T cells recognizing a peptide contaminant undetectable by mass spectrometry

TY - JOUR

T1 - T cells recognizing a peptide contaminant undetectable by mass spectrometry

AU - Brezar, Vedran

AU - Culina, Slobodan

AU - Østerbye, Thomas

AU - Guillonneau, François

AU - Chiappetta, Giovanni

AU - Verdier, Yann

AU - Vinh, Joelle

AU - Wong, F Susan

AU - Buus, Søren

AU - Mallone, Roberto

PY - 2011/12/14

Y1 - 2011/12/14

N2 - Synthetic peptides are widely used in immunological research as epitopes to stimulate their cognate T cells. These preparations are never completely pure, but trace contaminants are commonly revealed by mass spectrometry quality controls. In an effort to characterize novel major histocompatibility complex (MHC) Class I-restricted β-cell epitopes in non-obese diabetic (NOD) mice, we identified islet-infiltrating CD8+ T cells recognizing a contaminating peptide. The amount of this contaminant was so small to be undetectable by direct mass spectrometry. Only after concentration by liquid chromatography, we observed a mass peak corresponding to an immunodominant islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) 206-214 epitope described in the literature. Generation of CD8+ T-cell clones recognizing IGRP 206-214 using a novel method confirmed the identity of the contaminant, further underlining the immunodominance of IGRP 206-214. If left undetected, minute impurities in synthetic peptide preparations may thus give spurious results.

AB - Synthetic peptides are widely used in immunological research as epitopes to stimulate their cognate T cells. These preparations are never completely pure, but trace contaminants are commonly revealed by mass spectrometry quality controls. In an effort to characterize novel major histocompatibility complex (MHC) Class I-restricted β-cell epitopes in non-obese diabetic (NOD) mice, we identified islet-infiltrating CD8+ T cells recognizing a contaminating peptide. The amount of this contaminant was so small to be undetectable by direct mass spectrometry. Only after concentration by liquid chromatography, we observed a mass peak corresponding to an immunodominant islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) 206-214 epitope described in the literature. Generation of CD8+ T-cell clones recognizing IGRP 206-214 using a novel method confirmed the identity of the contaminant, further underlining the immunodominance of IGRP 206-214. If left undetected, minute impurities in synthetic peptide preparations may thus give spurious results.

U2 - 10.1371/journal.pone.0028866

DO - 10.1371/journal.pone.0028866

M3 - Journal article

C2 - 22194932

SN - 1932-6203

VL - 6

SP - e28866

JO - P L o S One

JF - P L o S One

IS - 12

ER -