title: Acidified chloroquine treatment for the removal of class I HLA antigens.
abstract: With the aim of reducing the damage to platelets while effectively removing class I HLA antigens from their surfaces, we developed a new method using acidified chloroquine diphosphate. Platelets were treated with a 0.2 M solution of chloroquine diphosphate (pH 4.0). More than 90% of the platelets remained viable after treatment. While a marked reduction in reactions of acidified chloroquine-treated platelets with multispecific HLA antisera was noted in comparison with phosphate-buffered-saline-(PBS)-treated platelets, reactions with platelet-specific antibodies were preserved. This was demonstrated by immunofluorescence tests and solid-phase and monoclonal antibody immobilization of platelet antigen assays. Aggregation responses, though reduced in comparison with PBS-treated platelets, were still preserved after acidified chloroquine treatment. Ultrastructural analysis did not show any significant difference from PBS-treated platelets. We conclude that treatment of platelets with acidified chloroquine diphosphate is a simple and effective method for removing class I HLA antigens from their surfaces with minimal damage to their structure and function.
authors.affiliation: Haematology Department, Westmead Hospital, Sydney, NSW, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Srivastava
authors.forename: H
authors.initials: H
authors.lastname: Pearson
authors.forename: J
authors.initials: J
authors.lastname: Bryant
authors.forename: E
authors.initials: E
authors.lastname: Favaloro
authors.forename: N
authors.initials: N
authors.lastname: Coulits
authors.forename: J
authors.initials: J
authors.lastname: Jindra
authors.forename: B
authors.initials: B
authors.lastname: Wylie
mesh_terms: D001792:Blood Platelets / Q000187:drug effects* / Q000276:immunology / Q000648:ultrastructure; D002448:Cell Adhesion / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D002738:Chloroquine / Q000031:analogs & derivatives*; D000939:Epitopes; D005434:Flow Cytometry; D015395:Histocompatibility Antigens Class I / Q000097:blood / Q000302:isolation & purification*; D006801:Humans; D006851:Hydrochloric Acid; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence
chemical_list: D000939:Epitopes; D015395:Histocompatibility Antigens Class I; C023676:chloroquine diphosphate; D002738:Chloroquine; D006851:Hydrochloric Acid