2), which had been shown to no longer hemagglutinate red blood cells and to have lost their respective sialic acid receptor binding properties [58]. These VLPs were constructed from mutant forms of the JCV capsid protein VP1, in which one amino acid in the sialic acid binding loop of VP1 had been substituted. The data show that 125I-JC-VLPL55F and 125I-JC-VLPS269F were removed from the circulation in a similar manner as the JC-VLPs made from Mad-1 JC-VP1 (named here as JC-VLP) (Table 2). After 60 min nearly all 125I-JC-VLPL55F, and 80% of the 125I-JC-VLPS269F were eliminated from blood (Figure 6A, C). Similarly to the JC-VLPs, acid soluble 125I-degradation products appeared in the circulation already after 10 min (Figure 6B, D).

Bottom Line: Most VLP-positive vessels in renal medulla did not express PV-1/Meca 32, suggesting location to the non-fenestrated part of vasa recta.The endothelial cells of these vessels also efficiently endocytosed a scavenger receptor ligand, formaldehyde-denatured albumin, suggesting high endocytic activity compared to other renal endothelia.We conclude that LSECs very effectively cleared a large fraction of blood-borne BK- and JC-VLPs, indicating a central role of these cells in early removal of polyomavirus from the circulation.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biology, UiT - The Arctic University of Norway, Tromsø, Norway.

ABSTRACT
Liver sinusoidal endothelial cells (LSECs) are specialized scavenger cells that mediate high-capacity clearance of soluble waste macromolecules and colloid material, including blood-borne adenovirus. To explore if LSECs function as a sink for other viruses in blood, we studied the fate of virus-like particles (VLPs) of two ubiquitous human DNA viruses, BK and JC polyomavirus, in mice. Like complete virions, VLPs specifically bind to receptors and enter cells, but unlike complete virions, they cannot replicate. 125I-labeled VLPs were used to assess blood decay, organ-, and hepatocellular distribution of ligand, and non-labeled VLPs to examine cellular uptake by immunohisto- and -cytochemistry. BK- and JC-VLPs rapidly distributed to liver, with lesser uptake in kidney and spleen. Liver uptake was predominantly in LSECs. Blood half-life (∼1 min), and tissue distribution of JC-VLPs and two JC-VLP-mutants (L55F and S269F) that lack sialic acid binding affinity, were similar, indicating involvement of non-sialic acid receptors in cellular uptake. Liver uptake was not mediated by scavenger receptors. In spleen, the VLPs localized to the red pulp marginal zone reticuloendothelium, and in kidney to the endothelial lining of vasa recta segments, and the transitional epithelium of renal pelvis. Most VLP-positive vessels in renal medulla did not express PV-1/Meca 32, suggesting location to the non-fenestrated part of vasa recta. The endothelial cells of these vessels also efficiently endocytosed a scavenger receptor ligand, formaldehyde-denatured albumin, suggesting high endocytic activity compared to other renal endothelia. We conclude that LSECs very effectively cleared a large fraction of blood-borne BK- and JC-VLPs, indicating a central role of these cells in early removal of polyomavirus from the circulation. In addition, we report the novel finding that a subpopulation of endothelial cells in kidney, the main organ of polyomavirus persistence, showed selective and rapid uptake of VLPs, suggesting a role in viremic organ tropism.

Show MeSH
Related in: MedlinePlus