Two functional reticulocyte binding-like (RBL) invasion ligands of zoonotic Plasmodium knowlesi exhibit differential adhesion to monkey and human erythrocytes

Amma A. Semenya, Tuan  Tran, Esmeralda Vs Meyer, John W. Barnwell, Mary R. Galinski

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Background: Plasmodium knowlesi is a monkey malaria species that is becoming a serious public health concern infecting hundreds and perhaps thousands of humans in Southeast Asia. Invasion of erythrocytes by merozoites entails a cascade of molecular interactions. One step involves the adhesion of Plasmodium reticulocyte binding-like (RBL) proteins. Plasmodium knowlesi merozoites express only two RBL invasion ligands, known as Normocyte Binding Proteins (PkNBPXa and PkNBPXb). Methods: Overlapping N-terminal regions of PkNBPXa and PkNBPXb were expressed in COS7 cells and tested for surface expression and adhesion to rhesus monkey erythrocytes. Subsequent tests to study specific receptor ligand interactions included adhesion to a panel of human and non-human primate erythrocytes, enzymatic treatment, and site directed mutagenesis. Results: An N-terminal cysteine-rich region of PkNBPXb (PkNBPXb-II) exhibited specific adhesion to rhesus monkey erythrocytes. Mutation of four of five cysteines in PkNBPXb-II interfered with its surface expression on COS7 cells, suggesting disulphide bond conformation is critical for intracellular trafficking. Binding of PkNBPXb-II was abolished when rhesus erythrocytes were pre-treated with chymotrypsin, but not trypsin or neuraminidase. PkNBPXb-II also bound other Old World monkey species and gibbon erythrocytes. However, erythrocytes from other primate species including humans did not bind to PkNBPXb-II or native PkNBPXb. Importantly, unlike PkNBPXb, PkNBPXa bound human erythrocytes, and this binding was independent of the Duffy blood group determinant. Conclusions: The data reported here begins to clarify the functional domains of the P. knowlesi RBLs. A binding domain has been identified and characterized in PkNBPXb. Notably, this study demonstrates that unlike PkNBPXb, PkNBPXa can bind to human erythrocytes, suggesting that PkNBPXa may function as a ligand to enable the invasion of P. knowlesi merozoites into human cells.

Original languageEnglish (US)
Article number228
JournalMalaria Journal
Volume11
DOIs
StatePublished - 2012
Externally publishedYes

Fingerprint

Plasmodium knowlesi
Reticulocytes
Zoonoses
Haplorhini
Erythrocytes
Ligands
Merozoites
Macaca mulatta
Primates
Cysteine
Carrier Proteins
Hylobates
Cercopithecidae
Southeastern Asia
Plasmodium
Neuraminidase
Blood Group Antigens
Site-Directed Mutagenesis
Disulfides
Malaria

Keywords

  • Adhesion
  • Binding protein
  • Erythrocyte
  • Invasion ligand
  • Malaria
  • Merozoite
  • Plasmodium knowlesi
  • RBLs
  • Reticulocyte

ASJC Scopus subject areas

  • Infectious Diseases
  • Parasitology

Cite this

Two functional reticulocyte binding-like (RBL) invasion ligands of zoonotic Plasmodium knowlesi exhibit differential adhesion to monkey and human erythrocytes. / Semenya, Amma A.; Tran, Tuan ; Meyer, Esmeralda Vs; Barnwell, John W.; Galinski, Mary R.

In: Malaria Journal, Vol. 11, 228, 2012.

Research output: Contribution to journalArticle

@article{d540cbc8cc304d9d90871193c8fecb3d,
title = "Two functional reticulocyte binding-like (RBL) invasion ligands of zoonotic Plasmodium knowlesi exhibit differential adhesion to monkey and human erythrocytes",
abstract = "Background: Plasmodium knowlesi is a monkey malaria species that is becoming a serious public health concern infecting hundreds and perhaps thousands of humans in Southeast Asia. Invasion of erythrocytes by merozoites entails a cascade of molecular interactions. One step involves the adhesion of Plasmodium reticulocyte binding-like (RBL) proteins. Plasmodium knowlesi merozoites express only two RBL invasion ligands, known as Normocyte Binding Proteins (PkNBPXa and PkNBPXb). Methods: Overlapping N-terminal regions of PkNBPXa and PkNBPXb were expressed in COS7 cells and tested for surface expression and adhesion to rhesus monkey erythrocytes. Subsequent tests to study specific receptor ligand interactions included adhesion to a panel of human and non-human primate erythrocytes, enzymatic treatment, and site directed mutagenesis. Results: An N-terminal cysteine-rich region of PkNBPXb (PkNBPXb-II) exhibited specific adhesion to rhesus monkey erythrocytes. Mutation of four of five cysteines in PkNBPXb-II interfered with its surface expression on COS7 cells, suggesting disulphide bond conformation is critical for intracellular trafficking. Binding of PkNBPXb-II was abolished when rhesus erythrocytes were pre-treated with chymotrypsin, but not trypsin or neuraminidase. PkNBPXb-II also bound other Old World monkey species and gibbon erythrocytes. However, erythrocytes from other primate species including humans did not bind to PkNBPXb-II or native PkNBPXb. Importantly, unlike PkNBPXb, PkNBPXa bound human erythrocytes, and this binding was independent of the Duffy blood group determinant. Conclusions: The data reported here begins to clarify the functional domains of the P. knowlesi RBLs. A binding domain has been identified and characterized in PkNBPXb. Notably, this study demonstrates that unlike PkNBPXb, PkNBPXa can bind to human erythrocytes, suggesting that PkNBPXa may function as a ligand to enable the invasion of P. knowlesi merozoites into human cells.",
keywords = "Adhesion, Binding protein, Erythrocyte, Invasion ligand, Malaria, Merozoite, Plasmodium knowlesi, RBLs, Reticulocyte",
author = "Semenya, {Amma A.} and Tuan  Tran and Meyer, {Esmeralda Vs} and Barnwell, {John W.} and Galinski, {Mary R.}",
year = "2012",
doi = "10.1186/1475-2875-11-228",
language = "English (US)",
volume = "11",
journal = "Malaria Journal",
issn = "1475-2875",
publisher = "BioMed Central",

