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The zymogen granule protein 2 (GP2) binds to scavenger receptor expressed on endothelial cells I (SREC-I).

Hölzl MA, Hofer J, Kovarik JJ, Roggenbuck D, Reinhold D, Goihl A, Gärtner M, Steinberger P, Zlabinger GJ - Cell. Immunol. (2010)

Bottom Line: Inhibition of SREC-I on moDCs with anti-SREC-I antibodies does not result in a decreased GP2 binding.Interaction of GP2 with SREC-I and uptake might have profound effects in antigen clearance and mediation of the immune response.In addition to SREC-I other presently unknown receptors for GP2 on DCs might be involved in this process.

View Article: PubMed Central - PubMed

Affiliation: Institute of Immunology, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, A-1090 Vienna, Austria.

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Related in: MedlinePlus

Endocytosis of GP2-bio after binding to Bw-SREC or moDCs (A) SREC-I expressing Bw cells were incubated with 5 μg/mL GP2-bio. Cells were stained with SA-PE before (bold line) or after a one-hour incubation step (grey histogram). For control, untransfected Bw cells were incubated with GP2-bio and stained with SA-PE before the one hour incubation step (thin line). (B) moDCs were stained with 5 μg/mL GP2-bio and stained with SA-PE (bold line) or secondary reagent only (thin line). (C) To assess the internalization of GP2, moDCs were incubated with GP2-bio. Cells were stained with SA-PE before (bold line) or after a one hour incubation step at 37 °C (grey histogram). For control, moDCs were stained with SA-PE (thin line). MFI = Mean fluorescence intensity. One representative result of four independently performed experiments is shown.
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f0015: Endocytosis of GP2-bio after binding to Bw-SREC or moDCs (A) SREC-I expressing Bw cells were incubated with 5 μg/mL GP2-bio. Cells were stained with SA-PE before (bold line) or after a one-hour incubation step (grey histogram). For control, untransfected Bw cells were incubated with GP2-bio and stained with SA-PE before the one hour incubation step (thin line). (B) moDCs were stained with 5 μg/mL GP2-bio and stained with SA-PE (bold line) or secondary reagent only (thin line). (C) To assess the internalization of GP2, moDCs were incubated with GP2-bio. Cells were stained with SA-PE before (bold line) or after a one hour incubation step at 37 °C (grey histogram). For control, moDCs were stained with SA-PE (thin line). MFI = Mean fluorescence intensity. One representative result of four independently performed experiments is shown.

Mentions: Since SREC-I has been shown to be a receptor with endocytic capacity [22], we were interested whether GP2 is taken up after ligation. Therefore Bw-SREC-I cells were incubated with GP2-bio at 4 °C and washed. SA-PE staining of the cells was either performed after the washing step or following a one hour incubation step at 37 °C. After the one hour incubation step at 37 °C, GP2-bio was no longer accessible for binding of SA-PE, whereas immediate application of the secondary reagent and subsequent incubation for one hour at 37 °C still resulted in a strong fluorescence signal (Fig. 3A). These results clearly demonstrate efficient endocytic uptake of GP2 by the Bw-SREC-I cells. moDCs have been shown to bind and internalize the GP2 homologue THP [23]. Therefore, we were also interested to test the interaction of GP2 with this cell type. moDCs were able to bind (Fig. 3B) and to internalize GP2-bio (Fig. 3C). Using the same approach as described before, we found that moDCs stained with SA-PE before the one hour incubation step retained surface staining with GP2-bio. In contrast, staining after incubation at 37 °C for one hour resulted in a complete loss of SA-PE binding, indicating uptake of GP2.


The zymogen granule protein 2 (GP2) binds to scavenger receptor expressed on endothelial cells I (SREC-I).

Hölzl MA, Hofer J, Kovarik JJ, Roggenbuck D, Reinhold D, Goihl A, Gärtner M, Steinberger P, Zlabinger GJ - Cell. Immunol. (2010)

Endocytosis of GP2-bio after binding to Bw-SREC or moDCs (A) SREC-I expressing Bw cells were incubated with 5 μg/mL GP2-bio. Cells were stained with SA-PE before (bold line) or after a one-hour incubation step (grey histogram). For control, untransfected Bw cells were incubated with GP2-bio and stained with SA-PE before the one hour incubation step (thin line). (B) moDCs were stained with 5 μg/mL GP2-bio and stained with SA-PE (bold line) or secondary reagent only (thin line). (C) To assess the internalization of GP2, moDCs were incubated with GP2-bio. Cells were stained with SA-PE before (bold line) or after a one hour incubation step at 37 °C (grey histogram). For control, moDCs were stained with SA-PE (thin line). MFI = Mean fluorescence intensity. One representative result of four independently performed experiments is shown.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3040788&req=5

f0015: Endocytosis of GP2-bio after binding to Bw-SREC or moDCs (A) SREC-I expressing Bw cells were incubated with 5 μg/mL GP2-bio. Cells were stained with SA-PE before (bold line) or after a one-hour incubation step (grey histogram). For control, untransfected Bw cells were incubated with GP2-bio and stained with SA-PE before the one hour incubation step (thin line). (B) moDCs were stained with 5 μg/mL GP2-bio and stained with SA-PE (bold line) or secondary reagent only (thin line). (C) To assess the internalization of GP2, moDCs were incubated with GP2-bio. Cells were stained with SA-PE before (bold line) or after a one hour incubation step at 37 °C (grey histogram). For control, moDCs were stained with SA-PE (thin line). MFI = Mean fluorescence intensity. One representative result of four independently performed experiments is shown.
Mentions: Since SREC-I has been shown to be a receptor with endocytic capacity [22], we were interested whether GP2 is taken up after ligation. Therefore Bw-SREC-I cells were incubated with GP2-bio at 4 °C and washed. SA-PE staining of the cells was either performed after the washing step or following a one hour incubation step at 37 °C. After the one hour incubation step at 37 °C, GP2-bio was no longer accessible for binding of SA-PE, whereas immediate application of the secondary reagent and subsequent incubation for one hour at 37 °C still resulted in a strong fluorescence signal (Fig. 3A). These results clearly demonstrate efficient endocytic uptake of GP2 by the Bw-SREC-I cells. moDCs have been shown to bind and internalize the GP2 homologue THP [23]. Therefore, we were also interested to test the interaction of GP2 with this cell type. moDCs were able to bind (Fig. 3B) and to internalize GP2-bio (Fig. 3C). Using the same approach as described before, we found that moDCs stained with SA-PE before the one hour incubation step retained surface staining with GP2-bio. In contrast, staining after incubation at 37 °C for one hour resulted in a complete loss of SA-PE binding, indicating uptake of GP2.

Bottom Line: Inhibition of SREC-I on moDCs with anti-SREC-I antibodies does not result in a decreased GP2 binding.Interaction of GP2 with SREC-I and uptake might have profound effects in antigen clearance and mediation of the immune response.In addition to SREC-I other presently unknown receptors for GP2 on DCs might be involved in this process.

View Article: PubMed Central - PubMed

Affiliation: Institute of Immunology, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, A-1090 Vienna, Austria.

Show MeSH
Related in: MedlinePlus