title: Nonspecific immunoglobulin M binding and chondroitin sulfate A binding are linked phenotypes of Plasmodium falciparum isolates implicated in malaria during pregnancy.
abstract: Binding of immunoglobulin M (IgM) antibodies from normal human serum to the surface of Plasmodium falciparum-infected red blood cells (iRBC) has previously been demonstrated only in parasites that form rosettes with uninfected red cells. We show that natural, nonspecific IgM but not IgG, IgA, IgD, or IgE also binds to the surface of iRBC selected for adhesion to chondroitin sulfate A (CSA), a placental receptor for parasites associated with malaria in pregnancy. The protease sensitivity of IgM-binding appears to match that of CSA binding, suggesting that the two phenotypes may be mediated by the same parasite molecule. We also show that a wide range of mouse monoclonal antibodies of the IgM class bind nonspecifically to CSA-selected iRBC, an important consideration in the interpretation of immunological assays performed on these parasite lines.
authors.affiliation: Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom. acreasey@ed.ac.uk
authors.forename: Alison M
authors.initials: AM
authors.lastname: Creasey
authors.forename: Trine
authors.initials: T
authors.lastname: Staalsoe
authors.forename: Ahmed
authors.initials: A
authors.lastname: Raza
authors.forename: David E
authors.initials: DE
authors.lastname: Arnot
authors.forename: J Alexandra
authors.initials: JA
authors.lastname: Rowe
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000378:metabolism; D000954:Antigens, Surface / Q000378:metabolism; D002809:Chondroitin Sulfates / Q000378:metabolism*; D004912:Erythrocytes / Q000276:immunology / Q000469:parasitology; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism*; D066298:In Vitro Techniques; D016778:Malaria, Falciparum / Q000150:complications* / Q000276:immunology / Q000469:parasitology; D010641:Phenotype; D010963:Plasmodium falciparum / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000276:immunology* / Q000469:parasitology; D012397:Rosette Formation
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D007075:Immunoglobulin M; D002809:Chondroitin Sulfates