Synthesis of heparan sulfate with cyclophilin B-binding properties is determined by cell type-specific expression of sulfotransferases.
Cyclophilin B (CyPB) induces migration and adhesion of T lymphocytes via a mechanism that requires interaction with 3-O-sulfated heparan sulfate (HS). HS biosynthesis is a complex process with many sulfotransferases involved. N-Deacetylases/N-sulfotransferases are responsible for N-sulfation, which is essential for subsequent modification steps, whereas 3-O-sulfotransferases (3-OSTs) catalyze the least abundant modification. These enzymes are represented by several isoforms, which differ in term of distribution pattern, suggesting their involvement in making tissue-specific HS. To elucidate how the specificity of CyPB binding is determined, we explored the relationships between the expression of these sulfotransferases and the generation of HS motifs with CyPB-binding properties. We demonstrated that high N-sulfate density and the presence of 2-O- and 3-O-sulfates determine binding of CyPB, as evidenced by competitive experiments with heparin derivatives, soluble HS, and anti-HS antibodies. We then showed that target cells, i.e. CD4+ lymphocyte subsets, monocytes/macrophages, and related cell lines, specifically expressed high levels of NDST2 and 3-OST3 isoforms. Silencing the expression of NDST1, NDST2, 2-OST, and 3-OST3 by RNA interference efficiently decreased binding and activity of CyPB, thus confirming their involvement in the biosynthesis of binding sequences for CyPB. Moreover, we demonstrated that NDST1 was able to partially sulfate exogenous substrate in the absence of NDST2 but not vice versa, suggesting that both isoenzymes do not have redundant activities but do have rather complementary activities in making N-sulfated sequences with CyPB-binding properties. Altogether, these results suggest a regulatory mechanism in which cell type-specific expression of certain HS sulfotransferases determines the specific binding of CyPB to target cells.
Deligny
Audrey
A
Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche 8576 du CNRS, Institut de Recherche Fédératif 147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, France.
Denys
Agnès
A
Marcant
Adeline
A
Melchior
Aurélie
A
Mazurier
Joël
J
van Kuppevelt
Toin H
TH
Allain
Fabrice
F
D000818:Animals; D002417:Cattle; D045744:Cell Line, Tumor; D021983:Cyclophilins / Q000378:metabolism*; D015536:Down-Regulation; D015971:Gene Expression Regulation, Enzymologic; D006493:Heparin / Q000378:metabolism; D006497:Heparan Sulfate / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D009928:Organ Specificity; D011485:Protein Binding; D034622:RNA Interference; D013379:Substrate Specificity; D013431:Sulfates / Q000378:metabolism; D015238:Sulfotransferases / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism
D021983:Cyclophilins; D006493:Heparin; D006497:Heparan Sulfate; D007527:Isoenzymes; D009584:Nitrogen; D013431:Sulfates; D015238:Sulfotransferases; C081786:cyclophilin B