Specific granule deficiency (SGD) is a rare disorder characterized by abnormal neutrophils evidenced by reduced granules, absence of granule proteins, and atypical bilobed nuclei. Mutations in CCAAT/enhancer-binding protein-ε (CEBPE) are one molecular etiology of the disease. Although C/EBPε has been studied extensively, the impact of CEBPE mutations on neutrophil biology remains elusive. Here, we identified two SGD patients bearing a previously described heterozygous mutation (p.Val218Ala) in CEBPE. We took this rare opportunity to characterize SGD neutrophils in terms of granule distribution and protein content. Granules of patient neutrophils were clustered and polarized, suggesting that not only absence of specific granules but also defects affecting other granules contribute to the phenotype. Our analysis showed that remaining granules displayed mixed protein content and lacked several glycoepitopes. To further elucidate the impact of mutant CEBPE, we performed detailed proteomic analysis of SGD neutrophils. Beside an absence of several granule proteins in patient cells, we observed increased expression of members of the linker of nucleoskeleton and cytoskeleton complex (nesprin-2, vimentin, and lamin-B2), which control nuclear shape. This suggests that absence of these proteins in healthy individuals might be responsible for segmented shapes of neutrophilic nuclei. We further show that the heterozygous mutation p.Val218Ala in CEBPE causes SGD through prevention of nuclear localization of the protein product. In conclusion, we uncover that absence of nuclear C/EBPε impacts on spatiotemporal expression and subsequent distribution of several granule proteins and further on expression of proteins controlling nuclear shape.

• Klíčová slova
• C/EBPε, granule organization, neutrophil granulocytes, primary immunodeficiency, specific granule deficiency,
• MeSH
• biologické markery MeSH
• cytoplazmatická granula imunologie   metabolismus   MeSH
• dítě MeSH
• dospělí MeSH
• epitopy imunologie   MeSH
• glykoproteiny imunologie   metabolismus   MeSH
• laktoferrin nedostatek   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• membránové glykoproteiny imunologie   metabolismus   MeSH
• mutace * MeSH
• neutrofily imunologie   metabolismus   MeSH
• poruchy leukocytů etiologie   metabolismus   MeSH
• předškolní dítě MeSH
• proteiny vázající zesilovač transkripce CCAAT genetika   MeSH
• proteom * MeSH
• proteomika metody   MeSH
• studie případů a kontrol MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• předškolní dítě MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• CEBPE protein, human MeSH Prohlížeč
• epitopy MeSH
• glykoproteiny MeSH
• laktoferrin MeSH
• membránové glykoproteiny MeSH
• proteiny vázající zesilovač transkripce CCAAT MeSH
• proteom * MeSH

Galectin-3 is an immunomodulatory protein with binding capacity for various glycoconjugates including IgE. It has been shown to be produced by epidermal keratinocytes and is present on the surfaces of skin Langerhans cells (LC). Therefore, it may have a role in the pathogenesis of various skin diseases, such as atopic dermatitis. To study the expression of galectin-3 in LC, we used, in addition to specific antibodies, a panel of synthetic, carrier-immobilized, specific oligosaccharides of the A- and B-histo-blood group, which are recognized by this lectin. In the mean time, Birbeck granules were visualized with an anti-Lag antibody. The double labeling experiments showed a remarkable colocalization of signals for Lag antigen (Birbeck granules) and galectin-3, as well as the binding sites for A- and B-histo-blood group trisaccharides. The specificity of the oligosaccharide binding was demonstrated by the lack of binding by Le(c), Le(d) (H blood group antigen), and sLe(x), which are not recognized by galectin-3. These results suggest that galectin-3 is present in Birbeck granules, where it retains reactivity for its glycoligands.

• MeSH
• ABO systém krevních skupin metabolismus   MeSH
• cytoplazmatická granula imunologie   MeSH
• diferenciační antigeny genetika   metabolismus   MeSH
• galektin 3 MeSH
• Langerhansovy buňky imunologie   metabolismus   MeSH
• lidé MeSH
• protilátky imunologie   MeSH
• trisacharidy metabolismus   MeSH
• vazebná místa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ABO systém krevních skupin MeSH
• diferenciační antigeny MeSH
• galektin 3 MeSH
• protilátky MeSH
• trisacharidy MeSH