}

TY - JOUR

T1 - Two functional reticulocyte binding-like (RBL) invasion ligands of zoonotic Plasmodium knowlesi exhibit differential adhesion to monkey and human erythrocytes

AU - Semenya, Amma A.

AU - Tran, Tuan 

AU - Meyer, Esmeralda Vs

AU - Barnwell, John W.

AU - Galinski, Mary R.

PY - 2012

Y1 - 2012

N2 - Background: Plasmodium knowlesi is a monkey malaria species that is becoming a serious public health concern infecting hundreds and perhaps thousands of humans in Southeast Asia. Invasion of erythrocytes by merozoites entails a cascade of molecular interactions. One step involves the adhesion of Plasmodium reticulocyte binding-like (RBL) proteins. Plasmodium knowlesi merozoites express only two RBL invasion ligands, known as Normocyte Binding Proteins (PkNBPXa and PkNBPXb). Methods: Overlapping N-terminal regions of PkNBPXa and PkNBPXb were expressed in COS7 cells and tested for surface expression and adhesion to rhesus monkey erythrocytes. Subsequent tests to study specific receptor ligand interactions included adhesion to a panel of human and non-human primate erythrocytes, enzymatic treatment, and site directed mutagenesis. Results: An N-terminal cysteine-rich region of PkNBPXb (PkNBPXb-II) exhibited specific adhesion to rhesus monkey erythrocytes. Mutation of four of five cysteines in PkNBPXb-II interfered with its surface expression on COS7 cells, suggesting disulphide bond conformation is critical for intracellular trafficking. Binding of PkNBPXb-II was abolished when rhesus erythrocytes were pre-treated with chymotrypsin, but not trypsin or neuraminidase. PkNBPXb-II also bound other Old World monkey species and gibbon erythrocytes. However, erythrocytes from other primate species including humans did not bind to PkNBPXb-II or native PkNBPXb. Importantly, unlike PkNBPXb, PkNBPXa bound human erythrocytes, and this binding was independent of the Duffy blood group determinant. Conclusions: The data reported here begins to clarify the functional domains of the P. knowlesi RBLs. A binding domain has been identified and characterized in PkNBPXb. Notably, this study demonstrates that unlike PkNBPXb, PkNBPXa can bind to human erythrocytes, suggesting that PkNBPXa may function as a ligand to enable the invasion of P. knowlesi merozoites into human cells.

AB - Background: Plasmodium knowlesi is a monkey malaria species that is becoming a serious public health concern infecting hundreds and perhaps thousands of humans in Southeast Asia. Invasion of erythrocytes by merozoites entails a cascade of molecular interactions. One step involves the adhesion of Plasmodium reticulocyte binding-like (RBL) proteins. Plasmodium knowlesi merozoites express only two RBL invasion ligands, known as Normocyte Binding Proteins (PkNBPXa and PkNBPXb). Methods: Overlapping N-terminal regions of PkNBPXa and PkNBPXb were expressed in COS7 cells and tested for surface expression and adhesion to rhesus monkey erythrocytes. Subsequent tests to study specific receptor ligand interactions included adhesion to a panel of human and non-human primate erythrocytes, enzymatic treatment, and site directed mutagenesis. Results: An N-terminal cysteine-rich region of PkNBPXb (PkNBPXb-II) exhibited specific adhesion to rhesus monkey erythrocytes. Mutation of four of five cysteines in PkNBPXb-II interfered with its surface expression on COS7 cells, suggesting disulphide bond conformation is critical for intracellular trafficking. Binding of PkNBPXb-II was abolished when rhesus erythrocytes were pre-treated with chymotrypsin, but not trypsin or neuraminidase. PkNBPXb-II also bound other Old World monkey species and gibbon erythrocytes. However, erythrocytes from other primate species including humans did not bind to PkNBPXb-II or native PkNBPXb. Importantly, unlike PkNBPXb, PkNBPXa bound human erythrocytes, and this binding was independent of the Duffy blood group determinant. Conclusions: The data reported here begins to clarify the functional domains of the P. knowlesi RBLs. A binding domain has been identified and characterized in PkNBPXb. Notably, this study demonstrates that unlike PkNBPXb, PkNBPXa can bind to human erythrocytes, suggesting that PkNBPXa may function as a ligand to enable the invasion of P. knowlesi merozoites into human cells.

KW - Adhesion

KW - Binding protein

KW - Erythrocyte

KW - Invasion ligand

KW - Malaria

KW - Merozoite

KW - Plasmodium knowlesi

KW - RBLs

KW - Reticulocyte

UR - http://www.scopus.com/inward/record.url?scp=84863498214&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84863498214&partnerID=8YFLogxK

U2 - 10.1186/1475-2875-11-228

DO - 10.1186/1475-2875-11-228

M3 - Article

VL - 11

JO - Malaria Journal

JF - Malaria Journal

SN - 1475-2875

M1 - 228

ER -