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Targeting mucosal sites by polymeric immunoglobulin receptor-directed peptides.

White KD, Capra JD - J. Exp. Med. (2002)

Bottom Line: Here by binding human secretory component to overlapping decapeptides of Calpha3, we confirm these residues and also uncover an additional site.Some transcytosis-selected peptides map to the same 402-410 pIgR-binding Calpha3 site.Further in vivo studies document that at least one of these peptides is transported in a rat model measuring hepatic bile transport.

View Article: PubMed Central - PubMed

Affiliation: Molecular Immunogenetics Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA.

ABSTRACT
Polymeric immunoglobulins provide first line humoral defense at mucosal surfaces to which they are specifically transported by the polymeric immunoglobulin receptor (pIgR) on mucosal and glandular epithelial cells. Previous studies from our laboratory suggested that amino acids 402-410 of the Calpha3 domain of dimeric IgA (dIgA) represented a potential binding site for the pIgR. Here by binding human secretory component to overlapping decapeptides of Calpha3, we confirm these residues and also uncover an additional site. Furthermore, we show that the Calpha3 motif appears to be sufficient to direct transport of green fluorescent protein through the pIgR-specific cellular transcytosis system. An alternative approach identified phage peptides, selected from a library by the in vitro Madin Darby Canine Kidney transcytosis assay, for pIgR-mediated transport through epithelial cells. Some transcytosis-selected peptides map to the same 402-410 pIgR-binding Calpha3 site. Further in vivo studies document that at least one of these peptides is transported in a rat model measuring hepatic bile transport. In addition to identifying small peptides that are both bound and transported by the pIgR, this study provides evidence that the pIgR-mediated mucosal secretion system may represent a means of targeting small molecule therapeutics and genes to mucosal epithelial cells.

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Basolateral to apical transport of phage peptides measured in the MDCK transcytosis system. Phage were added to the basolateral medium of wells containing 1.0 μm pore inserts confluent with either polarized nontransfected (negative control shown as solid fill) or pIgR-transfected (shown as no fill) MDCK cells. Transcytosis was allowed to occur for 4 h. The apical supernatant fluids were collected and phage titers determined. (a) Transport of RSR and SAM peptides; (b) transport of IPS and VDD peptides; (c) transport of QRN and MFV peptides; and (d) transport of WQA and LVL peptides. Results represent means from three independent experiments.
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fig5: Basolateral to apical transport of phage peptides measured in the MDCK transcytosis system. Phage were added to the basolateral medium of wells containing 1.0 μm pore inserts confluent with either polarized nontransfected (negative control shown as solid fill) or pIgR-transfected (shown as no fill) MDCK cells. Transcytosis was allowed to occur for 4 h. The apical supernatant fluids were collected and phage titers determined. (a) Transport of RSR and SAM peptides; (b) transport of IPS and VDD peptides; (c) transport of QRN and MFV peptides; and (d) transport of WQA and LVL peptides. Results represent means from three independent experiments.

Mentions: Eight phage peptides were selected for their positive transport through epithelial cells expressing pIgR. However, the definitive mechanism of transport was not determined. Therefore, the movement of the phage peptides through both pIgR-transfected and nontransfected MDCK cells was measured. The results indicate that the RSR, SAM, IPS, VDD, QRN, and MFV peptides displayed on the surface of the phage allow the phage to be selectively transported by the pIgR through MDCK cells (Fig. 5 , a–c). In contrast, the WQA and LVL phage peptides likely direct apical transport of phage by an alternate transcytosis pathway as there is no difference in transport by MDCK cells whether they are transfected with pIgR or not (Fig. 5 d).


Targeting mucosal sites by polymeric immunoglobulin receptor-directed peptides.

White KD, Capra JD - J. Exp. Med. (2002)

Basolateral to apical transport of phage peptides measured in the MDCK transcytosis system. Phage were added to the basolateral medium of wells containing 1.0 μm pore inserts confluent with either polarized nontransfected (negative control shown as solid fill) or pIgR-transfected (shown as no fill) MDCK cells. Transcytosis was allowed to occur for 4 h. The apical supernatant fluids were collected and phage titers determined. (a) Transport of RSR and SAM peptides; (b) transport of IPS and VDD peptides; (c) transport of QRN and MFV peptides; and (d) transport of WQA and LVL peptides. Results represent means from three independent experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196054&req=5

fig5: Basolateral to apical transport of phage peptides measured in the MDCK transcytosis system. Phage were added to the basolateral medium of wells containing 1.0 μm pore inserts confluent with either polarized nontransfected (negative control shown as solid fill) or pIgR-transfected (shown as no fill) MDCK cells. Transcytosis was allowed to occur for 4 h. The apical supernatant fluids were collected and phage titers determined. (a) Transport of RSR and SAM peptides; (b) transport of IPS and VDD peptides; (c) transport of QRN and MFV peptides; and (d) transport of WQA and LVL peptides. Results represent means from three independent experiments.
Mentions: Eight phage peptides were selected for their positive transport through epithelial cells expressing pIgR. However, the definitive mechanism of transport was not determined. Therefore, the movement of the phage peptides through both pIgR-transfected and nontransfected MDCK cells was measured. The results indicate that the RSR, SAM, IPS, VDD, QRN, and MFV peptides displayed on the surface of the phage allow the phage to be selectively transported by the pIgR through MDCK cells (Fig. 5 , a–c). In contrast, the WQA and LVL phage peptides likely direct apical transport of phage by an alternate transcytosis pathway as there is no difference in transport by MDCK cells whether they are transfected with pIgR or not (Fig. 5 d).

Bottom Line: Here by binding human secretory component to overlapping decapeptides of Calpha3, we confirm these residues and also uncover an additional site.Some transcytosis-selected peptides map to the same 402-410 pIgR-binding Calpha3 site.Further in vivo studies document that at least one of these peptides is transported in a rat model measuring hepatic bile transport.

View Article: PubMed Central - PubMed

Affiliation: Molecular Immunogenetics Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA.

ABSTRACT
Polymeric immunoglobulins provide first line humoral defense at mucosal surfaces to which they are specifically transported by the polymeric immunoglobulin receptor (pIgR) on mucosal and glandular epithelial cells. Previous studies from our laboratory suggested that amino acids 402-410 of the Calpha3 domain of dimeric IgA (dIgA) represented a potential binding site for the pIgR. Here by binding human secretory component to overlapping decapeptides of Calpha3, we confirm these residues and also uncover an additional site. Furthermore, we show that the Calpha3 motif appears to be sufficient to direct transport of green fluorescent protein through the pIgR-specific cellular transcytosis system. An alternative approach identified phage peptides, selected from a library by the in vitro Madin Darby Canine Kidney transcytosis assay, for pIgR-mediated transport through epithelial cells. Some transcytosis-selected peptides map to the same 402-410 pIgR-binding Calpha3 site. Further in vivo studies document that at least one of these peptides is transported in a rat model measuring hepatic bile transport. In addition to identifying small peptides that are both bound and transported by the pIgR, this study provides evidence that the pIgR-mediated mucosal secretion system may represent a means of targeting small molecule therapeutics and genes to mucosal epithelial cells.

Show MeSH