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HNA‐3a–specific antibodies recognize choline transporter–like protein‐2 peptides containing arginine, but not glutamine at Position 154
Author(s) -
Curtis Brian R.,
Sullivan Mia J.,
Holyst M. Trudy,
Szabo Aniko,
Bougie Daniel W.,
Aster Richard H.
Publication year - 2011
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.2011.03145.x
Subject(s) - epitope , antibody , antigen , context (archaeology) , peptide , glutamine , epitope mapping , arginine , transporter , cyclic peptide , peptide sequence , biochemistry , biology , amino acid , chemistry , immunology , gene , paleontology
BACKGROUND: Antibodies specific for the neutrophil antigen HNA‐3a cause severe, sometimes fatal transfusion‐related acute lung disease (TRALI) when transfused, but it has not been possible to screen blood donors for anti‐HNA‐3a because using neutrophils as targets was impractical and molecular properties of the antigen were unknown. Recently it was shown that HNA‐3a is carried on choline transporter–like protein‐2 (CTL2) and that the HNA‐3a/b phenotype is closely correlated with an R154Q amino acid polymorphism in CTL2. However, it has not been shown by direct experiment that R154 is essential for the HNA‐3a epitope. STUDY DESIGN AND METHODS: Preliminary attempts to express recombinant full‐length CTL2 (R154) recognized by anti‐HNA‐3a were unsuccessful. We therefore tested HNA‐3a–specific antibodies from donors implicated in TRALI reactions for reactivity against chemically synthesized linear and cyclic CTL2 peptides containing R154 or Q154. RESULTS: Nine of 20 HNA‐3a antibodies recognized the R154, but not the Q154 version of a cyclic 36‐residue CTL2 peptide (D131‐K166). However, 11 others failed to distinguish between the two versions of this peptide. CONCLUSION: The findings provide direct evidence that R154 in the context of CTL2 D131‐K166 is necessary to create the HNA‐3a epitope but, in the context of cyclic CTL2 peptide D131‐K166, is sufficient to detect only about one‐half of the HNA‐3a–specific antibodies implicated in TRALI. It is likely that fragments of CTL2 longer than can be made on a large scale with an automated synthesizer will be needed to produce a target capable of detecting all examples of anti‐HNA‐3a in donated blood.