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The P1 histo-blood group antigen is present on human red blood cell glycoproteins

Stenfelt, Linn LU ; Westman, Julia S. LU ; Hellberg, Åsa LU and Olsson, Martin L. LU (2019) In Transfusion 59(3). p.1108-1117
Abstract

BACKGROUND: The P1 antigen was first described in 1927 and belongs to the P1PK histo-blood group system, together with Pk and NOR. The A4GALT-encoded 4-α-galactosyltransferase synthesizes these antigens and has been considered to extend glycolipids exclusively. However, contradicting studies have been published regarding the presence of P1 on human glycoproteins. In other species, P1 occurs on glycoproteins. Furthermore, human ABH antigens occur on both glycolipids and glycoproteins and are biochemically related to P1. Thus, we hypothesized that P1 is present on RBC glycoproteins in humans. STUDY DESIGN AND METHODS: RBCs of known P1/P2 status (phenotype and rs8138197 genotype) were used. The RBC surface... (More)

BACKGROUND: The P1 antigen was first described in 1927 and belongs to the P1PK histo-blood group system, together with Pk and NOR. The A4GALT-encoded 4-α-galactosyltransferase synthesizes these antigens and has been considered to extend glycolipids exclusively. However, contradicting studies have been published regarding the presence of P1 on human glycoproteins. In other species, P1 occurs on glycoproteins. Furthermore, human ABH antigens occur on both glycolipids and glycoproteins and are biochemically related to P1. Thus, we hypothesized that P1 is present on RBC glycoproteins in humans. STUDY DESIGN AND METHODS: RBCs of known P1/P2 status (phenotype and rs8138197 genotype) were used. The RBC surface glycans were modified with α-galactosidases, papain, and/or peptide-N-glycosidase F. RBC membrane proteins were analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis/immunoblot. A new P1/P2-allelic discrimination assay based on rs5751348 was validated. RESULTS: P1 occurs on various glycoproteins, seen as smearlike patterns in anti-P1-stained immunoblots with RBC membranes of P1 but not P2 or p phenotype. There was a significant difference between the staining of P1-homozygous and P1-heterozygous RBCs (P1P1 > P1P2), as well as intragenotypic variation. Immunoblotting banding patterns show major carriers at approximately 50 and 100 kDa. P1 staining was lost after treatment of RBCs with α-galactosidase of broad Galα-1,3/4/6-specificity. Peptide-N-glycosidase F treatment reduced the P1 signal, while papain or α-1,3-specific galactosidase did not. P1/P2 status was confirmed by a new rs5751348 assay. CONCLUSION: Our data indicate that the P1 antigen can reside on human RBC glycoproteins. Glycosidase studies suggest that at least part of the epitopes occur on N-glycans.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Transfusion
volume
59
issue
3
pages
1108 - 1117
publisher
Wiley-Blackwell
external identifiers
  • scopus:85059266063
ISSN
0041-1132
DOI
10.1111/trf.15115
language
English
LU publication?
yes
id
8fe976a8-589b-4d7c-bff9-01c3218cd4b3
date added to LUP
2019-01-11 09:49:35
date last changed
2019-05-20 09:28:49
@article{8fe976a8-589b-4d7c-bff9-01c3218cd4b3,
  abstract     = {<p>BACKGROUND: The P1 antigen was first described in 1927 and belongs to the P1PK histo-blood group system, together with P<sup>k</sup> and NOR. The A4GALT-encoded 4-α-galactosyltransferase synthesizes these antigens and has been considered to extend glycolipids exclusively. However, contradicting studies have been published regarding the presence of P1 on human glycoproteins. In other species, P1 occurs on glycoproteins. Furthermore, human ABH antigens occur on both glycolipids and glycoproteins and are biochemically related to P1. Thus, we hypothesized that P1 is present on RBC glycoproteins in humans. STUDY DESIGN AND METHODS: RBCs of known P<sub>1</sub>/P<sub>2</sub> status (phenotype and rs8138197 genotype) were used. The RBC surface glycans were modified with α-galactosidases, papain, and/or peptide-N-glycosidase F. RBC membrane proteins were analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis/immunoblot. A new P<sup>1</sup>/P<sup>2</sup>-allelic discrimination assay based on rs5751348 was validated. RESULTS: P1 occurs on various glycoproteins, seen as smearlike patterns in anti-P1-stained immunoblots with RBC membranes of P<sub>1</sub> but not P<sub>2</sub> or p phenotype. There was a significant difference between the staining of P<sup>1</sup>-homozygous and P<sup>1</sup>-heterozygous RBCs (P<sup>1</sup>P<sup>1</sup> &gt; P<sup>1</sup>P<sup>2</sup>), as well as intragenotypic variation. Immunoblotting banding patterns show major carriers at approximately 50 and 100 kDa. P1 staining was lost after treatment of RBCs with α-galactosidase of broad Galα-1,3/4/6-specificity. Peptide-N-glycosidase F treatment reduced the P1 signal, while papain or α-1,3-specific galactosidase did not. P<sup>1</sup>/P<sup>2</sup> status was confirmed by a new rs5751348 assay. CONCLUSION: Our data indicate that the P1 antigen can reside on human RBC glycoproteins. Glycosidase studies suggest that at least part of the epitopes occur on N-glycans.</p>},
  author       = {Stenfelt, Linn and Westman, Julia S. and Hellberg, Åsa and Olsson, Martin L.},
  issn         = {0041-1132},
  language     = {eng},
  number       = {3},
  pages        = {1108--1117},
  publisher    = {Wiley-Blackwell},
  series       = {Transfusion},
  title        = {The P1 histo-blood group antigen is present on human red blood cell glycoproteins},
  url          = {http://dx.doi.org/10.1111/trf.15115},
  volume       = {59},
  year         = {2019},
}