Supplementary Figure 9: JAGN1-mutated human neutrophils exhibit severely aberrant glycosylation.
From: JAGN1 deficiency causes aberrant myeloid cell homeostasis and congenital neutropenia
MALDI-TOF mass spectrometry of permethylated N-glycans from (a) JAGN1-mutated peripheral blood neutrophils from patient P12 and (b) bone marrow–derived neutrophil granulocytes from patient P3. Red peaks depict the glycans whose abundance is markedly altered in patients. Other conditions are identical to those in Supplementary Figure 6. N-glycans from JAGN1-mutated human neutrophil samples from these patients exhibited an abnormal increase in the agalactosylated structures found at m/z = 1,835.9 and 2,081.0. Their low-mass N-glycome was characterized by abnormally high abundance of truncated bi- and triantennary agalactosylated structures (m/z = 1,835.9 and m/z = 2,081.0, respectively). Concomitant with this increase in immature glycans was a substantial reduction in all high-molecular-weight tri- and tetra-antennary glycans, including the complete absence of components above an m/z of 3,800. Consequently, these patients’ neutrophils have a dramatic reduction in functional glycan epitopes, including LeX and sialylated sequences.
